Three-dimensional Measurement of the Zygomatic-maxillary Complex in the Class III Malocclusion Patients with Maxillary Retrusion

This study investigated the anatomic features of the zygomatic-maxillary complex in patients with maxillary retrusion without clefts. Individuals were grouped, and craniofacial measurements were performed for 21 individuals with skeletal Class III malocclusion with maxillary retrusion (CIII) and 48 individuals from the control group (CG). We evaluated the predetermined hard-tissue and soft-tissue points of the facial profile in each group. Independent sample t-tests were performed to determine the differences between groups (significance set at P<0.05). Multiple points on the midface, including the most posterior point on the contour of the maxillary alveolar process, lowest point of the zygomaticomaxillary suture, furthest point to the zygomatic self-base plane, superior point in the infraorbital foramen, and lowest point of the inferior margin of the orbit to the coronal plane were smaller in CIII than in CG (all P<0.05). The soft tissue thickness in these regions was significantly increased compared with that in the normal group. In summary, for class III malocclusion patients with maxillary retrusion, the deficiency in the midface gradually decreased going upward, with the deficiency at the maxillary alveolar level being the most serious. To some extent, soft tissues compensate for the deficiencies in the facial skeleton, and standard Le Fort I osteotomy advancement was sufficient to achieve a harmonious appearance.