## 2 Materials and Methods  
This retrospective study was carried out utilizing a review of clinical records of North Cyprus patients who were referred to Dr. Burhan Nalbantoglu State Hospital, Department of Oral and Maxillofacial Surgery clinic for a period of one year (December 2012-December 2013). Dr. Burhan Nalbantoglu State Hospital is the only hospital that has an oral and maxillofacial surgery department among the state hospitals in North Cyprus. A total of 1752 third molars in 550 patients were included in the study.  
The study started with the approval of the Turkish Republic of Northern Cyprus Ministry of Health inpatient treatment institutions (Ref: YTK0,000-6000-14/446/Approval/2014). This study was based on the retrospective evaluation of radiographs. Only archived data were used for the study. However, before taking any radiograph examinations, patients gave their informed consent before any application according to the principles of the Helsinki Declaration, including all amendments and revisions. Collected data was only accessible to the researchers.  
All panoramic radiographs were taken with standardized equipment and specifications. Data regarding age, gender, number of erupted and impacted third molars, the location (mandible or maxilla), sides (left/right), and type of impaction were obtained from patients' records, and panoramic radiographs were retrospectively assessed by a single oral and maxillofacial surgeon on a transparency projector under constant lighting conditions.  
The third molars were divided into three groups: erupted, partially erupted third molars, and completely impacted third molars [3, 10, 11, 12, 13].  
The angulation of the impacted third molar was documented based on [PERSON]'s classification regarding the angle formed between the intersected longitudinal axes of the second and third molars, namely vertical impaction (\(10^{\circ}\) to \(-10^{\circ}\)), mesoangular impaction (\(11^{\circ}\) to \(79^{\circ}\)), horizontal impaction (\(80^{\circ}\) to \(100^{\circ}\)), distoangular impaction (\(-11^{\circ}\) to \(-79^{\circ}\)), others (\(111^{\circ}\) to \(-80^{\circ}\)), and buccalingual impaction (any tooth oriented in a buccolingual direction with crown overlapping the roots) [17]. The axis of the teeth was measured on panoramic radiographs obtained from the patients by using a ruler and compass (Figure 1a,b).  
The pathologies and diagnoses of these pathologies associated with impacted teeth were defined in [PERSON] et al.'s study [3]: pericoronitis, infection of the soft tissue surrounding a partially erupted tooth; caries, a clinical cavity or radiographic lesion reaching at least to the amelodentinal junction; periodontitis, bone loss of the adjacent tooth of more than 5 mm below the cementoenamel junction that is diagnosed both radiographically and by probing the gingival pocket; abscess-cyst, lesions with a pericoronal space of the dental follicle of more than 4 mm that is verified radiographically or surgically; caries on the second molar and root resorption of the adjacent teeth, clear loss of substance in the root surface revealed radiographically.  
Data collected were entered into a spreadsheet (Excel 2000; Microsoft, Redmond, DC, USA) and analyzed subsequently using Statistical Package for Social Sciences (SPSS) version 16.0. The prevalence of impacted third molars according to age, gender, and type was assessed and displayed by frequency and percentage. A \(p\)-value less than 0.05 among gender, age, and sides was considered statistically significant through the Pearson Chi-square test.