Peripheral Odontogenic Fibroma and Epulis in Dog Epulis, Ossifying Epulis, Fibromatous Epulis, Fibroosseous Epulis

What is an Epulis or Peripheral Odontogenic Fibroma?

Peripheral Odontogenic Fibroma (Epulis) is the most common oral mass found in dogs. Epulis, ossifying epulis, fibromatous epulis, and fibroosseous epulis are all terms that have been used in the past. Peripheral Odontogenic Fibroma is the preferred name of a mass in the oral cavity of a dog that is derived from the periodontal ligament cells that hold the tooth in the socket. Treatment involves removal of the mass, the associated tooth, and if extension into bone, any bone that is involved. Curettage of the alveolus (tooth socket) is required to remove all remaining periodontal ligament cells to ensure complete removal and eliminate the possibility of recurrence.

Figure 1 and 2 GO

Epulis involving the rostral maxilla of a basset hound dog preoperative image.

How can I spot a Peripheral Odontogenic Fibroma (Epulis)?

The Peripheral Odontogenic Fibroma is a clinical term referring to a slow growing, localized, exophytic mass on the gingiva resulting from chronic irritation. On presentation, the area of concern typically is a firm, pink, smooth swelling of the gingiva and normally seen as gingival hyperplasia.

The most common clinical signs associated with epulis are facial deformation, discomfort, difficulty eating, decrease in activity, weight loss, halitosis, swelling of jawbone, excessive salivation, oral bleeding, lymph node enlargement, dental disruption or loss and no signs at all other than a small swelling

This is the most common benign tumor found in the oral cavity of dogs, more specifically brachycephalic breeds. They are, however potentially very invasive if left untreated.

Epulis involving the rostral maxilla of a basset hound dog postoperative and one month followup images.

Epulids are typically seen in dogs over the age of 6 but, can be seen at any age. Peripheral Odontogenic Fibromas are not commonly seen in cats but when present often present as multiple epulides.

How do I know if my pet has a Peripheral Odontogenic Fibroma (Epulis)?

A biopsy is required in order to definitively diagnose Peripheral Odontogenic Fibromas. Other diagnostic options are to do intra-oral radiographs. This can be helpful to determine if the tumor is benign or a more aggressive neoplasia or lesion. Radiographs can show varying degrees of calcification and opacity in the gingiva. Although rare, Peripheral Odontogenic Fibroma’s have been known to show variable amounts of bone and bone matrix. It is termed "ossifying epulis" when the bone matrix/bone predominates in the stromal core. Epulides of this type exhibit variable attachment to underlying bone, but they typically do not exhibit invasion of bone. Pathology reports show proliferated fibroblast of connective tissue accompanied by proliferated Odontogenic epithelium with a variety of osteoid, cementum, or dentin like material. Isolated strands of odontogenic epithelium are always present.

Incision made to present tumor.

How do I treat this condition?

Complete surgical excision with appropriate margins is nearly always curative resulting in nearly 95% effectiveness; however, tumors may recur if not completely excised. An incision is made to ensure all of the Peripheral Odontogenic Fibroma is removed. Wide margins are not needed however no abnormal tissue should be left following excision. The teeth associated with the mass are extracted and the bone excised. Any remaining tooth socket (alveolus) is contoured with a diamond bur to remove any remaining periodontal ligament fibers. The excision and extraction site are typically closed with 4-0 monocryl in a large dog or 5-0 monocryl in a small dog. Recurrence is not expected.

Incision site closed with 4-0 monocryl

Preoperative and initial incision to completely excise an epulis (peripheral odontogenic fibroma) from the mouth of a dog .

Post removal and closure to completely excise an epulis (peripheral odontogenic fibroma) from the mouth of a dog .

What should pet parents expect after treatment?

Peripheral odontogenic fibromas are benign and do not metastasize. If left untreated they can become extremely large. In cases where treatment is delayed, trauma from teeth and infection of the mass can result. In some cases partial mandibulectomy is required to completely excise the mass and eliminate the trauma. Prognosis is greater with the least delay of treatment. Dogs that undergo excision of Peripheral Odontogentic Fibromas do well post-operatively with minimal to no change in appearance as well as quality of life greatly heightened. Pain reliever will be sent home to ease post operative pain. It is not uncommon for the patient to experience blood tinged saliva for the first 24-48 hours. The incision site typically heals within in 10-14 days while sutures take 2-4 weeks to fully dissolve. In this time period, pet parents should feed soft food only, especially if mass was located in the caudal oral cavity, to ensure that the healing process is not disrupted. Dogs are very adaptive and will quickly learn their new ways of eating, drinking, grooming, and playing if the mass is large and extensive tissue removal is needed. Pet parents should refrain from ever allowing your dog to have hard chew toys as they increase the potential to fracture teeth.

Pet parents worried that your dog might be a candidate for epulis, there are several steps you can take.

  • Monitor your dogs mouth regularly at home by lifting his lips and inspecting the gum line.
  • Follow all recommendations from your veterinarian for at home oral care.
  • Recognize symptoms associated with an oral mass and take notes to share with your veterinarian such as bad breath, excessive drooling, changes in behavior, or blood.
  • Call your veterinary office and set up an appointment for an oral exam as soon as epulis is suspected, as delay can affect how invasive the procedure might be.
  • Discontinue the availability of hard bones or toys.
  • Make regular check-up appointments for your dog to be examined by your veterinarian.

    Peripheral Odontogenic Fibroma found on oral exam Complete curettage of mass to be submitted for histopathology Incision site closed

    Dr. Brett Beckman is a board certified veterinary dentist. He provides practical courses to train veterinarians around the world to provide exceptional oral care for their dog and cat patients.

    "Teaching 5000 vets to treat 2,000,000 pets to eliminate the silent suffering from hidden oral disease."

    Dr. Beckman sees patients in: Orlando, Florida and Atlanta, Georgia


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