Purpose: Little objective investigation has been published regarding factors influencing masticatory performance of post-maxillectomy patients with obturator prosthesis. This study aimed to assess the relationship between masticatory performance and sociological and post-surgical factors, and to develop a theoretical equation predicting masticatory performance using significant factors.
Methods: In 37 post-maxillectomy patients with obturator prosthesis, their age, gender, resection of hard and soft palate, number of posterior maxillary teeth, occlusal support, and mouth-opening distance on masticatory performance were investigated, and masticatory performance was measured using a gummy jelly. The influence of these items was evaluated quantitatively using multiple regression analysis (Quantification Method type I). The strength of influence of each explanatory factor on the masticatory performance, identified by the category weight and theoretical value of masticatory performance of each subject, was calculated by totaling the category weights and the constant. Pearson correlation coefficient was used to analyze the correlation between actual values and theoretical values of masticatory performance.
Results: The order of strength of influence on masticatory performance was identified by the category weights: extent of hard palate resection (1229.9) > occlusal support (1113.0) > mouth-opening distance (280.8) > age (209.0) > resection of soft palate (194.2) > number of posterior maxillary teeth (186.4). There was a high correlation (R²=0.863, P<0.01) between the theoretical values calculated by the predictive equation and the actual values.
Conclusion: Masticatory performance of post-maxillectomy patients could be predicted with high accuracy in patients with soft palate defect limited to the anterior part.