Correction of condylar displacement following intraoral vertical ramus osteotomy.

Fifteen patients who demonstrated condylar sag after intraoral vertical ramus osteotomy for the correction of mandibular prognathism were treated nonsurgically to establish the desired postoperative occlusion. A mean inferior displacement of 3.33 mm and anterior displacement of 2.18 mm were observed tomographically after surgery. Postoperatively, a geometric splint was constructed to compensate for the magnitude of condylar displacement and was used to replace the original splint to hold the distal segment in an overcorrected position. Skeletal fixation was maintained for 5 to 6 weeks. Tomographic evaluation of the temporomandibular joint (TMJ) during maxillomandibular fixation showed a slight superior (1.03 mm) and posterior (0.51 mm) movement of the condyle in the fossa. After release of fixation and removal of splint, a further superior (2.05 mm) and posterior (1.01 mm) repositioning of the condyle was observed. This later movement correlated with the placement of light class III elastic traction to seat the condyles into the glenoid fossae and establish a class I occlusion. Temporomandibular joint tomograms confirmed complete seating of the condyles in the fossa and lateral cephalograms demonstrated a corresponding change in the position of the mandible to the desired postoperative position. This technique has been effective in preventing postoperative malocclusion resulting from condylar sag.