Extraction Treatment For Class Ⅰ Malocclusion With Crowding

Objective: To relieve denture crowding, prove denture arch protrusion and coordinate the teeth quantity with the bone quantity by extraction treatment. To keep the class I molar relationship and get the proper overbite and overjet relationship.Materials and methods: Extraction for Class I malocclusion with crowding by transpalate bar.Results: The course of orthodontical treatment is 29 months. Compared the changes between pre-treatment and post-treatment: Molar relationship still kept class I relationship. SNA and SNB decreased 1 degree, ANB kept still. The proper anterior overbite and overjet were also abtained. The L1-MP angle had changed from 80 degree to 83 degree. The mandibular plane was controlled well, so was the profit profile of soft tisse. The soft tissue measurement such as Z angle, H angle and Ns-Sn-Pos angle has not changed during the pre-treatment and post-treatment.Conclusion: Extraction is an effective treatment which can collect Class I malocclusion and get rid of crowding. The effective anchorage cotroll during the treatment is play an important part in closing space and adjusting of molar relationship. The patient was satisfied with the result of orthodontical treatment.