Report of the ‘Distraction in Bruges’ meeting, held under the auspices of the EACMFS

Journal of Cranio-Maxillofacial Surgery (1999) 27, 387±388 # 1999 European Association for Cranio-Maxillofacial Surgery

Conference report

Report of the `Distraction in Bruges' meeting, held under the auspices of the EACMFS Maurice Mommaerts, Glyn Wreakes

Orthognathic and alveolar crest distraction was the topic of the 4th meeting on Facial Deformities, organized by the Division of Maxillo-Facial Surgery of the GH St John, Bruges, held 9±11 September 1999. One hundred and twenty-two delegates from 14 nations were represented. Following the welcoming address, Dr Lammens (Belgium) opened the scienti®c programme with his paper on the biology of distraction osteogenesis. He presented basic research into the bone formation cascade and into applications for callus stimulation using osteogenic proteins. He concluded that many basic questions remain unanswered concerning the biological control of the neo-osteogenesis. Dr Klein (Germany) discussed the limits of callus distraction when used to reconstruct tumour and birth defects in the craniofacial region. He demonstrated that the soft tissues play an important role in vector control and relapse in moderate or severe osteodistraction cases. Dr Papageorge (USA) opened the session on alveolar ridge distraction. She presented animal studies and the clinical applications for creating sucient bone and soft tissues prior to dental implant placement. Dr Gaggl (Austria) discussed results of 26 patients treated with the DISSIS device. This distraction implant unites the dual qualities of a distraction apparatus with those of a dental implant. Dr Hidding (Germany) continued by showing the versatility of micro- and macro-distractors in treating dentulous and edentulous jaw segments. Free papers by Dr Bellini (Italy) and Dr Melo Soares (Brazil) addressed histochemical and radiographic data of the distracted callus in 7 and 22 patients respectively. The afternoon session on orthognathic distraction surgery was opened by Dr Walker (Canada) who concluded from a primate study that the sagittal ramus osteotomy o€ers an increased distraction surface area compared to body ramus osteotomy and additionally the opportunity to allow distraction osteogenesis in a longitudinal and transverse axis. Dr Van Strijen (The Netherlands) reported on problems with the intraoral distractor when used for orthognathic mandibular lengthening. In 15 patients he noticed after one year a 40% relapse at cephalometric point B. In a group of 40 patients, there was an anterior open bite relapse in two patients and condylar resorption in one patient. The incidence of initial paresthaesia was low (19.5%). His overall conclusion was that the length of the stabilisation period should be increased. Dr Gonzalez (USA)

presented the concept of simultaneous mandibular advancement and symphyseal widening by distraction to treat AP and transverse mandibular de®ciency. Dr Van Sickels (USA) further explored the use of callus distraction to correct intra-arch discrepancies in both maxilla and mandible. Dr Mommaerts (Belgium) demonstrated the use of the TPD as a method for maxillary expansion. He reported the results of a study conducted by Dr Pinto (India), namely that a bone-born device such as TPD expands the maxilla without untoward dental or segmental tipping. Dr Hendrickx (Belgium) discussed the rationale of MD-DOS in the correction of sagittal mandibular hypoplasia under local anaesthesia. A cephalometric study lead to the conclusion that the positional movements of both distal and proximal segments were similar to those observed after mandibular advancement with bilateral sagittal split osteotomies. Dr Philippart (Belgium) demonstrated the use of tooth-born devices to move osteotomized segments postoperatively. Dr Cornelius (Germany) illustrated nicely the use of Delaire and Polley devices in cleft maxillary retrognathia. In all 15 cases overcorrection of 1±2 mm could be achieved. Patient inconvenience by the external distraction device was surprisingly low. Dr Swennen and colleagues (Belgium±Germany) initially used a similar treatment protocol, but observed untoward dental compensations which led them to apply ®xation directly to the bone. They presented a comparison between the two groups, their conclusion being that no dental compensatory movements occurred when ®xation was applied directly to the bone. On the second day, four distraction operations were performed, these being viewed by a televized link to the auditorium. The ®rst case concerned maxillary constriction with bilateral crossbite, crowding and `buccal corridors'. The surgery involved bilateral corticotomies through a buccal sulcus approach of the zygomatic and piriform buttresses and opening the palatal suture with a prying osteotome through an anterior buccal sulcus approach. Mobility of the segments was con®rmed by digital manipulation and the abutment plates of the TPD were then screwed into the palatal shelves. It was planned to insert the expansion module one week later and commence the distraction. The second case was a unilateral cleft patient that had undergone one-piece maxillary surgery and six-piece mandibular surgery three months earlier. The goal was to vertically 387

388 Journal of Cranio-Maxillofacial Surgery

distract the anterior edentulous part of the lesser cleft segment in order to reconstruct a major triangular defect and to prepare the case for future implant surgery. A macrodistractor was placed and the soft tissue alveolar cleft was closed. An unfavourable fracture occurred in the osteotomized segment during mobilization. This posed no real problems during ®xation of the segment and when the distraction device was tested. The next patient was 12-year-old boy who will need all Ilizarov limb lengthening and who agreed to have his 12 mm overjet treated in the same way. For demonstration purposes, the MDDOS devices were applied bilaterally under general anaesthesia rather than the usual local anaesthesia. The last case concerned a traumatic avulsion of an upper central incisor, 3 months earlier. Dr Gaggl decided wisely that bony healing was not so advanced that DISSIS could be ®xed rigidly. An alternative approach was therefore used by employing a Microdistractor. In order to have good AP width of the distracted segment, the sharp edge had to be reduced over 6 mm and the distractor installed at a high level. Mobilization of the segment proved to be tedious because the cephalad osteotomy was in the basal maxillary bone. In between the operations, two videos were shown, one on mandibular widening

with the Dynaform device and the other with the TMD device. The idea of avoiding premolar extraction by widening the apical base to increase arch perimeter and intercuspid distance is an attractive concept. The ®nal day involved ®ve workshops and model demonstrations by surgeons and the distraction manufacturers' technical sta€. The three-day meeting enjoyed a lively atmosphere and stimulated interest in the possibilities of distraction in the maxillofacial area. The Indian summer weather in combination with the ambience of a location in the centre of the historic city of Bruges contributed to the general success of the event. Dr Dr Maurice Y. Mommaerts Div. Maxillo-Facial Surgery AZ St. Jan-Ruddershove 10 B-8000 Bruges Belgium Paper received 26 October 1999 Accepted 1 December 1999