Characteristics of the Maxillofacial Morphology in Patients with Idiopathic Mandibular Condylar Resorption

Idiopathic mandibular condylar resorption (ICR) is a pathological condition characterized by idiopathic resorption of the mandibular condyle, resulting in a decrease in the size and height of the mandibular condyle. The purpose of this study was to characterize the maxillofacial morphology of ICR patients. Subjects were selected from patients that attended our orthodontic clinic between 1991 and 2019. Twenty-five patients were diagnosed with ICR by magnetic resonance imaging; however, growing patients were excluded. In total, 18 patients were finally selected. The control group comprised 18 healthy volunteers. Lateral and frontal cephalograms were also used. The ICR group had significantly more severe skeletal class II malocclusions than the control group, mainly due to retrusion of the mandible. In the ICR group, there was a tendency for a skeletal open bite due to a significantly larger clockwise rotation of the mandible than in the control group. There was no significant difference between the two groups in the inclination of the upper and lower central incisors or protrusion of the upper and lower central incisors and first molars. ICR patients have been suggested to exhibit skeletal open bite and maxillary protrusion with changes in maxillofacial morphology due to abnormal resorption of the mandibular condyle.