Adjustable Removable Traction Appliance With Surgically Assisted Eruption for Impacted Maxillary Central Incisors

Impacted maxillary central incisors (MCIs) can seriously affect children's appearance, verbal abilities, and maxillofacial development. Clinically, a combination of surgically assisted eruption and orthodontic traction is the treatment modality most acceptable to dentists and children's families. However, previously used traction methods have been complex and required a long treatment time.

The study intended to evaluate the clinical effects of the use of the research team's adjustable removable traction appliance combined with a surgically assisted eruption of impacted MCIs.

The research team performed a controlled prospective study.

The study took place at Department of Orthodontics, Hefei Stomatological, Hospital.

10 patients with impacted MCIs, aged 7-10 years, who had visited the hospital between September 2017 and December 2018.

The research team assigned the impacted MCIs to the intervent ion group and contral ateral normal MCIs to thecontrol group. For the intervention group, the research team performed a surgical eruption and inserted the adjustable removable traction appliance. The control group received no treatments.

Postintervention, the research team determined the mobility of both groups' teeth. At baseline and immediately postintervention for both groups, the team performed cone-beam computed tomography (CBCT) and measured root length, apical-foramen width, volume, surface area, and root-canal wall thickness for the labial and palatal sides. For both groups, after the intervention group's treatments, the team: (1) performed electric pulp testing and periodontal probing on the participants' teeth; (2) measured and documented pulp vitality, gingival index, periodontal probing depth, and gingival height (GH)for the labial and palatal sides; and (3) measured labial-and-palatal, alveolar bone level and alveolar bone thickness.

At baseline, the intervention group showed delayed root development, and that group's root length was significantly shorter (P < .05) and apical-foramen width (P < .05) was significantly greater than those of the control group. The intervention group's treatment success rate was 100%. And the intervention group did not have any adverse reactions, such as tooth loosening, gingival redness and swelling, or bleeding. Postintervention, the intervention group's labial GH was significantly higher than that of the control group, at 10.58 ± 0.45 mm and 9.47 ± 0.31 mm, respectively (P = .000). The increase in the intervention group's root length postintervention was significantly greater than that of the control group, at 2.80 ± 1.09 mm and 1.84 ± 0.97 mm, respectively (P < .05). The intervention group also had significantly greater decrease in the apical-foramen width than the control group did, at 1.79 ± 0.59 mm and 0.96 ± 0.40 mm, respectively (P < .05). At the end of traction, the intervention group had significantly higher labial-and-palatal alveolar-bone levels, at 1.77 ± 0.37 mm and 1.23 ± 0.21 mm, respectively, than the control group did, at 1.25 ± 0.26 mm (P = .002) and 1.05 ± 0.15 mm (P = .036), respectively. The labial alveolar-bone thickness in the intervention group was thinner than that of the control group, at 1.49 ± 0.31 mm and 1.80 ± 0.11 mm, respectively (P = .008). The volume and surface area (P < .01) of the intervention group's impacted teeth had increased significantly postintervention (both P < .01), but both were significantly smaller than those of the control group, both at baseline and postintervention.

An adjustable removable traction appliance combined with a surgically assisted eruption can be a reliable treatment for impacted MCIs and can provide root development and a good periodontal-pulp condition postintervention.