A case of anterior open bite associated with idiopathic condylar resorption treated with miniscrew-assisted orthodontics

Abstract

We successfully treated a Class II Division 1 patient with an anterior open bite accompanied by idiopathic condylar resorption (ICR) using miniscrew-assisted orthodontics. A female patient, aged 20 years 7 months, had a convex profile with retropositioned chin, a severe open bite, and an excessive overjet due to a skeletal Class II jaw-base relationship. Panoramic radiograph showed condylar atrophy with generalized sclerosis in the temporomandibular joints bilaterally, and cone-beam computed tomography (CBCT) revealed severe condylar resorption with avascular necrosis bilaterally. Segmental arches were placed on maxillary and mandibular premolars and molars. After leveling, titanium miniscrews were obliquely implanted between the maxillary first and second molars, and maxillary molar intrusion was initiated. At 11 months of treatment, a repeat CBCT was performed and we confirmed no active resorption. Maxillary first premolars were extracted bilaterally to reduce an excessive overjet. After 33 months of active orthodontic treatment, a proper facial profile and an acceptable occlusion were achieved with 2.0 mm intrusion of the maxillary molars. The resultant occlusion was stable throughout the 1-year retention period. In conclusion, we believe that correction of ICR-related anterior open bite by molar intrusion using titanium miniscrews is effective for the treatment of patients with severe degenerative joints.