【Objective】 In cases with congenital missing teeth, there are various restriction in orthodontic treatment and an effective treatment plan has to be considered carefully. The present case report shows an adult female case with congenitally missing canines whose maxillary molars were moved mesially by utilizing TAD.
【Case】 The patient was a 24-year-old female. Her chief complaint was the spaced arch in the maxillary dentition. Overjet and overbite were +7.0 mm and +4.5 mm. Class II and Class I molar relationship were seen on the right and left sides, respectively. The maxillary canines were congenitally missing in both sides. The skeletal Class II relationship ( ANB 5.5°) and the low mandibular plane angle ( FMA 23.0°) were seen. The maxillary incisors were proclined ( U1 to SN 114.0°). Treatment objectives were to retract the maxillary incisors by 4.0 mm and move the maxillary left molars mesially by 5.0 mm.
【Discussion and Summary】 After the mesial movement of the maxillary left first premolar, TAD was placed in the distal part of this tooth and the mesial movement of the left molars was performed. After the treatment, the maxillary left first molar was moved mesially by 5.5 mm and functional occlusion was obtained with a full Class II molar relationship. In the treatment of mesial molar movement, determination of the insertion site and timing of TAD together with appropriate force system has to be planed carefully for the effective treatment.