Photogrammetric evaluation of corrective surgery for trigonocephaly.

The aim of this study was to capture preoperative, postoperative, and follow-up head shapes of male trigonocephaly patients who underwent fronto-orbital remodelling (FOR), using three-dimensional (3D) photography. Fifty-seven male infants with metopic synostosis operated on using standardized FOR during a 5-year period were included. All measurements were compared with those of an age-matched healthy control cohort (n = 253 for early postoperative comparison, n = 43 for the 1-year follow-up comparison) to determine the effect of FOR at 14 days and at 1 year post-surgery. Intracranial volume, frontal angle, nasofrontal angle, interfrontoparietal-interparietal ratio, and inter-orbital distances were measured 1 day preoperatively, 14 days and 1 year postoperatively. Mean age at surgery was 9.7 ± 1.1 months. Prior to surgery, boys with metopic synostosis showed a reduced intracranial volume (-7.0%, P < 0.001), frontal angle (-10.2%, P < 0.001), interfrontoparietal-interparietal ratio (-4.9%, P < 0.01), and orbital distances (-6.5%, P < 0.001) compared to the reference group, but values did not differ significantly from the specific control group after surgery (all P> 0.05). This was consistent by the time of the follow-up examination. Corrective surgery should therefore aim to achieve volume expansion and correction of the deformity. Furthermore, 3D photogrammetry provides a valuable alternative to computed tomography scans in the diagnosis of metopic synostosis, significantly reducing the amount of radiation exposure to the brain.

High oblique sagittal split osteotomy of the mandible: assessment of the positions of the mandibular condyles after orthognathic surgery based on cone-beam tomography.

High oblique sagittal split osteotomy is an orthognathic technique to move the mandible. Our aim was to evaluate changes in the position of the condyle in the glenoid fossa and its angulation before and after high oblique sagittal split osteotomy (HSSO). Fifty patients (32 women and 18 men, mean age 26.3 (SD 7.4) years) had cone-beam computed tomographyic (CT) scans before operation, immediately postoperatively, and before removal of the osteosynthesis nine months postoperatively. The images were analysed to look for changes in the sagittal, coronal, and axial positions of the condyles. Twenty-four patients with class II malocclusion had a mean (SD) mandibular advancement of 6.51 (2.41) mm, and 26 patients with class III malocclusion had a mean (SD) mandibular setback of 4.16 (2.77) mm. The joint space increased significantly (p<0.05) relative to baseline immediately postoperatively, but there was no significant increase at the nine-month follow-up. The changes in position in the sagittal, coronal, and axial planes were comparable. Despite there being a short proximal joint-bearing segment, the results indicate that this technique allows free-hand condylar positioning into the fossa safely without any clinically relevant dislocations.