Oral Cutaneous Fistulas 

Updated: Mar 06, 2017
Author: James E Cade, DDS; Chief Editor: William D James, MD 



A fistula is an abnormal pathway between two anatomic spaces or a pathway that leads from an internal cavity or organ to the surface of the body. A sinus tract is an abnormal channel that originates or ends in one opening. An orofacial fistula is a pathologic communication between the cutaneous surface of the face and the oral cavity.

In the literature, the terms fistulas and sinuses are often used interchangeably. Stedman's Medical Dictionary defines a sinus as a fistula or tract leading to a suppurating cavity. Orofacial fistulas are not common, but intraoral sinus tracts due to dental infections are common. When infection or neoplasia is involved, immediate treatment is necessary. Dental infections, salivary gland lesions, neoplasms, and developmental lesions cause oral cutaneous fistulas, fistulas of the neck, and intraoral fistulas.

Chronic dental periapical infections or dentoalveolar abscesses cause the most common intraoral and extraoral fistulas. These dental periapical infections can lead to chronic osteomyelitis, cellulitis, and facial abscesses. Infection can spread to the skin if it is the path of least resistance. Fascial-plane infections, space infections, and osteomyelitis can cause cutaneous fistulas. Fascial-plane infections often begin as cellulitis and progress to fluctuant abscess formation. Compared with the other conditions, fluctuant abscess formation is more likely to result in cutaneous fistulas.

A cutaneous lesion such as a furuncle can be misdiagnosed as a sinus tract to the skin of the face. One case report[1] demonstrates this occurrence from a periapical infection from the right central mandibular incisor, which drained to the patient's chin. Because the tooth could not be restored, it was extracted, which resolved the lesion.

Another case with cutaneous manifestations involved a 44-year-old woman with a draining lesion to the skin just lateral to the nasofacial sulcus. Oral antibiotics did not help resolve the lesion. The patient had poor dentition, and a panoramic radiograph showed 2 periapical radiolucencies of the maxillary right lateral incisor and canine. The teeth were extracted, which resolved the lesion. Sheehan et al[2] recommend a dental examination and radiographs to rule out infection of dental origin to the cutaneous face or neck.

For general information on dental infections, see Dental Infections in Emergency Medicine.


Origins and spread, salivary gland fistulas, oral antral and oral nasal fistulas, iatrogenic fistulas (eg, dental implant placement), and miscellaneous orocutaneous fistulas are addressed here.

Origins and spread

Dentoalveolar abscesses originate from direct extension or continuity from an acute irreversible pulpitis that spreads beyond the apex of the tooth. Another cause of dentoalveolar abscesses is an acute exacerbation of a chronic apical periodontitis or periapical granuloma. Periapical granulomas may remain quiescent because the inflammatory cells are walled off by connective tissue. A periapical granuloma may exacerbate to an acute infection if the patient's resistance to the organism decreases or if the number of microorganisms increases. This condition is also termed a phoenix abscess.

Unusual dental malformations may lead to periapical dental infections. Dens in dente or dens evaginatus, an axial invagination of enamel and dentin into the dental papilla, frequently develops periapical infections, which can lead to sinus tract formation.[3, 4, 5] Even more rarely, taurodontism[6] consisting of elongated crowns or apically placed furcations with pulp chambers with increased occlusal-apical height can cause periapical disease, leading to a sinus tract or parulis.

Most of these dental infections remain intraoral, and they most often spread to the facial or buccal side of the alveolar ridge. If the dental roots are closer to the lingual side, as they often are with the maxillary anterior teeth and the lingual roots of the maxillary molars, a palatal sinus tract may develop. When a sinus tract appears as an intraoral papule or pustule, it is called a parulis. When a chronic infection is acutely exacerbated or persistent, the infection can spread to the facial skin, most commonly in the area of the chin. Numerous barriers, including bone, muscle, and facial planes, determine the path of infection spread.

Yasui et al[7] reported a cutaneous fistula of dental origin. A 75-year-old Japanese woman presented with the chief complaint of a left-cheek skin lesion with mild pain. A subcutaneous nodule with erythematous skin was on her left cheek. Dental examination demonstrated a radiolucent area in the left-lower first molar periapical region. The tooth was asymptomatic. Antibiotic therapy and endodontic therapy eliminated the subcutaneous nodule. The authors recommend a complete dental evaluation be performed when a subcutaneous facial nodule is encountered.

Extraoral sinus of dental origin occurs when infection of dental pulp necrosis spreads through the path of least resistance from the root apex to the skin on the face. Patients presenting with an oral cutaneous sinus often see a physician or dermatologist first, since the lesion may resemble an infected sebaceous cyst, a basal cell carcinoma, or other dermatological lesion. Unnecessary treatment can be avoided if a dental origin is considered.[8]

If the infection originates from a region of the maxillary molar, intraoral spread of the infection occurs buccally. When the infection spreads inferior to the superior attachment of the buccinator muscle, it remains in the oral cavity. If the infection path moves superior to this attachment, cutaneous spread with fistula formation is possible. Infection from the maxillary molar teeth can spread to the palate and into the maxillary sinus, depending on the position of the lingual roots of the teeth.

