Preoperative assessment for and outcomes of mandibular conservation surgery

The role of marginal mandibulectomy and other conservative resective procedures for patients with early cortical mandibular invasion from squamous carcinoma of the oral cavity remains poorly defined. The purpose of this retrospective study was to evaluate the efficacy of preoperative assessment for bone invasion and the outcomes of different mandibular resective procedures that preserve mandibular continuity.

The charts of 222 patients treated at the University of Texas M. D. Anderson Cancer Center between 1960 and 1990 were reviewed. All patients had a biopsy-confirmed diagnosis of squamous carcinoma involving either the lower gingiva, floor of mouth, oral tongue, or retromolar trigone. All patients had a surgical resection that involved removing less than a segment of the mandible. Patient data were analyzed to determine the usefulness of preoperative assessment and outcomes of therapy.

Clinical evaluation of mandibular bone invasion was more sensitive than radiologic evaluation, whereas radiologic assessment was more specific and had a higher reliability index. The overall local and regional recurrence and distant metastasis rates for all T stages were 14.4%, 18.0%, and 2.7%, respectively. Sixty-nine point eight percent of all patients were without evidence of disease 2 years after treatment.

Mandibular conservation surgery is oncologically safe for patients with early mandibular invasion. Accurate preoperative assessment that combines clinical examination and radiographic evaluation is better than either modality alone, but clinical judgment is still necessary for proper patient selection.