Comparison of dental radiography and computed tomography: measurement of dentoalveolar structures in healthy, small-sized dogs and cats

Abstract

Background: Dental diseases are common in dogs and cats, and accurate measurements of dentoalveolar structure are important for planning of treatment. The information that the comparison computed tomography (CT) with dental radiography (DTR) is not yet reported in veterinary medicine.

Objectives: The purpose of this study was to compare the DTR with CT of dentoalveolar structures in healthy dogs and cats, and to evaluate the CT images of 2 different slice thicknesses (0.5 and 1.0 mm).

Methods: We included 6 dogs (2 Maltese and 1 Spitz, Beagle, Pomeranian, mixed, 1 to 8 years, 4 castrated males, and 2 spayed female) and 6 cats (6 domestic short hair,8 months to 3 years, 4 castrated male and 2 spayed female) in this study. We measured the pulp cavity to tooth width ratio (P/T ratio) and periodontal space of maxillary and mandibular canine teeth, maxillary fourth premolar, mandibular first molar, maxillary third premolar and mandibular fourth premolar.

Results: P/T ratio and periodontal space in the overall dentition of both dogs and cats were smaller in DTR compared to CT. In addition, CT images at 1.0 mm slice thickness was generally measured to be greater than the images at 0.5 mm slice thickness.

Conclusions: The results indicate that CT with thin slice thickness provides more accurate information on the dentoalveolar structures. Additional DTR, therefore, may not be required for evaluating dental structure in small-sized dogs and cats.

Keywords: Dental radiography; multi-detector computed tomography; periodontal space; pulp cavity.

Fig. 1. Pulp cavity (A), to tooth wide (B) and POS (C). Measurements of P/T ratio were perfomed at the level of cemento-enamel junction of tooth. POS were measured by drawing line that axis of pulp cavity and perpendicular to axis line.

P/T ratio, pulp cavity to tooth width ratio; POS, periodontal space; CMJ, cementoenamel junction.

Fig. 2. Difference of P/T ratio according to measurement method of dogs (A) and cats (B) and difference of POS of dogs (C) and cats (D). In both dogs and cats, P/T ratio and POS were measured significantly larger (p < 0.001) in CT 0.5 than DTR, and larger in CT 1.0 than CT 0.5.

P/T ratio, pulp-cavity to tooth width ratio; POS, periodontal space; DTR, dental radiography; CT 0.5, 0.5 mm slice thickness computed tomography; CT 1.0, 1.0 mm slice thickness computed tomography.