Preoperative Detection of Mandibular Invasion in Oral Squamous Cell Carcinoma Using Cone-Beam Computed Tomography: Validation Against Surgical and Histopathological Findings

Abstract

Background:
Mandibular invasion by OSCC is an important determinant of treatment planning and surgical extent. Accurate preoperative identification of bone involvement is therefore essential for achieving adequate oncological clearance while avoiding unnecessarily extensive mandibular resection. Cone-beam computed tomography (CBCT) provides detailed visualization of osseous structures and may assist in the assessment of mandibular involvement.
Aim:
To evaluate the diagnostic performance of CBCT in the preoperative detection of mandibular invasion in patients with OSCC and to compare CBCT findings with intraoperative surgical assessment and histopathological examination
Materials and Methods:
A total of 60 patients with OSCC who underwent preoperative CBCT evaluation followed by surgical management were included. CBCT images were assessed for radiographic features of mandibular involvement, including cortical erosion or destruction, medullary bone involvement, inferior alveolar canal involvement, and pathological mandibular fracture. The overall CBCT interpretation was categorized as positive or negative for mandibular invasion. Intraoperative findings and histopathological examination of the resected specimens were subsequently documented. Histopathology was considered the definitive reference standard, while intraoperative assessment was evaluated separately as a surgical reference standard. Diagnostic indices, including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), diagnostic accuracy, and likelihood ratios, were calculated.
Results:
CBCT identified mandibular invasion in 34 of 60 cases (56.7%). Histopathological examination confirmed mandibular invasion in 32 cases (53.3%), while intraoperative assessment demonstrated gross mandibular involvement in 31 cases (51.7%). When compared with histopathology, CBCT demonstrated a sensitivity of 93.8%, specificity of 85.7%, PPV of 88.2%, NPV of 92.3%, and overall diagnostic accuracy of 90.0%. The positive and negative likelihood ratios were 6.56 and 0.07, respectively. Using intraoperative findings as the reference standard, CBCT demonstrated a sensitivity of 93.5%, specificity of 82.8%, PPV of 85.3%, NPV of 92.3%, and diagnostic accuracy of 88.3%.
Conclusion:
CBCT demonstrated high sensitivity and good overall diagnostic accuracy for the preoperative detection of mandibular invasion in OSCC. Its strong negative predictive value and low negative likelihood ratio suggest particular usefulness in excluding clinically significant mandibular involvement. CBCT may therefore serve as a valuable component of preoperative imaging assessment and surgical planning in patients with OSCC.