Changes in the mandibular ramus following osteotomy--a long-term review

A radiographic investigation was undertaken to determine changes in the ascending ramus in the first 15 years after sagittal split and vertical sub-sigmoid osteotomies. The effects of coronoidotomy, carried out as part of the vertical sub-sigmoid procedure were included. Forty-nine patients were examined by means of orthopantomographic and postero-anterior cephalometric radiographs, which were first assessed for accuracy and reliability. Errors in these radiographs were smallest across the narrowest part of the ramus, and this distance was measured in ll cases, and the results discussed. Marked resorption occurred in 30 per cent of V.S.S. cases, but in only 5 per cent of sagittal split patients. The width of the ramus was less than 20 mm after V.S.S. osteotomy in two cases. The appearances of the caronoid process after sectioning are described.