Cephalometric comparison of adult anterior open bite treatment using clear aligners and fixed appliances

Abstract

Objectives: To compare fixed appliances and clear aligner therapy in correcting anterior open bite and in controlling the vertical dimension in adult patients with hyperdivergent skeletal patterns.

Materials and methods: In this retrospective study, two treatment groups of adult (≥18 years old) hyperdivergent patients (mandibular plane angles of ≥38°) with anterior open bites were included: 17 fixed appliance patients and 36 clear aligner patients. Thirteen cephalometric measurements representing the vertical dimension were reported for each group. A two-sample t-test was used to assess differences in changes in mandibular plane angle and overbite between the two treatment groups.

Results: There were no statistical differences found in the magnitude of overbite correction and the changes in any of the cephalometric measurements for vertical control. The clear aligner group showed a slightly greater amount of lower incisor extrusion ( P = .009). The main mechanism of open bite correction was similar between the two treatment groups and was accomplished through retroclination of the upper and lower incisors while maintaining the vertical position of the upper and lower molars.

Conclusions: Cephalometric comparison of anterior open bite correction and changes in the mandibular plane angle associated with use of clear aligners and fixed appliances did not demonstrate statistically significant differences in adult hyperdivergent patients.

Keywords: Adult; Clear Aligner; Fixed appliance; Hyperdivergent; Open bite; Vertical control.

Figure 1

Sampling process.

Figure 2

Sample distribution for fixed appliance and clear aligner groups during sampling period (2008–2014).

Figure 3

Cephalometric analysis.

Figure 4

Sample distribution by severity of anterior open bite at T1.