Three-dimensional cone-beam computed tomography analysis of the mandibular lingula and mandibular foramen with clinical implications for ramus osteotomy.

BACKGROUND

The location of the mandibular foramen (MF) and mandibular lingula (ML) is essential in orthodontic patients who require adjunctive operations, such as orthognathic surgery, cortectomy-assisted tooth movement, or temporary anchorage device placement in the mandibular ramus region. These structures are closely related to the inferior alveolar neurovascular bundle and serve as key landmarks for sagittal split ramus osteotomy, routinely performed to correct deformities. Variations in the position and morphology of the ML and MF may influence the safety of surgical access and the effectiveness of treatment planning. Radiological evaluation using cone-beam computed tomography (CBCT) enables three-dimensional visualization of these landmarks and relationships to the surrounding cortical boundaries of the mandibular ramus.

METHODS

This retrospective CBCT study analyzed 288 hemimandibles. All scans were obtained using a standardized CBCT protocol. The anatomical positions and dimensions of the ML and MF were evaluated. Linear measurements included MF dimensions, distances between the ML, MF, and surrounding mandibular landmarks, and proportional indices. Measurements were independently performed by two examiners and repeated after a three-week interval. Sex- and age-related differences were analyzed using independent t-tests and one-way analysis of variance.

RESULTS

The mean mediolateral and anteroposterior dimensions of the MF were 2.85 ± 0.47 mm and 4.60 ± 0.92 mm, respectively, and the mean distance between the ML and MF was 9.75 ± 2.03 mm. Significant sex-related differences were observed across multiple linear measurements, with males generally exhibiting larger mandibular dimensions than females (P < 0.05). In contrast, age-related differences were minimal, with only the mediolateral width of the MF showing a statistically significant difference among age groups (P = 0.035).

CONCLUSION

The anatomical relationship and position of the ML and MF exhibit clear sex-related differences while remaining largely stable across adult age groups. The normative data provided may assist clinicians in the more accurate localization of critical orthognathic landmarks.