Review

of

oral

appliances

for

treatment

of

sleep-disordered

breathing

Between

and

there

were

distinct

publications

dealing

with

oral

appliance

therapy

involving

a

total

of

patients

which

reported

results

of

sleep

studies

performed

with

and

without

the

appliance

These

studies

which

constitute

a

very

heterogeneous

group

in

terms

of

methodology

and

patient

population

are

reviewed

and

the

results

summarized

This

review

focused

on

the

following

outcomes

sleep

apnea

-LRB-

i.e.

reduction

in

the

apnea/hypopnea

index

or

respiratory

disturbance

index

-RRB-

ability

of

oral

appliances

to

reduce

snoring

effect

of

oral

appliances

on

daytime

function

comparison

of

oral

appliances

with

other

treatments

-LRB-

continuous

positive

airway

pressure

and

surgery

-RRB-

side

effects

dental

changes

-LRB-

overbite

and

overjet

-RRB-

and

long-term

compliance

We

found

that

the

success

rate

defined

as

the

ability

of

the

oral

appliances

to

reduce

apnea/hypopnea

index

to

less

than

is

The

response

rate

defined

as

at

least

reduction

in

the

initial

apnea/hypopnea

index

-LRB-

although

it

still

remained

above

-RRB-

is

When

only

the

results

of

randomized

crossover

placebo-controlled

studies

are

considered

the

success

and

response

rates

are

and

respectively

Snoring

was

reduced

by

In

the

studies

comparing

oral

appliances

to

continuous

positive

airway

pressure

-LRB-

CPAP

-RRB-

or

to

uvulopalatopharyngoplasty

-LRB-

UPPP

-RRB-

an

appliance

reduced

initial

AHI

by

CPAP

reduced

it

by

and

UPPP

by

The

majority

of

patients

prefer

using

oral

appliance

than

CPAP

Use

of

oral

appliances

improves

daytime

function

somewhat

the

Epworth

sleepiness

score

-LRB-

ESS

-RRB-

dropped

from

to

in

patients

A

summary

of

the

follow-up

compliance

data

shows

that

at

months

of

patients

continue

to

use

oral

appliance

Side

effects

are

relatively

minor

but

frequent

The

most

common

ones

are

excessive

salivation

and

teeth

discomfort

Efficacy

and

side

effects

depend

on

the

type

of

appliance

degree

of

protrusion

vertical

opening

and

other

settings

We

conclude

that

oral

appliances

although

not

as

effective

as

CPAP

in

reducing

sleep

apnea

snoring

and

improving

daytime

function

have

a

definite

role

in

the

treatment

of

snoring

and

sleep

apnea

Introduction

Treatment

of

sleep-disordered

breathing

-LRB-

i.e.

snoring

upper

airway

resistance

syndrome

sleep

apnea

syndrome

-RRB-

can

be

divided

into

four

general

categories

These

include

-LRB-

-RRB-

lifestyle

modification

i.e.

weight

loss

cessation

of

evening

alcohol

ingestion

sleep

position

training

-LRB-

-RRB-

upper

airway

surgery

-LRB-

-RRB-

oral

appliances

and

-LRB-

-RRB-

CPAP

Although

the

latter

category

provides

the

most

reliable

therapeutic

modality

and

is

the

most

widely

used

method

to

treat

sleep-disordered

breathing

today

it

is

also

the

most

cumbersome

one

Many

patients

particularly

young

non-apneic

snorers

find

it

unappealing

difficult

to

tolerate

and

unacceptable

The

only

other

non-invasive

alternative

which

can

produce

favorable

results

within

a

short

time

is

oral

appliances

Although

there

are

several

reviews

of

oral

appliances

which

have

appeared

since

the

start

of

the

new

millennium

-LSB-

-RSB-

including

a

recent

review

and

practice

parameters

for

treatment

of

snoring

and

sleep

apnea

-LSB-

-RSB-

this

treatment

modality

is

still

underutilized

Even

the

dentists

who

are

primary

providers

of

this

treatment

lack

education

in

this

area

For

example

Bian

-LSB-

-RSB-

surveyed

general

dentists

in

the

state

of

Indiana

and

found

that

knew

little

or

nothing

about

oral

appliances

for

treatment

of

obstructive

sleep

apnea

Unarguably

the

knowledge

about

oral

appliances

among

dentists

and

physicians

varies

geographically

being

higher

in

large

urban

centers

which

provide

more

educational

opportunities

locally

but

the

results

of

the

survey

certainly

indicate

a

need

for

more

education

in

this

area

This

review

will

summarize

our

current

state

of

knowledge

of

the

efficacy

of

oral

appliances

for

the

treatment

of

snoring

and

obstructive

sleep

apnea

We

shall

not

limit

this

review

to

a

simple

summary

of

the

effect

of

oral

appliances

on

nocturnal

respiration

but

will

also

examine

other

aspects

of

this

therapy

such

as

the

reduction

in

symptoms

vascular

consequences

side

effects

and

compliance

However

the

main

objective

of

this

review

will

remain

to

be

the

examination

of

the

current

data

dealing

with

the

efficacy

of

oral

appliance

therapy

for

the

treatment

of

snoring

and

sleep

apnea

Historical

aspects

George

Cattlin

-LSB-

-RSB-

was

probably

the

first

person

who

seriously

thought

that

the

route

of

breathing

may

influence

sleep

quality

and

daytime

function

He

attributed

good

health

of

the

native

North

American

Indians

compared

to

their

immigrant

European

counterparts

to

the

fact

that

they

are

taught

from

the

early

age

to

breathe

through

the

nose

rather

than

the

mouth

He

pointed

out

that

breathing

through

the

nose

promotes

more

restful

and

better

quality

sleep

which

translates

into

better

daytime

function

and

better

general

health

After

the

publication

of

his

book

there

appeared

many

patents

describing

devices

designed

to

promote

nasal

breathing

Some

of

the

early

patented

appliances

are

shown

in

Fig.

Fig.

of

early

oral

appliances

However

modern

published

clinical

work

begins

in

when

Pierre

Robin

first

described

a

device

called

the

monoblock

for

the

treatment

of

glossoptosis

-LSB-

-RSB-

More

than

years

later

he

used

an

oral

appliance

to

reposition

the

mandible

-LSB-

-RSB-

For

the

next

years

little

work

was

done

in

this

field

It

took

almost

another

years

to

start

using

oral

appliances

for

the

treatment

of

snoring

and

sleep

apnea

when

Cartwright

and

Samelson

-LSB-

-RSB-

described

the

tongue

retaining

device

in

This

work

stimulated

further

investigations

resulting

in

many

subsequent

studies

many

of

which

will

be

summarized

in

this

review

Types

of

appliances

Although

the

type

and

number

of

specific

appliances

may

be

bewildering

and

is

still

growing

-LRB-

Table

-RRB-

all

may

be

divided

into

three

general

groups

soft

palate

lifters

-LRB-

SPL

-RRB-

tongue

retaining

devices

-LRB-

TRD

-RRB-

and

mandibular

advancement

appliances

-LRB-

MAA

-RRB-

The

first

category

is

virtually

no

longer

in

use

today

The

second

category

is

used

very

seldom

mainly

if

there

are

dental

reasons

precluding

the

construction

of

MAA

The

last

category

-LRB-

MAA

-RRB-

is

by

far

the

most

common

type

of

dental

appliance

in

use

today

It

protrudes

the

mandible

forward

thus

preventing

or

minimizing

upper

airway

collapse

during

sleep

These

devices

can

be

either

fixed

-LRB-

i.e.

the

protrusion

distance

can

not

be

changed

-RRB-

or

variable

-LRB-

i.e.

protrusion

can

be

increased

or

decreased

-RRB-

The

final

protrusion

distance

represents

a

delicate

balance

between

side

effects

and

efficacy

For

this

reason

the

construction

and

fitting

of

the

appliance

should

be

done

by

a

dentist

with

an

expertise

in

this

area

who

is

familiar

with

different

appliances

is

capable

of

selecting

the

appropriate

one

based

on

the

dental

examination

and

has

access

to

a

sleep

laboratory

where

the

objective

efficacy

of

the

appliance

can

be

verified

Table

of

oral

appliancesOral

appliancesThe

EquilizerJasper

jumperEsmarkThe

SilencerPM

PositionerTPEKlearwayTongue

locking

applianceSnoreExNAPAAdjustable

soft

palate

lifterHAPTAPZ-training

applianceTessiTOPSSnore-no-moreSnore

GuardSNOARElastometricSilent

NightHerbstSUADTheraSnore

Mechanism

of

action

of

oral

appliances

Much

was

written

on

how

and

why

oral

appliances

may

improve

snoring

and

sleep

apnea

The

results

show

that

upper

airway

obstruction

during

sleep

may

occur

at

any

site

between

the

nasopharynx

and

the

larynx

The

most

common

sites

of

obstruction

are

behind

the

base

of

the

tongue

-LRB-

retroglossal

-RRB-

and

behind

the

soft

palate

-LRB-

retropalatal

-RRB-

This

partial

or

complete

occlusion

of

the

upper

airway

during

sleep

is

a

consequence

of

abnormal

anatomy

and

physiology

-LRB-

i.e.

the

airway

is

narrow

and

floppy

-RRB-

There

is

still

a

lively

debate

as

to

the

relative

contributions

of

abnormal

anatomy

vs

abnormal

physiology

in

the

pathogenesis

of

upper

airway

obstruction

during

sleep

-LSB-

-RSB-

This

debate

is

partially

fuelled

by

the

fact

that

airway

narrowing

or

even

a

complete

occlusion

is

a

normal

physiological

event

during

sleep

In

patients

with

sleep

apnea

this

normal

response

is

exaggerated

The

question

then

becomes

whether

this

exaggerated

response

is

due

to

abnormal

neuromuscular

control

superimposed

on

the

otherwise

anatomically

normal

airway

or

is

the

airway

anatomically

narrower

than

normal

without

any

abnormalities

in

the

neuromuscular

control

It

is

now

an

accepted

fact

that

a

combination

of

abnormal

anatomy

and

physiology

is

necessary

to

produce

pathological

repetitive

narrowing

-LRB-

or

complete

occlusion

-RRB-

of

upper

airway

during

sleep

i.e.

sleep

apnea

Given

that

sleep

apnea

and

snoring

are

a

consequence

of

abnormal

anatomy

and

physiology

of

the

upper

airway

is

there

evidence

that

oral

appliances

can

correct

these

abnormalities

at

least

in

some

patients

There

are

several

studies

not

only

during

wakefulness

but

also

during

sleep

indicating

that

advancing

the

mandible

forward

can

enlarge

the

airway

and

reduce

pharyngeal

collapsibility

-LSB-

-RSB-

in

normal

subjects

and

patients

with

sleep

apnea

These

investigations

confirmed

the

effect

of

oral

appliances

on

upper

airway

properties

Some

authors

suggested

that

measurements

of

airway

pressures

during

sleep

may

even

predict

the

beneficial

response

to

oral

appliances

For

example

recently

Battagel

et

al.

