Patient and observation:
A healthy 20-years- old male patient was referred by a general
practitioner to the department of dentistry at the university hospital
Sahloul for cutaneous productive sinus tract mimicking acne.
The patient reported a 4-years-history of a drained and recurrent
abscess in his right cheek that has previously been treated with
different therapeutic procedure such as topical antibiotics and steroids
(Bactrim, dermocort) prescribed by his dermatologist, however, no
response was noted.
Besides, the patient did not report any history of dental pain or
infection.
The extra-oral examination showed the persistence of a cutaneous fistula
with a crusted appearance located on the lower part of right cheek
measuring about 5 mm in diameter
(Figure1.a). Gentle pressure on
the surrounding tissue elicited a purulent discharge on the surface
(Figure1.b).
Palpation showed the presence of a cord‑like tissue that linked to
fistula to the mandibular vestibular bone.
The endobuccal examination revealed a poor oral hygiene as well as a
decayed mandibular first molar (tooth 46) (Figure 2).
Pulp testing, percussion, and
periodontal probing were carried out for the tooth, and revealed normal
responses. No sign of mobility was present. Neighboring and
contralateral teeth were also tested and were all within normal.
Panoramic radiograph revealed a large radiolucency of 2 cm diameter with
a well-defined cortical border in relation with the roots of
the tooth 46 (Figure 3)
Computed tomography (CT) scan was
indicated and the axial slices confirmed the periapical cystic lesion
associated to the roots of 46. It also
revealed a local perforation on
the buccal alveolar table in front of the corresponding
tooth (Figure 4).
The diagnosis of infected radicular cyst associated to a cutaneous sinus
tract was made.
Extraction of the tooth 46 and
cyst enucleation under local anesthesia was indicated. Thus, a
mucoperiosteal flap was elected and revealed a cord-like tract attached
to the vestibular bone in the periapical region. The tooth 46 was
extracted followed by the excision of the radicular cyst (Figure 5.a). A
meticulous curettage of the alveolar site (Figure 5.b) followed by the
dissection and the excision of the cord like tract. The part of the
tract attached to the bone was released (Figure 5.c). Immediately after
the excision of the whole sinus tract (Figure 5.d), the skin was
undermined to relax the affected area and restore normal facial
contour. Sutures were placed
(Figures 5.e), and the patient was prescribed antibiotic therapy
(amoxicillin – clavulanic acid) as well as antiseptic mouth wash and
pain killers for 1 week.
Histopathological examination of the lesion confirmed the diagnosis of
odontogenic radicular cyst.
Follow up was marked by the progressive healing to the cutaneous tract.
At 1 month follow up the lesion almost totally disappeared. (figure 6.a;
Figure 6.b)
DISCUSSION
Cutaneous fistula of dental origin are uncommon lesions, but have been
well documented in the literature. However, misdiagnosis and
inappropriate treatment often arise (1).
Due to their location on the head and neck region, odontogenic cutaneous
fistulas are the interest of several medical specialties (6). These
tracts often have a clinical appearance similar to other skin lesions
(7). The dermatologists and general practioners are often consulted
first (6). In this context, our patient consulted three general
practioners and two dermatologists, during four years, and was always
prescribed different topical treatments including antibiotics and
steroids but no remission was observed.
Besides, in most cases, cutaneous sinus tracts of dental origin may not
have any apparent dental symptoms and may progress over a long period of
time without alarming the patient (7).
The odontogenic cutaneous sinus tract on the oro-cervicofacial region
often develops as a result of chronic apical lesion caused by pulp
degeneration or necrosis. The apical infection may spread through the
narrow space, then perforate the cortical alveolar bone. In soft tissue,
the infection may spread through the path of least resistance between
facial spaces and finally perforate a mucosal or cutaneous surface (7).
In this fact, when diagnosing and treating sinus tracts of unknown
etiology in the facial and cervical area, dermatologist or plastic
surgeon should always refer patients to the dentists to eliminate a
possible dental infection (7).
Such diagnostic and therapeutic misadventures highlight the importance
of collaboration between medical and dental practitioners in the
management of patients with head‑and‑neck lesions (8).
Early diagnosis and appropriate treatment are essential. A proper
diagnosis should include medical history of the patient, inspection and
palpation of the cutaneous lesion.
Clinically, a cutaneous dental fistula has nonspecific skin
manifestations and may resemble a pimple, ulcer, nodule, draining lesion
or indurated cystic area with purulent discharge (9) which in the most
cases are found on the chin and the cheek area but rarely in the nasal
region (10).
