A quantitative analysis of facial changes after orthodontic treatment with vertical control in patients with idiopathic condylar resorption

This study aimed to investigate temporomandibular joint (TMJ) stability and three-dimensional (3D) facial changes in class II hyperdivergent patients with stable idiopathic condylar resorption (ICR) after orthodontic camouflage treatment with vertical control by using temporary anchorage devises (TADs).Nineteen skeletal class II hyperdivergent patients who were diagnosed with stable ICR underwent bicuspid extraction orthodontic treatment with vertical control via TADs were enrolled. TMJ was evaluated with the cone beam computerized tomography (CBCT) and clinical records before and after treatment. Changes in dental and skeletal parameters were evaluated with cephalometric and dental cast measurements. The 3D morphable model (3DMM) method was performed with the MeshMonk toolbox for the 3D facial analysis. After the reposition and landmark setting process, 3D facial heatmaps were used to illustrate facial changes, and the 3D deviations of landmarks were calculated.Both the imaging evaluation and clinical examination proved that TMJs remained stable after treatment. The retrusion of the upper and lower incisors reached 6.63 ± 0.79 mm and 3.78 ± 1.49 mm. The intrusion of the upper first molar reached 2.65 ± 0.75 mm, with a 2.27 ± 0.82° counterclockwise rotation of the mandibular plane. An upward shift of the soft tissue pogonion (2.34 ± 2.03 mm) and protrusion of Po-NB (0.82 ± 0.70 mm) was gained. Larger intrusion was found in the lower lip (3.29 ± 0.80 mm) than in the upper lip (2.20 ± 0.69 mm).Camouflage orthodontic treatment with TAD for vertical control is acceptable for skeletal class II hyperdivergent patients with ICR, which can improve the facial profile.