Data on the age of apical closure in felines is limited. Moreover, differences in age of apical closure between male and female cats have not been studied. The aim of this study was to determine the timing of apical closure in cats and determine if sex or position in the dental arch affected closure. In this retrospective descriptive study, intraoral radiographs were obtained at monthly or multiple-monthly intervals for 18 cats. Nine were intact females and 9 were neutered males, ranging from 6 to 9.4 months of age at the start of the study which ranged over an 8-month period. Radiographs were evaluated to establish age of apical closure for all canine teeth as well as the mandibular premolar and molar teeth. Mandibular canine tooth apices closed between 10 and 12 months of age and maxillary canine tooth apices closed between 12 and 14 months of age. The mesial and distal root apices of both the mandibular third and fourth premolar teeth closed between 8 and 9 months. The mandibular first molar tooth mesial and distal root apices closed between 8 and 8.5 months. Root apices of canine teeth closed earlier in female cats than in male cats with mandibular canine tooth root apices closing significantly earlier than maxillary canine tooth roots in both sexes. These findings suggest that there are notable differences in age of apical closure between male and female cats and discernible trends in timing of apical closure among teeth in the dental arcade.
Keywords: apex; cat; closure; feline; root; tooth.