ABSTRACT
To compare a novel body mandibular horizontal plane (mental foramen–protuberance menti; Body-MHP) with the conventional border mandibular horizontal plane (gonion–menton [Me]; Border-MHP) to assess mandibular body inclination and dental compensation of skeletal Class III patients with and without facial asymmetry.
Retrospective data obtained from diagnostic cone-beam computed tomography of 90 skeletal Class III patients (mean age, 21.67 ± 2.93 years; range, 15.0–30.6 years) were divided into symmetry (n = 30) and asymmetry groups (n = 60). The asymmetry group was subdivided into roll (n = 30) and non-roll types (n = 30). The differences in body inclination and dental measurements (distance and angle) according to two mandibular planes (Body-MHP and Border-MHP) were assessed in the groups and subgroups.
Mandibular body inclinations relative to the Body-MHP were not different in the roll-type asymmetric mandible between the sides, while those relative to the Border-MHP were different (P < .001). For the mandibular first molar positions relative to the Border-MHP, the differences in vertical distance between the sides were undermeasured and the inclination differences were overmeasured when compared relative to the Body-MHP.
The Body-MHP demonstrated better bilateral similarity in body inclination compared with the Border-MHP in patients with roll-type facial asymmetry. The novel body mandibular plane ensures an accurate diagnosis for tooth movement and jaw surgery, particularly in the roll-type asymmetric mandible.
Author notes
Assistant Professor, Department of Orthodontics, School of Dentistry, Kyungpook National University, Daegu, Korea.
Professor and Chair, Department of Orthodontics, School of Dentistry, Kyungpook National University, Daegu, Korea.
