Epineural dissection to preserve the inferior alveolar nerve in excision of an ameloblastoma of mandible: case report

Perineural infiltration of the inferior alveolar nerve in mandibular ameloblastomas

Our aim was to evaluate the histological association of mandibular solid and multicystic ameloblastoma with the inferior alveolar nerve, both in situ and in segments of the nerve that had been removed separately, to assess the feasibility of preserving the nerve during resection of mandibular ameloblastomas. In this prospective histological examination of 13 resected hemimandibulectomy specimens, we studied the proximity of tumour cells to the inferior alveolar nerve. In group 1 (n=8) this association was examined with the nerve still within the mandibular segment after resection, while in group 2 (n=5) the nerve was removed from the resected tumour and examined separately. Perineural and intraneural involvement of the ameloblastoma with the nerve was confirmed in 5 cases in group 1 and 2 cases in group 2. Tumour cells abutted the nerve directly in group 1. In group 2 tumour was removed with, and found within, the nerve. On this evidence we cannot recommend preservation of the inferior alveolar nerve during operation for large, advanced, mandibular ameloblastomas.

Mandibular resection and reconstruction in the management of extensive ameloblastoma

PURPOSE

To present our experience with the management of 31 extensive mandibular ameloblastomas treated with segmental mandibulectomy, reconstruction with free fibula or iliac crest flap, and rehabilitation with immediate or delayed endosteal dental implants.

PATIENTS AND METHODS

The study sample comprised 31 patients with histologically confirmed mandibular ameloblastomas. Primary ameloblastomas were treated in 23 patients, and recurrent ameloblastomas affected 8 patients. Mandibular defect sizes ranged from 3.5 to 12.5 cm (mean, 5.6 cm). A free fibula osseous or osteocutaneous flap was used 17 times for reconstruction; in the remaining 14, a free iliac crest osseous or osteomuscular flap was chosen. Dental implants were positioned in 25 patients; implant procedures were performed simultaneously with reconstruction in 21 cases.

RESULTS

All flaps were transplanted successfully, and no major complication occurred postoperatively. Final histologic examinations showed 27 multicystic and 4 unicystic ameloblastomas. Free margins were achieved in all patients. The duration of follow-up was 18 to 120 months (mean, 53.6 months). No patient showed clinical or radiologic signs of recurrence. The dental implant success rate was 100%.

CONCLUSIONS

Segmental mandibular resection followed by immediate defect reconstruction with bone-containing free flaps with immediate dental implant placement should be considered as the treatment of choice for extensive mandibular ameloblastomas.