Evaluation of mandibular indices and cephalometric parameters in adolescents with impacted maxillary canines

Maxillary impacted canines have an important place in orthodontics for the reason of being a common anomaly and its treatment is time consuming and difficult. The aim of this study was to investigate the mandibular indexes and cephalometric parameters in adolescents with impacted maxillary canines. The radiographs of 4026 patients aged 12–19 years old were scanned and a total of 155 patients were included in the study. Subjects were divided into three groups according to the permanent maxillary canines: Bilateral impacted canine (BIC) (52 subjects; mean age 15.02 ± 1.74 years), unilaterally impacted canine (UIC) (51 subjects; mean age 14.89 ± 1.39 years), and the control (52 subjects; mean age 14.84 ± 1.65 years) groups. Skeletal, soft tissue and dental measurements were performed on cephalometric radiographs. Mandibular index analyzes including the panoramic mandibular index (PMI), mental index (MI), antegonial index (AI), and gonial index (GI) measurements and also angular measurements of impacted maxillary canines were performed on panoramic radiographs. Data were analyzed statistically and P < 0.05 was considered significant. Maxillary skeletal and dental measurements showed retrusive positioned maxillary dental arch in the sagittal direction in the impacted canine groups (P < 0.05). PMI and MI values were greater in the BIC and UIC groups than in control group (P < 0.05). There was no statistically significant difference in AI value among groups (P < 0.05). GI value of BIC group was found statistically lower than other groups (P < 0.05). Individuals with impacted maxillary canines have more retrusive maxillary dental arch and soft-tissue components. Furthermore, mandibular cortex was thicker in subjects with impacted maxillary canine than individuals with not and clinicians should keep in mind this when examine the panoramic radiographs in terms of early diagnosis of impacted maxillary canine teeth.