Association between gonial angle on orthopantomogram and reline frequency in removable partial denture wearers

Purpose: Removable dentures are a reasonable option for prosthetic treatment. However, continuous residual ridge resorption and reline procedures are inevitable owing to the strong pressure exerted on the mucosa or inappropriate pressure distribution. This study aimed to elucidate the association between the gonial angle on orthopantomogram (GAO) with occlusal force and reline frequency in removable partial denture wearers. Methods: Participants were patients who had previously received removable partial denture treatment for a free-end defect. Age, sex, number of remaining teeth, remaining opposing teeth, and occlusal support were investigated. GAO was measured using panoramic radiographs. The mean relining interval was calculated as the mean number of days between denture insertion and the first relining or subsequent relining. The association between the mean relining interval and each factor was investigated. Results: Sixty-five subjects (33 females) were analyzed. The median value of the mean relining interval was 533.3 days, and the median GAO was 123 degrees. There was a significant positive correlation between the mean relining interval and GAO (rs = 0.335). The number of remaining opposing teeth and occlusal support exhibited weak negative correlations with mean relining interval (rs =-0.187 and -0.214, respectively). Multivariate analysis using a generalized linear model showed that GAO was a significant explanatory variable for the mean relining interval. Conclusion: Within the limitations of this study, GAO was found GAO was found to contribute to the increased frequency of relining due to ridge resorption in patients with a small GAO.