External dental fistula often presents with facial sinus, and patients visit dermatology clinics.  Usually, diagnosis is not difficult by orthopantomography. We present a case of external dental fistula which was not detected by orthopantomography, but examination by cone-beam computed tomography (CT) revealed a small sequestrum.

CASE REPORT

A 62-year-old woman was referred to our hospital, complaining of a nodular lesion on her right cheek, with 2 months’ duration.  Previously, she visited otolaryngology department, and needle biopsy showed no malignancy.  Administration of antibiotics resulted in no effects.  On the initial visit to our department, a physical examination showed a reddish dimpled nodule located on the right cheek (Figure 1). Clinical diagnosis was external dental fistula, however, examination by pantomography did not detect any abnormalities.  Histological examination showed non-specific granulation with dense infiltration of inflammatory cells composed of lymphocytes, neutrophils, histiocytes and plasma cells in the whole dermis (Figure 2). Tissue cultures for bacteria, mycobacterium tuberculosis and non-tuberculous mycobacterium were all sterile. Also, polymerase chain reaction (RCR) analysis for mycobacterium tuberculosis and non-tuberculous mycobacterium were negative.  Laboratory examination showed no abnormalities including liver and kidney function, and tuberculin test revealed negative reaction.  Cone-beam computed tomography revealed the presence of a small sequestrum (Figure 3).  Surgical treatment with sequestrectomy resulted in improvement with scar within 3 months.

DISCUSSION

REFERENCES

1. Wilson SW, Ward DJ, Burns A (2001) Dental infections masquerading as skin lesions. Br J Plast Surg 54: 358-360. PMID: 11355994

2. Patel S, Kanagasingam S, Mannocci F (2010) Cone beam computed tomography (CBCT) in endodontics. Dent Update 37: 373-379. PMID: 20929151