Introduction: Oral cavity squamous cell carcinoma (OCSCC), being more prevalent in developing countries due to the intake of chewable tobacco, is treatable if patients present at an early stage. According to the American Joint Committee on Cancer, T4b disease is termed inoperable and treated with palliative intent. However, with the passage of time, these have been operated on, with comparable disease-free survival rates with T4a disease. On radiological investigation, the mandibular notch is a structure dividing the infratemporal fossa into two. The objective is to determine the frequency of supra-notch and infra-notch T4b OSCC tumours and to compare them with surgeons’ perspective in terms of operability.

Methods: T4b staged patients of OCSCC were retrospectively reviewed along with the computed tomography (CT) scans to term them as infra-notch and supra-notch cases. They were then reviewed by two surgeons for surgical intervention as the treatment option and these two decisions were evaluated for agreement.

Results: Of the 51 patients included, 36 were primary for buccal mucosa. According to the radiologist, 30 were infra-notch and the remaining 21 were supra-notch diseases. The first surgeon deemed 33 cases as operable and 18 as inoperable, whereas the second surgeon labelled 30 as operable and 21 as inoperable. For infra-notch cases, the first surgeon’s opinion was operability in 27 and the second surgeon’s opinion was operability in 24 cases. For supra-notch cases, the results were similar as both deemed 71.4% as inoperable i.e., 15 out of 21 patients. The agreement between radiologist and first surgeon, analysed by Cohen’s Kappa, was 0.514, which is a moderate agreement, and between radiologist and second surgeon was 0.628, which shows substantial agreement.

Conclusion: Therefore, we conclude that mandibular notch can be used as a landmark to classify supra-notch and infra-notch tumours. Supra-notch tumours are most likely inoperable.