Maxillary dental infections also may spread to the canine fossa, buccinator space, lateral pterygoid space, and infratemporal space. Spread of infection to the lateral pterygoid and infratemporal spaces is associated with trismus. Infection of maxillary premolars almost always stays confined to the oral cavity and most commonly spreads to the buccal side of the alveolar ridge. Infection from the maxillary anterior teeth is usually contained within the oral cavity. Spread of infection superior to the levator anguli oris muscle or orbicularis oris muscle may result in cutaneous spread.

Infection from the mandibular molars is usually confined to the lingual aspect of the oral cavity by the mylohyoid muscle and to the buccal aspect by the inferior attachment of the buccinator muscle. If the infection penetrates to the lingual area inferior to the mylohyoid muscle, infections of the submandibular, sublingual, and submental spaces may result. If the infection spreads inferior to the buccinator muscle attachment, cutaneous spread may occur with fistulation.

Infection of the mandibular premolars is almost always confined by the buccinator muscle in the oral cavity and most commonly spreads to the buccal side. Infection of the mandibular anterior teeth is usually confined to the oral cavity and spreads facially. If the infection spreads below the mentalis muscle, cutaneous spread may occur. Mandibular space infections may involve the submandibular, submental, pterygomandibular, masseteric, lateral and posterior pharyngeal, parotid, and carotid spaces.

Chronic osteomyelitis more frequently drains through an extraoral sinus opening than through an intraoral opening. Osteomyelitis is more likely to develop in patients with uncontrolled diabetes, in those who have undergone jaw irradiation because of a previous malignancy (osteoradionecrosis), and in those with metabolic bone diseases such as Paget disease (osteitis deformans) or Albers-Schönberg disease (osteopetrosis).

Garré osteomyelitis is a unique chronic osteomyelitis with a prominent periosteal inflammatory reaction that follows periapical disease or tooth extraction. It is uncommon, with average age of 13 years. Elimination of pulpal periapical infection through endodontic therapy without endodontic surgery was shown to be an effective treatment. In this case report,[9] total bone healing was observed 1 year later.

Lymphatic spread is also common. Lymphadenopathy with movable tender nodes is a common finding with dental infections. Inflammatory lymph nodes caused by dental infection rarely result in cutaneous fistulas.

Salivary gland fistulas

Salivary gland fistulas are rare except with minor salivary gland mucocele. Saliva from damaged salivary glands or ducts finds the path of least resistance but rarely escapes through the skin or mucosa. The parotid duct or Stensen duct comes close to the cutaneous surface as the duct crosses the outer surface of the masseter muscle. A rare submandibular fistula was reported in association with a ranula of the submandibular gland. A case was reported with a cutaneous opening caused by an ectopic salivary gland. This instance mimicked a branchial cleft or branchial cyst fistula. Gerhard et al[10] state that ectopic salivary gland fistulas should be in the differential diagnosis of branchial fistulas.

One interesting case is of a 4-year-old boy with an anterior cervical fistula, which secreted salivalike fluid while he was eating. Head and neck examination revealed an opening posterior to the hyoid bone. The fistula ascended superficially to the anterior cervical muscles, with a cyst anterior to the hyoid bone, continuing to the left submandibular gland. According to Hayasaka et al,[11] no previous reports have described the Wharton duct running from the submandibular gland to the anterior cervical skin.

A 24-year-old man presented with intermittent clear drainage in both sides the neck. Eating did not cause an increase of salivation. Fistulas were present on both sides of the neck, anterior to the sternocleidomastoid muscles. Surgical excision of the lesion was performed on both sides, and the pathological examination revealed heterotopic salivary gland tissue. A family history of associated head and neck anomalies is occasionally seen with this condition, but not in this case presentation.[12]

Trauma, microorganisms, neoplasms, xerostomia, immunosuppression, and malnutrition usually are the cause of infections that result in fistulas from salivary glands. Iatrogenic causes include surgery and radiation therapy. Patients who are ill or debilitated may be prone to these infections. Actinomycosis, syphilis, tuberculosis, salivary calculi, and malignancy are other etiologic agents that cause salivary gland infections. Staphylococcus aureus, Streptococcus viridans, and Escherichia coli most commonly are found in these infections.

Sjögren syndrome, which has a female-to-male ratio of 10:1, is an immunologic disease that causes xerostomia. Patients with this disease have dry eyes, a dry mouth, and, in the secondary form, immunologic connective-tissue disorders, most commonly rheumatoid arthritis. Patients with Sjögren syndrome may be more prone to parotid gland infection, but this infection rarely results in sinus tract formation to the skin or oral mucosa.

