Associations between the extent of maxillary defects and oral functions in patients with maxillectomy and definitive obturators

PURPOSE: We aimed to verify the hypothesis that patients who undergo prosthetic treatment with a definitive obturator following maxillectomy for oral tumors show decreased oral functions when the maxillary defects are extensive. METHODS: This study comprised 77 patients (46 men, 31 women; mean age, 71.0 years) who underwent prosthetic treatment with definitive obturators designed to restore maxillary defects following maxillectomy owing to an oral tumor. Oral function, masticatory performance, maximum bite force, tongue pressure, and tongue-lip motor function (oral diadochokinesis /pa/, /ta/, /ka/) were evaluated. The extent of maxillary defects was evaluated based on Aramany's classification. The maxillary defects were classified into three groups, namely, no oroantral communication (NOC), small oroantral communication (SOC), and large oroantral communication (LOC) groups. Multiple regression analyses were performed with each oral function as the objective variable and age, sex, maximal mouth opening, history of radiotherapy, number of functional teeth, and the extent of the maxillary defect as explanatory variables. RESULTS: The number of functional teeth and LOC were significant as explanatory variables for masticatory performance, while sex, number of functional teeth, and LOC were significant as explanatory variables for maximum bite force. Regarding other oral functions, the extent of the jaw defect was not significant as an explanatory variable. CONCLUSIONS: In patients with maxillary defects wearing definitive obturators, a defect exceeding half of the palate and communicating with the nasal cavity was significantly associated with lower masticatory performance and maximum bite force.