Considerable advances have been made in dental and orthodontic diagnosis resulting from the development of a device known as a limited cone beam dental compact-CT (3DX). This report documents the diagnostic procedures and treat-ment performed on an eight year old female patient who presented with clinical signs and symptoms of a temporo-
mandibular disorder (TMD). Evaluation of a bony abnormality of the temporomandibular joint (TMJ) using the limit-ed cone-beam CT (3DX) proved to be of considerable value. A three-dimensional image of the right TMJ showed ero-sion and flattening of the condyle. Following treatment, there was marked alleviation of the clinical symptoms while considerable improvement of the bony abnormalities was clearly evident on a three-dimensional image.