-LSB-

-RSB-

performed

sleep

nasendoscopy

in

patients

with

sleep

apnea

The

mandible

was

gently

advanced

by

mm

to

simulate

the

effect

of

the

mandibular

appliance

The

authors

suggested

that

this

procedure

may

help

to

determine

whether

a

particular

patient

is

a

candidate

for

oral

appliance

therapy

Similarly

Ng

et

al.

-LSB-

-RSB-

measured

upper

airway

pressures

during

natural

sleep

in

patients

with

obstructive

sleep

apnea

to

identify

the

site

of

airway

collapse

The

authors

found

that

oropharyngeal

rather

than

velopharyngeal

collapse

was

predictive

of

the

beneficial

response

to

oral

appliance

However

another

study

of

patients

with

sleep

apnea

where

esophageal

pressure

was

measured

during

sleep

found

no

significant

differences

in

nadir

esophageal

pressure

or

cephalometric

parameters

between

the

patients

who

responded

to

oral

appliance

therapy

and

those

who

did

not

-LSB-

-RSB-

It

is

safe

to

conclude

at

this

time

that

anatomical

changes

in

the

oropharynx

produced

by

mandibular

advancement

result

in

the

alterations

of

the

intricate

relationships

between

different

muscle

groups

controlling

the

upper

airway

caliber

In

some

patients

with

sleep

apnea

these

alterations

may

prevent

the

obstruction

in

others

worsen

the

obstruction

and

yet

in

others

particularly

in

those

with

low

level

obstruction

the

part

of

the

airway

where

the

obstruction

occurs

may

be

unaffected

There

is

currently

no

reliable

way

to

predict

the

outcome

of

treatment

with

oral

appliance

in

individual

patients

and

therefore

to

select

appropriate

candidates

for

this

treatment

Clinical

features

also

do

not

seem

to

offer

much

help

in

trying

to

predict

who

will

respond

to

oral

appliances

or

just

the

opposite

to

identify

patients

who

are

not

likely

to

respond

to

this

therapy

When

two

expert

maxillofacial

surgeons

examined

-LRB-

in

a

blind

fashion

-RRB-

patients

with

sleep

apnea

to

determine

if

there

were

any

contraindications

to

mandibular

advancement

devices

they

found

that

primary

contraindications

were

present

in

of

patients

-LSB-

-RSB-

This

relatively

high

rate

of

contraindications

and

disagreements

between

individual

experts

only

point

out

that

a

team

approach

is

necessary

to

select

the

proper

treatment

for

patients

with

sleep

apnea

Results

of

clinical

trials

The

onset

of

the

new

millennium

carried

forward

the

momentum

started

by

Cartwright

and

Samelson

-LSB-

-RSB-

resulting

in

the

increased

use

of

oral

appliances

for

the

treatment

of

snoring

and

sleep

apnea

However

the

emphasis

on

the

type

of

appliances

has

changed

Tongue

retaining

devices

are

currently

seldom

used

being

almost

completely

replaced

by

the

mandibular

advancement

appliances

The

latter

are

sometimes

also

called

mandibular

repositioners

protruders

devices

splints

prosthesis

etc.

