ABSTRACT
Lesch–Nyhan Syndrome (LNS) is a rare X-linked genetic disorder involving lack of the enzyme hypoxanthine guanine phosphoribosyl transferase (HGPRT). The deficiency of HGPRT activity leads to excessive uric acid acumulation resulting in neurological, renal and musculoskeletal manifestations. It is characterized by selfinjurious behaviour which results in destruction of oral and perioral tissues. Several treatment approaches have been administered to manage the severe oral and perioral self- injury behaviour such as drug trials, extraction of teeth, orthognathic surgery and intra-oral appliance. A seven-years-old boy with LNS Syndrome was referred to the Peadiatric Dentistry Clinic at GATA. His parents requested interception of self mutilation of severe buccal mucosa injuries by the child’s own teeth. An acrylic mandibular appliance was designed and producted an occlusal plate raising the bite plane. After two weeks healing of oral lesions is observed. The patient was request to attend the clinic for follow-up every months.