Factors Affecting Length of Impacted Maxillary Central Incisors after Surgical-Orthodontic Treatment

The purpose of this study is to identify the factors affecting the treatment outcome after surgical-orthodontic treatment of the maxillary impacted incisors using multiple regression analysis. The study enrolled 83 patients who had surgical-orthodontic treatment in impacted maxillary central incisor between January 2005 and December 2015. Possible explanatory variables related to the prognosis of impacted incisor were age, gender, tooth developmental stage, height, position and angle of the teeth. The results of multiple regression analysis showed that as the height of the stem cell from apical papilla (SCAP) increased, the tooth length ratio increased by 0.345 units (p < 0.01). There was no statistically significant difference in gender, tooth development stage, distance and angle between the center line and the tooth, and the height of incisal tip of the tooth. In conclusion, the height of the SCAP of the impacted central incisor is factor affecting the tooth length after orthodontic traction.