but

the

common

feature

of

all

these

appliances

is

their

ability

to

adjust

the

degree

of

mandibular

advancement

to

achieve

resolution

of

snoring

and

sleep

apnea

In

what

follows

we

shall

summarize

the

results

of

clinical

trials

employing

oral

appliances

for

the

treatment

of

sleep

apnea

and

snoring

In

addition

we

shall

review

and

summarize

the

information

regarding

changes

in

daytime

function

as

a

result

of

using

the

appliance

clinical

and

dental

side

effects

and

compliance

with

treatment

Oral

appliances

for

the

treatment

of

sleep

apnea

Table

summarizes

the

results

of

individual

studies

using

oral

appliances

starting

with

the

polysomnographic

study

of

TRD

by

Cartwright

and

Samelson

-LSB-

-RSB-

until

the

present

The

only

criterion

for

the

inclusion

of

a

particular

study

into

this

table

and

thus

the

only

common

feature

of

all

studies

listed

was

the

availability

of

at

least

partial

results

of

nocturnal

monitoring

of

respiration

with

and

without

oral

appliance

Otherwise

the

studies

are

highly

variable

in

their

design

methodology

data

analysis

outcome

definition

and

assessment

and

presentation

of

results

This

makes

the

interpretation

of

individual

results

and

particularly

any

attempt

to

summarize

all

of

them

very

challenging

Before

describing

the

methods

of

analysis

and

presenting

the

summary

of

the

data

it

is

very

important

to

keep

in

mind

the

following

points

Table

studies

with

oral

appliances

rate

-LRB-

-RRB-

Response

rate

-LRB-

-RRB-

Comments

-LSB-

-RSB-

series

AI

-LSB-

-RSB-

series

AI

-LSB-

-RSB-

series

all

patients

had

SMR

or

UPPP

AI

-LSB-

-RSB-

Case

report

AI

-LSB-

-RSB-

series

Esmarch

prosthesis

AI

-LSB-

-RSB-

series

Esmarch

prosthesis

AI

-LSB-

-RSB-

series

NAPA

AI

-LSB-

-RSB-

series

modified

functional

appliance

-LSB-

-RSB-

Case

report

mandibular

repositioning

appliance

-LSB-

-RSB-

series

-LSB-

-RSB-

Case

report

mandibular

repositioning

appliance

-LSB-

-RSB-

series

-LSB-

-RSB-

series

fixed

splint

AI

-LSB-

-RSB-

series

fixed

dental

orthosis

-LSB-

-RSB-

Case

series

fixed

prosthesis

AI

-LSB-

-RSB-

case

reports

intra-oral

fixed

prosthesis

RDI

-LSB-

-RSB-

series

NAPA

RDI

-LSB-

-RSB-

case

series

Herbst-like

RDI

-LSB-

-RSB-

Case

series

of

CPAP

failures

Herbst

-LSB-

-RSB-

series

Esmarch

AI

-LSB-

-RSB-

Case

series

Herbst

vs

MR

-LRB-

muscle

relaxation

-RRB-

appliance

result

for

Herbst

-LSB-

-RSB-

Case

series

Herbst

vs

MR

-LRB-

muscle

relaxation

-RRB-

appliance

result

for

MR

-LSB-

-RSB-

Case

series

mandibular

advancement

splint

fixed

of

maximum

protrusion

-LSB-

-RSB-

series

fixed

intra-oral

prosthesis

apneas/night

-LSB-

-RSB-

Case

series

Esmarch

AI

-LSB-

-RSB-

comparing

AMP

device

with

CPAP

-LSB-

-RSB-

prospective

crossover

comparing

the

Snore-Guard

with

CPAP

-LSB-

-RSB-

series

mandibular

repositioning

device

most

patients

were

CPAP

failures

RDI

-LSB-

-RSB-

Case

report

elastometric

sleep

appliance

-LSB-

-RSB-

series

SnorEx

appliance

RDI

-LSB-

-RSB-

crossover

comparing

the

AMP

device

with

CPAP

-LSB-

-RSB-

series

mandibular

advancing

positioner

-LSB-

-RSB-

Case

report

fixed

dental

appliance

-LSB-

-RSB-

Fixed

mandibular

splint

maximum

protrusion

median

AHI

-LSB-

-RSB-

Fixed

mandibular

splint

of

maximum

protrusion

median

AHI

-LSB-

-RSB-

series

prospective

mandibular

advancement

device

-LSB-

-RSB-

series

of

UPPP

failures

Herbst

-LSB-

-RSB-

series

mandibular

positioning

device

RDI

-LSB-

-RSB-

Case

series

of

snorers

mandibular

advancement

device

snores/h

of

sleep

-LSB-

-RSB-

series

Serenox

-LSB-

-RSB-

randomized

parallel

groups

comparing

dental

appliance

with

UPPP

-LSB-

-RSB-

series

TAP

appliance

-LSB-

-RSB-

Case

series

dental

appliance

-LSB-

-RSB-

Case

series

Klearway

appliance

-LSB-

-RSB-

series

elastic

mandibular

advancement

device

-LSB-

-RSB-

series

three

fixed

appliances

with

and

mm

protrusion

-LSB-

-RSB-

series

comparing

MAA

-LRB-

Snore-Guard

-RRB-

with

TRD

and

with

soft

palate

lifter

-LRB-

SPL

-RRB-

-LSB-

-RSB-

Ibid

-LSB-

-RSB-

Ibid

-LSB-

-RSB-

series

Herbst

-LSB-

-RSB-

series

Klearway

-LSB-

-RSB-

Randomized

crossover

comparing

Herbst

vs

monoblock

results

given

for

Herbst

-LSB-

-RSB-

Case

series

SnorBan

-LSB-

-RSB-

series

mandibular

advancement

device

-LSB-

-RSB-

series

modified

functional

appliance

-LSB-

-RSB-

placebo-appliance-controlled

crossover

mandibular

advancement

splint

-LSB-

-RSB-

Case

series

either

Herbst

or

monoblock

-LSB-

-RSB-

series

adjustable

mandibular

splints

-LSB-

-RSB-

Randomized

placebo-appliance-controlled

crossover

series

of

snorers

snoring

measured

on

a

scale

-LSB-

-RSB-

Prospective

case

series

mandibular

advancement

device

-LSB-

-RSB-

crossover

comparing

mm

with

mm

inter-incisal

opening

results

for

mm

opening

-LSB-

-RSB-

series

Herbst-like

-LSB-

-RSB-

parallel

groups

comparing

UPPP

and

MAA

-LSB-

-RSB-

series

Karwetzky

activator

-LSB-

-RSB-

Case

series

Karwetzky

activator

median

AHIs

-LSB-

-RSB-

crossover

placebo-appliance-controlled

-LSB-

-RSB-

series

titration

study

results

for

maximum

protrusion

Klearway

-LSB-

-RSB-

Randomized

crossover

comparing

CPAP

with

ISAD

appliance

-LSB-

-RSB-

Randomized

crossover

comparing

CPAP

with

mandibular

repositioning

splint

-LSB-

-RSB-

Randomized

crossover

placebo-appliance-controlled

mandibular

advancement

splint

-LSB-

-RSB-

Case

series

comparing

patients

on

CPAP

who

switched

to

MAA

-LSB-

-RSB-

Prospective

randomized

crossover

comparing

MAS

with

CPAP

soft

one-piece

mandibular

advancement

splint

-LSB-

-RSB-

randomized

parallel

groups

comparing

and

of

mandibular

protrusion

results

for

group

-LSB-

-RSB-

randomized

parallel

groups

comparing

and

of

mandibular

protrusion

results

for

group

-LSB-

-RSB-

series

The

Silencer

appliance

-LSB-

-RSB-

Randomized

crossover

controlled

comparing

mandibular

advancement

splint

with

CPAP

and

with

placebo

tablet

-LSB-

-RSB-

series

titration

protocol

Herbst-like

-LSB-

-RSB-

series

titration

protocol

Klearway

-LSB-

-RSB-

Case

series

mandibular

advancement

devices

-LSB-

-RSB-

Prospective

case

series

of

non-apneic

snorers

Herbst

-LSB-

-RSB-

Case

series

fixed

mandibular

advancement

device

-LSB-

-RSB-

series

of

consecutive

patients

TAP

appliance

-LSB-

-RSB-

Case

series

of

patients

with

CHF

mandibular

advancement

device

-LSB-

-RSB-

series

Herbst

-LSB-

-RSB-

Prospective

randomized

crossover

comparing

Twin

Block

and

Herbst

median

AHI

-LSB-

-RSB-

Mail

survey

of

patients

RDI

mainly

Klearway

few

mandibular

repositioners

fewer

TRDs

-LSB-

-RSB-

series

Klearway

appliance

-LSB-

-RSB-

Case

series

questionnaires

bed

partners

replies

recorded

-LSB-

-RSB-

Median

AHI

case

series

weeks

use

split

polysomnography

-LSB-

-RSB-

Case

series

-LSB-

-RSB-

Prospective

randomized

placebo-appliance-controlled

weeks

study

-LSB-

-RSB-

Case

series

-LSB-

-RSB-

series

OSA

defined

as

AHI

First

Table

contains

the

studies

from

the

two

extreme

ends

of

the

spectrum

of

scientific

rigor

At

the

highest

end

of

the

spectrum

there

are

prospective

randomized

crossover

controlled

-LRB-

either

against

placebo-appliance

or

another

treatment

modality

-RRB-

studies

At

the

lowest

end

of

the

spectrum

are

individual

case

reports

Some

studies

are

prospective

case

series

but

most

studies

are

retrospective

analysis

of

series

of

cases

Second

the

investigations

listed

in

Table

form

a

very

inhomogeneous

group

with

respect

to

several

variables

time

of

follow-up

study

type

of

polysomnography

which

respiratory

variables

measured

presentation

of

results

type

of

oral

appliance

used

missing

data

etc.

The

time

interval

between

the

diagnostic

and

with

appliance

polysomnography

varied

from

a

few

hours

to

a

few

months

In

some

studies

split

polysomnography

-LRB-

i.e.

diagnostic

part

followed

by

with

appliance

part

-RRB-

was

carried

out

while

in

others

the

two

sleep

studies

were

separated

by

a

couple

of

days

to

several

months

In

some

investigations

formal

in-hospital

polysomnography

was

performed

while

in

others

only

at-home

monitoring

of

oxygen

saturation

was

carried

out

In

some

of

the

earliest

investigations

only

the

apnea

index

-LRB-

AI

-RRB-

was

measured

Later

investigations

reported

the

oxygen

desaturation

index

-LRB-

number

of

times

per

hour

of

sleep

that

oxygen

saturation

falls

by

more

the

from

the

baseline

-RRB-

Recent

investigations

all

reported

either

the

apnea

hypopnea

index

-LRB-

AHI

-RRB-

or

the

respiratory

disturbance

index

-LRB-

RDI

-RRB-

Most

investigations

presented

only

the

mean

values

rather

than

the

individual

data

and

some

presented

only

the

median

values

Oral

appliances

used

by

the

investigators

included

tongue

retaining

devices

soft

palate

lifters

and

fixed

and

variable

mandibular

advancement

appliances

In

the

vast

majority

of

investigations

the

mandibular

advancement

appliance

was

used

less

than

ten

investigations

employed

the

TRD

and

only

one

investigation

used

the

soft

palate

lifter

In

many

investigations

not

all

patients

who

had

a

diagnostic

sleep

study

also

had

a

follow-up

with

appliance

study

Clearly

the

above

factors

have

a

significant

effect

on

the

analysis

of

the

pooled

data

presented

in

Table

The

first

step

in

analyzing

the

results

of

individual

investigations

is

to

decide

on

which

outcome

variables

to

analyze

Since

we

are

interested

in

sleep

apnea

the

following

four

variables

are

an

obvious

choice

baseline

index

of

respiration

-LRB-

we

shall

denote

this

as

AHIbase

-RRB-

with

appliance

index

of

respiration

-LRB-

denoted

as

AHIappl

-RRB-

success

rate

defined

as

the

reduction

of

AHIbase

to

a

value

less

than

the

defining

value

for

sleep

apnea

and

response

rate

defined

as

the

reduction

of

AHIbase

by

greater

than

while

still

remaining

higher

than

the

defining

value

for

sleep

apnea

Table

lists

distinct

investigations

involving

a

total

of

patients

Inspection

of

the

individual

results

indicates

the

widest

possible

variability

Respiration

is

analyzed

in

terms

of

AI

AHI

or

RDI

The

definition

of

sleep

apnea

was

based

either

on

AI

AHI

RDI

or

Success

and

response

rates

were

defined

differently

in

many

studies

however

whenever

possible

we

extracted

the

information

to

calculate

the

success

and

response

rates

according

to

the

standard

definition

given

above

In

other

words

no

matter

what

definition

of

sleep

apnea

was

employed

in

a

particular

study

i.e.

whether

it

was

defined

as

AI

AHI

or

ODI

etc.

the

success

rate

we

calculated

was

based

on

the

percent

of

patients

in

whom

AHIappl

was

less

than

and

the

response

rate

was

calculated

as

the

percent

of

patients

in

whom

AHIappl

AHIbase

Clearly

it

is

not

possible

to

carry

out

a

meta-analysis

of

these

studies

because

of

the

differences

in

study

design

data

collection

statistical

analysis

and

presentation

of

the

data

Even

the

simple

descriptive

statistics

based

on

the

pooled

data

must

be

interpreted

with

caution

due

to

the

methodological

differences

listed

above

To

obtain

the

general

information

about

the

efficacy

of

oral

appliances

we

analyzed

the

results

of

individual

investigations

in

several

different

ways

as

follows

First

we

rejected

all

case

reports

-LSB-

-RSB-

and

all

studies

which

did

not

report

the

mean

AI

the

mean

AHI

or

the

mean

RDI

-LSB-

-RSB-

These

studies

reported

either

the

total

number

of

apneas

per

night

snoring

only

median

AHI

or

etc.

This

procedure

left

a

total

of

studies

involving

patients

We

used

this

pooled

data

to

calculate

the

pooled

means

for

each

outcome

variable

AHIbase

AHIappl

success

rate

and

response

rate

If

an

individual

study

did

not

report

this

outcome

variable

it

was

not

used

in

the

calculation

of

pooled

means

For

example

to

calculate

the

AHIbase

we

only

had

to

reject

study

-LSB-

-RSB-

where

this

variable

was

not

reported

thus

leaving

studies

with

patients

To

calculate

the

AHIappl

we

had

to

reject

studies

-LSB-

-RSB-

thus

leaving

studies

with

a

total

of

patients

Similarly

looking

at

Table

we

can

easily

see

which

studies

had

to

be

rejected

to

calculate

the

success

and

the

response

rates

The

results

are

shown

in

Table

We

note

that

oral

appliance

reduced

the

AHIbase

from

to

The

success

and

response

rates

were

and

respectively

Table

of

the

outcome

variables

for

studies

listed

in

Table

of

patientsNo

of

Response

Success

A

second

way

to

analyze

the

data

presented

in

Table

is

to

select

only

those

investigations

where

all

four

outcome

variables

-LRB-

AHIbase

AHIappl

success

rate

response

rate

-RRB-

were

reported

This

left

studies

involving

patients

It

is

interesting

to

note

that

the

results

shown

in

Table

are

almost

identical

to

what

was

found

in

a

larger

dataset

Table

of

results

for

complete

studiesResults

for

complete

studiesNo

of

of

Success

A

third

way

to

analyze

the

data

is

to

select

only

the

randomized

crossover

placebo-controlled

studies

There

are

only

five

such

studies

all

done

after

the

year

and

all

using

the

mandibular

advancement

appliance

Inactive

appliance

was

used

as

placebo

in

four

studies

-LSB-

-RSB-

and

a

pill

was

used

as

placebo

in

one

study

-LSB-

-RSB-

In

the

latter

study

only

the

mean

AHIs

were

reported

but

not

the

success

and

response

rates

The

results

are

shown

in

Table

We

note

that

-LRB-

-RRB-

only

patients

with

mild

to

moderate

sleep

apnea

were

studied

-LRB-

-RRB-

in

two

out

of

five

studies

the

mean

AHI

was

reduced

by

less

than

-LRB-

-RRB-

the

success

and

response

rates

differ

depending

on

the

cut-off

value

of

the

AHI

-LRB-

either

five

or

ten

-RRB-

-LRB-

-RRB-

for

AHI

cut-off

the

success

rate

is

very

similar

to

that

of

the

uncontrolled

trials

but

the

response

rate

is

lower

The

overall

conclusion

from

these

placebo-controlled

crossover

trials

is

that

oral

appliances

significantly

improved

sleep

apnea

by

reducing

AHIbase

from

to

with

the

combined

success

and

response

rates

of

Table

of

results

if

randomized

crossover

placebo-controlled

studiesReferenceNAHIbaseAHIapplSuccess

rate

-LRB-

-RRB-

Response

rate

-LRB-

-RRB-

Comments

-LSB-

-RSB-

AHI

AHI

cutoff

-LSB-

-RSB-

AHI

cutoff

-LSB-

-RSB-

results

for

AHI

and

AHI

cutoffs

-LSB-

-RSB-

Tablet

used

as

placebo

CPAP

arm

was

also

present

-LSB-

-RSB-

For

AHI

For

AHI

AHI

AHI

cutoff

One

of

the

issues

facing

the

effective

use

of

oral

appliances

is

our

ability

to

determine

the

appropriate

degree

of

protrusion

necessary

to

resolve

apnea

and

snoring

Until

recently

the

only

way

to

do

so

was

to

advance

the

mandible

forward

as

much

as

is

tolerated

by

the

patient

to

carry

out

polysomnography

and

hope

that

sleep

apnea

is

eliminated

Unlike

CPAP

which

may

be

controlled

remotely

without

waking

the

patient

the

design

of

most

appliances

requires

removing

it

from

patient

's

mouth

to

change

the

degree

of

protrusion

This

wakes

up

the

patient

repeatedly

resulting

in

a

high

probability

that

the

titration

study

will

be

unsuccessful

thus

wasting

valuable

resources

However

several

titration

protocols

were

described

recently

to

eliminate

this

problem

Fleury

et

al.

