Statistical signal processing methods for intraoral pressure curve analysis in orthodontics

A thorough understanding of the intraoral pressure conditions of patients with different forms of malocclusion may help to characterize their aetiology in more detail and improve orthodontic treatment approaches by adding strategies to achieve a normalization of intraoral pressure levels. These pressure curve analyses should not only provide information on intraoral activity or during rest but also detail characterization of swallowing features and pressure plateau stages. For this purpose, algorithms for extracting swallowing peaks and plateau stages were developed and evaluated. Established curve characteristics such as the average or maximum pressure as well as the number of swallowing peaks or resting phases were compared between each other. Their usefulness and correlation (Kendall's tau) were evaluated in a data example of different occlusal groups (Angle Class I: n = 30; Angle Class II division 1: n = 12; and Angle Class II division 2: n = 13). Curve characteristics were compared among these groups using the Kruskal-Wallis test. Some of the derived curve characteristics were found to be uncorrelated, thus providing different information concerning the intraoral pressure condition of subjects. Based on these findings, it is recommended to employ the curve characteristics described in this study to obtain a holistic image of factors that may affect the formation of the dentition.