Evaluation of Soft and Hard Tissue Changes Following the Use of Rapid Molar Intruder for the Management of Skeletal Anterior Open Bite in Mixed Dentition: A Randomized Controlled Trial

Objective The aim of the study was to evaluate skeletal, dentoalveolar, and soft tissue changes following early anterior open bite (AOB) treatment using a rapid molar intruder (RMI). Materials and methods A two-arm, parallel-group, randomized controlled trial was conducted on 40 patients aged 8-12 years with anterior open bites. They were randomly allocated to the RMI group and the untreated control group (UCG) with a 1:1 allocation ratio. At the beginning of the treatment (T1) and after nine months of treatment (T2), lateral cephalometric images were taken of each patient. The primary outcome measures were skeletal, dentoalveolar, and soft tissue changes. A two-sample t-test was used in the intergroup comparisons of the cephalometric measurement. Results The findings showed that the overbite increased significantly in the RMI group compared to the control group (x = 4.44 mm, x = 0.19 mm, respectively; p<0.001). A statistically significant intrusion of the upper and lower first molars was observed in the RMI group (x = 2.9 mm, x = 1.54 mm, respectively) compared to a slight extrusion in the control group. The differences between the two groups were significant (p<0.001). The SN: GoMe angle and the sum of Bjork decreased significantly in the RMI group compared to an increase observed in the control group. The differences between the two groups were significant (p<0.001). Conclusion The rapid molar intruder is an effective appliance for correcting anterior open bites in mixed dentition, inducing favorable skeletal, dentoalveolar, and soft tissue changes.