DENTISTRY · August 20th, 2017
Dentigerous Cysts: More Common than You Think
Dentigerous cysts are a type of benign odontogenic cyst that are associated with impacted teeth. They are most commonly diagnosed in impacted mandibular 1st premolar teeth of brachycephalic breeds (Pugs, Boxers, Boston Terriers), although they can be seen in any impacted tooth of any breed (Figure 1). Significant bony destruction can occur secondary to expansion of the cyst, leading to disease of the neighboring teeth if they remain undiagnosed for a period of time. The pathogenesis is unknown, but they are thought to arise from proliferation of tissue remnants of the enamel organ.
How are dentigerous cysts diagnosed?
Clinically, dentigerous cysts can present as a large, fluctuant swelling, simply as a missing tooth, or as an incidental finding on whole mouth dental radiography. Radiographic features of dentigerous cysts are considered pathognomonic as the crown of the unerupted tooth will be enclosed by a radiolucent halo of variable size (Figure 1). Needle aspirate of the fluid, although not typically necessary for diagnosis, will reveal a brown tinged transudate.
The treatment of a dentigerous cyst involves a surgical approach using a gingival flap to accomplish extraction of the impacted tooth, curettage of the cyst lining, and possibly a bone graft if the bony defect is extensive.
Step 1: Obtain pre-operative dental radiograph
Step 2: Make a wide gingival flap, allowing access to the affected area
Step 3: Extract the impacted tooth and any neighboring affected teeth with the use of appropriate burs on a water-cooled high-speed dental unit.
Step 4: Utilize bone graft material if indicated
Step 5: Obtain post-operative dental radiograph
Step 6: Suture gingival flap
Untreated dentigerous cysts can lead to significant bone destruction with possible secondary pathologic fractures of the weakened bone, pulpitis of adjacent teeth, or malignant transformation of the cyst to a more aggressive disease…ameloblastoma or squamous cell carcinoma. Intraoral radiographs are therefore important to evaluate any missing teeth noted on oral examination. Early diagnosis is imperative and any impacted tooth should ideally be extracted to prevent the occurrence of this preventative destructive disorder.
Oral and Maxillofacial Surgery in Dogs and Cats: “Clinical Behavior and management of odontogenic cysts”; F Verstraete, M Lommer; Saunders Elsevier, 2012.
Journal of Veterinary Dentistry: “Endodontic Therapy of a Mandibular Canine Tooth with Irreversible Pulpits Secondary to
Dentigerous Cyst”; S MacGee; Vol 31, No 1, Spring 2014
This article was submitted by Dr. Laura Sasser, DVM. Questions? Please reach out to the Medical Advisory Board at MAB@nvanet.com.