The influence of dilacerated impacted maxillary central incisors on the incisive canal and nasal cavity characteristics: a retrospective comparative study

Dental anomalies significantly impact oral structures, particularly impacted maxillary central incisors. These anomalies can complicate interactions with nearby anatomical features like the incisive canal and nasal cavity. Accordingly, this study aimed to three-dimensionally and comprehensively assess the effects of dilacerated impacted maxillary central incisors on the characteristics of incisive canal and nasal cavity. A seventeen cone-beam computed tomography images with an average age of 8.98 ± 0.925 years were classified into a control group and a dilacerated impacted maxillary central incisor group (DIMCI group), each containing 35 patients. A linear, angular, and volume measurements of the incisive canal and nasal cavity were measured using Mimics 21 and Anatomage Invivo Dental 6.0 software. The incisive canal measurements were performed at three levels: H1, the lowest point of the incisive canal buccal wall; H2, midlevel; H3, root apex level. The incisive canal volume was significantly lower in the DIMCI group compared to the control group, measuring 109.39 ± 12.28 versus 93.17 ± 12.72 mm³, respectively. Furthermore, the incisive canal widths at the palatal opening and levels H2 and H3 were significantly reduced in the DIMCI group compared to the control group (P < 0.05). Additionally, the contralateral central incisor's angulation was considerably greater (113.18 ± 2.77 vs. 109.09 ± 3.74°), and the anterior nasal floor was significantly narrower (12.27 ± 1.60 vs. 13.61 ± 1.57 mm) in the DIMCI group than in the control group. The impaction of the maxillary central incisor is related to an increased buccal inclination of the contralateral central incisor and decreased anterior nasal floor width in pediatric patients, indicating a potential need for maxillary expansion. Moreover, a precise evaluation of the incisive canal is necessary for safe management during surgical exposure and orthodontic treatment.