Lang LG, Wilkinson TE, White TL, et al.
Introduction/Purpose: Although computed tomography (CT) of the skull is a commonly performed diagnostic procedure in veterinary referral institutions, the role of CT in veterinary dental evaluation has not been fully investigated. Recognition of dental disease when performing CT of the skull is important to the overall health of the patient. Tooth resorption is a common dental disease in cats that can cause severe dental pain. Clinical evaluation of tooth resorption currently involves oral exam and dental radiography. The detection of tooth resorption with CT compared to oral exam and digital dental radiographs remains to be determined. The purpose of this study is to evaluate the sensitivity and specificity of CT for diagnosis of tooth resorption in cats, compared to the current clinical gold standard of oral exam and intraoral digital dental radiography.
Methods: Cat cadavers (euthanized for reasons unrelated to this study) were evaluated for tooth resorption using oral exam, intraoral digital dental radiography, and computed tomography. The oral exam and dental radiographs were performed by a single observer (board-certified veterinary dentist). Radiographs were evaluated by the above board-certified veterinary dentist and a DVM experienced in dentistry by a consensus statement. CT images (obtained at four different slice thicknesses: 3 mm, 2mm, 1 mm,nd and 0.5 mm) were evaluated via a consensus by a board-certified radiologist and a 2 year radiology resident. The sensitivity and specificity of CT for diagnosis of tooth resorption were calculated for each slice thickness using oral exam and digital dental radiography combined as the gold standard. Teeth (excluding incisors) diagnosed as having tooth resorption on either oral exam or radiography were considered positive for tooth resorption. Teeth diagnosed as not having tooth resorption on either oral exam or radiographs were considered negative for tooth resorption.
Results: Twenty-eight cat cadavers were included in the study. The sensitivity and specificity of CT for diagnosis of tooth resorption for each slice thickness was as follows: 3 mm (42%, 96%), 2 mm (49%, 93%), 1 mm (58%, 93%), and 0.5 mm (57%, 93%).
Discussion/Conclusion: Tooth resorption lesions in cats identified on CT images of the skull are highly specific and suggestive of true tooth resorption. However, the low sensitivity of CT for diagnosis of tooth resorption in cats precludes its use as a valuable screening test.