Salivary gland stones or sialoliths can be a site of infection. These are most commonly associated with the Wharton duct, the major duct for the submandibular gland. Any gland can be affected. The sialolith blocks the ductal secretion of saliva, causing a fluid buildup that creates a potential site for infection. A ranula or mucous retention phenomenon of the floor of the mouth results from this blockage; when this is large, it is treated by marsupialization. This technique exteriorizes a cyst or other such enclosed cavity by resecting its anterior wall and suturing the cut edges of the remaining wall to adjacent edges of the skin, thereby creating a pouch.

Drage et al[13] presented 3 cases of a migrating salivary stone or sialolith to adjacent tissues, resulting in cutaneous fistulas from salivary gland origin. Two patients were treated successfully surgically, which resulted in resolution of the fistulas.

A mucocele or mucous retention phenomenon occurs when minor salivary gland ducts are damaged. The walling off of mucin with granulation tissue causes a cystlike structure; on the floor of the mouth, this structure is called a ranula. This lesion is usually painless, and the patient often reports that it swells and breaks with a fluid discharge. More than 50% of patients with a mucocele or mucous retention phenomenon are younger than 21 years, and it occurs equally in males and females. Patients may remember biting their lip.

Clinically, the mucocele appears as a clear or bluish fluctuant vesicle. It is most common on the lower lip and can be found in minor salivary glands of the palate and retromolar pad area. It is extremely rare on the upper lip. Physical trauma to the lower lip is the most common cause of mucoceles. Most upper lip swellings are due to cysts, odontogenic infections, and salivary gland tumors. The differential diagnoses include salivary gland neoplasms, especially mucoepidermoid carcinoma, vascular malformation, hemangiomas, and fibrous nodules or fibroma.

Mucocele or mucous retention phenomenon lower lip. Mucocele or mucous retention phenomenon lower lip.

Oral antral and oral nasal fistulas

Tooth extraction, tuberculosis, syphilis, leprosy, malignant neoplasms, phycomycoses, midline granuloma (a form of lymphoma), and developmental clefts may cause oral antral and oral nasal fistulas. The most common cause of oral antral fistulas is tooth extraction. Maxillary first molars account for 50% of oral antral fistulas caused by extractions. Maxillary second and third molar extractions account for the other 50%. Prior to extraction, infection of these teeth may create a communication with the antrum. Approximately 10% of all sinusitis cases have a dental origin.

Lopatin et al[14] concluded that an endoscopic approach to chronic maxillary sinusitis of dental origin is a dependable technique associated with less morbidity and a lower rate of complications.

When patients ingest food and liquids, these may enter the nasal cavity and antrum, causing an unpleasant salty taste and fetid breath. Infection may cause sinusitis, which results in throbbing headaches that are aggravated by head movement. Nocturnal cough and epistaxis may result from drainage of exudate to the oropharynx and nose. Swelling and redness over the sinus and pain beneath the eye, especially with palpation, may occur.

In all cases of idiopathic sinusitis, causes such as infection, polyps, and neoplasms should be excluded. Neoplasms, such as squamous cell carcinoma, may manifest as sinusitis until the neoplasm enlarges enough to show signs of malignancy. By this stage, metastasis may have occurred.

Midline upper-lip fistulas are very rare. Fewer than 30 have been cited in the literature since 1970. Recurring swelling of the upper lip was the primary symptom in this case. Surgical excision of the cyst or of the fistulous tract prevents recurrence.[15]

Medication-related osteonecrosis of the jaw (MRONJ), formally known as bisphosphonate-related osteonecrosis of the jaws (BRONJ)

An additional cause for oral cutaneous fistulas is MRONJ, formally known as BRONJ.[16] The change in nomenclature is due to the growing number of antiresorptive (eg, denosumab) and antiangiogenic therapies other than bisphosphonates.

Fortunately, only a small percentage of patients develop MRONJ.[17] Bisphosphonates and other antiresorptive medications that are intravenously administered are used to treat patients with osteoporosis, patients with cancer who have hypercalcemia associated with malignant disease, and patients with multiple myeloma or metastatic tumors (breast, lung, prostate) in the bones.

Bisphosphonates are bone resorption inhibitors, inhibiting osteoclast activity and thus decreasing vascular supply of oxygen and host defense cells. Malignancy in bone, dexamethasone therapy, and intravenous bisphosphonate therapy increase the chances of developing MRONJ.[18] Oral/dental causes increasing MRONJ include abscesses, periodontal disease, dental caries, exostoses and tori, and dental extractions.[19]

Preventive dentistry plays the most important role for prevention of MRONJ. One study showed that complete prevention of this complication is not currently possible. However, preventive dental care reduces this incidence, and nonsurgical dental procedures can prevent new cases. For those who present with painful exposed bone, effective control to a pain free state without resolution of the exposed bone is 90.1% effective using a regimen of antibiotics along with 0.12% chlorhexidine antiseptic mouth rinses.[18]

One study used platelet-derived growth factors (PDGFs). The authors treated 12 patients with refractory MRONJ and a history of long-term bisphosphonate therapy. Each patient had mucosal ulceration with exposed necrotic bone. The treatment also included bone resection. The surgical intervention they used was a marginal resection limited to the alveolar bone. Ten of the patients recovered with complete mucosal and bone healing.[17]

The treatment objectives for patients with an established diagnosis of MRONJ are to eliminate pain, control infection of the soft and hard tissue, and minimize the progression or occurrence of bone necrosis. Patients should have regular check-ups before, during, and after bisphosphonate therapy. Management includes antibiotics, pain control, and chlorhexidine mouth rinses over long periods of time.

