Condylar Changes After Mandibular Setback Surgery: Intraoral Vertical Versus Sagittal Split Ramus Osteotomy

Abstract

Patients with class III malocclusion usually complain of a poor facial esthetics, but it may also be associated with functional problems, temporomandibular disorders, or psychosocial issues. The most common surgical procedures for correction of mandibular deformities are the bilateral sagittal split ramus osteotomy (BSSO) and the intraoral vertical ramus osteotomies (IVRO). The aim of our research is to radiographically evaluate the changes in condylar morphology and position in patients undergoing mandibular setback orthognathic surgery for the treatment of class III deformities. Fourteen patients were allocated and divided randomly into two groups. Group I had undergone BSSO surgery while group II underwent IVRO surgery. The patient’s soft tissue and dental measurements were recorded on a treatment planning sheet attached to the patient’s file. Pre-orthodontic phase prepares the patient to undergo surgery and aims mainly to reverse the teeth compensations. The results as shown, the condyle showed lateral displacement immediately after BSSO, while showed antero-inferior movement immediately after IVRO, with tendency to move back to its original position at 1 year follow up in both groups. The condylar axis angle in axial plane showed inward (medial) rotation of the condylar head after BSSO, while showed outward (lateral) rotation after IVRO. The condylar volume decreased significantly after both BSSO and IVRO setback surgeries at 1 year follow up. The condylar volume decrease was shown to be higher in IVRO than BSSO group without statically significant difference.