Transverse and sagittal angulations of proximal segment after sagittal split and vertical ramus osteotomies and their influence on the stability of distal segment.

Background/purpose: This study aimed at comparing the transverse and sagittal angulations of proximal segment after sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO), and examining their influences on the stability of distal segment.

Methods: Patients who received SSRO (n = 21) or IVRO (n = 11) for mandibular setback were included. Lateral and posteroanterior cephalograms taken within 1 month before surgery (T1), within 1 week after surgery (T2), and at least 6 months after surgery (T3) were analyzed.

A pilot study applying digital radiography for estimating ratio of supported single-root surface area.

Background: The prognosis of a tooth with periodontitis is affected by the amount of supporting bone. A key factor in retaining a tooth is the ratio of supported root surface. Currently, root surfaces cannot be accurately measured using conventional dental radiographs, which only measure the length of bone support on proximal surfaces.

Accuracy of supported root ratio estimation from projected length and area using digital radiographs.

Background: The purpose of this study was to evaluate the accuracy of supported single-root surface ratio estimated from the length and projected area of the tooth, using digital dental radiographs.

Methods: Eight extracted, single-root teeth were three-dimensionally digitized using a contact technique for surface area measurement. The data were then processed using engineering application software and length, projection area, and true surface area of the root at a designated length were obtained.