Reliability of the anterior functional device in recording the centric relations of patients with posterior tooth loss.

STATEMENT OF THE PROBLEM: The recording of centric relations (CRs) in patients with posterior tooth loss is a process that is subject to inaccuracy. A number of techniques and devices, including the anterior functional device (AFD), have been developed in the pursuit of better results. PURPOSE: The purpose of this in vivo study was to evaluate the reliability of the AFD for the recording of the CR in participants with different types of posterior tooth loss. MATERIAL AND METHODS: Two CR records were obtained (CR1, CR2), and 2 maximal intercuspal position records were obtained (MIP1, MIP2) by a single operator at intervals of 5 minutes. This study included 45 participants of both sexes aged between 18 and 65 years who were divided into 3 groups. The first group had intercalated tooth loss (n=19), the second group had distal extensions (n=11), and the third group had no tooth loss (n=15). The distance between the CR and MIP was termed the condylar displacement and was measured in millimeters in the vertical, horizontal, and transversal planes with a condylar position indicator (CPI). The condylar displacements between the CR and MIP in both stages of the study (D1 and D2) were compared with the CPI after mounting the casts on a semiadjustable articulator. Repeated-measures analyses of variance with one factor were used to compare the records for each group in each of the planes: right vertical (RV), left vertical (LV), horizontal right (HR), horizontal left (HL), and transverse (T) (alpha=.05). No significant differences between the records in any of the planes (RV, LV, HR, HL, or T) were observed; thus, the means of the records of each plane were used to compare the groups (the intercalated tooth loss, distal extension, and no tooth loss groups). The means of the records of the HR and HL planes were compared by ANOVA because the data were normally distributed. The means of the records of the RV, LV, and T planes were compared by using nonparametric Kruskal-Wallis tests because the data were non-normally distributed. RESULTS: No statistically significant difference (P >.05) was found between the condylar displacements for any of the studied variables in the 3 considered groups: RV (.512), LV (.690), HR (.179), HL (.494), and T (.644). CONCLUSIONS: Repeatability of the condylar displacement was observed between the CR and MIP (D1, D2), which indicates the reliability of the AFD method for recording the CR in participants with posterior tooth loss. The AFD was demonstrated to be a user-friendly tool and permitted the recording and evaluation of excursive movements with tracings.