Maxillary ameloblastomas: a review of the literature and of a 15-year database.

Introduction: Cases of maxillary ameloblastomas from 15-year database (1986-2000) collected in the Department of Cranio-Maxillofacial Surgery of the University Hospital of Zurich were evaluated.

Patients: Twenty-six patients suffering from ameloblastoma had been collected. Five of them, had a maxillary ameloblastoma, three females and two males.

Methods: A clinical retrospective study was performed. In addition a review of the literature was undertaken and the findings have been compared and contrasted.

Patients: The overall incidence of ameloblastoma within the mandible (21) was four times higher than in the maxilla (5). In 69 per cent of the cases (18) it occurred in men, in 31 percent (8) in women. The sex ratio differed with the maxillary ameloblastomas: 40 percent male (2) and 60 per cent female (3). Although slow growing and nearly painless, it can reach a considerable size within the mid-face involving such highly specialized structures as the orbit, skull-base and brain. Wide resections with a safety margin of healthy bone to prevent local recurrence were undertaken. Nevertheless, recurrence was frequent due to invasion of the adjacent bone.

Conclusion: On the one hand, a recurrence was found after a simple curettage of a 'dental cyst'. On the other hand, extensive bone destruction, involvement of the nasal cavity, the ethmoidal and sphenoidal sinuses, infiltration of the skull-base and distant metastasis were observed. The current treatment of choice is partial maxillectomy with a 10-15 mm safety margin of healthy bone including the alveolar ridge, the hard palate, the mucosa of the maxillary sinus and the lateral nasal wall. For the removal of tumours close to or invading the retromaxillary space the temporal approach gives ample access.