title: Odontogenic cutaneous sinus tract associated with a mandibular second molar having a rare distolingual root: a case report.
abstract: BACKGROUND
  Odontogenic cutaneous sinus tracts are often misdiagnosed as lesions of non-odontogenic origin, leading to the treatment of patients with unnecessary and ineffective therapies. Sinus tracts of endodontic origin usually respond well to endodontic therapy. However, root canal treatment of mandibular molars with aberrant canal anatomy can be diagnostically and technically challenging. Herein we present a patient with a cutaneous odontogenic sinus tract in the right submandibular area.
  
  
  METHODS
  A 23-year-old Chinese female patient presented with a cutaneous odontogenic sinus tract that was initially misdiagnosed as a sebaceous cyst. The patient had undergone surgical excision and traditional Chinese medical therapy before endodontic consultation. With the aid of cone beam computed tomography (CBCT), it was confirmed that the causative factor of the cutaneous odontogenic sinus tract was chronic periapical periodontitis of the right mandibular second molar, which had a rare and curved distolingual root. The resolution of the sinus tract and apical healing was accomplished following nonsurgical root canal treatment.
  
  
  CONCLUSIONS
  A dental aetiology must be included in the differential diagnosis of cutaneous sinus tracts in the neck and face. Elimination of odontogenic cutaneous sinus tract infection by endodontic therapy results in resolution of the sinus tract without surgical excision or systemic antibiotic therapy. This case report also indicates that CBCT imaging is useful for identifying the tooth involved, ascertaining the extent of surrounding bone destruction and accurately managing the aberrant canal morphology.
authors.affiliation: Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Affiliated Stomatological Hospital, Guangdong Province Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China. tianjun080511@126.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Tian
authors.affiliation: Department of Prosthodontics, Guanghua School of Stomatology, Affiliated Stomatological Hospital, Guangdong Province Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China. lguobin08979701@163.com.
authors.forename: Guobin
authors.initials: G
authors.lastname: Liang
authors.affiliation: Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Affiliated Stomatological Hospital, Guangdong Province Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China. qiwting@163.com.
authors.forename: Wenting
authors.initials: W
authors.lastname: Qi
authors.affiliation: Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Affiliated Stomatological Hospital, Guangdong Province Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China. dentistjohnwein@gmail.com.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Jiang
mesh_terms: D054893:Cone-Beam Computed Tomography / Q000379:methods; D017577:Cutaneous Fistula / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D003751:Dental Fistula / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008334:Mandible / Q000601:surgery; D008963:Molar / Q000503:physiopathology / Q000601:surgery*; D011671:Pulpitis / Q000000981:diagnostic imaging / Q000601:surgery*; D035583:Rare Diseases; D018570:Risk Assessment; D012390:Root Canal Therapy / Q000379:methods*; D014092:Tooth Root / Q000000981:diagnostic imaging / Q000601:surgery; D016896:Treatment Outcome; D055815:Young Adult