MRONJ treatment can be surgical or nonsurgical. Nonsurgical management includes antibiotics, systemic or topical antifungals, antimicrobial rinses, ceasing bisphosphonate therapy, and stopping dental therapy. Surgical solutions for MRONJ are limited due to the patient’s decreased healing ability. Before treatment with an intravenous bisphosphonate, the patient should have a thorough oral examination, extract nonrestorable teeth, complete all invasive dental procedures, and obtain best possible periodontal health. Patients with full or partial dental prostheses should be examined for areas of mucosal trauma. Patients need to be educated as to the importance of dental hygiene and regular dental evaluations, and instructed to report any pain, swelling, or exposed bone.

Patients who take oral bisphosphonates for less than 3 years and have no clinical risk factors, no alteration or delay in dental surgery is necessary. The risk of developing MRONJ with oral bisphosphonates is very small but increases when therapy exceeds 3 years.[20] For patients who are taking oral bisphosphonates for less than 3 years with or without corticosteroids, the prescribing physician should consider discontinuing therapy for 3 months prior to oral surgery, if systemic conditions permit. The bisphosphonate should not be restarted until healing has occurred.

A misdiagnosis can occur when seeking the cause of MRONJ. A 75-year-old woman was seen in an oral medicine clinic for a persistent infection causing an oral cutaneous sinus tract. The diagnosis was that her antiresorptive agent caused the osteonecrosis. She had a history of breast cancer. Later,  a root fracture was discovered as the lesion continued. The tooth was extracted, which eliminated the cause for her infection. The article stressed that patients on antiresorptive therapy could have a dental or other source of infection that needs proper diagnosis and treatment.[21]

Miscellaneous orocutaneous fistulas

An oral cutaneous fistula leads to esthetic problems due to the continual leakage of saliva from the oral cavity to the face. Malignancy, inflammation, and trauma are the most common causes.

Traumatic fistulas may be due to injury or surgical repair in areas where mucosal and epidermal surface epithelia line the fistula wall. No inflammation is associated with this type of fistula unless an infection develops (see the image below).

Gunshot wound causing an oral cutaneous fistula. C Gunshot wound causing an oral cutaneous fistula. Courtesy of Alexander Pazoki, DDS, LSU School of Dentistry, New Orleans, La.

Dental implants can develop infections, leading to intraoral and possibly extraoral sinus tract drainage. One case report[22] described an implant failure causing a peri-implantitis. This was treated successfully without removal of the implant. In most cases, the implant must be removed when peri-implantitis occurs. This case involved an adjacent tooth with apical periodontitis that may have spread from the tooth or the peri-implantitis spread to the tooth, causing its demise. Treatment included a root canal, debriding the apical bone lesion, and using guided bone regeneration. Normal healing occurred and an esthetic result was achieved.

Failed endodontic therapy or treatment after endodontic therapy can be a source of dental infection. Tanalp et al[23] reported a persistent sinus tract occurring after a post and core was placed on an anterior tooth. Two separate root perforations were causing the persistent infection. Granulation tissue was removed, the perforations were sealed with mineral trioxide aggregate, and bone graft was packed in the resorptive bone areas. Four months after treatment, the patient had no signs or symptoms.

Ricucci et al[24] reported 2 cases in which calculus formation was reported as a cause of a persistent sinus tract after root canal therapy. In one case, a sinus tract developed that did not heal after conventional root canal therapy and apical surgery. Extraction of this tooth revealed calculuslike material on the root surface. The other case showed radiographic signs of healing after apicectomy. Histology of the apical biopsy specimen demonstrated a calculuslike material on the surface of the root apex. The presence of calculus on the root surfaces of these teeth may have contributed to endodontic treatment failure.

Neoplastic fistulas result from the penetration of a neoplasm from the oral cavity to the outlying skin. The most common malignancy in the oral cavity is squamous cell carcinoma. Fistulas caused by squamous cell carcinoma have a poor prognosis because of skin lymphatic drainage (see the images below). Also see Cancers of the Oral Mucosa.

Squamous cell carcinoma causing an oral cutaneous Squamous cell carcinoma causing an oral cutaneous fistula. Courtesy of Alexander Pazoki, DDS, LSU School of Dentistry, New Orleans, La.
Squamous cell carcinoma of the sinus that penetrat Squamous cell carcinoma of the sinus that penetrates the maxillary ridge.

