Cone-beam Computed Tomography as a Noninvasive Assistance Tool for Oral Cutaneous Sinus Tract Diagnosis: A Case Series
An oral cutaneous sinus tract is a relatively uncommon condition that is generally associated with long-standing periapical inflammation. The traditional process of oral cutaneous sinus tract diagnosis is an invasive method based on the insertion of a lacrimal probe or wire. The present article describes the use of cone-beam computed tomographic imaging as a noninvasive assistant tool for the verification of the odontogenic origin.Significance
Cone-beam computed tomographic imaging is a noninvasive assistant tool for verification of the odontogenic origin of oral cutaneous sinus tract.
A chronic apical abscess can be caused by root canal infection, resulting in an abscess draining from an enclosed area of inflammation, through oral communication, to the gingival or cutaneous surface1. This condition is known as an odontogenic sinus tract (ST)2. Drainage of the infected material (pus) through an intraoral opening in the gingival area (in the alveolar mucosa, free gingiva or periodontal ligament)3 is most common. Infrequently, drainage through the skin occurs, and an oral cutaneous sinus tract (OCST) opening appears4.
OCSTs, rather than intraoral STs, are likely to occur if the apices of the teeth are superior to the maxillary muscle attachments or inferior to the mandibular muscle attachments5.
Although OCSTs have been previously documented, they continue to represent a diagnostic challenge6. OCSTs are often misdiagnosed as lesions of nonodontogenic origin because the differential diagnosis of an OCST orifice may include a wide range of pathologies5, 7. An incorrect diagnosis leads to multiple inappropriate treatments that may result in temporary amelioration of symptoms5, 6, 7. After some time, recurrence of the OCST will occur, which might eventually lead the patient to seek dental therapy7. The principle of managing such lesions is to remove the source of dental infection6 because recurrence is likely unless the dental focal infection is treated4.
Unlike intraoral STs, OCSTs may heal with granulation tissue, and a residual scar may therefore occasionally persist8.
The traditional diagnostic approach for the origin of oral cutaneous lesions is an invasive method based on the insertion of a lacrimal probe or wire4, 6. This diagnostic procedure has several disadvantages, including possible damage to the tissues of odontogenic or nonodontogenic lesions, the discomfort of the patient, and stress of the operator9. Those disadvantages lead to the search for other noninvasive assistant diagnostic tools for OCSTs.
The use of cone-beam computed tomographic (CBCT) imaging is prevalent in the field of endodontics10. This technique allows visualization of the dentition, maxillofacial skeleton, and surrounding anatomic structures in 3 dimensions11.
The purpose of this case series was to present cases of OCST in which CBCT imaging is used as an assistant tool in the diagnostic process.
A 20-year-old woman with general good health was referred to the Department of Endodontics, Oral Maxillo-Facial Surgery at Tel Hashomer Medical Center, Israel Defense Forces Medical Corps, Tel Hashomer, Israel. The reason for this referral was nonpainful cutaneous ulceration that had existed for 8 months (Fig. 1A). During this period, the patient was examined by 2 dermatologists who recommended local treatment without resolution of the ulcer.
Two months before visiting our department, class II amalgam restoration was performed in the left mandibular first molar (tooth #19) because of secondary carries under a previous restoration.
Extraoral examination revealed an oral cutaneous ulcer opposite the left mandible in close proximity to the left molar area. Intraoral examination revealed extensive class II amalgam restoration with a composite component in tooth #19. The tooth did not respond to cold testing and was sensitive to palpation and percussion. The soft tissue was normal, without swelling or sinus tract; periodontal probing up to a 3-mm depth was performed, and physiological mobility was measured.
A diagnostic periapical radiograph of tooth #19 (Fig. 1B) revealed a high pulp horn in the mesial portion of the pulp chamber and an extensive radiolucent area surrounding the mesial and distal roots. The patient was referred for small field of view CBCT imaging (Carestream 9300; Carestream Health, Rochester, NY) in our department (Fig. 2A–C). CBCT imaging revealed a radiolucent area around the mesial and distal roots that advanced toward the buccal side and penetrated the cortical bone, supporting an odontogenic origin of the cutaneous ulceration (ie, an OCST).