Incidental finding: Ossification of the anterior longitudinal ligament of the spine depicted on a panoramic radiograph – A case report with narrative review of the literature

A 55-year-old male had a panoramic radiograph taken at the University of Western Australia Dental Radiographic assessment depicted periapical lesions, caries, fractured teeth, horizontal periodontal bone loss, and a distinct ossification anterior to the cervical spine stretching from C2 to C4: (partial) Ossification of the anterior longitudinal ligament (OALL). Differential diagnosis: Osteophytes and segmental OALL. Relevant patient’s history: Motor vehicle accident with facial and dentoalveolar trauma. Subsequently, a narrative literature review was conducted to verify the prevalence and etiology of OALL. A PubMed ® search was conducted for ossified anterior longitudinal ligament, Forestier disease, and diffuse idiopathic skeletal hyperostosis (DISH). Radiology handbooks were also consulted. It was found that this ossification, first identified as senile ankylosing hyperostosis (Forestier disease), was renamed later: DISH. Its prevalence varies between 2.9 and 25%. The spinal form of DISH is characterized by OALL with involvement of the cervical spine in 76% of patients (typical C4-C5 level). Cervical spine OALL can be associated with dysphagia, obstructive sleep apnea, and pain. Segmental OALL and anterior vertebral osteophytes can be confused with DISH. Its etiology is unknown, but associations have been suggested with advanced age, obesity, and type 2 diabetes mellitus. This case emphasizes the importance to include the assessment of the cervical spine, if visible, on dental and maxillofacial radiographs, as it may prompt more targeted questions toward patients, referral to medical specialists and help diagnose conditions that have been unnoticed or misdiagnosed. of the anterior longitudinal ligament of the depicted