Actinomycosis, although rare, is one of the most common infections that result in a fistula from the oral cavity to the skin. These infections respond to large doses of penicillin or beta-lactam/beta-lactamase inhibitors administered for a minimum of 6 weeks.

Actinomycosis has been documented as a cause of continual, recurrent, periapical disease associated with endodontically treated teeth. One case presented by Jeansonne[25] demonstrated persistent periapical disease with recurrent sinus tracts. No pain or swelling was present after clinically acceptable initial endodontic treatment, but a periapical lesion developed. After routine endodontic retreatment, the periapical lesion persisted and a sinus tract developed. The sinus tract healed with antibiotic therapy but recurred within a few months. The sinus tract recurred and disappeared with antibiotic therapy over a period of 5 years. After histological diagnosis confirmed actinomycosis, the lesion was treated with antibiotics and periapical surgery. It finally resolved in 5 months.

Fistulas may arise from developmental cysts of the neck region, such as thyroglossal duct, dermoid, sebaceous, preauricular, and branchial arch cysts. Nasopalatine duct cysts occasionally secrete fluid to the anterior palate and the site of the duct.

Intracranial extension and a cutaneous sinus tract are rarely seen with craniofacial dermoid cysts. Scolozzi et al[26] reported a case of a 1-year-old girl who was initially seen with a cutaneous fistula of the frontotemporal region, from an intracranial dermoid cyst. The patient was treated surgically with a right lateral orbitotomy by a bicoronal approach. The cyst was seated within the lateral orbital wall, with intracranial extension through the temporal and sphenoidal bones to the dura of the temporal lobe. Histopathologic analysis confirmed the diagnosis of a dermoid cyst. Craniofacial dermoid cysts may rarely be associated with a cutaneous sinus tract and/or intracranial extension. Failure to identify and treat these lesions may lead to recurrent infection with a potential for meningitis or cerebral abscess. The authors strongly recommend CT scanning and MRI before surgical treatment of any cutaneous fistula in the head and neck region.

The thyroglossal duct cyst is the most common of the developmental cysts of the neck. In embryonic development, the duct follows a path from the tongue to the normal position of the thyroid. These cysts have an equal incidence in females and males, and they usually are observed within the first 2 weeks of life. Proliferation of duct tissue may continue, causing enlargement of the thyroglossal tract. If a sinus opening to the neck occurs, the most frequent location is just below the hyoid bone. The epithelial lining may consist of squamous or pseudostratified columnar epithelium. Infection may occur anywhere along the duct tract, causing purulent exudate. Complete surgical removal of the thyroglossal duct epithelium is the treatment of choice; however, complete removal is difficult and recurrence is frequent.

The lateral branchial arch cyst is the most common developmental cyst of the lateral neck. It occurs when the second branchial arch or second pharyngeal pouch is not eliminated in normal development. The endoderm of this pouch normally becomes the tonsil. A cutaneous sinus, a mucosal sinus, or both may occur. Lateral branchial arch cysts occur equally in males and females, and they may be familial. They can be unilateral or bilateral. They may occur in children; ruptured cysts may occur in adults. Usually, the opening is near the anterior border of the sternocleidomastoid muscle just above the sternoclavicular joint. The differential diagnosis includes a fistula or sinus from an infected or cancer-containing lymph node.

Preauricular fistulas or sinuses occur in approximately 1% of the population. They are observed more commonly in blacks and Asians than in whites and occur equally in males and females. Approximately one fourth of preauricular fistulas are bilateral. They may be associated with other congenital anomalies such as Treacher-Collins syndrome. Preauricular fistulas originate from the abnormal development of the first and second branchial arches from the external ear. The most common site is the marginal helix of the ear at the junction with facial skin. Usually, preauricular fistulas are asymptomatic and require no treatment unless they become secondarily infected. They can be differentiated from first branchial arch anomalies because the first branchial arch usually opens into the external auditory canal and has a purulent discharge. Fistulas are an extremely rare variant of congenital facial malformations.

Lymph nodes infected with mycobacteria cause scrofula, a condition in which infection spreads from the node to the skin through a sinus tract.

Four cases of patients with orofacial lesions diagnosed as tuberculosis were reported. The authors presented the following four criteria to make this diagnosis[27] :

  • Suspicious lymph nodes that should undergo biopsy
  • Excision biopsy of nonhealing, fistulous, or nonresponsive lesions
  • Histopathological evidence of granulomatous inflammation with epithelioid cells and Langerhans giant cells or acid-fast bacilli with positive Ziehl-Neelsen staining
  • Detailed examination of patients' medical records, to include chest radiography findings and positive sputum smear and culture results

These patients were treated with antituberculous therapy successfully. The authors state that tuberculosis should be considered with persistent lymph nodes in the head and neck region.[27]

Cat scratch disease is another consideration in the differential diagnosis of sinus tracts from lymph nodes.

