Oral Presentations Orthognatic surgery: mandible III 77

Wednesday, 13 September 2006, 14.30−15.40 Hall 8

Orthognatic surgery: mandible III

O.274 Change of condyle angulation after BSSO

M. Szalwinski1,2, J. Piekarczyk1, M. Jagielak1, P. Piekarczyk1.12nd Department of MaxilloFacial Surgery, 2Department ofAnatomy, Medical University of Warsaw, Poland

The aim of our study was to evaluate potential changes inmandible condyle and ramus angulation after bilateral sagittalsplit osteotomies.The material contained 30 dry specimens of human mandiblesand their digital photographs before and after BSSO.The method: Each mandible was photographed in three differentaspects – from behind, laterally and from above. The positionof mandibles in front of camera objective was always constant,and so was the distance for statistic recurrence. Using standardsurgical equipment sagittal osteotomies were performed due tomandibular prognathism 15 cases and retrogenia 15 cases. Di-ameter between condyles was maintained. Digital photographswere processed in DICOM. Using computer software followeddata were reported: angulation of mandible ramus to frontal,transversal and sagittal plane, angulation of condyles to eachother.Changes in the condyle angulation depending on the osteotomymethod were reported. No significant role of osteotomy methodwere reported. However, osteotomy plane may be significant. Al-though results of our study performed in vitro, without occlusionwith maxilla could be disputable, we cannot deny influence ontemporo-mandibular joint.

O.275 Modifications in surgical treatment ofmandibular prognathism – Own experiences

M. Baran, T. Tomaszewski, J. Wojciechowicz. MaxillofacialSurgery, University Hospital, Lublin, Poland

Introduction: The most frequently utilized technique for surgicaltreatment of mandibular deformities is bilateral sagittal split os-teotomy (BSSO), originally described by Obwegeser and Trauner.To this technique that is modified by Dal Pont and Hunsuck,several changes were added in our Department. The changes aimat limiting the soft tissues dissection, obtaining stable bone unionand elimination of possible complications: excessive bleeding,unfavourable fractures, facial palsy.Methods: The orthodontic decompensation and the third molarsprevious removal are essential. The medial osteotomy is per-formed with 45º angulation to the medial plane of ramus. Theosteotomy does not cross the mandibular foramen, is led downand forward across temporal crest, does not reach the obliqueridge and in most cases ends half a way between them. Tostraighten the osteotomy line, the connecting osteotomy passessmoothly on both the medial and lateral osteotomy, performed atthe second molar level. The lateral osteotomy passes through boththe lateral and inferior cortex of the horizontal ramus reachinglingual surface. The split is begun in the superior part, then inretromolar area and is completed in lateral osteotomy area.Results: Between years 1993 and 2006, described BSSO wasperformed in 97 patients with excellent outcomes. Complicationssuch as relapse, facial palsy, dangerous hemorrhage or pseu-doarthrosis, were not observed.Conclusions: The modified osteotomy line and removal of thethird molars bring larger thickness of bone segments. The treat-ment results show that the proposed BSSO modifications decrease

the risk of serious intraoperative and postoperative complicationsin the tretment of mandibular prognathism.

O.276 Endoscopic-assisted rigid fixation in intra-oralvertical subsigmoid osteotomy: A preliminarystudy

L.O. John, L.K. Cheung. Oral & Maxillofacial Surgery, Facultyof Dentistry, The University of Hong Kong, China

Introduction: Intra-oral vertical subsigmoid osteotomy (IVSO)is a mandibular ramus osteotomy technique used to correctmandibular prognathism. It is an easily learned surgical pro-cedure executed transorally, and results in fewer neurosensorydisturbances than sagittal split osteotomy. However, the intra-oralroute limits visibility and makes access to the application of rigidfixation difficult. Post-operative intermaxillary fixation (IMF) forseveral weeks is mandatory to ensure stability for bone healing.Objectives: (1) To illustrate the clinical technique of endoscope-assisted rigid fixation in intra-oral vertical subsigmoid osteotomy(VSO); and (2) to report on early post-operative morbidities.Material and Methods: Six patients presenting with Class 3skeletal profile were recruited. The osteotomy was performedthrough an intra-oral route. Rigid fixation was achieved with a3mm stab incision located inferior to the ear pinna allowingaccess to the transbuccal trocar. A rigid endoscope was intro-duced intra-orally to improve visibility during fixation. Patients’preoperative and 3-month post-operative radiographs and clini-cal morbidities (neurosensory status & temporomandibular joint(TMJ) function) were assessed.Results: 83.3% of patients fully recovered inferior alveolar nervefunction, and 66.6% recovered TMJ function. The scar from thestab incision was effectively camouflaged by the ear pinna, andwas not noticeable by the patients.Conclusion: This preliminary study confirms that the applicationof endoscope-assisted rigid fixation in intra-oral VSO is clini-cally feasible. All the patients presented with minimal clinicalmorbidities and good stability at the early post-operative period.

O.277 Facial palsy after mandibular bilateral splitosteotomy – Analysis of a rare and seldomcomplication

E.-L. Barth, N.-C. Gellrich, P. Brachvogel. Department forCranio-Maxillofacial Surgery, Hannover Medical School,Carl-Neuberg-Str. 1, 30625 Hannover, Germany

Introduction and Objectives: Since Obwegeser introduced hisoperation technique in the 1950’s, it had become, with slightmodifications (DAL PONT, EPKER, HUNSUCK), the mostused surgical procedure to treat mandibular growth anomalies.Although it is a highly standard procedure with calculable risks,the literature shows many reports about facial nerve palsies as arare and seldom complication.Material, Methods and Results: In a retrospective surveyover 23 years (1983–2006) we followed up 1826 patients whounderwent orthognathic surgery in our department. In 9 patientsa facial palsy occurred post-operatively (0.49%) In 8 cases it wastransient, in 1 case a permanent facial nerve paralysis. The aimof the study was to analyse the dependent factors which led tothe nerve injury and how it is possible to prevent such a seriouscomplication.Conclusions: However orthognathic surgery is a kind of electivesurgery in healthy people, the appearance of a postoperativefacial palsy is nearly the worst case for both sides, patient andsurgeon, because quality of life, especially social interaction, issignificantly reduced.