The objective of the present randomized controlled trial is to assess the fracture pattern, condylar segment positioning, frequency of complications, and PROMs following BSSO with or without impacted mandibular third molars. this is illustrated by the fact that the test group had their wisdom teeth removed in connection with the sagittal split of the mandible (the BSSO surgery). Subsequently, all outcome measures are compared with the control group, who had their wisdom teeth removed 6 months prior their BSSO surgery.

The fracture pattern of the mandible following BSSO will be assessed by CBCT scans (i-CAT; Imaging Sciences International, Hatfield, PA, USA) obtained preoperatively, and one week after surgery. The CBCT will be taken by fixed exposure parameters of 120 kV, 160 × 60 mm field of view, 0.30 mm voxel size, and 8.9-second images. The fracture pattern of the mandible will be classified according to LSS by the study investigator (KBØ). The LSS consisted of 4 categories based on the path of the fracture line on the lingual side of the mandibular ramus.

The mandibular condylar segment positioning will be assessed in the sagittal, vertical, and transverse dimension by superimposing the pre- and postoperative CBCT scan using dedicated software (OnDemand3D Application, version 10; Cybermed, Seoul, South Korea). The orbital bony walls on the preoperative CBCT will be used as the reference and matched with the orbital walls on the postoperative CBCT. Pair-wise registration will be done, based on the automated detection of hundreds of virtual landmarks in the volumes, which can subsequently be manually adjusted, based on visible anatomical landmarks.To estimate the condylar displacement in all three dimensions, the intertransverse distance in millimeters between the center of the condyles is measured on the pre- and postoperative CBCT. Moreover, the distance between the mandibular condyle to the glenoid fossa is measured in the sagittal and vertical dimension. The measurements will be conducted by the study investigator (KBØ).

OHIP-14 is a validated questionnaire for assessment of OHRQoL. OHIP-14 states the patient's overall oral impairment and does not take a specific treatment site into account. OHIP-14 is organized into seven conceptual dimensions including functional limitation, physical discomfort, psychological discomfort, physical disability, psychological disability, social disability and handicap. The response format of OHIP-14 is: Very often = 4; Fairly often or many times = 3; Occasionally = 2; Hardly ever or nearly never = 1; Never/I don´t know = 0. Thus, OHIP-14 scale ranged from 0 to 56 and dimension score ranged from 0 to 8. Values of the 14 items and each dimension are summed to calculate the OHIP-14 severity score and higher scores indicate poorer OHRQoL

The intraoperative length of BSSO will be measured by a stopwatch (iPhone 14 Pro or similar) from the incision to the last suture in both groups. The intraoperative length of BSSO will be registered by the surgeon.