Computer-assisted condyle positioning in orthognathic surgery.
OBJECTIVE
Le Fort I repositioning osteotomy can affect the position of the temporomandibular joints (TMJs). During the operation, the surgeon does not have direct visual control of the TMJ. In this study, the TMJ movements in patients undergoing a Le Fort I repositioning osteotomy were recorded intraoperatively using the Surgical Segment Navigator (SSN) computer-assisted navigation system.


METHODS
Unintended TMJ positions resulting from conventional repositioning of the maxillary segment were recorded. The TMJ positions in these patients were then corrected in relation to the skull base, using information obtained from the SSN. The position of the condyle was then redetermined. The accuracy of conventional and SSN-guided segment adjustments were compared in terms of their influence on TMJ position in the same group of patients.


RESULTS
The median spacial malposition of the condyles without navigation was 2.4 mm. Corrective "SSN positioning" on the same patients reduced this to 0.7 mm.


CONCLUSIONS
SSN allows accurate intraoperative navigation of the TMJ.
Marmulla
Rüdiger
R
Department of Cranio-Maxillofacial Surgery, University of Heidelberg, Heidelberg, Germany. Ruediger_Marmulla@med.uni-heidelberg.de
Mühling
Joachim
J
D016302:Centric Relation; D002508:Cephalometry / Q000295:instrumentation; D004724:Endoscopy / Q000379:methods; D006801:Humans; D008335:Mandibular Condyle / Q000033:anatomy & histology* / Q000601:surgery; D008437:Maxilla / Q000601:surgery*; D003765:Models, Dental; D009971:Orthodontics, Corrective / Q000295:instrumentation / Q000379:methods; D019340:Osteotomy, Le Fort / Q000379:methods*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013704:Temporomandibular Joint / Q000033:anatomy & histology* / Q000601:surgery; D016896:Treatment Outcome