Читать книгу Practical Procedures in Dental Occlusion - Ziad Al-Ani - Страница 20

The control of position and movement of the muscle/tendon complex is achieved by a combined Golgi tendon organ (GTO) and muscle spindle (MS) feedback. The jaw closing muscles are richly supplied with MSs which provide information related to length and contraction velocity of muscle fibres and generate muscle activation patterns in a predictable manner. The GTO provides information related to tension of the tendons (Kistemaker et al. 2013). This is a feedback loop system which plays a role in CPGs and given the superior tactile discriminative abilities of dentate subjects in comparison with those with implant‐supported or removable prostheses, PDMRs provide a more sensitive indicator of jaw position and movement.

What happens when we increase the occlusal vertical dimension (OVD)? An increase in OVD results in stretching or increased MS length. Muscles show a high degree of functional adaptability/plasticity; Yabushita et al. (2006) found that there is a significant decrease in MS sensitivity up to 2 weeks post increase of OVD. This has similarities to Clark et al.'s (1999) 68‐year review on occlusal interference studies in that any muscle symptoms were transient. The changes in spindle function may be due to changes in occlusal function producing alterations in CNS masticatory controls combined with the different PDMR input. Therefore, to ensure the information entering the system is correct, assessment of muscles is crucial before embarking on complex reorganised dentistry.