Abstracts

STABILITY AFTER LE FORT I OSTEOTOMY
IN CLEFT LIP AND PALATE PATIENTS

R. Saelen, K. Tornes and A. Halse

Le Fort I osteotomies were performed in 20 patients with cleft lip and palate as a one segment movement, and the fragments were fixed with miniplates without bone grafting. Tracings of preoperative and serial postoperative lateral cephalograms were used to determine changes in maxillary position. The posterior nasal spine, not subjected to extensive changes during surgical procedures and remodelling, was found to be the most reliable landmark for measuring maxillary advancement and stability. The mean maxillary advancement was 5.96 mm. Analysis did not reveal significant changes in linear and angular measurements from immediately postoperative to six months postoperative. A modest maxillary advancement by Le Fort I osteotomy, along with alleviation of palatal scar tissue tension and miniplate fixation, is a stable surgical method in patients with cleft lip and palate.

International Journal of Adult Orthodontics and
Orthognathic Surgery
1998; 13: 317-23

AN ANALYSIS OF MALOCCLUSION IN
CHILDREN WITH OTITIS MEDIA

S. Watase, A. P. Mourino and G. A. Tipton

Purpose: The purpose of this study was to examine the occlusion of children younger than 6 years with a diagnosis of otitis media.

Methods The study consisted of 112 children diagnosed with otitis media by their pediatrician. Parents were surveyed regarding their child's history of pacifier use, thumb/fingersucking habit, mouthbreathing habit, method of feeding, day care attendance, snoring, allergies, asthma, upper respiratory infections, otitis media in the family, and the number of people who smoke in the home. The children's occlusions were examined.

Results: In this study, 52% of the population presented with some type of malocclusion, with anterior open bite (17%) and an overbite measuring greater than 70% (17%) being the most prominent. This study showed that the

following factors were common in children with otitis media: bottle feeding, smoking in the home, daycare attendance, upper respiratory infection, history of otitis media in a sibling, pacifier habit, snoring and mouthbreathing habit.

Conclusion: A logistic regression analysis showed no significant association between malocclusion and factors related to otitis media.

Pediatric Dentistry
1998; 20: 327-30

THE RELATIONSHIP BETWEEN
TEMPOROMANDIBULAR DISORDERS
AND STRESS-ASSOCIATED SYNDROMES

A. Korszun, E. Papadopoulos, M. Demitrack,
C. Engleberg, L. Crofford and A. Arbor

Objectives: The purpose of this study was to determine the comorbidity of temporomandibular disorders and other stress-associated conditions in patients with chronic fatigue syndrome and fibromyalgia.

Study design: Of 92 patients who fulfilled the criteria for chronic fatigue syndrome or fibromyalgia (or both), 39 (42%) reported a prior diagnosis of temporomandibular disorder. Further questionnaires were sent to the members of this group, and 30 patients responded.

Conclusions: Patients appearing for treatment with chronic facial pain show a high comorbidity with other stress-associated syndromes. The clinical overlap between these conditions may reflect a shared underlying pathophysiologic basis involving dysregulation of the hypothalamic-pituitary-adrenal stress hormone axis in predisposed individuals. A multidisciplinary clinical approach to temporomandibular disorders would improve diagnosis and treatment outcomes for this group of patients.

Oral Surgery Oral Medicine Oral Pathology
1998; 86: 416-20
# THE LONGEVITY OF SPACE MAINTAINERS: A RETROSPECTIVE STUDY

M. A. Qudeimat and S. A. Fayle

Methods: This retrospective study investigated the longevity of 301 space maintainers fitted in 41 patients aged 3.4-22.1 years in the Department of Paediatric Dentistry at Leeds Dental Institute between 1991 and 1995.

Results: Failure occurred in 190 space maintainers (63%), of which 36% were due to cement loss, 24% breakage, 10% design problems, and 9% were lost. Using the life table method, the median survival time (MST) for space maintainers was found to be 7 months. Band and loop (B&L) appliances had the highest MST of 13 months, while the lower lingual holding arch (LLHA) had the lowest of 4 months. Unilateral space maintainers survived longer than bilateral space maintainers (MST of 13 months vs. 5 months). Left B&L had had a MST of 16 months, compared with only 4 months for right B&Ls. Gender, age, arch in which the appliance was placed, the operator planning it, fixed vs. removable, and adequacy of pre-treatment assessment did not have a significant effect on survival time.

Pediatric Dentistry
1998; 20: 267-72

# THE EFFECT OF EXTRACTION OF THIRD MOLARS ON LATE LOWER INCISOR CROWDING: A RANDOMIZED CONTROLLED TRIAL

N.W.T. Harradine, M. H. Pearson and B. Toth

The problem of late mandibular incisor crowding is a well-established phenomenon, the cause of which has been the substance of considerable debate over the years. A central issue is the possible role of the third molar though no definitive conclusions have been consistently drawn. This prospective study was designed to investigate the effects of randomly assigned early extraction of third molars on late crowding of the mandibular incisors. One hundred and sixty-four patients entered the study from 1984 following completion of retention after orthodontic treatment. Seventy-seven patients (47%) returned for records up to a mean of 66 months later, and their start and finish study casts were digitised on a reflex microscope to determine Little's index of irregularity, intercanine width and arch length. Forty-four of the patients had been randomised to have third molars removed. There was no evidence of responder bias. Where third molars were extracted the mean increase in lower labial segment irregularity was reduced by 1.1 mm from a mean of 2.1 mm for the group where third molars were retained (p=0.15, not statistically significant). This difference was also not considered to be clinically significant. The principal conclusion drawn from this randomised prospective study is that the removal of third molars to reduce or prevent late incisor crowding cannot be justified.

