This case report describes a 3 year old spider monkey who had persistent facial deformity. Multiple dietary and environmental adjustments were made but facial swelling persisted. CT revealed complete loss of maxillary bone. Parathyroid hormone was elevated despite low normal calcium and low vitamin D. Biopsy of the affected area revealed fibrous osteodystrophy. The patient was supplemented with dietary calcium and vitamin D along with correction of UV-B light. (Note: This is currently ongoing and subsequent results will be available by the time of the conference.)