Abstracts

EARLY VERSES LATE TREATMENT
OF CROWDED FIRST PREMOLAR
EXTRACTION CASES:
POSTRETENTION EVALUATION OF
STABILITY AND RELAPSE.

T. Haruli and R. Little

The aim of this study was to evaluate the
differences in the long term stability of
orthodontically induced changes in arch form
between patients who receive early orthodontic
treatment (Hellman's dental age III B, mixed
dentition, n=36) and those who were treated later
(Hellman's dental age III C or after, permanent
dentition, n=47). Dental casts were evaluated
before treatment, after treatment, and after a
minimum of 10 years after retention. All patients
had received routine Edgewise orthodontic
treatment that included maxillary and mandibular
first premolar extraction. There were no significant
differences between these groups at pre-treatment
and post-treatment. In the majority of cases, some
degree of mandibular crowding occurred during the
postretention period. There was a significant
difference in the mandibular irregularity index at
postretention between these groups. Regarding the
deviation of the midline of the central incisors,
there were no significant differences between these
groups at pretreatment and post-treatment, but
there was a significant difference at postretention.
At the postretention stage, the late treatment
group had greater mandibular anterior irregularity
and deviation of the midline.

The Angle Orthodontist
1998; 68(1): 61-68

EARLY RADIOGRAPHIC DIAGNOSIS
OF APICAL ROOT RESORPTION
DURING ORTHODONTIC
TREATMENT: A STUDY OF
MAXILLARY INCISORS

E. Levander, R. Bajka and O. Malmgren

The aim of this study was to evaluate the sensitivity of digital radiographs for detection of (i) simulated root resorption cavities in an experimental model and (ii) orthodontically-induced apical root resorption in vivo. The severity of root resorption after three and six months treatment was studied in relation to root form. The experimental study cavities, drilled in mandibular roots in a dry skull, were recorded in conventional and digital radiographs. In vivo root resorption was evaluated on digital radiographs of 92 maxillary incisors after three and six months treatment with fixed appliances.

The results showed a similar sensitivity for the two
methods. Sensitivity increased significantly with
cavity size. After three months apical root resorption
was detected in only a few teeth. The number had
increased significantly after six months. There was a
higher degree of root resorption in teeth with blunt
and pipette-shaped apices. In such teeth a three-
month radiographic control is recommended.

European Journal of Orthodontics
1998; 20: 57-63

THE EFFECTS, LIMITATIONS, AND
LONG-TERM DENTOFACIAL
ADAPTATIONS TO TREATMENT
WITH THE HERBST APPLIANCE

H. Pancherz

The aim of this article is to summarise the existing
scientific data with respect to the short and long-term
effects of the Herbst appliance on the occlusion and
on the maxillo-mandibular complex. The article also
discusses the treatment indications and possible
treatment limitations. The Herbst method is most
effective in the treatment of Class II malocclusions.
Long term stability seems to be dependent on a
stable cuspal interdigitation. Marked mandibular
morphological changes occur during therapy and
sagittal condylar growth is increased. Post-treatment,
most of the mandibular morphological changes revert
and no long-term influence of Herbst treatment on
mandibular growth can be verified. The appliance
effect on the maxillary complex can be compared
with that of a high-pull headgear. Without proper
retention, however, this effect is of a temporary
nature. Herbst treatment is especially indicated in the
permanent dentition at or just after the pubertal peak
of growth. Mixed dentition treatment is not
recommended, as a stable cuspal interdigitation after
therapy is difficult to achieve and relapses are prone
to occur. In the non-growing patient, the appliance
should be used with great caution.

Seminars in Orthodontics
1997; 3: 232-243

PATIENT AND PARENT OPINION
OF THE USE OF RECYCLED
ORTHODONTIC BRACKETS: AN
INTERNATIONAL COMPARISON

R. Oliver, A. Miles, M. Greenslade and M. Harkness

The purpose of this study was to determine the
opinion of patients and parents to the use of recycled
orthodontic brackets. The design consisted of a
questionnaire survey, which took place in the
orthodontic departments of two teaching hospitals
(Cardiff, Wales and Dunedin, New Zealand). The
subjects were patients (and parents of those under
18 years) undergoing active fixed appliance treatment
and similar groups for those on the waiting list for
fixed appliance treatment. There were no significant
differences of opinion between gender, patient,
parent, or centre. There were significant differences of
opinion between those on the waiting list; those
under treatment were less concerned about wearing
recycled brackets than those waiting for treatment. All
respondents felt that they should be told if recycled
brackets were to be used, and any cost savings arising
from their use passed on to the consumer.

British Journal of Orthodontics
1997; 24: 329-332

SURGICAL CLASS III TREATMENT:
LONG-TERM STABILITY AND
PATIENT PERCEPTIONS OF
TREATMENT OUTCOME

T. Bailey, H. Duong and W. Proffit

To evaluate long-term changes after surgical
correction of skeletal Class III deformity,
postoperative cephalometric radiographs at one
year and two or more years postsurgery were
digitised for 92 patients who had received either a
bilateral sagittal split osteotomy for mandibular
setback, Le Fort I maxillary advancement, or

combination of the two procedures. Patients'
perceptions of treatment were determined by four
self-administered questionnaires: satisfaction,
postsurgical perception of occlusion and function,
problems with facial sensation, and postsurgical
perceptions. From 1 year to the longest follow-up,
there were almost no mean changes in landmark
positions for the maxillary advancement group and
minimal mean changes in the mandibular setback
and two-jaw groups. In all three groups, more than
90% of the patients showed no clinical significant
long-term changes, which suggests that long-term
changes are less likely after Class III than Class II
treatment. At the long-term recall, 89% of the
patients expressed satisfaction with their treatment
and would recommend it to others, 74% reported
improved social interaction, and 63% said their
appearance changed as they expected. The
predominant problems reported were altered facial
sensation for 67% of the patients and surprise at
the length of recovery for 52 per cent.

Orthognathic Surgery
1998; 13: 35-44

EFFECT OF LAVAGE WITH
INJECTION OF SODIUM
HYALURONATE FOR PATIENTS
WITH NON-REDUCING DISK
DISPLACEMENT OF THE
TEMPOROMANDIBULAR JOINT

S. Sato, M. Ohta, H. Ohki, H. Kawamura
and K. Motegi

Objective. The aim of this study was to determine
whether lavaging of the superior joint space with
injection of sodium hyaluronate can be used as an
alternative treatment method for non-reducing disk
displacement of the temporomandibular joint.

Study Design. In 26 patients with non-reducing disk
placement of the temporomandibular joint, the
superior joint space was rinsed with 1% xylocaine,
and then sodium hyaluronate was injected there
(experimental group). As a control group, 50
patients with non-reducing disk displacement of the
temporomandibular joint who received no
treatment were used (control group). The
frequency of the patients with successful clinical
resolution was evaluated in each group during six
months.

Results. The frequency of the patients with
successful resolution in the experimental group
(73.1%) was significantly higher than that in the
control group (36.0%) at the six-month follow-up
(chi-squared test, p<0.05).

Conclusions. This therapy appears to represent an
alternative treatment method for non-reducing disk
displacement of the temporomandibular joint.

Oral Surgery, Oral Medicine, Oral
Pathology, Oral Radiology, and
Endodontics 1997; 84: 241-244