Ngan P, Hu A M, Fields H W
Department of Orthodontics, West Virginia University, School of Dentistry, USA.
Pediatr Dent. 1997 Sep-Oct;19(6):386-95.
Etiology of Class III malocclusion can be genetic or environmental. Proclination of mandibular incisors and retroclination of maxillary incisors can cause posturing of the mandible in an anterior position due to incisal interference, a condition called pseudo Class III malocclusion that can be misleading in evaluating a patient with skeletal Class III malocclusion. Unfortunately, cephalometric evaluation may not be the most reliable tool in differentiating whether the maxilla or the mandible contributes to the skeletal disharmony. The most consistent findings seem to be the dental characteristics of Angle's Class III molars and canines, retroclined mandibular incisors, and the presence of an edge-to-edge or an anterior crossbite occlusion. This paper presents a diagnostic scheme to differentiate between dental and skeletal crossbites. Early treatment of Class III malocclusion can help to minimize the adaptations and limitations that are often seen in severe malocclusion of the late adolescence. However, treatment of skeletal crossbites remains a continuous challenge to the profession. Due to the diversity and variability in facial growth, accurate individualized growth prediction is not possible at the moment. Treatment directed at the mandible seems to invite relapse during the pubertal growth period. Treatment directed at the maxilla shows promising results and is awaiting long-term clinical results following early orthopedic interventions. Several intraoral appliances have proved to be successful in eliminating dental crossbites.
III类错牙合畸形的病因可能是遗传或环境因素。下颌切牙前倾和上颌切牙后倾可因切牙干扰导致下颌处于前位,这种情况称为假性III类错牙合畸形,在评估骨骼III类错牙合畸形患者时可能会产生误导。不幸的是,头影测量评估可能不是区分上颌骨还是下颌骨导致骨骼不协调的最可靠工具。最一致的表现似乎是安氏III类磨牙和尖牙的牙齿特征、下颌切牙后倾以及存在对刃或前牙反牙合。本文提出了一种区分牙性和骨性反牙合的诊断方案。III类错牙合畸形的早期治疗有助于将青春期后期严重错牙合畸形中常见的适应性变化和局限性降至最低。然而,骨性反牙合的治疗仍然是该专业持续面临的挑战。由于面部生长的多样性和变异性,目前尚无法进行准确的个体化生长预测。针对下颌骨的治疗在青春期生长期间似乎会引发复发。针对上颌骨的治疗显示出有希望的结果,并且正在等待早期正畸干预后的长期临床结果。几种口腔内矫治器已被证明在消除牙性反牙合方面是成功的。