Movement of the proximal segment after intraoral vertical ramus osteotomy versus short lingual osteotomy with physiological positioning strategy.

PURPOSE: To clarify whether intraoral vertical ramus osteotomy (IVRO) or short lingual osteotomy (SLO) induces less proximal segmental movement after surgery without bone fixation.

METHODS

This study included patients who underwent IVRO or SLO without bone fixation. Cephalograms were taken before surgery (T1), immediately after surgery (T2), and >6 months after surgery (T3) to assess postoperative movement of the proximal segment and skeletal stability. The condylar angle was measured using computed tomography images taken at T1 and T3 to assess rotation.

RESULTS

Ninety patients were included (IVRO, n = 25; SLO, n = 65). The proximal segment swung laterally on the frontal cephalogram in the asymmetrical IVRO group at T3. The condylar head was rotated outwardly 6.52 ± 4.49° (p < 0.0001) in the symmetrical IVRO group and 8.06 ± 6.88° (p = 0.030) on the non-deviated side in the asymmetrical IVRO group at T3. The condyles were almost stable in the SLO group. Temporomandibular joint disorders were found in 2 of 22 IVRO patients and in 2 of 42 SLO patients with asymmetry at T3.

CONCLUSION

This study suggests that SLO with the physiological positioning strategy (PPS) should be preferred over IVRO with the PPS whenever possible.