Is There A Relationship Between Chewing Side Preference and Brain Laterality in Bruxers and Non-Bruxers?

Objective: There is no consensus on the etiology of unilateral mastication. While some studies argue that environmental factors such as missing teeth, teeth with restoration, pain, dental caries and temporomandibular disorder affect chewing side preference, others claim that brain laterality associated with hand, foot, ear and eye preferences also influences a chewing side preference. The aim of this study was to evaluate the relationship between the direction of unilateral chewing preference and brain laterality in fully dentate bruxers and non-bruxers (fully dentate or with missing and/or restored teeth). Methods: Brain laterality of the subjects (n=132) was determined based on responses to questions about extremity and sensory preferences. The reliable visual analogue scale (VAS), Kazazoglu’s method and the sunflower seed shell cracking test were used to determine chewing side preference (CSP). Results: CSP as determined by VAS was not associated with brain laterality. While extremity and sensory preferences were predominantly right-sided (dominant left hemisphere) in all groups, the frequency of the left-side chewing was found to be high only among bruxers (p>0.05). No significant association was found between the results of VAS and other techniques (p>0.05). Conclusion: The left-side CSP is observed more commonly in bruxers, suggesting that different central and peripheral mechanisms may be involved in bruxers.