SPECT bone scintigraphy in the diagnosis and management of mandibular condylar hyperplasia

Isotope bone scans have been used for a number of years to assess growth ac tivity in the mandibular condyle in patients who present with facial asymme try. The aim is to distinguish normal bone growth within the condyle from i ncreased activity that may be the cause of the asymmetry. Previous studies have, however, relied only on planar images. SPECT (single photon emission computed tomography) has been used with quantitative assessments of one man dibular condyle to clivus or lumbar spine, but we have compared one condyle with the other, which is more sensitive and accurate in detecting abnormal activity. A relative percentage uptake of 55% or more in the affected mand ibular condyle is considered to be abnormal, and this has been validated by comparison with an age-matched control group. We have used SPECT as an aid to diagnosis and treatment in 18 patients with asymmetrical growth and hav e constructed a therapeutic algorithm to aid the treatment of these patient s.