Occlusion and temporomandibular The issue of temporomandibular disorders (TMD) diagnosis and treatment has become a matter of increasing interest in the medical legal field in recent years. The old-fashioned theories based on the occlusal paradigm was proven to be erroneous, and clinicians who still provide irreversible treatments to TMD patients have to be conscious of the potential legal consequences of their behavior. The present paper described an illustrative case report of a patient to whom extensive and irreversible occlusal therapies were performed with the unique aim to provide relief from TMD symptoms. The treatment was unsuccessful and the dental practitioner was called into cause for a professional liability claim. The clinician was judged guilty of malpractice on the basis of the lack of scientific evidence of the irreversible occlusal approaches to TMD, which were erroneously used and did not give the patient any benefit, thus forcing him to a non necessary financial and biological cost. The failure to satisfy the contract with the patient, which is usually not covered by any insurance company, forced the practitioner to give the money back to the patient. The ethical and legal implications of such case were discussed, with particular focus on the concept that medical legal advices need to satisfy the highest standards of evidence and have to be strictly based on scientific knowledge.