1.The patient had protruding face with Class I molar relationship before treatment, so mandibular and maxillary buccal arch expansion, intruding and IPR were performed. After treatment, the patient had straight face and the upper and lower lip were closed naturally.
2. This patient is an adult female. When smiling, the middle lower edge of her upper lip is slightly convex to the downwards, and bilateral corners of the mouth are lifted upward slightly. Upper edge of her lower lip is consistent with radian of upper dental arch. Smile radian showed by angulation of upper anterior teeth and anterior teeth exposure meets the aesthetic standards, and is the key to successful treatment of this case.
3.Align the upper and lower teeth and obviously improve the overbite and overjet of anterior teeth to reach the expected orthodontic effect. 
4.IPR must be performed on proximal surface of adjacent teeth. Conduct return visits and implement monitoring to prevent off-tracking of brace. Patient’s cooperation is very important.