하악 제1대구치가 상실된 II급 1류 부정교합 환자의 치험례

Treatment of Class II, Division 1 Malocclusion with Hopeless Mandibular First Molars

Class II, Division 1 malocclusion patients have characteristics such as mild to severe lip protrusion and Class II molar and canine relationships. The treatment goal is usually to make an appropriate anterior tooth position through controlled retraction of the maxillary and mandibular anterior teeth to achieve a proper esthetic goal and to make a proper posterior anchorage loss in the mandible to get Class I molar and canine relationships. If there is an excessive extraction space in the mandibular arch, the closure of the extraction space can increase the difficulty of Class II treatment. Since introduction of the skeletal anchorage, protraction of the posterior teeth has become easier. However, if the treatment goal can be achieved using a well-planned distribution of tooth anchorage and minimal mini-implants, it can be a better treatment for both orthodontists and patients. The anteroposterior, vertical, and transverse biomechanical considerations must be well designed in the treatment plan. This case is a Class II, Division 1 malocclusion patient with moderate lip protrusion and bilateral missing of the mandibular first molars. The proper orthodontic goal was achieved with extraction of the maxillary first premolars, two mini-implants inserted in the maxilla, and the mandibular shoe-horn closing loops.