Dentigerous cysts are fluid filled, expansile, cystic lesions that can form around unerupted teeth. In our experience dentigerous cysts can affect any breed of dog however brachycephalic or short nosed breeds (Pugs, Frenchies, Boxer dogs) and micro breeds such as chihuahuas are most often affected.
The most frequently affected teeth in the dog are the mandibular first premolar teeth. These cysts are expansile and if not treated can result in extensive damage to the surrounding teeth and bone, even causing pathologic jaw fracture. The cysts may become very large before they become evident externally.
Ideally, any patients with missing teeth should have these regions examined more closely with dental radiographs. In many cases, this allows for detection of unerupted teeth early when cysts are small or before they have a chance to form resulting in less invasive treatments being required.
If a dentigerous cyst is detected not only does the unerupted tooth require extraction, but the tissue that is present lining the cyst wall also needs meticulous debridement and removal. If some of this lining remains there is a possibility of recurrence of the swelling and cyst and need for repeat surgery however this is rare. For this reason, we do recommend patients having dentigerous cyst removal also have follow-up radiographs to ensure resolution 6 months after treatment.
In many cases extraction of neighbouring teeth is also required. This is required when the cyst has undergone significant expansion and is involving the roots of other teeth in the jaw, in some cases resorption of neighbouring tooth roots may also be observed. This can result in extensive surgery being required for large cysts. The full extent of damage is often only apparent when dental radiographs are obtained.
Dentigerous cysts are benign in nature and generally classic in radiographic appearance, however, other types of lesions can present in a similar fashion and rarely dentigerous cysts can undergo transformation into malignant tumours. For this reason, we generally send a sample of the cyst lining to a pathologist for further assessment and to confirm the diagnosis. If any sign of malignancy is detected further surgery would generally be indicated.
Wound breakdown is a possibility post-operatively with extensive lesions and we do see this from time to time. In cases of wound breakdown, the surgical site may be managed as an open wound however in some cases involving extensive breakdown repeat surgery may be required.
Dentigerous cysts associated with unerupted teeth are encountered with some frequency in our pets. Early detection and treatment of unerupted teeth is preferable to avoid the need for more extensive and invasive surgeries. Patients rarely show any clinical signs to alert their owners and cysts are often very large before they become visible externally. If a tooth is noted to be missing we recommend radiographs to aid in early detection and treatment of this condition.