SPAEY Y, BETTENS R, MOMMAERTS M, VAN LANDUYT HW, ABELOOS J, DE CLERCQ C, LAMORAL PH, NEYT L.
A PROSPECTIVE STUDY ON INFECTIOUS COMPLICATIONS IN A SAMPLE OF 850 CONSECUTIVE ORTHOGNATHIC SURGERIES.

Aim
4.7 % of the 1106 patients who underwent corrective facial orthopaedic surgery at the GH St. Jan, Brugge, from 1992 till 1997, suffered from a postoperative wound infection (Acebal-Blanco et al., 2000). The antibiotic scheme in that era was 3 doses of 2g IV cephamandolnaftate on the day of surgery. Next, amoxycillin, 4 times a day, was given orally for 5 days. When the Belgian government implemented new rules for antibiotic prophylactics, a new antibiotic scheme following Peterson (1990) was started in our service. A prospective study was set up in October 1999 with the aim to analyse infection frequency, microbial spectrum and antibiotic sensitivity.

Materials and methods
The study protocol was supervised by a microbiologist and approved by the local Ethics Committee (#06 065). It was planned to administer cephazolin in a dose of 1g IV at time of induction and to repeat this every 4 hours. No postoperative antibiotics were planned for, except in case of haematoma. When an infection would occur, a swab culture had to be done according to a standardised protocol, abscess drainage had to be carried out and antibiotics to be given per-orally. At the moment of the writing of this abstract 502 patient charts had been analysed. In three hundred fifty surgeries, the study protocol was followed. This comprised 236 female and 114 male patients. There were 189 osteotomy procedures in the maxilla, 238 in the posterior mandible, 71 in the symphyseal area and 120 other accompanying procedures.

Results
Within the first 6 postoperative weeks, 24 infections (6,8%; 4 male and 20 female patients) with pus production occurred. All abscesses originated in the sagittal split area. The aerobe cultures showed in 8 cases a normal flora. In 6 of the anaerobe cultures the identified species was Bacteroides, all the others were sterile. Bacteroides is sensitive to amoxyclav and clindamycin, but resistant to cephazolin.

Conclusion
The current infection rate is higher than that of the years when antibiotics were prescribed for 6 days. We will present the rate, results of the cultures and any statistical difference with the former antibiotic scheme. The fact that all infections occurred in the sagittal split area requires further stratification (type of drain, transbuccal/transoral screw osteosynthesis). Definitive analysis will show if the current prophylactic antibiotic scheme will be maintained.

References

Acebal-Blanco F, Vuylsteke  PLPJ, Mommaerts MY, De Clercq CAS: Perioperative complications in corrective facial orthopedic surgery. A 5 year retrospective study. J Oral Maxillofac Surg 58: 754-760, 2000

Peterson LJ:  Antibiotic prophylaxis against wound infections in oral and maxillofacial surgery. J Oral Maxillofac Surg 48: 617-20, 1990

 
POLSBROEK R, MOMMAERTS MY, SANTLER G, CORREIA PEGS, ABELOOS JVS, VAN DEN AKKER H.
DENTAL AND PERIODONTAL BEHAVIOUR IN THE ACTIVE AND CONSOLIDATION PHASE OF SYMPHYSEAL DISTRACTION. A PROSPECTIVE STUDY

Aim:
To analyse prospectively the dental and periodontal behaviour in the active phase of symphyseal distraction.

Material and Methods
Fourteen consecutive patients (8 female, 4 male) planned to undergo transmandibular distraction, were selected. At time of analysis, two files were discarded (1 of a male, 1 a female patient) because of incompleteness of the records. Alginate impressions were taken at the time of placement of the distractor (mean age 19y 11m, min 12,2, max 35,2), when the activation phase was ended and at the time of the removal of the device, 2 months later. The plaster models were measured with a Polhemus 3-D digitizer to study the amount of distraction and spatial movement of the canines and incisors. Cold-sensitivity and mobility tests were performed, as well as pockets depths measured in the frontal region before distraction, at the start of the activation and at the end of the consolidation period. Intra-Rater reliability was tested with the Intraclass Correlation Test. Differences were tested with the T-test for Paired Differences.

Results:
At the end of active symphyseal distraction there was increased mobility, and deepened periodontal pockets of the teeth in the proximity of the osteotomy. Cold sensitivity testing resulted in diminished responses. After two months of consolidation, periodontal pocket depths were decreased. Mobility increase, especially of the first incisors, had stabilised. Cold sensitivity did not return to a normal level and longer follow-up will be needed to evaluate responses. One central incisor that showed discoloration and a negative cold sensitivity response underwent endodontic therapy. Considering this, the unilateral “wine-glass” osteotomy might be advantageous. The resilient central part of the Transmandibular Distractor (Mommaerts, 2000) allowed for condylar rotation (mean 9,4°, SD 5). This is in contrast to all other bone and tooth-borne distractors (Braun et al. 2002), that invoke lateral condylar translation. The incisor teeth tend to protrude, not to extrude, during the active phase of distraction.

References

Braun S, Bottrel JA, Legan HL Condylar displacement related to mandibular symphyseal distraction. Am J Orthod Dentofacial Orthop 121:162-5, 2002

Mommaerts, M. Transmandibular distraction as a method to broaden a small anterior apical base. Br. J. Oral Maxillofac. Surg. 39: 8-12, 2001

 
ABELOOS JVS, DE CLERCQ CAS, LAMORAL PH, MOMMAERTS MY, NEYT LF
OUTCOME OF MANDIBULAR ASYMMETRIES TREATED WITH UNILATERAL SAGITTAL SPLIT OSTEOTOMIES.