-LSB-

-RSB-

studied

a

protocol

where

this

titration

was

done

at

home

over

a

period

of

several

weeks

by

advancing

the

mandible

in

mm

steps

and

recording

symptoms

and

The

effective

protrusion

was

defined

as

that

which

results

in

either

resolution

in

symptoms

or

reduction

in

to

below

ten

Using

this

protocol

they

were

able

to

determine

the

protrusion

which

abolished

sleep

apnea

in

of

patients

Tsai

et

al.

-LSB-

-RSB-

described

a

remotely

controlled

mandibular

advancement

device

which

could

be

titrated

during

the

night

in

much

the

same

way

that

the

CPAP

is

titrated

The

mandible

was

advanced

remotely

during

the

night

in

mm

increments

until

respiratory

events

were

eliminated

The

success

was

confirmed

subsequently

by

carrying

out

all

night

polysomnography

with

the

oral

appliance

set

to

the

effective

protrusion

determined

during

the

titration

study

The

positive

predictive

value

of

this

titration

protocol

was

On

the

other

hand

Kuna

et

al.

-LSB-

-RSB-

found

that

the

titration

protocol

was

not

predictive

of

the

response

during

chronic

use

In

this

investigation

out

of

patients

with

OSA

achieved

reduction

in

AHI

to

less

than

during

titration

However

of

them

demonstrated

the

same

beneficial

response

during

longer

use

of

the

appliance

at

home

with

the

effective

protrusion

determined

during

the

titration

night

These

results

indicate

that

oral

appliance

titration

to

predict

the

amount

of

mandibular

advancement

required

to

reduce

AHI

to

less

than

ten

is

still

imprecise

and

must

be

used

with

caution

when

determining

the

appliance

settings

for

home

use

Nevertheless

the

application

of

titration

protocols

is

a

new

and

important

development

in

this

field

which

may

improve

the

success

of

oral

appliance

therapy

by

identifying

patients

who

are

likely

to

respond

to

this

treatment

Predicting

who

will

respond

to

the

oral

appliance

therapy

is

not

yet

possible

although

there

are

several

studies

where

the

differences

in

various

parameters

-LRB-

mainly

weight

and

measures

of

airway

size

and

collapsibility

-RRB-

were

studied

in

responders

and

non-responders

-LSB-

-RSB-

The

best

correlates

were

always

weight

and

oropharyngeal

airway

size

However

although

these

studies

provide

useful

information

particularly

with

respect

to

the

factors

that

determine

airway

occlusion

they

do

not

as

yet

provide

us

with

a

method

to

predict

who

will

respond

to

this

therapy

Oral

appliances

vs

CPAP

Since

CPAP

remains

as

the

gold

standard

treatment

of

sleep

apnea

the

objective

success

rate

of

any

other

treatment

must

be

judged

against

it

There

are

seven

randomized

crossover

studies

which

compared

mandibular

advancement

appliances

against

CPAP

The

results

are

summarized

in

Table

We

note

that

the

findings

of

all

such

studies

are

remarkably

consistent

CPAP

results

in

better

improvement

in

AHI

than

oral

appliances

In

all

studies

except

one

CPAP

normalized

the

respiration

bringing

AHI

to

less

than

ten

In

one

study

where

AHI

with

CPAP

remained

above

ten

the

highest

pressure

used

was

cm

which

is

probably

too

low

However

patients

subjectively

prefer

oral

appliances

over

CPAP

In

five

out

of

seven

studies

the

patients

expressed

preference

for

an

oral

appliance

in

one

study

neither

treatment

was

preferred

and

in

another

study

CPAP

was

preferred

Table

crossover

CPAP

vs

oral

appliance

studiesReferenceNAHIbaseAHIapplAHI

CPAPComments

-LSB-

-RSB-

of

patients

were

satisfied

with

OA

vs

with

CPAP

-LRB-

p

-RRB-

-LSB-

-RSB-

preferred

-LSB-

-RSB-

preferred

OA

preferred

CPAP

-LSB-

-RSB-

Patients

identified

oral

appliance

as

being

easier

to

use

-LSB-

-RSB-

Neither

treatment

was

significantly

preferred

by

patients

-LSB-

-RSB-

out

of

the

subjects

who

completed

both

arms

of

the

study

preferred

the

MAS

-LSB-

-RSB-

Although

subjects

reported

that

CPAP

was

the

most

difficult

treatment

to

use

they

felt

that

it

was

the

most

effective

and

overall

preferred

it

to

the

MAS

which

was

in

turn

preferred

to

placebo

appliance

preferred

overall

There

are

additional

investigations

-LSB-

-RSB-

which

are

not

listed

in

Table

because

of

missing

data

regarding

follow-up

sleep

study

Nevertheless

these

investigations

provide

interesting

information

regarding

the

comparison

of

oral

appliances

and

CPAP

Smith

and

Stradling

-LSB-

-RSB-

attempted

to

determine

whether

oral

appliances

can

substitute

CPAP

at

least

for

month

The

authors

found

that

patients

achieved

similar

reduction

in

with

CPAP

-LRB-

from

to

-RRB-

as

with

oral

appliance

-LRB-

from

to

-RRB-

However

the

patients

did

not

like

their

oral

appliance

and

were

refusing

to

use

it

Out

of

patients

on

CPAP

who

were

switched

to

oral

appliance

only

were

still

using

it

by

end

of

month

Most

patients

discontinued

its

use

because

of

discomfort

side

effects

or

treatment

failure

This

study

therefore

favors

CPAP

On

the

other

hand

McGown

et

al.

-LSB-

-RSB-

carried

out

a

questionnaire

survey

of

patients

treated

with

oral

appliances

There

were

patients

who

had

tried

both

CPAP

and

oral

appliance

preferred

oral

appliance

preferred

CPAP

and

were

unsure

This

study

favors

oral

appliance

We

conclude

therefore

that

CPAP

is

more

effective

than

oral

appliances

in

reducing

AHI

but

despite

this

most

patients

prefer

oral

appliances

undoubtedly

because

they

find

them

to

be

less

cumbersome

than

CPAP

Oral

appliances

vs

other

treatments

Since

there

were

several

studies

-LSB-

-RSB-

which

compared

either

different

types

of

appliances

different

degrees

of

protrusion

or

different

inter-incisal

distance

The

results

are

listed

in

Table

Columns

labeled

base

and

appl

show

the

AHIbase

and

AHIappl

respectively

The

column

labeled

comp

gives

the

AHI

measured

when

other

i.e.

comparison

treatment

was

used

The

type

of

oral

appliance

employed

and

the

precise

variables

that

were

compared

are

described

in

the

last

column

Since

most

studies

employed

parallel

group

design

baseline

AHI

before

comparison

treatment

is

also

shown

in

this

column

Table

comparing

oral

appliances

to

treatments

other

than

CPAPReferenceNAHICommentsBaseApplComp

-LSB-

-RSB-

Parallel

groups

OA

MAA

with

max

protrusion

comp

MAA

with

of

maximum

protrusion

but

double

inter-incisal

opening

baseline

AHI

for

comp

group

-LSB-

-RSB-

groups

OA

MAA

comp

UPPP

prospective

randomized

baseline

AHI

for

UPPP

group

results

at

months

-LSB-

-RSB-

group

OA

MAA

with

mm

protrusion

comp

mm

protrusion

recorded

-LSB-

-RSB-

group

OA

MAA

comp

TRD

only

patients

agreed

to

try

TRD

-LSB-

-RSB-

group

comp

SPL

only

patients

agreed

to

try

SPL

-LSB-

-RSB-

randomized

OA

MAA

-LRB-

Herbst

-RRB-

comp

monoblock

-LSB-

-RSB-

groups

OA

TRD

comp

somnoplasty

baseline

RDI

same

for

both

groups

-LSB-

-RSB-

randomized

OA

MAA

with

mm

inter-incisal

opening

comp

MAA

with

mm

opening

-LSB-

-RSB-

groups

randomized

OA

MAA

comp

UPPP

baseline

AHI

for

UPPP

group

results

at

years

-LSB-

-RSB-

groups

randomized

OA

MAA

with

protrusion

comp

MAA

with

protrusion

baseline

AHI

for

group

results

at

months

-LSB-

-RSB-

groups

randomized

OA

MAA

with

protrusion

comp

MAA

with

protrusion

baseline

AHI

for

group

results

at

months

-LSB-

-RSB-

prospective

randomized

OA

Herbst

comp

Twin

Block

median

AHIs

Examination

of

the

individual

investigations

reveals

that

when

oral

compliances

are

compared

to

each

other

either

two

different

appliances

or

the

same

appliance

with

different

degrees

of

protrusion

or

opening

it

is

cleat

that

the

efficacy

-LRB-

objective

and

subjective

-RRB-

is

very

much

dependent

on

the

type

of

appliance

and

the

degree

of

advancement

This

further

emphasizes

the

point

that

oral

appliance

therapy

should

be

carried

out

by

a

dentist

with

expertise

in

this

field

who

is

familiar

with

different

types

of

appliances

and

can

select

the

most

appropriate

one

for

the

particular

patient

There

is

no

best

appliance

The

best

one

is

that

which

is

comfortable

to

the

patient

and

achieves

the

desired

efficacy

There

are

several

studies

mainly

case

series

comparing

oral

appliances

with

surgical

treatments

Comparisons

with

UPPP

-LSB-

-RSB-

demonstrated

the

superiority

of

oral

appliances

At

year

follow-up

sleep

apnea

was

resolved

-LRB-

AHI

-RRB-

in

of

the

oral

appliances

group

and

of

the

UPPP

group

With

longer

follow-up

this

success

rate

deteriorates

At

years

follow-up

of

the

oral

appliance

group

and

of

the

UPPP

group

continue

to

have

AHI

One

parallel

group

study

of

oral

appliance

-LRB-

TRD

-RRB-

vs

radiofrequency

ablation

-LRB-

somnoplasty

-RRB-

found

that

both

treatments

significantly

reduced

sleep

time

spent

with

loud

snoring

However

there

was

no

difference

between

oral

appliance

and

somnoplasty

-LSB-

-RSB-

A

recent

small

case

series

of

patients

-LRB-

out

of

treated

with

oral

appliances

-RRB-

who

elected

maxillomandibular

advancement

surgery

-LSB-

-RSB-

showed

that

initial

AHI

dropped

to

with

oral

appliance

and

to

after

surgery

Oral

appliances

for

the

treatment

of

snoring

Although

everyone

can

recognize

snoring

it

proved

to

be

a

very

elusive

entity

to

measure

objectively

One

can

define

the

sound

properties

-LRB-

i.e.

