Unilateral sagittal split mandibular ramus osteotomy: indications and geometry.

Small mandibular asymmetries may be corrected by unilateral sagittal split ramus osteotomy (USSO). This study had two objectives: first to define the geometric changes in the mandibular condyle and the lower incisor teeth that result from the rotation of the major segment (n=26), and secondly to examine in a clinical study the temporomandibular joints (TMJ) of 23 patients after correction of mandibular asymmetry by USSO to find out if there were any long-term adverse effects. Small mandibular asymmetries (<5mm) can be corrected by USSO. Secondary anteroposterior changes as a result of setback or advancement on the operated side should be taken into account during the planning of treatment. The small rotational changes of the condyle did not adversely affect the TMJ.