Pressure QST of masticatory muscles with 3 different probes in healthy subjects

Objectives: There is no gold standard pressure probe for evaluating pressure sensitivity of masticatory muscles. The aim of this study was to identify using human finger replicas of different sizes whether finger size plays a role in the examination process of TMD patients. Therefore differences in pressure pain of the masseter muscle were analyzed with the standardized attachment of the Algometer and two different silicone finger replicas.
Methods: Methods: In 50 healthy students aged 22 to 29 pain pressure threshold (PPT) of the masseter muscle was determined on one side (drawn by lots). PPT was determined on three different points (anterior, middle, posterior) at the belly of the masseter muscle. At each of the examination points, the PPT was measured with 3 different probes (large human finger replica, small human finger replica and standard attachment of the Algometer).
Results: At the anterior examination point the average value of PPT for the small finger was 2.46kg (range 1.1 to 6.3kg), the large finger 2.61kg (range 1.1 to 5.6kg) and the standard attachment 2.06kg (range 0.9 to 4.9kg).
At the middle examination point the average value of PPT for the small finger was 2.36kg (range 0.8 to 4.1kg), the large finger 2.55kg (range 0.9 to 5.8kg) and the standard attachment 2.08kg (range 0.7 to 4.2kg)
At the posterior examination point the average value of PPT for the small finger was 2.45kg (range 0.8 to 5kg), with the large finger 2.57kg (range 1.2 to 4.6kg) and the standard attachment 2.15kg (range 1.1 to 4.2kg).
Conclusions: 1) Using the same finger or attachment no differences were found between the three examination points (anterior, middle, posterior)
2) PPT was the lowest for the standard attachment of the Algometer, followed by the small finger. The large Finger showed the highest PPT.
3) In healthy subjects there is no PPT for the masseter muscle below 0.8kg.