Oral Cutaneous Fistulas Clinical Presentation

Updated: Mar 03, 2022
  • Author: James E Cade, DDS, FACD; Chief Editor: William D James, MD  more...
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Acute dental infections cause extreme pain when they occur in a confined area. Chronic dental infections are often asymptomatic. The pulp is confined in a hard structure, namely, the pulp chamber. Most nerve receptors in the tooth are type A delta nerve fibers, which detect pain sensation. These fibers interpret the pressure due to edema in infection and inflammation as pain.

Acute periapical inflammation also causes pain when it is confined to a bony space.

Pain often decreases or disappears when a sinus tract forms, relieving pressure.

In chronic osteomyelitis with drainage, pain may not be a symptom.


Physical Examination

An intraoral sinus tract or parulis may be raised or appear as a red-to-yellow ulcer that bleeds easily and exudes pus.

If infection from the mandible remains confined to the oral cavity or if the infection spreads to the skin, the site of fistulation may be distant from the intraoral infection site.

In some cases of actinomycosis, yellow granules (often called sulfur granules) are observed at clinical examination. These granules have a characteristic histologic appearance.

Lesions can appear as dimpling with a small depression or can be nodular with pus. Misdiagnosis of the lesions may lead the patient to a dermatologist. One study found the most common manifestation of oral cutaneous fistulas was dimpling (41.2%), followed by a nodule (32.4%). [34] Other manifestations included abscess and cysts.

Signs and symptoms of salivary gland infections include swelling, pain, and trismus if the parotid gland is involved. Major salivary gland fistulas are diagnosed by means of probing or sialography.

A thorough head and neck examination, including palpation of head and neck lymph nodes, is needed to rule in or out dental infections versus other dermatologic infections and neoplasms.



Poor oral hygiene and trauma cause most dental infections.

Compared with other individuals, patients who are immunocompromised, those who are receiving chemotherapy, and those with blood dyscrasias are more likely to have dental infections.

Xerostomia leads to additional caries due to increased salivary acidity. This effect enhances the growth of cariogenic bacteria and increases the adherence of plaque to the teeth.

Gram-positive bacteria and gram-negative microorganisms such as Streptococcus mutans; Staphylococcus epidermidis; S aureus; and Porphyromonas, Actinomycoses, Bacteroides, and Fusobacterium species are found in dental infections and periodontal infections.

Oral cutaneous fistula from a dental infection. Oral cutaneous fistula from a dental infection.

Reportedly, an occult root fracture that resulted from excessive endodontic sealer caused an infection and a chronic fistula lasting more than a year. When the root fracture was discovered and treated, the cutaneous sinus resolved within 1 month. [35]

Bisphosphonates, antiangiogenic medications, and other antiresorptive medications for the treatment of osteoporosis, steroid therapy, and neoplasms in or invading bone may reduce the blood supply, increasing the infection potential of the jaws.

Fracture of the jaw with concomitant infection can result in infection. A 37-year-old reported to the office of the author's dental practice with a large parulis of the right lower mandible. Further examination revealed a fracture of the right jaw illustrated in the image below.

Clinical view of a parulis with a sinus tract from Clinical view of a parulis with a sinus tract from a fractured mandible.
Fractured mandible panoramic radiograph. Fractured mandible panoramic radiograph.

An iatrogenic cause for an oral cutaneous fistula is an infected implant. Zygomatic implants are used to restore the edentulous atrophic maxilla as an alternative to bone grafting. One of 4 case reports resulted in a cutaneous fistula in the left zygomatic orbital area caused by aseptic necrosis at the apical part of the implant. The patient had a previous history of periodontitis and wanted immediate treatment. The infection was treated by removing the infected portion of the fistula and implant. The restoration was maintained after alleviation of the infection. Ten-year follow-up showed no more infection. [36]

Another iatrogenic cause for oral cutaneous fistulas is surgical treatment of oral cancer. A survey of 587 oral cancer patients treated with surgery at a tertiary cancer center revealed that 9% developed oral cutaneous fistulas. Surgical site infection and bilateral neck dissection procedures were identified as the greatest risk factors. [37]  Additionally, a systematic review and meta-analysis including 5400 patients who underwent reconstruction for oral cavity resection found an oral cutaneous fistula incidence of 7.71%. There was no significant difference in risk based on resection technique, but prior radiation increased the risk for oral cutaneous fistula. [38]



Cavernous sinus thrombosis

Cavernous sinus thrombosis is a serious sequela of infection, but one that is rarely life threatening. This condition can originate from an infection of the anterior maxillary teeth, which is usually confined to the anterior maxillary vestibule; however, if it hematogenously spreads above the levator anguli oris muscle, it can involve the floor of the nose; the facial, angular, or ophthalmic veins; and the cavernous sinus. If the hematogenous spread does not extend beyond the facial vein, periorbital swelling and fistula formation can occur. Infection spread because of continuity through the tissue can produce the same result.

Cavernous sinus thrombosis can also develop from an infection of the maxillary third molars that hematogenously spreads through the pterygoid plexus of veins to the angular vein, ophthalmic vein, and cavernous sinus. This process may be more subtle than that of a maxillary cuspid infection that spreads through the periorbital region because the spread of infection is not as rapid.

Periocular facial swelling is a sign of infection and thrombosis of the cutaneous sinus, which is a life-threatening condition.

Infection of the periorbital region can extend through hematogenous spread via the ophthalmic vein to the cavernous sinus. Spreading via the facial or external route is rapid because of the large open system of veins that directly leads to the cavernous sinus. Once infection reaches this sinus, the abducens nerve, which causes abduction of the eye and is closest to the sinus, is often affected. Other structures in the wall of the cavernous sinus include the internal carotid artery, trochlear nerve, oculomotor nerve, maxillary vein, and ophthalmic vein. Paralysis of the external ocular muscles, vision impairment, headache, nausea, and fever can occur. The cavernous sinus is located at the base of the brain, from where infection can spread to the meninges and brain. Brain abscesses and meningitis were invariably fatal until the advent of antibiotics, and they remain serious complications.

Ludwig angina

Ludwig angina occurs when septic cellulitis is present in the bilateral submental, submandibular, and sublingual spaces, with elevation of the tongue. The most common sources of this infection are infections in the dental apices or an impaction of the mandibular second and third molars. Ludwig angina is a life-threatening cellulitis that can close the airway. Patients with Ludwig angina often require a tracheotomy (see the image below). In addition, infection can spread to the masticator space and, in rare instances, to the lateral pterygoid space.

Cutaneous fistula due to a dental infection that c Cutaneous fistula due to a dental infection that causes Ludwig angina. Courtesy of Alexander Pazoki, DDS, LSU School of Dentistry, New Orleans, La.

Trismus with cavernous sinus thrombosis and Ludwig angina

Trismus is present with cavernous sinus thrombosis and Ludwig angina, and immediate intervention by means of incision and drainage and antibiotic therapy is imperative to prevent its spread to the mediastinum. From the lateral pterygoid space, infection can spread to the posterior pharyngeal space and mediastinum. Once the infection spreads to the mediastinum, treatment is difficult, and death may occur. If the infection spreads to the carotid space, erosion of the carotid artery may occur and create a great potential for hemorrhage.