Part 1: Veterinary dental radiography: a vital practice resource
High-quality veterinary dentistry is impossible without the diagnostic tool of dental radiography. The extreme importance to patient care of full-mouth radiography will be demonstrated in this series of articles.
The results of two prospective nested case-control studies conducted at the University of California-Davis are worth a close look. Researchers found that of 226 dogs studied, dental radiography of teeth without clinical lesions demonstrated clinically significant lesions in 27.8 percent of dogs.1 In a similar study involving 115 cats, radiographs of teeth without clinical lesions nonetheless demonstrated clinically significant findings in 41.7 percent of subjects.2
A 5-year-old spayed female miniature schnauzer was presented for routine oral evaluation and professional teeth cleaning. The only abnormality noted was a missing first premolar on both mandibles (Photo 1). Radiography revealed bilateral dentigerous cysts associated with the unerupted teeth (Photo 2).
Dentigerous cysts are classified as odontogenic cysts and arise from the epithelial components of the developing tooth follicle or remnants thereof.3 Normally on eruption, the follicle becomes the junctional epithelium, which is present at the base of a normal tooth sulcus. If the tooth doesn't erupt, this epithelium has a strong tendency to produce cysts.
Dentigerous cysts are a common finding when teeth are missing, especially the mandibular first premolars. Brachycephalic and small-breed dogs seem to be predisposed. The mandibular first premolar is not the only tooth whose absence should prompt suspicion. Any areas of either jaw that are missing teeth should be evaluated radiographically in all breeds of dogs and cats to determine whether cysts are present. In my experience, most teeth that are unerupted will form cysts. Treatment involves referral to a veterinary dental specialist ( http://avdc.org/) for surgical exposure and complete removal of the tooth and cyst (Photos 3 and 4).