frequency

spectrum

and

intensity

-RRB-

relationship

to

breathing

-LRB-

i.e.

waxing

and

waning

sound

generally

during

inspiration

-RRB-

and

measure

this

sound

during

sleep

However

subjective

recognition

of

sound

which

satisfies

some

pre-defined

snoring

criteria

as

de

facto

snoring

depends

very

much

on

the

listener

This

is

contrary

to

the

case

of

apneas

or

even

hypopneas

whose

definition

is

independent

of

any

subjective

perception

These

difficulties

with

the

definition

of

snoring

are

the

reasons

why

objective

measurement

of

sound

is

seldom

a

routine

part

of

polysomnography

However

snoring

is

the

cardinal

symptom

of

sleep

apnea

In

fact

it

is

frequently

the

only

reason

why

these

patients

come

to

the

sleep

clinic

in

the

first

place

Consequently

when

polysomnography

does

not

reveal

sleep

apnea

in

these

patients

the

physician

still

has

to

deal

with

their

snoring

Unfortunately

this

is

often

ignored

by

physicians

The

most

frequent

scenario

is

that

a

patient

is

referred

to

a

sleep

specialist

because

of

snoring

polysomnography

is

carried

out

no

sleep

apnea

is

found

the

patient

is

reassured

advised

to

loose

weight

stop

smoking

and

drinking

alcohol

embark

on

an

exercise

program

and

discharged

from

the

clinic

Sometimes

this

advice

dispensed

in

the

form

of

preprinted

sheets

is

given

also

to

non-obese

non-smokers

Clearly

the

patient

leaves

unhappy

the

referring

physician

is

dissatisfied

with

the

help

received

from

the

specialist

and

nothing

was

accomplished

to

justify

the

expense

incurred

in

the

process

of

investigations

For

apneic

snorers

the

problem

is

simpler

because

treatment

with

CPAP

will

abolish

snoring

Non-apneic

snorers

without

daytime

symptoms

do

not

tolerate

CPAP

well

Many

of

them

will

agree

to

try

it

but

the

majority

will

stop

using

it

after

a

short

time

-LRB-

generally

a

few

weeks

to

a

few

months

-RRB-

Oral

appliances

therefore

constitute

an

attractive

alternative

for

the

treatment

of

snoring

In

fact

they

were

originally

invented

precisely

for

that

reason

Many

but

not

all

investigations

of

oral

appliances

comment

on

their

efficacy

in

reducing

snoring

Recognizing

that

the

objective

measurement

of

sound

during

polysomnography

may

not

correspond

to

the

perception

of

this

sound

as

being

snoring

subjective

assessment

is

generally

employed

This

assessment

varies

from

simply

asking

an

informal

question

is

your

snoring

improved

to

employing

a

more

formal

method

which

is

usually

a

visual

scale

-LRB-

analogue

or

digital

-RRB-

to

rate

snoring

Unfortunately

in

almost

all

studies

the

answers

to

these

subjective

questions

are

given

by

the

snorers

who

of

course

are

unaware

of

their

snoring

rather

than

by

the

bed

partner

Although

snoring

is

recorded

as

the

patient

's

chief

complaint

it

is

really

not

the

patient

's

complaint

at

all

it

is

the

complaint

of

the

bed

partner

The

implicit

assumption

in

most

investigations

is

that

the

patient

's

responses

reflect

those

of

the

bed

partner

Nevertheless

the

efficacy

of

snoring

treatment

must

be

assessed

by

the

same

bed

partner

not

by

the

snorer

This

poses

great

logistical

problems

in

carrying

out

appropriate

investigations

However

some

support

for

this

assumption

of

equivalence

between

the

responses

of

snorers

and

listeners

is

provided

by

a

recent

questionnaire

data

of

Bates

and

McDonald

-LSB-

-RSB-

who

found

that

of

snorers

and

of

the

bed

partners

reported

improvement

in

snoring

after

using

a

mandibular

repositioning

splint

for

months

Table

lists

investigations

which

utilized

oral

appliances

The

only

common

feature

among

these

investigations

and

the

reason

why

other

investigations

were

not

included

is

that

all

of

the

listed

ones

contained

a

specific

comment

regarding

snoring

The

types

of

snoring

assessment

carried

out

in

these

investigations

ranged

from

an

informal

question

about

snoring

to

rating

the

snoring

using

a

visual

scale

and

objective

sound

measurement

together

with

subjective

assessment

Very

few

investigations

included

objective

measurement

of

snoring

Investigations

with

subjective

assessment

of

snoring

using

questionnaires

form

a

very

inhomogeneous

group

because

they

used

different

types

of

questionnaires

with

different

rating

methods

Given

these

differences

in

methodology

it

is

not

possible

to

rigorously

summarize

the

results

However

certain

generalizations

can

be

made

Table

measureCommentsBaseAppl

-LSB-

-RSB-

Snoring

decreased

or

completely

disappeared

-LSB-

-RSB-

reported

substantial

reduction

of

sonorous

sleeping

-LSB-

-RSB-

After

appliance

insertion

immediate

reduction

in

snoring

-LSB-

-RSB-

Snoring

severity

assessed

subjectively

-LRB-

max

score

-RRB-

snoring

eliminated

in

-LSB-

-RSB-

reduced

although

never

eliminated

in

-LSB-

-RSB-

Snoring

on

a

scale

from

to

improvement

also

on

a

scale

from

to

result

-LSB-

-RSB-

No

of

snores/min

snoring

eliminated

in

improved

in

-LSB-

-RSB-

less

than

moderate

in

pts

-LSB-

-RSB-

patients

-LRB-

-RRB-

reported

subjective

improvement

in

snoring

-LSB-

-RSB-

Visual

analog

scores

of

snoring

were

also

reduced

significantly

in

-LRB-

-RRB-

subjects

-LSB-

-RSB-

loud

snore

duration

was

reduced

from

a

median

of

min

to

min

-LSB-

-RSB-

Snoring

was

satisfactorily

reduced

in

patients

-LRB-

-RRB-

-LSB-

-RSB-

snores/h

given

snoring

loudness

and

time

spent

snoring

also

improved

-LSB-

-RSB-

Snoring

was

reported

to

be

satisfactorily

controlled

in

-LRB-

-RRB-

-LSB-

-RSB-

no

snoring

mild

snoring

-LSB-

-RSB-

No

of

snores/h

of

sleep

at

baseline

and

months

follow-up

-LRB-

NS

-RRB-

-LSB-

-RSB-

Dramatic

reduction

in

the

attributes

of

snoring

was

achieved

-LSB-

-RSB-

-LRB-

-RRB-

snoring

either

eliminated

or

acceptable

-LSB-

-RSB-

of

snores/h

sleep

results

for

Herbst

appliance

disturbed

by

snoring

at

baseline

vs

with

appliance

-LSB-

-RSB-

of

time

spent

in

loud

snoring

-LSB-

-RSB-

Time

with

snoring

dropped

significantly

from

to

-LSB-

-RSB-

eliminated

in

significantly

reduced

in

success

rate

-LRB-

-RRB-

-LSB-

-RSB-

survey

were

still

using

the

device

at

year

and

were

satisfied

-LRB-

-RRB-

-LSB-

-RSB-

survey

patients

fitted

with

appliance

thought

it

reduced

snoring

no

benefit

-LSB-

-RSB-

survey

out

of

patients

reported

improvement

in

snoring

-LSB-

-RSB-

of

snores/h

of

sleep

subjective

improvement

as

well

-LSB-

-RSB-

Randomized

controlled

vs

placebo-appliance

non-apneic

snorers

frequency

of

snoring

-LRB-

nights/week

-RRB-

p

greatly

improved

with

MAA

vs

with

placebo

-LSB-

-RSB-

had

short-term

satisfactory

treatment

results

with

the

device

-LSB-

-RSB-

controlled

vs

placebo-appliance

snores/h

of

sleep

-LRB-

p

-RRB-

mean

snoring

intensity

significantly

reduced

the

majority

of

patients

reported

substantial

improvement

in

snoring

-LRB-

-RRB-

-LSB-

-RSB-

controlled

vs

placebo-appliance

snores/h

of

sleep

-LRB-

p

-RRB-

mean

and

maximum

snoring

intensity

significantly

reduced

significant

subjective

reduction

in

snoring

-LSB-

-RSB-

Randomized

placebo-controlled

crossover

frequency

of

snoring

-LRB-

nights/week

-RRB-

-LRB-

p

-RRB-

no

significant

difference

in

loudness

of

snoring

-LSB-

-RSB-

Duration

of

snoring/h

of

sleep

-LRB-

p

-RRB-

-LSB-

-RSB-

The

patients

and

their

bed

partners

thought

that

snoring

improved

-LSB-

-RSB-

epochs/h

-LRB-

p

-RRB-

randomized

crossover

study

vs

CPAP

-LSB-

-RSB-

Duration

of

snoring/h

of

sleep

-LRB-

p

-RRB-

comparison

of

two

protrusions

results

for

protrusion

group

-LSB-

-RSB-

of

two

protrusions

results

for

protrusion

group

problems

with

apneas

and

snoring

decreased

by

-LSB-

-RSB-

snoring

patients

have

benefited

from

oral

appliance

therapy

and

their

spouses

will

testify

to

the

same

-LSB-

-RSB-

assessment

on

average

a

mean

reduction

of

of

the

intensity

of

snoring

was

reported

by

the

patients

-LSB-

-RSB-

It

is

estimated

that

of

the

snorers

and

sleep

apnea

patients

had

treatment

success

or

subjective

beneficial

effects

-LSB-

-RSB-

level

measured

out

of

subjects

had

a

significant

reduction

in

snore

noise

sound

level

-LSB-

-RSB-

VAS

scale

-LRB-

p

-RRB-

result

at

months

follow-up

subjectively

were

satisfied

-LSB-

-RSB-

survey

out

of

patients

who

returned

questionnaire

thought

snoring

was

satisfactorily

controlled

-LSB-

-RSB-

snoring

time

-LSB-

-RSB-

snoring

markedly

improved

-LSB-

-RSB-

however

VAS

scale

no

difference

-LSB-

-RSB-

of

users

of

appliance

reported

control

of

snoring

of

non-users

of

appliance

also

thought

snoring

was

controlled

-LSB-

-RSB-

was

reported

to

be

improved

by

of

the

responding

bed

partners

First

the

majority

of

the

investigations

concluded

that

oral

appliances

are

beneficial

in

reducing

snoring

in

the

majority

of

patients

Second

all

of

the

randomized

placebo-appliance-controlled

studies

except

one

-LSB-

-RSB-

found

significant

reduction

in

snoring

independently

of

whether

it

was

assessed

objectively

or

subjectively

Johnston

et

al.

