Introduction: Odontogenic extraoral sinus tracts are rare conditions that can be misdiagnosed as skin lesions and lead to unnecessary treatments. They are caused by dental infections spreading through bone and draining externally. Conservative nonsurgical endodontic treatment should be pursued first. However, conventional instrumentation and irrigation techniques cannot fully decontaminate root canal systems. New disinfection techniques, including ultrasonic activation of irrigation, photodynamic therapy (PDT), and lasers, have been developed as adjunctive techniques. Photobiomodulation (PBM) (also known as low-level laser therapy) has also demonstrated beneficial effects on tissue healing. Case Presentation: This report presents a case of an extraoral sinus tract associated with a necrotic mandibular molar that was treated successfully with nonsurgical endodontic therapy using ultrasonically-activated PDT, PBM, and high-intensity laser therapy (HILT). Six- and 12-month follow-ups showed resolution of the sinus tract and healing of the apical lesion radiographically. The extraoral lesion had diminished significantly. Conclusion: Combining nonsurgical endodontic treatment with PDT with ultrasonic activation, PBM, and HILT allowed successful management of an odontogenic extraoral sinus tract without surgical intervention. Using PDT combined with ultrasonic activation enhanced disinfection while PBM and HILT improved wound healing. This report demonstrates a conservative approach to treating these lesions.