In vivo determination of tooth mobility after fixed orthodontic appliance therapy with a novel intraoral measurement device.

Abstract

Valid measurement systems recording tooth mobility upon displacement within the subtle range of physiological strains are missing. Here, we introduce a novel in vivo measurement device and demonstrate a first clinical application by monitoring tooth mobility changes during retention after fixed multibracket appliance therapy. Tooth mobility was measured in vivo on 21 patients (11 female, 10 male; mean age 16.1±3.1years) by displacing the upper first incisor 0.2mm lingually for 0.2, 0.5, 1, 2, 5, and 10s with the novel intraoral device. Measurements were recorded directly after, as much as 2, 7, and 14days and up to 6months after appliance debonding. Device performance was precise and valid in clinical use. Data revealed significant interindividual varying tooth mobility, which was very high during the first 2days after appliance removal. After 1week, mobility values decreased, but were generally higher upon short loadings compared to long ones. After 3months, tooth mobility was significantly lower than directly after debonding. Interestingly, males exhibited significantly less mobility than females. Our work is the first using an in vivo measurement device capable of performing and recording tooth displacements within this delicate range and in such precision. Furthermore, our findings elucidate tooth mobility changes after multibracket treatment, giving important information for retention periods. Establishment of this novel measurement device in clinical use is an important improvement when approaching the complexity of tooth mobility in vivo regarding different issues like orthodontics, periodontal disease, or bruxism.