-LSB-

-RSB-

did

not

find

a

significant

difference

in

either

the

loudness

-LRB-

measured

using

the

VAS

to

scale

-RRB-

or

the

frequency

-LRB-

nights/week

-RRB-

of

snoring

However

an

earlier

study

from

the

same

group

-LSB-

-RSB-

employing

similar

methodology

but

different

patient

population

-LRB-

non-apneic

snorers

-RRB-

did

demonstrate

significant

reduction

in

snoring

This

further

illustrates

the

difficulties

with

subjective

assessment

of

snoring

in

different

patient

populations

Even

in

the

same

patient

population

there

is

a

discrepancy

between

objective

measurement

and

subjective

perception

as

found

by

Lawton

et

al.

-LSB-

-RSB-

We

shall

present

the

summary

of

the

individual

investigations

listed

in

Table

as

follows

First

we

selected

only

those

investigations

where

a

numerical

value

describing

snoring

with

and

without

appliance

was

given

These

results

are

shown

in

Table

There

are

studies

involving

patients

All

except

one

-LSB-

-RSB-

employed

the

mandibular

adjustment

appliance

All

of

these

investigations

give

a

number

to

quantify

snoring

We

note

the

diversity

of

measurement

of

snoring

in

each

study

the

number

in

Table

represents

either

a

VAS

score

number

of

snorers/h

-LRB-

or

min

-RRB-

of

sleep

amount

of

time

spent

with

loud

snoring

per

hour

of

sleep

or

per

night

number

of

nights

per

week

spent

with

disturbing

snoring

or

noise

level

etc.

However

we

can

calculate

the

percent

change

between

the

baseline

night

and

the

with

appliance

night

displayed

in

the

last

column

of

Table

We

note

that

despite

the

diversity

of

snoring

measurements

in

all

investigations

the

percent

change

is

negative

which

indicates

that

the

investigators

always

found

reduction

in

snoring

with

oral

appliances

The

mean

reduction

in

snoring

using

the

pooled

data

was

Table

with

measurement

of

snoringReferenceNSnoring

measureExplanation

of

snoring

measurementPercent

changeBaseAppl

-LSB-

-RSB-

Visual

analogue

scale

-LSB-

-RSB-

Number

of

snores/min

-LSB-

-RSB-

of

snores/h

-LSB-

-RSB-

Number

of

snores/h

-LSB-

-RSB-

of

snores/h

-LSB-

-RSB-

of

sleep

time

spent

in

loud

snoring

-LSB-

-RSB-

of

snores/h

-LSB-

-RSB-

Nights/per

week

with

disturbing

snoring

-LSB-

-RSB-

of

snores/h

-LSB-

-RSB-

of

snores/h

-LSB-

-RSB-

Nights/per

week

with

disturbing

snoring

-LSB-

-RSB-

Minutes

of

snoring/h

of

sleep

-LSB-

-RSB-

epochs/h

of

sleep

-LSB-

-RSB-

Minutes

of

snoring/h

of

sleep

-LSB-

-RSB-

level

-LSB-

-RSB-

Visual

analogue

scale

-LSB-

-RSB-

snoring

time

-LSB-

-RSB-

of

snores/h

of

sleep

Effect

of

oral

appliances

on

daytime

function

In

assessing

the

effect

of

oral

appliances

on

sleep

apnea

syndrome

it

is

not

sufficient

to

focus

only

on

the

apnea/hypopnea

index

or

snoring

We

must

also

demonstrate

the

effect

of

this

treatment

on

daytime

function

which

is

almost

always

compromised

in

patients

with

sleep

apnea

and

sometimes

in

non-apneic

snorers

also

There

are

several

tools

used

to

assess

daytime

function

but

there

is

little

consistency

in

using

these

tools

in

investigations

involving

oral

appliances

Table

summarizes

the

results

of

investigations

where

some

assessment

of

daytime

function

was

performed

no

matter

how

primitive

The

methods

of

assessment

differ

in

each

investigation

Some

relied

on

answers

to

questions

regarding

daytime

sleepiness

and

tiredness

others

utilized

visual

scales

yet

other

investigations

measured

response

time

to

various

tasks

etc.

