Clinical photography of a single, small nodular lesion in the submental/chin region, illustrating the cutaneous terminus of an odontogenic sinus tract. Modality: Clinical photography; technique: high-resolution frontal close-up, color-calibrated lighting, macro field to document surface contour, color, and surrounding skin. Not applicable staining or contrast. Magnification: close-up macro. Acquisition parameters: standard clinical imaging, consistent white balance. Anatomical location: on the chin, within the submental region, along the lower facial dermis; skin and subcutaneous tissue are involved; midline/central projection. Visual features: a solitary, dome-shaped, erythematous-to-flesh-colored papule approximately a few millimeters in diameter; smooth surface with possible faint crust; no obvious surrounding edema visible in this image; the lesion represents the cutaneous manifestation of a concealed dental infection, at the end of a sinus tract beneath the skin, with potential drainage. Clinical significance: indicates chronic odontogenic infection with cutaneous fistulization; supports diagnosis of odontogenic sinus tract/periapical granuloma. Differential diagnoses include sebaceous cyst, pyogenic granuloma, foreign-body granuloma, basal cell carcinoma, and other skin nodules. Correlate with dental history and radiographs (periapical/CBCT) to locate the tooth and plan root canal therapy or extraction; treat source to resolve tract. Educational use: dermatology and dentistry case illustrating cross-disciplinary diagnostics and fistula tracking.

This diagnostic image is a high-frequency (18 MHz) grayscale ultrasonography of the chin and submental region. The scan demonstrates a distinct, wide hypoechoic band (indicated by a double-headed arrow) that represents an inflamed, tortuous sinus tract. This tract originates from the deeper structures and traverses vertically through the subcutaneous tissue layers toward the skin surface. The tract terminates near the mandibular bone, marked with an asterisk, showing a direct anatomical connection between the deep osseous tissue and the superficial soft tissue. The surrounding soft tissues show heterogenous echogenicity, consistent with inflammatory changes. This visual evidence is a key diagnostic feature for an odontogenic cutaneous fistula (OCF), illustrating the pathway of chronic infection from a dental origin through the mandible to a cutaneous exit point. The image is used in medical education to teach the sonographic appearance of fistulous tracts and the importance of identifying deep dental sources in persistent cutaneous nodules of the head and neck.

A clinical photograph capturing the inferior view of a patient's submental and chin region. The image demonstrates a non-healing, extraoral draining sinus tract located centrally in the submental area. The lesion is characterized by a small, irregular cutaneous opening with evidence of active seropurulent or yellowish discharge. The immediately surrounding skin exhibits localized erythema, swelling, and hyperpigmentation, consistent with chronic inflammation. This clinical presentation is typical of an odontogenic cutaneous sinus tract, which often results from chronic periapical infections such as dental cysts or abscesses that have tracked through the mandibular bone to the skin surface. The image is a significant diagnostic example in both oral surgery and dermatology for identifying extraoral manifestations of dental pathology, such as odontogenic keratocysts or infected periapical cysts.

Imaging modality: Clinical photograph. This frontal view of the lower face documents a cutaneous lesion at the end of a dental sinus tract, i.e., an odontogenic cutaneous fistula terminating on the chin/perioral skin. The lesion is a small erythematous papule/nodule with a raised, smooth surface and subtle surrounding erythema. Minimal crust; no evident purulent drainage. Anatomically, it overlies the chin/lower face near the mandible with midline alignment; no atrophy or ulceration is evident. The photograph captures surface morphology without radiographic or histologic data, but the suggested diagnosis is a granulomatous response to a chronic dental infection, where a sinus tract drains via the skin. Clinically this finding indicates an odontogenic source rather than a primary dermatologic process. Pathologically, cutaneous granulomas associated with dental infection reflect granulomatous inflammation along the fistulous tract and may be accompanied by periapical inflammation of pulpal origin. Diagnostic significance lies in directing dental evaluation, radiographic imaging (panoramic/periapical), and source control through root canal therapy or extraction. Differential considerations include odontogenic cutaneous fistula, foreign body granuloma, and chronic dermatitis; clinical correlation with dental status is essential. Management typically requires multidisciplinary care integrating dentistry and dermatology to eradicate infection and close the sinus.