Iatrogenic causes

Pharyngocutaneous fistulae in patients undergoing total laryngectomy at a single institution were investigated. Authors reviewed 59 cases of total laryngectomies over an 11-year period. They found 20 patients (34%) developed fistulas after surgery. They found preoperative tracheostomy, postoperative hemoglobin, and surgical technique are important in determining the risk of fistula.[28]


Preauricular fistulas or sinuses occur in approximately 1% of the population.


Dental infections have no racial predilection. Preauricular fistulas or sinuses are observed more commonly in blacks and Asians than in whites.


Dental infections occur equally in males and females. Preauricular fistulas or sinuses occur equally in males and females. Mucocele or mucous retention phenomenon occurs equally in males and females.


Dental infections occur in persons of all age groups. More than 50% of patients with a mucocele or mucous retention phenomenon are younger than 21 years.


With mucoceles, removal of the fluid-filled sac and surrounding minor salivary glands results in an excellent prognosis for cure.

Most dental infections are treated with incision and drainage and antibiotics, which result in an excellent prognosis. Usually, no morbidity and mortality occur. Cellulitis can lead to Ludwig angina and cavernous sinus thrombosis.

The mortality rate of cavernous sinus thrombosis was 75% but now has decreased to 30% with newer antibiotics and steroid therapy. See Cavernous Sinus Thrombosis for more information.

The mortality rate for Ludwig angina was 50% before the use of newer antibiotics. Now, the mortality rate is less than 10%. Deaths are due to complications such as aspiration pneumonia, spread to the mediastinum, sepsis, pleural cavity infection, and respiratory obstruction.

Trismus is present with cavernous sinus thrombosis and Ludwig angina, and immediate intervention is imperative to prevent its spread to the mediastinum. Once the infection spreads, treatment is difficult, and death is more likely.

Patient Education

For patient education resources, visit theOral Health Center. Additionally, see the patient education articles Dental Abscess and Toothache.




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%).[31] 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 dermatological 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.[29]

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.[30]


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.



Diagnostic Considerations

The differential diagnoses include any dental and periodontal infection, odontogenic cysts and tumors, salivary gland lesions and neoplasms, and other benign and malignant neoplasms. The most common neoplastic cause of oral cutaneous fistulas is squamous cell carcinoma. Unless secondarily infected, oral cutaneous fistulas rarely, if ever, develop from benign neoplasms and cysts.

Because oral cutaneous fistulas are not common, misdiagnosis of those from a dental origin is not unusual. Several cases below illustrate this.

Dental infections may also mimic dermatological infections.[32] An example of this was a lesion diagnosed clinically as a sebaceous cyst. Using cone-beam CT, the lesion was discovered to be a cutaneous odontogenic sinus tract from an aberrant formed canal caused by periapical periodontitis of the right mandibular second molar. Root canal therapy was performed, which eliminated the infection.[31]

Two cases of recurrent suppurative oral cutaneous fistulas were misdiagnosed and treated with oral antibiotics without response. One of the lesions was thought to be a pyogenic granuloma and the other a cutaneous furuncle. Both patients were treated with antibiotics without success because the odontogenic or dental cause was not discovered initially. Clinical findings included palpable facial nodules with drainage and poor dentition with gingivitis. Neither patient had obvious signs or symptoms. Radiographs showed periapical lesions. Both situations presented with nonrestorable teeth and therefore were extracted.[33]

Another case of misdiagnosis is presented. A facial fistula developed 8 years following a dental extraction. It occurred in a 42-year-old female patient not known to have any chronic medical illness. She presented with a submandibular skin fistula and was treated with antibiotics and local creams for 3 months with no improvement. She was later referred to an oral and maxillofacial clinic complaining of recurrent pus discharge from her neck for the past 6 months, with no history of dental pain. Examination showed an extraoral fistula in the left submandibular region with pus discharge upon palpation. Intraoral examination showed no soft tissue abnormalities in this area with all molar teeth missing. Panoramic radiography showed a round radiolucent lesion in the left mandible with a radiopaque area consistent with a remaining root. The cone-beam CT evaluation showed a 1-cm X 1-cm round radiolucent lesion causing displacement of the inferior alveolar canal. The root was previously endodontically treated. The remaining root was removed and the surrounding infected tissue was excised completely, preserving the inferior alveolar nerve.[34]

The following case illustrates another situation that was misdiagnosed because of not considering the infection could be from odontogenic origin. This case report describes an 11-year-old patient with an abscess that was not causing any pain. The draining sinus tract in his left cheek was not originally detected. He was tested for Mycobacterium tuberculosis infection, the results of which were negative. The radiograph showed a periapical radiolucency in tooth number 19, with three roots with a large restoration, which was shown radiographically to be in the pulp chamber. The lesion was treated with root canal therapy and the lesion resolved. This tooth had three roots with four canals. Accurate diagnosis and treatment and eliminating the source of infection can reduce the incidence of complications and relieve the pain, if symptomatic, of the patient.[35]

Differential Diagnoses



Laboratory Studies

Culture and sensitivity testing and, in selected cases, DNA probe testing may be used to identify the causative organism and determine treatment.