Aim
Mild to moderate mandibular asymmetry with malocclusion, can be corrected by a unilateral sagittal split osteotomy of the ascending ramus (USSO). As compared to bilateral sagittal split osteotomies, a longer operation and possibly surgical complications (mainly infections and sensitivity alterations in the inferior alveolar nerve) can be avoided. The aim of the retrospective study was to evaluate postoperative jaw and joint function in a sample of USSO. Condylar rotation at the non-operated side could indeed provoke a joint dysfunction.

Material and Methods
Out of 2528 patients who underwent orthognathic surgery in our service, from 1991 till 2001, 54 underwent an USSO. Three-plane cephalometric radiographs immediately post- and long-term postoperatively, and clinical parameters (click, pain, trismus) were analysed. Records were complete for 24 cases.

Results
Condylar rotation at the operated side was 2,7° (SD 2,7°) and at the non-operated site 3,4° (SD 2,3°). A click was present in 12,5% of the patients preoperatively and in none postoperatively. No joint pain present preoperatively but it was present in 8,3% of the cases postoperatively, and only at the operated side. The mean mouth-opening was 47,5mm preoperatively (range 37-60) and 52,5mm postoperatively (range 39-65).

Conclusion
Changes in condylar position are within the range of adaptability of the joints.
Moderate correction of mandibular asymmetry can be done by means of a USSO.

 
ALI N, MOMMAERTS MY, CORREIA PEGS
BIMAXILLARY TRANSVERSE OSTEODISTRACTION. A STORY ABOUT SMILE AESTHETICS AND STABILITY

Severe crowding due to a narrow upper and lower apical base can be corrected by four-premolar-extractions or by bimaxillary transverse osteodistraction. The first strategy is prone to unaesthetic changes in lip posture, nasolabial angle and buccal corridors. Life-long retention is necessary because of the known correlation between increased inter-canine distance and relapse of crowding. The second strategy involves surgery and the final outcome regarding stability is not known yet. Theoretically, because the canines have not been moved outside of the skeletal envelope, and because the functional matrix positively influences the dental arches, relapse of crowding should be less. Facial appearance is improved because of the reduction of the buccal corridors and the fullness of the mouth in rest and upon smiling. An in-depth literature study on aesthetic outcome and stability will be discussed and the potential of bimaxillary transverse osteodistraction will be highlighted

 
Ph. PELLERIN* ; N. CAPON DEGARDIN* ; P. DHELLEMMES** ; M. VINCHON** ; J. DELPIERRE*
PLACE DE LA DISTRACTION DANS LE TRAITEMENT DES DYSOSTOSES CRANIOFACIALES (CRANIOFASCIOSTENOSES)

*Service de Chirurgie Plastique Reconstructrice – Hôpital Roger Salengro – CHRU – 59037 Lille Cedex - France
**Clinique de Neurochirurgie Pédiatrique – Hôpital Roger Salengro – CHRU – 59037 Lille Cedex – France

Historiquement la première intervention de Chirurgie Crânio-Faciale était une ostéotomie totale de la face réalisée par Paul Tessier selon un tracé de Lefort chez un patient atteint d'une maladie de Crouzon.
Cette ostéotomie, intervention majeure et complexe, à la morbidité élevée de part sa difficulté, est longtemps restée l'intervention de chirurgie crânio-faciale par excellence.
La distraction faciale a révolutionné la prise en charge de ces patients, qu'il s'agisse de protocoles de distraction précoce sans ostéotomie chez le jeune enfant tels que nous les réalisons et qui sont devenus pour nous systématiques, ou qu'il s'agisse de l'association ostéotomie type Lefort III et distraction chez le grand enfant et l'adolescent. Ces protocoles sont maintenant parfaitement codifiés, ils sont réitérables, permettant de traiter tous les aspects fonctionnels et esthétiques des maladies de Crouzon, de Pfeiffer et d'Apert.

 
C. MALEVEZ , M. MEHBOD, F. SCHUTYSER, B. KOVACS, A. DE MEY, (H.U.D.E, ULB)
MANDIBULAR ANGLE CONTOURING IN HEMIFACIAL MICROSOMIA

The correction of the asymetrical hemifacial microsomia involves reconstructing hard and soft tissues in order to obtain an optimal esthetic result.
Distraction osteogenesis allows to correct the mandibular body and ramus length in case of severe difformities. Unfortunately, if the bone lengthening is quite satisfactory, the bone volume is still insufficient. Numerous techniques have been reported in order to compensate the lack of soft and hard tissue, using autogenous as well as alloplastic materials. Some of them have been successful but no long term results of these techniques are published. Mostly, the pre- and per-operative determination of the volume to be corrected is done by empiric evaluation.
With the use of a 3D image-based planning software (Maxilim), a mirror image of the normal mandibular angle is obtained and transposed to the affected area. In this software, an experimental toolbox was added to estimate the volume of bone grafting and to design a titanium plate implant. That titanium plate will provide a strong support to on-lay bone grafting and insure the symmetry of both mandibular angles improving facial contouring.