The effect of the root dilaceration on the treatment duration and prognosis of unilateral impacted immature maxillary central incisors

This study aimed to investigate the effect of root dilaceration on the closed-eruption technique treatment and prognosis on impacted immature maxillary central incisors.In this retrospective study, we compared the age at the beginning of the treatment, the treatment duration, root development, and alveolar bone mass after the closed-eruption technique between the impacted immature maxillary central incisors with dilacerated roots (group 1) and those with straight roots (group 2).The mean age at the time of the surgery of group 1 was 0.9 years younger than that of group 2 (P = 0.008). The mean traction time was greater in group 1 (8.0 ± 1.8 months), with a difference of 1.4 months than in group 2 (6.6 ± 2.1 months) (P = 0.042). The measurements of lingual bone thickness at the alveolar crest (C) showed significant differences between the 2 groups (P = 0.025). No significant differences were found in other treatment duration or measurements of root development and alveolar bone mass between the 2 groups.Patients with impacted immature incisors with dilacerated roots were younger at the beginning of the closed-eruption treatment and had a longer traction time than those with impacted immature incisors having straight roots. The root dilaceration had little or no effect on root development and alveolar bone mass after the closed-eruption treatment. The closed-eruption treatment of impacted immature incisors with root dilaceration is suggested to commence as early as possible.