The use of SPECT to evaluate growth cessation of the mandible in unilateral condylar hyperplasia

Abstract

In unilateral condylar hyperplasia, for surgical intervention to be effective, the status of condylar bone growth has to be assessed correctly. Previously this assessment relied on serial clinical observations. This study aimed to evaluate the MDP-SPECT method of assessing condylar growth in unilateral condylar hyperplasia. Twenty-six MDP-SPECT of the mandible had been performed; 21 were diagnosed as condylar hyperplasia and five as non-mandibular disease. Three isotope parameters: isotope counts, pixel counts and counts per pixel were summed for each condyle per subject. The percentage difference in isotope uptake of the three parameters between the two condyles was calculated as the ratio of the combined counts of the two sides. These differences significantly correlated with each other (Pearson r=0.78-0.98) and with the clinical status of bone growth (Spearman rho=0.72-0.86). There was a significant difference for the count per pixel between the 'growing' condyle (transaxial, T: 15.05+/-7.14, coronal, C: 12.29+/-7.88), the 'no further growth' condyle (T: 5.22+/-4.08, C: 5.67+/-3.88) and the 'normal' condyle (T: 0.82+/-0.76, C: 1.34+/-0.66). This method was able to separate 'active growth' from 'growth cessation' of the condyle by a single MDP-SPECT of the mandible. However, further studies are needed to confirm this finding.

Bone scintigraphy as a diagnostic method in unilateral hyperactivity of the mandibular condyles: a review and meta-analysis of the literature

“…The planar bone scanning technique was used in 8 studies 1,3,7-9,11,25,26 , SPECT scanning in 1 study 22 and a combination in 4 studies 2,12,21,29 . In 2 studies 18,30 , the scanning technique used was not specified.…”

“…Seven studies 1,9,11,12,22,25,29 presented results in enough detail (i.e. number of patients with presence/absence of UCH and number of abnormal and normal bone scan results) to calculate the index test characteristics (i.e.…”

Condylar Hyperplasia and Facial Asymmetry: Report of Five Cases

“…Previous studies have, however, relied only on planar images [15,16]. SPECT (Single Photon Emission Computed Tomography) [17,18] has been used with quantitative assessments of one mandibular condyle to clivus or lumbar spine, but when one condyle is compared with the other, it is more sensitive and accurate in detecting abnormal activity. A relative percentage uptake of 55% or more in the affected condyle is considered to be abnormal, and this has been validated by comparison with an age-matched control group.…”

Unilateral condylar hyperplasia recurrence after orthognathic surgery: a case report

“…This procedure is widely used in the evaluation of patient with suspected UCH. Literature based on control studies indicate that normal individuals or patients without progressive facial asymmetry show a difference in radiotracer uptake values between the left and right condylar regions less than 10%, whereas a difference greater than 10% is strongly suggestive of active UCH [12]. Nevertheless, a systematic review of the literature by Saridin et al reported a large variability between studies from different centers performing SPECT scan [5].…”