Jaw Morphology and Factors Associated with Upper Impacted Canines: Case-Controlled Trial

Introduction and aim: Orthodontic treatment of impacted maxillary canines is challenging and expensive. This study investigated factors associated with impaction risk and the need for surgical exposure. Methods: Seventy-five participants of similar age, skeletal maturity, and gender (32 impacted canines, 43 controls) were included in the case-controlled trial. Three-dimensional study models were created (Trios 3, 3Shape), and panoramic radiographs were taken. The 3D digital models were measured using software to obtain morphological characteristics of the maxilla, such as maxillary surface area (mm2) and volume (mm3). Results: The impacted canine group displayed a significantly higher prevalence of deep bite (OR = 5.01), hypoplastic lateral incisors (OR = 5.47), and rotated adjacent teeth (OR = 3.56) compared to the control group. The impacted canine group exhibited a smaller maxillary surface area and volume. Within the impacted canine group, factors associated with a greater need for surgical exposure included the presence of a persistent deciduous canine (OR = 10.15), a palatal canine position (OR = 7.50), and a steeper canine angulation (p < 0.001). Conclusions: These findings suggest that several signs can serve as potential predictors of increased risk for maxillary canine impaction and the need for surgical intervention. Identifying these factors can aid in early diagnosis and treatment planning for improved patient outcomes.