Frequency of impacted teeth and categorization of impacted canines: A retrospective radiographic study using orthopantomograms

Abstract

Objective: The objective of this study is to determine the frequency of impacted maxillary canines using seven subtype classification system. For this purpose, impacted maxillary canines have been divided into seven various subtypes.

Materials and methods: This is a descriptive, cross-sectional, and retrospective study conducted using radiographic data of residents of Madinah, Al Munawwarah. Radiographic data of 14,000 patients, who attended College of Dentistry, Taibah University, from January 2011 to February 2015, were screened against the selection criteria for the presence of impacted teeth. The individuals with maxillary impacted canines were matched to maxillary canine impaction. The occurrence of each subtype of impacted canines was calculated.

Results: Impacted teeth are more common in the maxilla compared to mandible. The impacted canine represented the highest proportion of all impacted maxillary teeth followed by the second premolars and the central incisors. According to the classification system represented, Type II of canine impaction comprised the highest proportion (51%) while Type IV (0.5%) comprised the lowest frequency. The maxillary canine is the most frequently impacted tooth followed by mandibular canines.

Conclusions: Although there are many variations, the majority of impacted canines fall into Type II of the classification of impacted canines.

Keywords: Canine; impaction; maxillary teeth; orthodontics.

Figure 1

Schematic representation of the classification system of maxillary canine impaction used in this study: seven different types have been used based on anatomical relationship of impacted canines. Tooth 3 represents maxillary canine; teeth 2 and 4 represent maxillary lateral incisor and first premolar, respectively

Figure 2

Maxillary canine impaction classification. Type I (canine embedded between lateral incisor and first premolar); Type II (crown is mesially tipped overlapping, pressing lateral incisor tooth to provide a distal tipping of the lateral); Type III (distally tipped canine with an overlapped canine crown and the root of the first premolar); Type IV/V (canine long axis is orientated horizontally); Type VI (canine crown is directed up toward orbitale fossae); Type VII (canine long axis in horizontal direction with its crown placed buccally or interchanging with adjacent teeth)