After

the

majority

of

investigations

employed

the

Epworth

sleepiness

score

-LRB-

ESS

-RRB-

The

results

generally

show

improvement

in

daytime

symptoms

with

oral

appliances

Table

assessmentReferenceNTest

or

questionResultCommentsBaseAppl

-LSB-

-RSB-

function

reported

improvement

-LSB-

-RSB-

Improved

-LSB-

-RSB-

Reaction

time

-LRB-

p

-RRB-

-LSB-

-RSB-

sleepiness

Daytime

somnolence

was

eliminated

or

diminished

markedly

-LSB-

-RSB-

somnolence

patients

reported

increased

alertness

and/or

reduction

in

daytime

sleepiness

-LSB-

-RSB-

of

daytime

sleepiness

of

these

patients

reported

no

more

sleepiness

with

orthosis

use

-LSB-

-RSB-

sleepiness

Daytime

sleepiness

was

improved

in

all

but

two

patients

-LSB-

-RSB-

score

-LRB-

including

sleepiness

-RRB-

Significant

-LRB-

p

-RRB-

improvement

in

daytime

symptoms

-LSB-

-RSB-

and

improvement

using

Likert

Improvement

on

Likert

scale

at

months

-LSB-

-RSB-

tired

patients

-LSB-

-RSB-

of

mistakes

in

vigilance

p

-LSB-

-RSB-

daytime

scale

p

-RRB-

for

all

symptoms

-LSB-

-RSB-

of

p

significant

reduction

in

prevalence

of

other

symptoms

-LSB-

-RSB-

with

-LSB-

-RSB-

using

VAS

Reduction

in

scores

-LRB-

p

-RRB-

in

of

patients

who

were

compliant

with

treatment

-LSB-

-RSB-

p

EDS

improved

in

patients

-LSB-

-RSB-

Median

score

p

-LSB-

-RSB-

score

p

-LSB-

-RSB-

with

daytime

-LSB-

-RSB-

with

moderate

and

severe

daytime

-LSB-

-RSB-

sleepiness

on

scale

Prospective

randomized

UPPP

group

and

OA

group

in

comparison

with

their

baseline

values

a

significant

-LRB-

p

-RRB-

reduction

in

subjective

daytime

sleepiness

-LSB-

-RSB-

-LSB-

-RSB-

of

life

-LRB-

vitality

contentment

sleep

-RRB-

improvement

compared

to

baseline

two

parallel

groups

OA

vs

UPPP

no

difference

in

vitality

and

sleep

-LSB-

-RSB-

of

patients

refreshed

by

sleep

Most

of

the

regular

users

had

an

improvement

in

their

quality

of

sleep

and

day

time

somnolence

-LSB-

-RSB-

p

identical

result

for

two

different

MAAs

-LSB-

-RSB-

of

patients

whose

sleepiness

-LRB-

-RRB-

of

patients

reported

subjective

improvement

in

excessive

daytime

sleepiness

-LSB-

-RSB-

p

-LSB-

-RSB-

p

at

to

months

follow-up

-LSB-

-RSB-

p

randomized

placebo-controlled

crossover

trial

of

non-apneic

snorers

-LSB-

-RSB-

of

patients

reporting

reduction

in

-LSB-

-RSB-

identical

result

for

two

different

MAAs

-LSB-

-RSB-

Scale

from

-LRB-

maximum

deterioration

-RRB-

to

-LRB-

maximum

improvement

-RRB-

-LSB-

-RSB-

After

days

only

patients

continued

to

wear

MAA

initial

ESS

based

on

patients

final

on

-LSB-

-RSB-

p

randomized

crossover

vs

CPAP

-LSB-

-RSB-

randomized

crossover

vs

CPAP

extensive

tests

of

daytime

function

these

results

do

not

support

these

MRS

devices

as

first-line

treatment

for

sleepy

patients

with

SAHS

-LSB-

-RSB-

-RRB-

the

proportion

of

patients

with

normal

subjective

sleepiness

was

significantly

higher

with

the

MAS

than

with

the

control

device

-LRB-

vs

p

-RRB-

but

this

was

not

so

for

objective

sleepiness

-LRB-

vs

p

-RRB-

-LSB-

-RSB-

NS

randomized

placebo-controlled

crossover

trial

of

apneic

snorers

-LSB-

-RSB-

p

prospective

randomized

comparing

and

protrusion

result

for

initial

value

patients

final

value

-LSB-

-RSB-

EDSRandomized

comparison

of

two

protrusions

of

patients

in

group

-LRB-

n

-RRB-

and

in

group

-LRB-

n

-RRB-

reported

a

decrease

in

daytime

sleepiness

-LSB-

-RSB-

p

-LSB-

-RSB-

p

randomized

vs

placebo

pill

and

CPAP

-LSB-

-RSB-

p

-LSB-

-RSB-

p

-LSB-

-RSB-

median

values

-LSB-

-RSB-

median

values

-LSB-

-RSB-

values

-LSB-

-RSB-

users

of

OA

in

non-users

ESS

fell

from

to

-LSB-

-RSB-

energy

levels

sleep

quality

ESS

given

of

responders

reported

improvement

-LSB-

-RSB-

and

full

battery

of

neuropsychological

Total

score

of

all

self-report

measures

given

prospective

randomized

placebo-appliance-controlled

weeks

study

Because

of

the

diversity

of

methods

assessing

daytime

function

it

is

difficult

to

pool

and

summarize

the

individual

data

One

way

of

doing

this

is

to

select

only

those

investigations

which

employed

identical

methods

of

assessment

and

summarize

the

mean

results

as

was

done

in

the

previous

tables

The

most

common

single

way

of

assessing

daytime

function

in

most

investigations

was

the

ESS

These

investigations

are

listed

in

Table

There

are

of

them

involving

a

total

of

patients

However

not

all

investigations

could

be

used

in

calculating

pooled

data

We

rejected

four

investigations

-LSB-

-RSB-

involving

patients

where

only

the

median

and

not

the

mean

values

of

the

ESS

were

reported

Consequently

we

are

left

with

investigations

involving

patients

As

a

group

these

patients

were

only

mildly

sleepy

with

the

mean

ESS

of

In

all

investigations

the

ESS

dropped

with

the

use

of

oral

appliances

For

the

entire

group

there

was

a

significant

reduction

in

the

ESS

from

to

Table

assessment

using

ESSReferenceNESSCommentsBaseAppl

-LSB-

-RSB-

p

EDS

improved

in

patients

-LSB-

-RSB-

Median

score

p

-LSB-

-RSB-

score

p

-LSB-

-RSB-

-LSB-

-RSB-

p

identical

result

for

two

different

MAAs

-LSB-

-RSB-

p

-LSB-

-RSB-

p

at

to

months

follow-up

-LSB-

-RSB-

p

randomized

placebo-controlled

crossover

trial

of

non-apneic

snorers

-LSB-

-RSB-

identical

result

for

two

different

MAAs

-LSB-

-RSB-

After

days

only

patients

continued

to

wear

MAA

initial

ESS

based

on

patients

final

ESS

on

-LSB-

-RSB-

p

randomized

crossover

vs

CPAP

-LSB-

-RSB-

randomized

crossover

vs

CPAP

extensive

tests

of

daytime

function

these

results

do

not

support

these

MRS

devices

as

first-line

treatment

for

sleepy

patients

with

SAHS

-LSB-

-RSB-

-RRB-

the

proportion

of

patients

with

normal

subjective

sleepiness

was

significantly

higher

with

the

MAS

than

with

the

control

device

-LRB-

vs

p

-RRB-

but

this

was

not

so

for

objective

sleepiness

-LRB-

vs

p

-RRB-

-LSB-

-RSB-

NS

randomized

placebo-controlled

crossover

trial

of

apneic

snorers

-LSB-

-RSB-

p

prospective

randomized

comparing

and

protrusion

result

for

initial

n

patients

final

n

patients

-LSB-

-RSB-

p

-RRB-

-LSB-

-RSB-

p

randomized

vs

placebo

pill

and

CPAP

-LSB-

-RSB-

p

-LSB-

-RSB-

p

-LSB-

-RSB-

median

values

-LSB-

-RSB-

median

values

-LSB-

-RSB-

values

-LSB-

-RSB-

for

users

of

OA

in

non-users

ESS

fell

from

to

-LSB-

-RSB-

Prospective

randomized

placebo-appliance-controlled

weeks

References

were

excluded

-LRB-

no

mean

values

were

given

-RRB-

In

two

investigations

-LSB-

-RSB-

both

randomized

crossover

and

controlled

-LRB-

one

vs

placebo

and

another

one

vs

CPAP

-RRB-

reduction

in

ESS

was

not

significant

Engleman

et

al.

-LSB-

-RSB-

carried

out

a

very

extensive

study

of

daytime

function

comparing

the

effect

of

oral

appliance

to

CPAP

Functional

assessment

included

maintenance

of

wakefulness

test

measures

of

daytime

sleepiness

and

symptoms

measures

of

well-being

-LRB-

using

the

questionnaire

HADS

anxiety

and

depression

score

-RRB-

and

cognitive

performance

The

results

favored

CPAP

in

out

of

variables

-LRB-

including

the

ESS

AHI

effectiveness

and

symptoms

-RRB-

and

showed

no

difference

between

CPAP

and

oral

appliance

in

other

variables

-LRB-

including

the

maintenance

of

wakefulness

tests

cognitive

performance

and

treatment

preference

-RRB-

Johnston

et

al.

-LSB-

-RSB-

compared

oral

appliance

to

placebo

but

did

not

carry

extensive

investigations

of

daytime

function

only

the

ESS

and

a

scale

describing

how

refreshed

the

patients

felt

in

the

morning

The

authors

found

significant

improvement

compared

to

placebo

but

only

in

non-apneic

snorers

-LSB-

-RSB-

not

in

patients

with

sleep

apnea

-LSB-

-RSB-

In

all

other

randomized

crossover

controlled

studies

there

was

a

statistically

significant

improvement

in

the

ESS

but

not

in

other

subjective

measures

of

daytime

performance

In

fact

of

the

studies

demonstrated

a

significant

improvement

in

all

of

the

subjective

outcomes

studied

This

is

not

surprising

because

almost

all

studies

comparing

placebo

treatment

with

active

treatment

no

matter

what

it

is

always

demonstrate

a

significant

placebo

effect

Probably

the

most

complete

assessment

of

neuropsychological

function

was

carried

out

by

Naismith

et

al.

-LSB-

-RSB-

in

a

prospective

randomized

placebo-appliance-controlled

study

of

patients

treated

for

weeks

The

authors

demonstrated

significant

improvement

in

the

measures

of

self-reported

sleepiness

fatigue

and

energy

levels

but

no

improvement

in

the

measured

speed/vigilance

-LRB-

except

for

the

improved

reaction

time

-RRB-

attention/working/verbal

memory

or

visuospatial/executive

functioning

Walker-Engstrom

et

al.

-LSB-

-RSB-

compared

the

quality

of

life

in

two

parallel

groups

of

patients

with

sleep

apnea

year

after

treatment

with

either

oral

appliance

or

UPPP

The

ESS

was

not

measured

but

there

was

other

extensive

assessment

of

three

quality

of

life

dimensions

-LRB-

vitality

contentment

and

sleep

-RRB-

Both

groups

improved

compared

to

the

baseline

There

was

no

difference

in

vitality

and

sleep

dimensions

between

the

two

groups

but

the

UPPP

group

was

more

content

than

the

oral

appliance

group

The

effect

of

oral

appliances

on

daytime

function

was

not

studied

as

fully

and

extensively

as

for

CPAP

For

example

there

are

no

studies

comparing

driving

simulator

performance

in

patients

treated

with

oral

appliance

no

studies

comparing

multiple

sleep

latency

or

maintenance

of

wakefulness

Recognizing

the

limited

nature

of

the

data

the

conclusion

from

all

of

the

investigations

taken

as

a

group

must

be

that

oral

appliances

improve

daytime

function

although

they

are

not

necessarily

superior

or

consistently

preferred

than

other

treatments

such

as

CPAP

and

UPPP

Effect

of

oral

appliances

on

vascular

disease

Numerous

investigations

examined

the

relationship

between

sleep

apnea

and

vascular

events

such

as

coronary

artery

disease

hypertension

and

cerebro-vascular

disease

Fewer

but

still

many

investigations

were

carried

out

to

examine

the

effect

of

the

treatment

of

sleep

apnea

with

CPAP

on

changes

in

these

conditions

Quite

the

opposite

situation

is

seen

regarding

the

effect

of

oral

appliances

on

vascular

disease

There

are

only

three

studies

examining

the

effect

of

the

treatment

of

sleep

apnea

with

oral

appliance

on

blood

pressure

Both

studies

employed

the

randomized

controlled

crossover

design

The

first

study

was

carried

out

by

Gotsopoulos

et

al.

-LSB-

-RSB-

specifically

for

the

purpose

of

examining

the

effect

of

weeks

treatment

with

a

mandibular

advancement

splint

on

blood

pressure

in

patients

with

sleep

apnea

-LRB-

mean

AHI

-RRB-

There

was

approximately

mmHg

drop

in

the

systolic

and

diastolic

blood

pressure

with

treatment

but

only

during

wakefulness

There

was

no

change

in

blood

pressure

during

sleep

The

second

study

by

Barnes

et

al.

-LSB-

-RSB-

compared

the

effect

of

months

treatment

with

oral

appliance

to

CPAP

and

placebo

-LRB-

a

tablet

-RRB-

In

patients

with

sleep

apnea

-LRB-

mean

AHI

-RRB-

the

h

blood

pressure

was

measured

Treatment

with

oral

appliance

-LRB-

but

not

with

CPAP

or

placebo

tablet

-RRB-

resulted

in

the

significant

reduction

in

nighttime

diastolic

blood

pressure

by

mmHg

There

were

no

changes

in

diastolic

blood

pressure

during

wakefulness

and

no

changes

in

systolic

blood

pressure

either

during

wakefulness

or

sleep

The

third

study

was

carried

out

by

Yoshida

-LSB-

-RSB-

who

measured

blood

pressure

in

patients

with

sleep

apnea

before

and

after

days

of

treatment

with

oral

appliance

There

was

a

statistically

significant

drop

in

blood

pressure

from

to

mmHg

Regression

analysis

demonstrated

weak

but

significant

correlation

between

the

mean

arterial

and

baseline

blood

pressures

and

the

reduction

in

AHI

This

area

of

investigation

is

still

in

its

infancy

and

undoubtedly

more

results

will

be

forthcoming

in

the

future

There

are

no

rigorous

studies

of

the

effect

of

oral

appliances

on

other

vascular

diseases

Eskafi

et

al.

-LSB-

-RSB-

carried

out

a

single

night

unattended

home

sleep

study

in

patients

with

sleep

apnea

-LRB-

mean

AHI

-RRB-

and

congestive

heart

failure

with

periodic

breathing

before

and

after

intervention

with

a

mandibular

advancement

device

The

authors

found

improvement

in

sleep

apnea

-LRB-

mean

AHI

reduced

from

to

-RRB-

but

no

improvement

in

periodic

breathing

or

left

ventricular

ejection

fraction

after

months

of

treatment

There

is

not

enough

evidence

at

the

present

time

to

draw

any

conclusions

regarding

the

effect

of

oral

appliance

therapy

on

vascular

disease

This

remains

a

very

interesting

area

of

investigation

Given

the

differences

in

intra-thoracic

pressure

as

a

consequence

of

CPAP

vs

oral

appliance

it

is

possible

that

results

obtained

with

oral

appliances

therapy

will

be

different

from

those

obtained

with

positive

pressure

therapy

Side

effects

Almost

every

study

describing

oral

appliances

comments

on

the

side

effects

voiced

by

patients

The

type

of

side

effects

and

their

frequency

depend

on

the

questions

asked

the

rating

scale

the

number

of

patients

in

the

study

etc.

