Skeletal Class III malocclusion treatment using mandibular and maxillary skeletal anchorage and intermaxillary elastics: a case report

ABSTRACT Introduction: Skeletal Class III malocclusion is one of the most challenging malocclusions to treat. In around 40% of Class III patients, maxillary retrognathia is the main cause of the problem and in most patients, orthopedic/surgical treatments includes some type of maxillary protraction. Objective: The aim of this case report was to describe a treatment method for a patient with maxillary retrognathia and Class III skeletal discrepancy using mandibular and maxillary skeletal anchorage with intermaxillary elastics. Case report: A 13-year-old boy with maxillary retrognathia and mandibular prognathism was treated using bilateral miniplates. Two miniplates were inserted in the mandibular canine area and two other miniplates were placed in the infrazygomatic crests of the maxilla. Class III intermaxillary elastics were used between the miniplates. Results: After eight months of orthopedic therapy, ANB angle increased by 4.1 degrees and ideal overjet and overbite were achieved. Mandibular plane angle was increased by 2.1 degrees and the palatal plane was rotated counterclockwise by 4.8 degrees. Conclusion: This case showed that the skeletal anchorage treatment method may be a viable option for treating patients with Class III skeletal malocclusion.

摘要
引言：骨骼性III类错𬌗是治疗难度最高的错𬌗畸形之一。约40%的III类错𬌗患者以上颌后缩为主要致病原因，多数患者的正畸矫形/外科治疗会采用某种形式的上颌前方牵引。
研究目的：本病例报告旨在介绍一种针对上颌后缩伴骨骼性III类错𬌗畸形患者的治疗方法，该方法采用下颌及上颌骨支抗（skeletal anchorage）结合颌间弹力牵引。
病例报告：一名13岁男性上颌后缩伴下颌前突患者，采用双侧微型种植板（miniplates）进行治疗。于下颌尖牙区植入2块微型种植板，在上颌颧下嵴（infrazygomatic crests）区植入另外2块微型种植板，并在种植板间施加III类颌间弹力牵引。
结果：经过8个月的骨矫形治疗（orthopedic therapy）后，ANB角增大4.1°，获得理想的覆盖与覆𬌗。下颌平面角增大2.1°，腭平面逆时针旋转4.8°。
结论：本病例表明，骨支抗治疗方法可作为治疗骨骼性III类错𬌗畸形患者的可行方案。