Aim: Aims of this study are to investigate the prevalence and distribution of impacted permanent teeth (IPT) and also the relationship between impaction and dental arch form and length in a Turkish orthodontic patient population.
Materials and methods: Panoramic radiographs, intraoral photographs and dental casts of 1527 patients (947 females, 580 males) aged 13 and above who underwent orthodontic treatment at Selcuk University Department of Orthodontics from 1990 to 2005 were retrospectively reviewed for IPT (except third molars). A comprehensive chart review was conducted in all subjects. Patient and treatment-related data were registered in a computer database for comparative analysis.
Results: When impacted supernumerary teeth (IST) were excluded, prevalence of IPT was 9.10% with no significant differences between the genders (p=0.897). Prevalence of IPT including IST was 9.69%. Most commonly impacted teeth were maxillary canines (5.24%) followed by mandibular second premolars (2.23%), maxillary second premolars (1.11%) and mandibular canines (0.92%). IST (0.72%) and impacted molars (0.72%) were the least common anomalies after incisor impaction (0.65%). Maxillary to mandibular IPT ratio was 1.88 and majority of IPT were in the anterior segment with an anterior-posterior ratio of 1.45 in all patients.
Conclusion: Most commonly affected impacted teeth were maxillary canines, mandibular second premolars, maxillary second premolars and mandibular canines respectively in our population with no predisposition difference between the genders. Arch length deficiency was determined as 14% for patients with maxillary impaction and 10% for patients with mandibular impaction. None of the patients with IPT have shown square arch form.