Maxillary ameloblastoma: Factors associated with risk of recurrence.

BACKGROUND: Maxillary ameloblastomas are rare and associated with an aggressive course because of the anatomic composition of the maxilla and adjacent structures. The risk factors associated with recurrence were analyzed in this retrospective study. METHODS: Cases of maxillary ameloblastoma reported in a tertiary hospital from 2005 to 2015 were analyzed to identify clinicopathological and radiological factors associated with recurrence using univariate and multivariate Cox regression analyses. RESULTS: A total of 890 patients with ameloblastomas were treated in this study, of whom only 51 (5.7%) had maxillary ameloblastomas. The median follow-up period was 56 +/- 28.65 months. Of the maxillary ameloblastomas, 29 (56.8%) were primary and 22 (43.1%) were recurrent. Soft tissue or maxillary sinus invasion and primary or recurrent tumor status were risk factors significantly associated with recurrence in the univariate analyses (p = .006 vs p = .025, respectively), whereas the association between recurrence and surgical methods was borderline significant (p = .08). The multivariate Cox regression analysis showed that soft tissue or maxillary sinus involvement was significantly associated with recurrence (p = .023). CONCLUSION: Recurrent tumors and tumors with soft tissue or maxillary sinus involvement were risk factors for recurrence among patients with maxillary ameloblastoma. (c) 2017 Wiley Periodicals, Inc. Head Neck 39: 996-1000, 2017.