Derm Dx: A red bump on the jaw

Dental sinus tracts result from a chronic periapical abscess. A periapical abscess is due to the accumulation of inflammatory cells and bacterial debris at the apex of a tooth due to infection. In immunocompromised patients, or if the organism is...

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Dental sinus tracts result from a chronic periapical abscess. A periapical abscess is due to the accumulation of inflammatory cells and bacterial debris at the apex of a tooth due to infection.

In immunocompromised patients, or if the organism is particularly virulent, this abscess can extend into the medullary bone and cause osteomyelitis. Further extension into the overlying soft tissue and fascia may lead to cellulitis.

If the organism is only moderately virulent the abscess will be contained, but still may erode through either oral mucosa or facial skin. If the erosion occurs through oral mucosa, the patient presents with an intraoral dental sinus tract or “parulis.” Cutaneous dental skin tracts result from erosion through the facial skin.

A cutaneous dental sinus tract clinically presents as an erythematous papule or nodule with an umbilicated, ulcerated or depressed center with associated fibrosis. Occasionally, a cordlike sinus tract can be palpated beneath the surface of the gum, palate or periorificial skin.

The majority of periapical abscesses occur in mandibular teeth. Therefore the most common location for cutaneous dental sinus tracts is on the chin or along the jawline. However, lesions may appear anywhere from the inner ocular canthus to the neck. The sinus tract allows inflammatory cells and debris to escape from the periapical abscess. Therefore, the patients are often asymptomatic without significant pain or swelling.

The second type of dental sinus tract occurs intraorally. An intraoral dental sinus tract clinically presents as a soft, non-tender, erythematous papule that develops on the alveolar process, the thickened ridge of bone that contains the tooth sockets and teeth. Typically, the sinus tract presents in the same region as the apex of the offending tooth. Like cutaneous dental sinus tracts, intraoral lesions are also asymptomatic, though patients sometimes complain of an intermittent salty or bitter taste, which may be related to the drainage of the purulent exudate from the underlying periapical abscess.

Other answer choices
Cervicofacial actinomycosis, also known as lumpy jaw, affects patients with a history of poor dental hygiene, dental disease or a prior history of orofacial injury or procedures. Lumpy jaw initially presents as a bluish swelling in the mandibular area that progresses to indurated and erythematous nodules, which gradually increase in size.

Eventually, the nodules can form sinus tracts, which drain purulent material with characteristic yellow “sulfur granules.” The granules contain clumps of the actinomycosis bacteria. In addition to multiple sinus tracts, fever, pain and leukocytosis may develop. Lymphadenopathy is usually absent.

Microscopic examination of the purulent material detects the characteristic sulfur granules composed of the fine and delicate gram-positive branching filaments. Treatment is with large doses of penicillin G or ampicillin, and surgical drainage of devitalized tissue.

Mucoceles present as dome-shaped, bluish, translucent, and painless papules or nodules that are most commonly located on the lower labial mucosa. They can range in size from a few millimeters to more than a centimeter.

Mucoceles arise as a result of trauma or obstruction of minor salivary gland ducts. This disruption leads to an accumulation of mucinous material, which stimulates a reactive inflammatory response and the development of granulation tissue. The most common type is mucous extravasation into the lower lips caused by trauma from biting.

Biopsy shows spaces within connective tissue filled with mucinous material without an epithelial lining. Mucoceles may resolve spontaneously.  Alternately, excisional biopsy will document the diagnosis and eliminate the problem.

Oral leukoplakia is the most common oral premalignant condition and is most commonly associated with tobacco and alcohol use. Leukoplakia presents as a well-demarcated homogenous white patch or plaque or a non-homogenous speckled red and white plaque.

Leukoplakia usually develops after age 30 years with a peak incidence at age 50. The most common sites of involvement include the floor of the mouth, the lateral and ventral surfaces of the tongue and the soft palate. Because oral leukoplakia is considered premalignant, biopsy is mandatory.

Diagnosis & Treatment            

Diagnosis of a dental sinus is made by the clinical appearance as described above.  Dental radiography is important to identify the abscess.  When identified, these cases should be referred to dentists or oral surgeons. 

Treatment for dental sinus tracts centers on elimination of the focus of infection. This includes extraction of the involved tooth or root canal therapy. 

Christopher Chu, BS, is a medical student at Baylor College of Medicine. 

Adam Rees, MD, is a graduate of the University of California Los Angeles School of Medicine and a resident in the Department of Dermatology at Baylor College of Medicine also in Houston.

References