British Journal of Orthodontics
1998; 25: 117-22

# LONG-TERM CHANGES IN CLINICAL SIGNS AND SYMPTOMS AND DISC POSITION AND MORPHOLOGY IN PATIENTS WITH NON-REDUCING DISC DISPLACEMENT IN THE TEMPOROMANDIBULAR JOINT

S. Sato, M. Sakamoto, H. Kawamura and K. Motegi

Purpose: The purpose of this study was to examine disc position and configuration, as well as clinical findings, during the natural course of non-reducing disc displacement of the temporomandibular joint (TMJ).

Patients and Methods: The subjects were 21 patients (24 affected joints) for whom a diagnosis of anterior disc displacement without reduction in the TMJ had been made on arthrography, but who had received no treatment for more than 12 months. The disc position and configuration were examined at a mean follow up of 27.1 months using magnetic resonance imaging. Clinical signs and symptoms were also examined. As a control, 30 joints in 15 persons who had no current or previous TMJ symptoms were studied.

Results: The patients' clinical signs and symptoms tended to be alleviated during the follow-up period. In all patients, the disc was displaced anteriorly on mouth closure, and it did not reduce into normal position during mouth opening at the follow-up, where as normal disc position was found in all of the controls. In the patients, the disc deviated from the normal biconcave configuration found in all of the controls, frequently showing enlargement of the posterior band, even thickness, folding, and convex configurations in the follow-up magnetic resonance imaging.

Conclusion: Disc displacement does not resolve, and continued disc deformity is common in the natural course of non-reducing disc displacement of the TMJ, although the clinical signs and symptoms tend to become alleviated.

Journal of Oral and Maxillofacial Surgery
1999; 57: 23-9
# ORTHODONTIC CALENDAR

## 2000

### March 18-22

Seventeenth Australian Orthodontic Congress, Brisbane, Australia. Theme: Adults, Aesthetics: an Interdisciplinary Approach. Speakers include: Drs V. G. Kokich, B. U. Zacharisson, W. M. Smalley and R. G. Alexander.

### April 29-5

American Association of Orthodontics and International Orthodontic Congress, Chicago, USA.

### June 2-7

European Orthodontic Society Congress, Corfu, Greece

### September 24-27

British Orthodontic Conference, Brighton, UK.

### November 16-19

International Orthodontic Congress & 35th Indian Orthodontic Conference, Birla Scccience Centre, Jaipur. Tel: +319826, Fax: +91 337 280; Email: drpradeepjain@hotmail.com

## 2001

### May 5-9

American Association of Orthodontics, Toronto, Canada.

### June 18-23

European Orthodontic Society Congress, Brussels, Belgium.

## 2002

### May 4-8

American Association of Orthodontics, Philadelphia, USA.

### June 4-8

European Orthodontic Society Congress, Sorrento, Italy.

## 2003

### May 2-9

American Association of Orthodontics, Hawian Islands.

### June 10-14

European Orthodontic Society Congress, Prague, Czech Republic.

Please direct all news and notes, meeting queries and requests for inclusion in the calendar to:

Dr Tony Collett, 7 Dawson Street, Upper Ferntree Gully, Victoria, 3156.

Tel: (+61 3) 9756 0519;

Fax: (+61 3) 9758 6644;

Email: tonycol@netspace.net.au.

State branch secretaries are requested to forward details of forthcoming meetings to

Dr Collett as they become available. A PC disk (or Email) together with a hard copy is preferred.

All disks will be returned.

## News & Notices

The Australian Orthodontic Board is now fully established and members are urged to participate in this excellent self-education exercise. Congratulations are extended to Drs John Armitage, Joseph Bleakley, Barry Brown, Ted Crawford, Peter Ferguson, David Fuller, Brian Gerraty, James Hawkins, Brett Kerr, Michael Kirshon, Rodney Mason, Peter Miles, Colin Nelson, Anthony Shields, Tony Sutton, Tony Weir and Francis Wong on achieving full board status.

The University of Melbourne orthodontic department recently hosted a visit by Dr Gerry Sampson. Once again, a most entertaining and informative series of presentations were enjoyed by the post-graduate students and attending orthodontists.

Dr V. Kalra was a recent guest of the Victorian Branch of the Society and provided a half-day program, outlining his approach to mechanotherapy.

The Melbourne orthodontic school is in the process of forming an orthodontic alumni. Expressions of interest can be directed to Dr Jim Curtain.

The Queensland Branch is planning a clinic weekend in September 2000 featuring Dr McLaughlin. This lecture series has proved to be very popular with clinical orthodontists over the years.