Evaluation of maxillary arch morphology in children with unilaterally impacted incisors via three-dimensional analysis of digital dental casts: a controlled study

OBJECTIVE: The purpose of this work was to analyze variations in maxillary arch dimensions in subjects presenting unilaterally impacted maxillary permanent central incisors compared with a control group of subjects without eruption anomalies. METHODS: A group of 23 Caucasian children [8 females and 15 males, mean age 9.7 years, standard deviation (SD) 1.6 years] displaying unilaterally impacted maxillary permanent central incisors (impacted incisor group: IIG) were compared with a control group (CG) of 23 subjects (9 females; 14 males, mean age 8.8 years, SD 1.9 years) presenting no eruption disorders. Pretreatment dental casts were taken from each subject and the upper arch was scanned using a three-dimensional scanner. Linear measurements were taken on each digital model to analyze maxillary arch dimensions. Significant between-group differences were tested with the Student's t test (p < 0.05). RESULTS: The transverse and sagittal upper-arch measurements were significantly smaller in the IIG than in the CG. In particular, the anterior arch was 1.35 mm shorter in the IIG, while intercanine width was decreased by 2.51 mm on the impacted side. CONCLUSION: Children revealing unilaterally impacted maxillary central incisors demonstrated a significantly constricted maxillary transverse width and shorter arch on the impacted side compared with subjects with no eruption disorders.