Role of nuclear medicine in evaluation of treatment response for patient with TMJ disease

Introduction: Temporo Mandibular Joint TMJ disease is a growth abnormality and in severe hyperplasia makes patient worried and sometimes frustrated especially for young female patients.

Diagnose of TMJ disease is done by CT scan or radiography to detect any TMJ asymmetry but except the diagnosis of TMJ abnormality, it is really important to detect precisely the level of hyperplasia and also detect any pressure effect on mandible shaft, In this regard, nuclear medicine due to simply showing function and metabolism of cells became more valuable. The main purpose of this study is the predictive role of nuclear medicine in treatment response for patients with TMJ disease.

Methods: Fifteen patients with temporomandibular joint disorders ranging in age from 14 to 32 years old, of which 12 were female and 3 were male, were included in the study. Their consent was scanned at the request of the treating physician.

Diagnosis was made both by clinical manifestations and by confirmation of radiology and CT scan.

The purpose of isotope scan was to compare the abnormal side with the normal side and also to repeat it after surgical or symptomatic treatment of patients to define the treatment response values.

Patients were injected 20 mci of Tc99m-MDP radiopharmaceutical intravenously and 3 hours later images were obtained anteriorly-LL and RL of head and SPECT also performed.

Comparison of mandibular and TMJ shafts were by both visually and quantitatively by drawing ROI to find the percentage of activity on each side and also determining the ratio of activity between right and left in both joints and shafts and for SPECT images, it compare with the clivus bone in basal skull as reference bone activity.

Results: 12/15 patients had a high percentage of joint activity (hyperplasia) on the right side and 3/15 patients had higher joint activity on the left side. 10/20 subjects showed the compressive effect on the mandible of the opposite side.

The definition of the severity of condyle hyperplasia is determined by determining the ratio of the two sides to the reference bone and the background, which is classified as follows:

TMJ right and left activity ratio equal to 1 means normal.

A ratio of up to 1.2 means mild hyperplasia

A ratio of 1.2 to 1.5 means moderate hyperplasia

A ratio above 1.5 means severe hyperplasia.

6 patients showed severe deviation with pressure effect on mandible, 4 patients showed moderate deviation with pressure effect on mandible and 5 patients showed mild deviation without any effect of pressure.

Patients were re-scanned one year after treatment (invasive-non-invasive).

The response to treatment was assessed by reducing both activity and bilateral ratio as well as patient satisfaction.

For people with Mild disease, 2/5 percent of patients had a reduction in the ratio.

In the moderate disease group, 2/4 patients showed a relative response to decreased activity

But in the severe group, only 2/6 patients responded partially. And the second scan in this group did not show a significant change.

The basis of treatment was lack of progression of deviation and reduction of the effect of pressure on the opposite side of the jaw but there was not complete response in all severe / moderate patients .But the mild group, surgical therapy was useful.

Conclusions: TMJ's disease of the jaw and asymmetry of the joint is a concern for many people, which has a worrying effect not only on the appearance but also on the chewing action. Treatments, although costly, are somewhat effective and most patients have to always have this problem for good.

Role of isotope scanning in determining the response to treatment is clear, which determine which therapy is effective in which cases importantly, mild group but has low value in moderate and severe cases, and therefore nuclear scan can help to make the right decision to perform aggressive treatment or only symptomatic treatment.