Serious dental infections may increase the erythrocyte sedimentation rate and neutrophil count. With chronic infections, lymphocyte and monocyte counts may subsequently increase.

Imaging Studies

In chronic periapical infections, a well-circumscribed radiolucency may be observed radiographically; however, in early infections, radiographic evidence may not be observed.

On radiographs, osteomyelitis appears as an area of radiolucency, radiopacity, or mixed radiolucency with poorly defined borders. The mandible is most commonly involved. These findings are also present in osteoradionecrosis

Unless the infection is rampant and severe, imaging studies such as a CT scanning or MRI usually are not necessary. If infection persists despite therapy, CT scanning and MRI may be necessary to determine its extent and to rule out a neoplastic cause. Computer-aided rapid prototyping in a 3-dimensional format with CT scans was reported to analyze each tooth root to aid in nonsurgical root canal therapy.[36]

Panoramic radiographs, lateral jaw plain radiographs, Waters radiographs, or periapical radiographs may be necessary for diagnosis and treatment, depending on the location and extent of the infection.

Cone-beam studies may be very beneficial for the diagnosis of dental infections. This technique is excellent to find the exact origin and extent of the infection. More dental offices, and especially oral and maxillofacial surgeons' offices, use cone-beam technology for the following[37] :

  • Dental implant placement and evaluation of adequate bone with anatomical structures
  • Evaluation of the temporomandibular joints for an aid to diagnoses of temporomandibular disorders
  • Examination of teeth and facial structures for orthodontic treatment planning
  • Evaluation of extraction of mandibular third molars and the proximity of the inferior alveolar nerve
  • Evaluation of teeth and bone for signs of infections, cysts, or tumors

With oral antral and oral nasal fistulas, cloudy sinuses may be observed on panoramic or Waters radiographs. Radiographs occasionally show a break in the antral or nasal floor. If the opening to the palate is large enough, nasal speech occurs.

CT fistulography can be used to help diagnose an orodentocutaneous fistula of dental origin.[38]


The possibility of a neoplastic cause may require biopsy.

Histologic Findings

With acute infection, histologic sections show a preponderance of neutrophils and necrotic debris. Chronic infections are histologically characterized by numerous plasma cells, lymphocytes, and macrophages; often, a proliferation of blood vessels and connective tissue or granulation tissue is present.

In chronic osteomyelitis, sections of acellular bone are present, sometimes with little inflammatory infiltrate. When histologic sections are processed, decalcification of the specimen for sectioning can remove lacunar cells present in bone. This effect must be considered when histologic sections of bone are viewed.

Actinomycosis has characteristic pseudohyphae appearing as clublike projections that stretch out from a central basophilic-staining core. The absence of this finding does not rule out an actinomycotic infection.

Microscopic sections of mucoceles show minor salivary glands with chronic inflammation and a granulation wall that surrounds a pool of mucin.



Medical Care

To properly treat any infection, drainage is necessary to decrease the number of microbes and reduce the amount of substrate on which they grow. Antibiotic coverage is necessary to eliminate or reduce the number of microbes causing the infection.

With most dental infections, penicillin is the drug of choice. Penicillin and amoxicillin with or without clavulanic acid are administered empirically to treat the infection before culture and sensitivity results are available. If the patient has an allergy to penicillin, erythromycin (next antibiotic of choice), azithromycin, clarithromycin, or clindamycin can be administered.

Amoxicillin is often used because of its rapid absorption in the gastrointestinal tract. Amoxicillin with clavulanic acid (Augmentin) is effective in broad-spectrum infections with both gram-positive and gram-negative organisms.

Doxycycline is effective in the treatment of periodontal disease. The combination of amoxicillin and metronidazole is also effective in treating severe periodontitis in individuals who are HIV positive.

Intravenous medications that are useful in the treatment of serious facial and orbital infections include nafcillin; cefazolin; ceftriaxone; vancomycin; levofloxacin; and beta-lactam/beta-lactamase inhibitors, including piperacillin/tazobactam, ticarcillin/clavulanate, and ampicillin/sulbactam.

The treatment of osteomyelitis and actinomycoses infections may require the intramuscular or intravenous administration of penicillin G, followed by oral antibiotics for 6 weeks to 6 months. The removal of sequestered or necrotic bone also is indicated. Hyperbaric oxygen may be necessary in patients with severe osteomyelitis and osteoradionecrosis. Hyperbaric oxygen is used to promote vascularization, osteogenesis, and collagen synthesis.[39]

Andrews et al reported on the use of a negative-pressure vacuum-assisted closure technique for orocutaneous fistulas.[40]

The possibility of a neoplastic cause may require biopsy and further treatment. If the biopsy specimen is positive for malignancy, a complete medical workup including MRI, positron emission tomography, and/or CT scanning is needed.