Samir et al described a classic cutaneous fistula with dental origin as
an erythematous nodule of diameter up to 20 mm with or without drainage
presenting skin retraction after healing. (11)
In this case, patient consulted for a suppurative cutaneous sinus tract
with depression aspect in the right cheek with local alopecia of the
whole area.
Besides, intra oral examination may reveal one or several decayed teeth,
a healthy-looking tooth with an intact crown but an endodontic
infection, or injured tooth (7). With this regards, Chan et al reported
an odontogenic cutaneous sinus tract caused by vertical root fracture
(12). Calıskan et al. also reported a case of cutaneous sinus tract
caused by a fractured crown (13).
Pulp vitality test, percussion, and periodontal probing should be
performed on the suspect tooth and adjacent teeth (7).
Radiographic examinations, conventional or advanced imaging, should be
indicated to identify a radiolucency at the peri apical region of the
suspected teeth (8).
The indication of advanced 3D imaging is necessary, and patients should
be evaluated using panoramic radiograph and cone-beam computed
tomography (CBCT) to evaluate the extend of the lesion and eventually
confirm the causal tooth (14,15).
In the present case, the tooth 46 was severely decayed with an infra
gingival and juxta-osseous dental tissue destruction, but surprisingly
the patient didn’t report any episodes of pain or discomfort.
CBCT showed the existence of local perforation of the vestibular
alveolar bone as well as a local bone sclerosis, which was not revealed
by the conventional 2D radiography and which confirmed the chronic
progressive evolution of the lesion.
In some cases, the insertion of a probe or an endodontics gutta-percha
along the sinus tract is helpful for the ascertainment of the causal
tooth. (10)
But this is not usually possible with cutaneous sinus tracts- like in
this reported case- due to the distance between the fistula orifice and
the alveolar bone as well as the presence of multiple plans: mucosal,
muscular, and Cutaneous. (16)
The differential diagnosis includes traumatic lesions, fungal and
bacterial infections, pyogenic and foreign body granulomas, basal cell
carcinomas, local skin infections such as carbuncle and infected
epidermoid cysts, chronic tuberculosis lesion, osteomyelitis,
actinomycosis, and gumma of
tertiary syphilis. Rare entities to be included in the differential
diagnosis are developmental defects of thyroglossal duct origin or
branchial cleft, salivary gland and duct fistula, dacryocystitis, and
suppurative lymphadenitis. (10,17,18)
The treatment of odontogenic cutaneous sinus tracts requires the
elimination of the infection origin. Systemic antibiotic therapy was
reported to result in a temporary reduction of the drainage and an
apparent healing.
However, the extraction, when indicated, or the conventional root canal
treatment -when possible- are the treatment of choice. (19)
Antibiotics may be recommended as an adjunct to treatment in the setting
of diabetes, immunosuppression, or systemic signs of infection such as
fever, in fact systemic antibiotic administration is not indicated in
patients with a cutaneous odontogenic sinus tract who have a competent
immune system. (20)
After the eradication of the original source of infection, the sinus
tract regularly disappears within 7 to 14 days after root canal
treatment. (21)
In this case, the closure of sinus tract and the healing were seen 1
month later.
Root-canal therapy is the treatment of choice if the tooth is
restorable. Once the tooth is treated, the need for surgical excision is
controversial. Some reports have indicated a complete excision of the
sinus tract lining, while others have
suggested that surgical treatment and antibiotic therapy are not
necessary after dental treatment (19,22).
Root canal irrigation is a critical step on the success of root canal
therapy because of the bactericidal action and elimination of necrotic
tissue by the sodium hypochlorite. This step is usually followed by an
intracanal medication with Calcium hydroxide for its antimicrobial
effects due to its high alkalinity; it has a destructive effect on cell
membranes and protein structures, and stimulation of osseous repair.
(23)
Clinical and radiological follow up should be regularly performed to
detect the absence of healing and the persistence of peri apical lesion.
In this report, the extraction was indicated since that the tooth 46 was
non-restorable, thus the extraction was associated to the enucleation of
the radicular cyst as well as the simultaneous surgical excision of the
sinus.
The antibiotic indication, in this case, is due to the heaviness of
surgery following cyst enucleation.
In some cases, plastic surgery may be needed at a later step if healing
results in cutaneous retraction (16). Failure of a cutaneous sinus tract
to heal after adequate root canal therapy or extraction requires further
evaluation, microbiological sampling and biopsy (24).