56 朱庭葳 / Ting-Wei Chu
Main Instructor Chung-Li Wang
Department / Institution Department of Orthodontics, Chi Mei Medical Center, Tainan City, Taiwan.
Classification case report
Class III malocclusions are the least common type of malocclusion but the highest among the Asian populations. The complexity depends on the severity of bony discrepancy and surgical-orthodontic treatment is often required for complete correction. In patients with mild to moderate skeletal discrepancy, non-surgical compensation can be achieved with orthodontic tooth movement alone. The extraction of lower first premolars and upper seconds second premolars is the most common option; however, other choices extractions can also be concerned.
The 18-years-old female patient was diagnosed as skeletal class III with high mandibular plane angle; Angles Class III malocclusion with crowding, retroclined lower incisors. In addition, large previous restoration over bilateral mandibular first molar were noted.
After the extraction of poor prognosis mandibular first molars, we use elastic class I and class III for overjet correction without the using of TADs. After overjet was corrected, uprighting spring was added at lower anterior teeth as brake mechanism for ideal bilateral mandibular second and third molars protraction. The total active treatment period was 36 months. Bilateral molar and canine class I relationship was achieved.
In class III malocclusion patient with poor-prognosis-molars, extraction of first molars and substitution with third molars might be a solution. By the posterior segment moving mesially while the anterior segment retracting posteriorly, the overjet was corrected ultimately the lateral profile improved. In this case, the use of Tip-Edge PLUS brackets and brake method achieving an acceptable, functional and esthetic occlusion in a nonsurgical line of treatment.
Efficacy of Tip-Edge PLUS Brackets in the Orthodontic Treatment of Class III Patient with Mandibular First Molars Extraction