Correction of anterior open bite malocclusion with a temporary skeletal anchorage device–supported appliance

Abstract

To evaluate the dental and skeletal changes using a novel miniscrew-supported bite-closing appliance (MBCA) to correct anterior open bite. A novel MBCA that uses nickel-titanium springs connected to miniscrews combined with a biteplate and a low-hanging transpalatal arch to intrude posterior teeth was used. Using cone-beam computed tomography (CBCT) and cephalograms, skeletal and dental changes were measured and discussed in 25 patients with open bites consecutively treated with this appliance. The MBCA significantly decreased the open bite (2.9 ± 0.1 mm; P <0.0001). Relative to FH, intrusion was achieved on the maxillary second premolars (−2.0 ± 1.5 mm; P <0.0001), first (−2.3 ± 1.8 mm; P <0.0001), and second molars (−1.9 ± 1.6 mm; P <0.0001). This was supported by the results from the CBCT superimpositions that showed intrusion of the maxillary second premolar (−3.2 ± 1.6 mm) and the maxillary first and the second molars (−2.8 ± 1.5 mm and −2.1 ± 1.6 mm, respectively). This resulted in favorable skeletal changes exhibited by a significant decrease in FMA (−1.4 ± 2.2°; P <0.005), SN-MP (−1.8 ± 2.4°; P <0.005), and an increase in PFH (1.2 ± 1.4 mm; P <0.05) and SN-NPog (1.4 ± 2.2°; P <0.05). These results are consistent with the counterclockwise rotation of the mandible. A mandibular lingual holding arch resulted in better vertical control of the mandibular posterior teeth (P <0.05). Follow-up on patients with available posttreatment CBCTs (n = 8) suggests some dental relapse at the second premolar (1.5 ± 3.0 mm) and the first (1.7 ± 2.4 mm) and second molars (1.7 ± 2.4 mm), but the skeletal changes were maintained. Visual assessment of patients with posttreatment photographs (n = 18) showed that positive overbite was maintained in all subjects. MBCA can provide satisfactory correction of the anterior open bite through counterclockwise rotation of the mandible.