Expression of Lateralized Mastication Index.

The present study was made to examine LI presented as the index of the degree of lateralized mastication.On 104 subjects aged 23-30, the masticatory side was judged by gum chewing cycle, and the frequency ratio of lateralized mastication as determined from “(right masticatory number-left masticatory number)/(right masticatory number+left masticatory number)×100” was expressed in lateralized mastication index (LI) divided into 5 grades of every 20% for both positive and negative.The examination of the habitual masticatory side as judged from the questionnaire and first chewing cycle in confrontation with this LI revealed a good coincidence of both these and the usefulness of expressing the frequency ratio of lateralized mastication in LI.