Pandey Sushant, Gyawali Rajesh, Pokharel Prabhat Ranjan, Chaudhary Avinash, Sangroula Samikshya
Department of Orthodontics and Dentofacial Orthopaedics BP Koirala Institute of Health Sciences Dharan Nepal.
Clin Case Rep. 2024 Dec 19;12(12):e9700. doi: 10.1002/ccr3.9700. eCollection 2024 Dec.
The orthodontic management of patients with Class III malocclusion poses numerous treatment challenges. Various removable, fixed, orthopedic, and myofunctional appliances have been recommended for its correction. The Reverse Twin Block is a removable appliance which has been used for the early management of such cases. A 10-year-old female with no significant medical and family history presented with the chief complaint of forward placement of lower front teeth on biting. Extraoral examination revealed a mesoprosopic face, a prominent lower lip, and a shallow mentolabial sulcus. Facial profile was straight at rest and concave at maximum intercuspation. Intraoral examination revealed a Class III incisor relationship with premature contact between 21 and 31, causing a forward path of closure of the mandible. The patient had a reverse overjet of 2 mm, an overbite of 5 mm, and a bilateral Super-class I molar relationship at maximum intercuspation. Lateral cephalogram analysis revealed a mild skeletal class III denture base (ANB = 0°, Wits = -4 mm) due to a prognathic mandible (SNB = 82°). The treatment objectives included elimination of the premature contact, establishment of a positive overjet, and improvement of the facial profile. A Reverse Twin Block appliance was planned and prescribed for full-time wear for 8 months. At the end of treatment, the patient had a Class I incisor relationship, straight facial profile, Class I molar relationship on the left side, and Super-class I molar relationship on the right side. The Reverse Twin Block is a simple and well-tolerated appliance that can effectively correct developing Class III malocclusion in carefully selected cases.
对III类错牙合患者进行正畸治疗面临诸多挑战。人们推荐了各种可摘矫治器、固定矫治器、矫形矫治器和肌功能矫治器来矫正此类错牙合。反向双阻板矫治器是一种可摘矫治器，已被用于此类病例的早期治疗。一名10岁女性，无重大病史和家族史，主诉咬合时下前牙前突。口外检查显示面部中规，下唇突出，颏唇沟浅。面部侧面在休息时笔直，在最大牙尖交错位时呈凹面。口内检查显示为III类切牙关系，21和31之间有早接触，导致下颌闭合向前路径。患者反向覆盖为2mm，覆牙合为5mm，在最大牙尖交错位时双侧为超级I类磨牙关系。头影测量分析显示，由于下颌前突（SNB = 82°），存在轻度骨骼III类牙列（ANB = 0°，Wits = -4mm）。治疗目标包括消除早接触，建立正覆盖，并改善面部外形。计划并开出处方使用反向双阻板矫治器，全天佩戴8个月。治疗结束时，患者切牙关系为I类，面部侧面笔直，左侧为I类磨牙关系，右侧为超级I类磨牙关系。反向双阻板矫治器是一种简单且耐受性良好的矫治器，在精心挑选的病例中可有效矫正正在发展的III类错牙合。
