Chewing side preference in first and all mastication cycles for hard and soft morsels

Preferred chewing side is a still controversial matter and various methods used have yielded some inconsistencies.
The aim of this study is to compare the preference determined in different conditions. Nineteen healthy subjects
were offered hard (walnut) and soft (cake) foods, while the electromyography was recorded from their masseter
muscles, in 2009 in the Research Center of Physical Medicine and Rehabilitation, Tabriz University of Medical Sciences,
Tabriz, Iran. Four occurrences were determined as the side of the first chews/all chews in the two food types,
and then analyzed for correlations and agreements. For hard food 73.68% and for soft food 57.89% of the subjects
showed preference. The comparison of all chews showed a highly significant preference towards the right side in both
food types (p=0.000 & 0.003). There was both correlation and agreement between the first chew preferences in both
food types, and an agreement between the first and all chew preferences in the hard food. Therefore, there seems to
exist some laterality in mastication, which is more explicit when using hard food and assessing all chews