Some

studies

specifically

focused

on

the

side

effects

and

compliance

with

treatment

-LSB-

-RSB-

others

simply

asked

a

few

questions

about

the

side

effects

Table

summarizes

some

of

the

common

side

effects

there

is

also

a

reference

to

the

study

which

reported

the

highest

frequency

of

this

particular

side

effect

Table

reported

side

effects

of

oral

appliancesSide

effectPercent

of

patientsReference

reporting

maximum

percentDifficulty

in

-LSB-

-RSB-

Excessive

-LSB-

-RSB-

Dry

-LSB-

-RSB-

Tooth

-LSB-

-RSB-

Tongue

-LSB-

-RSB-

Jaw

-LSB-

-RSB-

Gum

-LSB-

-RSB-

-LSB-

-RSB-

Occlusive

-LSB-

-RSB-

TMJ

-LSB-

-RSB-

Masseter

muscle

-LSB-

-RSB-

No

side

effects

at

-LSB-

-RSB-

subjects

Excessive

salivation

mouth

and

teeth

discomfort

are

the

most

common

side

effects

reported

However

patients

seldom

consider

these

side

effects

troublesome

Provided

that

this

complaint

is

addressed

by

the

dentist

and

the

appliance

is

adjusted

they

continue

to

use

it

In

many

cases

the

side

effects

are

transient

and

disappear

with

continued

use

When

patients

stop

wearing

the

oral

appliances

it

is

mainly

because

of

ineffectiveness

rather

than

because

of

side

effects

although

in

some

studies

-LSB-

-RSB-

up

to

of

patients

discontinued

the

use

of

the

appliances

because

of

the

side

effects

One

study

-LSB-

-RSB-

involving

only

patients

all

using

the

Herbst

appliance

reported

that

of

the

patients

had

any

side

effects

The

conclusion

based

on

the

results

of

most

studies

is

that

when

oral

appliances

are

properly

constructed

by

the

dentist

with

expertise

in

this

area

they

are

relatively

comfortable

in

the

majority

of

patients

There

are

also

dental

effects

of

oral

appliances

It

is

still

not

entirely

clear

if

long-term

use

of

oral

appliances

will

lead

to

permanent

adverse

dental

changes

particularly

when

used

in

children

There

are

several

studies

addressing

various

dental

skeletal

changes

of

oral

appliances

using

various

imaging

techniques

One

of

the

most

common

effects

commented

upon

in

many

studies

is

the

degree

of

vertical

and

horizontal

overlap

of

the

teeth

-LRB-

overjet

and

overbite

respectively

-RRB-

These

results

are

summarized

in

Table

There

are

distinct

studies

involving

patients

with

mean

follow-up

time

of

months

Two

studies

-LSB-

-RSB-

were

rejected

because

only

the

median

results

were

given

and

one

study

-LSB-

-RSB-

was

rejected

because

no

mean

values

for

overjet

and

overbite

were

shown

only

changes

in

these

parameters

over

a

period

of

years

A

summary

of

the

remaining

data

involving

patients

with

mean

follow-up

of

months

shows

that

the

overbite

is

reduced

from

to

mm

and

the

overjet

is

reduced

from

to

mm

It

is

clear

that

dental

skeletal

effects

of

oral

appliances

are

certainly

present

but

the

long-term

results

and

their

clinical

significance

are

unknown

at

this

time

The

recent

studies

of

Marklund

-LSB-

-RSB-

and

de

Almeida

et

al.

-LSB-

-RSB-

described

patients

who

were

using

mandibular

advancement

appliances

for

more

than

years

Their

results

suggest

that

orthodontic

changes

-LRB-

-RRB-

are

variable

-LRB-

favorable

in

some

and

unfavorable

in

others

-RRB-

-LRB-

-RRB-

are

clinically

relevant

and

-LRB-

-RRB-

might

be

predictable

from

the

initial

dental

characteristics

of

the

patients

and

the

type

of

device

Table

effects

overjet

and

overbiteReferenceNF/U

-LRB-

months

-RRB-

OverjetOverbiteCommentsBaseF/UBaseF/U

-LSB-

-RSB-

Herbst

appliance

-LSB-

-RSB-

-LSB-

-RSB-

After

correction

for

magnification

error

-LSB-

-RSB-

Effects

evident

already

at

months

-LSB-

-RSB-

Median

results

at

follow-up

-LSB-

-RSB-

Significantly

larger

changes

compared

to

reference

group

-LSB-

-RSB-

Ibid

-LSB-

-RSB-

-LSB-

-RSB-

NS

compared

to

UPPP

-LSB-

-RSB-

Effects

evident

at

months

-LSB-

-RSB-

NS

for

protrusion

same

for

protrusion

-LSB-

-RSB-

Median

values

overbite

change

NS

orthodontic

side

effect

increase

with

treatment

time

and

more

frequent

use

-LSB-

-RSB-

patients

followed-up

for

years

measurements

made

from

models

unfavorable

change

group

-LSB-

-RSB-

As

above

no

change

group

-LSB-

-RSB-

As

above

favorable

change

group

-LSB-

-RSB-

Only

changes

but

not

baseline

values

in

overjet

and

overbite

are

given

-LRB-

and

respectively

over

years

-RRB-

small

but

significant

reductions

observed

mainly

during

the

first

References

-LSB-

-RSB-

were

Compliance

Compliance

with

oral

appliances

depends

strictly

on

the

balance

between

the

perception

of

benefit

and

side

effects

Most

patients

treated

with

oral

appliances

have

relatively

mild

sleep

apnea

and

relatively

few

daytime

symptoms

the

main

reason

for

treatment

was

snoring

Consequently

the

perception

of

benefit

is

generally

that

of

the

bed

partner

whereas

the

side

effects

are

experienced

by

the

wearer

of

the

appliance

This

is

why

the

assessment

of

compliance

is

a

complex

issue

In

some

cases

although

the

appliance

is

quite

comfortable

the

patient

may

stop

wearing

it

if

the

bed

partner

is

no

longer

present

or

no

longer

complains

of

snoring

Table

shows

the

results

of

studies

which

provide

compliance

data

All

of

them

except

one

-LSB-

-RSB-

employed

mandibular

advancement

devices

There

is

a

very

wide

variability

between

individual

investigations

from

as

little

as

to

as

high

as

at

the

end

of

year

Table

with

oral

appliancesReferenceNF/U

-LRB-

months

-RRB-

Compliance

-LRB-

-RRB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

-LSB-

-RSB-

The

largest

study

is

that

of

de

Almeida

et

al.

-LSB-

-RSB-

It

is

based

on

a

mail

survey

of

patients

of

whom

returned

the

questionnaire

on

the

average

of

almost

years

after

the

construction

of

the

appliance

The

majority

of

patients

were

fitted

with

MAAs

although

some

had

TRDs

At

the

time

of

follow-up

patients

continued

to

use

the

appliance

Assuming

the

worse

case

scenario

-LRB-

i.e.

all

those

who

did

not

return

the

questionnaire

were

no

longer

using

the

appliance

-RRB-

the

compliance

rate

is

while

in

the

best

case

scenario

the

compliance

rate

is

Among

those

who

used

the

appliance

of

bed

partners

were

satisfied

with

this

treatment

even

among

the

non-users

of

appliances

of

bed

partners

were

satisfied

The

main

reasons

for

discontinuing

the

use

of

the

appliance

were

discomfort

-LRB-

-RRB-

and

perception

of

little

or

no

benefit

-LRB-

-RRB-

Pooled

data

summarizing

all

reviewed

studies

involving

patients

showed

that

at

the

end

of

months

of

them

continued

to

wear

the

appliance

Conclusions

Oral

appliances

used

to

date

constitute

a

relatively

heterogeneous

group

of

devices

for

the

treatment

of

sleep

apnea

and

non-apneic

snoring

It

is

this

heterogeneity

which

partly

accounts

for

the

variability

in

their

benefit

and

side

effects

Another

reason

for

variability

is

the

diverse

methodology

employed

in

different

studies

The

evidence

available

at

present

indicates

that

oral

appliances

successfully

cure

mild-to-moderate

sleep

apnea

in

of

patients

and

significantly

improve

it

in

additional

They

reduce

but

do

not

eliminate

snoring

Side

effects

are

common

but

are

relatively

minor

Provided

that

the

appliances

are

constructed

by

qualified

dentists

of

patients

continue

to

use

them

for

several

years

Their

effectiveness

is

inferior

to

CPAP

It

is

similar

to

surgical

procedures

but

these

are

invasive

-LRB-

although

not

particularly

dangerous

-RRB-

and

irreversible

The

effect

of

oral

appliances

on

the

vascular

consequences

of

sleep

apnea

is

not

known

The

place

of

oral

appliances

in

the

spectrum

of

treatment

options

for

apneic

and

non-apneic

snorers

was

extensively

discussed

in

various

reviews

and

guidelines

including

the

most

recent

report

by

the

American

Academy

of

Sleep

Medicine

-LSB-

-RSB-

The

current

review

does

not

alter

those

conclusions

It

simply

illustrates

the

marked

variability

of

individual

responses

to

oral

appliance

therapy

and

therefore

the

necessity

to

approach

each

patient

on

an

individual

basis

Patients

with

sleep

apnea

should

be

informed

about

all

treatment

options

In

some

cases

the

decision

is

simple

after

informing

patients

about

all

available

options

a

strong

and

clear

recommendation

can

be

given

by

the

health

care

practitioner

In

other

cases

the

decision

regarding

treatment

is

arrived

at

only

after

individual

consideration

of

all

the

factors

urgency

of

clinical

situation

reimbursement

plan

available

to

patient

risk

factors

and

the

patient

's

ability

or

motivation

to

modify

them

patient

's

preferences

and

a

possibility

of

having

a

trial

of

treatment

with

oral

appliance

and

CPAP

There

are

patients

with

severe

sleep

apnea

successfully

treated

with

oral

appliances

just

as

there

are

non-apneic

snorers

with

or

without

upper

airway

resistance

syndrome

successfully

treated

with

CPAP

The

decision

regarding

treatment

in

each

individual

patient

is

best

made

by

medical

practitioners

with

experience

in

sleep

medicine

who

are

aware

of

all

options

and

who

are

preferably

a

part

of

a

specialized

sleep

disorders

center

An

important

issue

not

addressed

in

this

review

is

the

underuse

of

oral

appliances

currently

This

is

due

in

part

to

the

lack

of

qualified

dentists

working

in

this

area

and

in

part

to

reimbursement

policies

At

present

the

majority

of

government-sponsored

and

private

health

care

providers

will

cover

-LRB-

fully

or

partially

-RRB-

the

cost

of

CPAP

whereas

very

few

if

any

health

care

plans

will

cover

the

cost

of

oral

appliances

Considering

that

this

treatment

approach

is

the

only

non-invasive

alternative

to

CPAP

it

is

important

to

continue

to

lobby

health

care

providers

to

enable

this

treatment

for

qualified

patients

continuous positive airway pressure
sleep apnea
oral appliance