Clinical challenges in treating a patient with deviated dental midlines and delayed root development of the mandibular left second premolar.

This case report describes the treatment of a girl, aged 13.3 years, with a concave face and a Class I relationship on the right and Class III on the left at the first molars. The left canines were in full Class II occlusion. The overbite was excessive at 80%. The maxillary dental midline was deviated 2.0 mm to the right, and the mandibular dental midline was 3.0 mm on the opposite side with a 5-mm deviation between both arches. There was a -2-mm mandibular arch length discrepancy, but, considering the intrabony left second premolar with root-delayed development, the arch length discrepancy was -8 mm. The incisors were also retroclined. A nonextraction treatment plan was used. When space to the left of the intrabony second premolar was opened, the tooth erupted passively, and the root had a normal length. The esthetic results were functional and pleasing.