Research Paper
TMJ Disorders
The use of SPECT/CT to assess resorptive activity in mandibular condyles

https://doi.org/10.1016/j.ijom.2021.11.012Get rights and content

Abstract

The aim of this study was to clarify the clinical significance of bone metabolism in the mandibular condyles in determining condylar resorptive changes. Twelve condyles of patients with idiopathic condylar resorption and degenerative joint disease were analysed using 99mTc HMDP SPECT/CT at baseline and subsequent computed tomography during the follow-up period. Twenty-two healthy condyles were enrolled as controls. After generating three-dimensional SPECT/CT images, two independent observers scored the degree of condylar uptake and measured the morphological changes in the condylar height and condylar volume. In the group with positive condylar uptake, the follow-up computed tomography showed significant decreases in condylar height (−1.69 ± 0.93 mm) and condylar volume (−12.51 ± 10.30%) when compared to healthy controls (condylar height, 0.09 ± 0.54 mm; condylar volume, −0.29 ± 4.22%) (P < 0.001). Moreover, the degree of uptake correlated with the changes in condylar height (observer 1, P = 0.012; observer 2, P = 0.039) and condylar volume (observer 1, P = 0.005; observer 2, P = 0.037). These results suggest that condylar bone metabolism is closely related to the resorptive activity. Thus, SPECT/CT would be useful in the prognostic evaluation or determination of treatment strategies for idiopathic condylar resorption and degenerative joint disease.

Section snippets

Study design and sample

This study was performed in accordance with the ethics protocols approved by the Ethics Committee of Keio University (approval number 20190319). Patients with CR due to either ICR or DJD, based on the diagnostic criteria reported by Peck et al.8 (“Expanding the taxonomy of the diagnostic criteria for temporomandibular disorders”), diagnosed between 2013 and 2019, were included in this study. Patients with CR due to inflammatory joint diseases including rheumatoid arthritis and infectious

Clinical data

The CR group comprised eight condyles from four patients with bilateral ICR, two condyles from two patients with unilateral ICR, and two condyles from one patient with bilateral DJD (12 condyles in seven patients). All of the CR group patients were female. The mean observational period (from T0 to T1) in the CR group was 14.1 months (Table 1).

Analysis of bone metabolism in the mandibular condyles

The weighted kappa statistic showed excellent inter-observer agreement between the two observers (κ = 0.954). Ten condyles were considered positive (score

Discussion

This study is novel in describing the behaviour of bone metabolism corresponding to resorptive changes in detail. The relationship between bone metabolism and the subsequent morphological changes in the mandibular condyles was investigated. It was found that positive 99mTc HMDP uptake in the condyle was associated with a decrease in condylar height and condylar volume. In contrast, negative 99mTc HMDP uptake reflected morphological stability of the condyles. In addition, the degree of 99mTc

Funding

None.

Competing interests

None declared.

Ethical approval

Ethical approval (No. 20190319) was given by the Ethics Committee of Keio University School of Medicine.

Patient consent

The institutional review board of the hospital waived the need for informed consent from the patients.

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