Surgical Care

Dental infections: Incision and drainage is often necessary. This treatment includes extraction of the affected tooth, pulpotomy, or pulp removal and drainage. If the tooth is salvageable, endodontic therapy usually eliminates the infection. In more serious infections, an incision into the soft tissue with dissection may be necessary. Effective drainage in indurated cellulitis infections can be difficult.

Salivary gland fistulas[41, 42] : Treatment includes apposition of the severed duct ends, suturing of the proximal intact portion to the buccal mucosa, and creation of an artificial internal fistula, which drains into the oral cavity.

Mucoceles: Treatment includes removal of the fluid-filled sac and surrounding minor salivary glands. This treatment has an excellent prognosis for cure.

Intraoral and extraoral fistulas[43] : Intraoral fistulas and many extraoral fistulas do not need to be treated surgically. Many heal with antibiotic treatment.

Oral antral fistulas: Repair these fistulas as soon as possible to prevent the spread of infection and patient discomfort. Waiting until any infection is resolved before repair is best. Decongestants and intensive antibiotic therapy may be needed. Wider incision of the sinus or nasal antrostomy may be necessary to drain the infection more rapidly and promote healing. Removal and curettage of the fistula also aids healing and clearing of infection. If a cleft or fistula from the oral cavity to the sinus is too large for surgical closure, prosthetic devices such as dentures and obturators can be used to prevent nasal speech and aspiration of liquids and food.

Cutaneous fistulas: Scarring may occur. Plastic or oral and maxillofacial surgery can be performed to address scarring.


Always consult an ophthalmologist when patients have orbital involvement. Plastic or oral and maxillofacial surgeons can address scarring.


The early detection of dental problems and preventative dentistry are the best deterrents of oral cutaneous fistula formation. Because poor oral hygiene and trauma cause most dental infections, good hygiene and the prevention of trauma may prevent oral cutaneous fistula formation.

With oral antral fistulas, if a cleft or fistula from the oral cavity to the sinus is too large for surgical closure, prosthetic devices such as dentures and obturators can be used to prevent nasal speech and the aspiration of liquids and food.

Long-Term Monitoring

With any cutaneous fistula or sinus tract, careful follow-up is mandatory. The potential for infection with swelling and pain is always present. Fistulas provide natural pockets in which infection can start.

The patient may require supportive care. Fistulas are unsightly and cause patient distress. Severe persistent infections, especially actinomycosis and osteomyelitis, can be distressing and frustrating for the patient.



Medication Summary

The goals of pharmacotherapy are to eradicate infection, reduce morbidity, and prevent complications.


Class Summary

Therapy must be comprehensive and cover all likely pathogens in the context of this clinical setting.

Penicillin VK (Truxcillin, Veetids)

Penicillin inhibits the biosynthesis of cell wall mucopeptide. It is bactericidal against sensitive organisms when adequate concentrations are reached and is most effective during the stage of active multiplication. Inadequate concentrations may produce only bacteriostatic effects. Penicillin is the drug of choice in treating common orofacial infections caused by aerobic gram-positive cocci and anaerobes. Orofacial infections include cellulitis, periapical abscess, periodontal abscess, acute suppurative pulpitis, oronasal fistula, pericoronitis, osteitis, osteomyelitis, and postsurgical and posttraumatic infections. It is no longer recommended for dental procedure prophylaxis.

Amoxicillin (Amoxil, Larotid, Polymox, Trimox)

Amoxicillin is an analog of ampicillin with broad-spectrum bactericidal activity against gram-positive and gram-negative microorganisms. It interferes with cell wall mucopeptide synthesis during active multiplication, resulting in bactericidal activity against susceptible bacteria.

Amoxicillin and clavulanate (Augmentin)

This drug combination is used to treat bacteria resistant to beta-lactam antibiotics.

In children older than 3 months, base the dosing protocol on amoxicillin content. Owing to different amoxicillin/clavulanic acid ratios in the 250-mg tablet (250/125) versus the 250-mg chewable tablet (250/62.5), do not use the 250-mg tablet until the child weighs more than 40 kg.

Erythromycin (E.E.S., E-Mycin)

Erythromycin inhibits bacterial growth, possibly by blocking the dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest. It is used for the treatment of staphylococcal and streptococcal infections.

In children, age, weight, and severity of infection determine proper dosage. When twice-daily dosing is desired, half the total daily dose may be administered every 12 hours. For more severe infections, double the dose.

Clindamycin (Cleocin)

Clindamycin inhibits bacterial growth, possibly by blocking the dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest. It is a semisynthetic antibiotic produced by 7(S)-chloro-substitution of the 7(R)-hydroxyl group of the parent compound lincomycin.

Metronidazole (Flagyl)

Metronidazole is an oral synthetic antiprotozoal and antibacterial agent, 1-(beta-hydroxyethyl)-2-methyl-5-nitroimidazole. It is active in vitro against most obligate anaerobes but does not appear to possess clinically relevant activity against facultative anaerobes or obligate aerobes.