ABSTRACTS

SKELETAL STABILITY
FOLLOWING MINIPLATE
FIXATION AFTER
BILATERAL SAGITTAL
SPLIT OSTEOTOMY FOR
MANDIBULAR
ADVANCEMENT

Abeloos J, De Clerco C and
Luc Neyt

Skeletal stability after monocortical miniplate fixation of bilateral sagittal split osteotomies to advance the mandible was evaluated in 20 patients. Three angles and four linear measurements were analyzed on lateral cephalometric radiographs before surgery, immediately after surgery, and at least 6 months after surgery. The mean horizontal advancement at pogonion was 5.0 mm; 6 months after surgery the advancement increased 0.3 mm because of occlusal settling. The mean lengthening of the distance gonion to menton was 5.8 mm and a relapse of 0.3 mm (5.2%) was found. The mean increase of anterior facial height measured at long-term follow-up was 3.6 mm. This study shows that fixation of the advanced mandible with intraorally applied monocortical miniplates after the bilateral sagittal split osteotomy is a stable procedure.

J Oral Maxillofac Surg
1993; 5: 365-369.

OCCLUSAL PLANE
ALTERATION IN
ORTHOGNATHIC
SURGERY

Wolford LM, Chemello PD
and Hilliard FW

This article discusses correction of
functional and esthetic deformities by
surgically increasing or decreasing the
occlusal plane angulation. Clockwise
rotation, or increase of the occlusal plane
angulation, is a well-accepted technique
in orthognathic surgery. However,
counterclockwise rotation (decrease of
the occlusal plane angulation) has not
been a well-accepted treatment
approach. The functional and esthetic
characteristics of the low occlusal plane
and the high occlusal plane facial types
are presented, specific surgical
approaches to alteration of the occlusal
plane are described, and the long-term
stability of results with both clockwise and
counterclockwise rotations of the occlusal
plane are discussed. Cases illustrating
the application of these surgical
approaches are presented.

J Oral Maxillofac Surg
1993; 51: 730-740.

SIGNS AND SYMPTOMS OF
TEMPOROMANDIBULAR
JOINT MUSCLE PAIN
DYSFUNCTION

SYNDROME:

A RETROSPECTIVE STUDY
OF ONE HUNDRED
PATIENTS

Brunello GE and
Brunello DL

A retrospective serial study was carried
out on one hundred randomly selected
temporomandibular joint muscle pain
dysfunction syndrome (TMJMPDS)
patients who had attended a private
prosthodontic practice over an eight year
period. The study looked at common
signs, symptoms and referral patterns in
this group and compared them with those
quoted in a large section of the literature
on the subject.

Aust Pros Jour 1991; 5.

USE OF A SKELETAL
DISTRACTION DEVICE TO
WIDEN THE MANDIBLE:
A CASE REPORT

Perrott DH, Berger R,
Vargervik K, Kaban LB

Oral and maxillofacial surgeons commonly encounter clinical problems that require lengthening or widening of the maxilla and mandible. In most cases, this is accomplished by an osteotomy with or without a bone graft. When there is a combination of skeletal and soft tissue deficiency, standard reconstructive management may require osteotomy, bone grafting, and a soft tissue flap. Alternatively, gradual lengthening or widening by skeletal distraction may eliminate the need for bone grafting and a soft tissue flap.

Orthopaedic surgeons encounter a
similar challenge when lengthening a
shortened limb as a result of congenital
or acquired deformity. A technique to
lengthen an extremity without bone or
tissue grafts was published in 1905. The
technique, with resultant *in vivo* bone
formation and a soft tissue proliferation,
is known as distraction osteogenesis
(DO). In recent years, the technique has
been popularised by Illizarov, Moseley,
and De Bastiani *et al*.

In 1973, Snyder *et al* reported using DO
to lengthen the mandible in dogs
successfully. Although DO has been
used clinically on long bones, the
technique has had limited application in
the treatment of facial deformities such
as mandibular asymmetry or midface or
mandibular hypoplasia. This is a report of
the successful application of the principle
of distraction osteogenesis to produce
widening of the mandible and soft tissue
expansion in a patient with hypoglossia-
hy-podactyly syndrome.

J Oral Maxillofac Surg
1993; 51: 435-439.
THE EFFECTS OF
SURGICAL-ORTHODONTIC
CORRECTION OF
SKELETAL CLASS III
MALOCCLUSION ON
MANDIBULAR MOVEMENT

Takeshi Nagamine, Tadaharu
Kobayashi, Tamio Nakajima
and Kooji Hanada

The effects of surgical orthodontic treatment on mandibular movement were studied using the mandibular kinesiograph in 30 patients with skeletal class III malocclusion that was corrected by the sagittal split osteotomy (27 patients), a combination of the sagittal split osteotomy and body osteotomy (2 patients), or the sagittal split osteotomy and a posterior alveolar osteotomy of the maxilla (1 patient). Post-operatively, the mean maximum anterior and posterior excursions of the mandible increased significantly from 4.1 to 6.7 mm and from 0.6 to 2.6 mm, respectively. The lateral excursion to the right and left sides also showed significant increases from 4.8 to 7 mm and from 5.5 to 7 mm, respectively, after surgery. In analysis of the habitual and rapid opening and closing movements of the mandible, marked impairment was not observed in most patients except for crossing and discrepancy in the tracings of the habitual opening and closing movements in the sagittal plane observed in 11 patients. These findings were observed in only one patient post-operatively. The results indicate that the surgical orthodontic corrections of skeletal class III malocclusion has favourable effects on the function of the mandible.

J Oral Maxillofac Surg
1993; 51: 385-389.