Effects of low-intensity pulsed ultrasound (LIPUS) applied on the temporomandibular joint (TMJ) region on the functional treatment of class II malocclusion: A randomized controlled trial

Low-intensity pulsed ultrasound (LIPUS) is considered one of the techniques used to improve the mandibular growth. Many animal studies have reported that significant results can be obtained using LIPUS therapy with functional appliances. This research aimed to evaluate the dentoskeletal changes produced by the combination of LIPUS therapy and functional treatment during the correction of skeletal class II malocclusion. Forty-five patients aged 10.5-14 years with skeletal class II division 1 malocclusion were randomly divided into 3 equal groups: the LIPUS group, treated with a Twin-Block appliance in combination with LIPUS therapy; the TB group, treated with a Twin-Block appliance only; and the control group, which was observational and received no treatment. Cephalometric changes were compared between the 3 groups using the analysis of variance (ANOVA) and Tukey's post hoc tests at p < 0.05. A greater significant decrease in the ANB (A point, nasion, B point) angle was observed in the treated groups (-2.67° for the LIPUS group and -2.11° for the TB group) as compared to the control group (p < 0.001). A greater improvement in the mandibular length and position was observed in the LIPUS group than in the TB group (p < 0.001). The changes in the control group as a result of continuing growth were minimal and clinically non-significant. The application of LIPUS therapy in combination with functional treatment can have a great effect on growth stimulation during the correction of class II malocclusion. In addition, LIPUS was effective in reducing the duration of functional treatment.