Occlusion and Mastication

Abstract

The pattern of occlusion of the teeth is highly variable in humans and in orthodontics there is an increasing tendency to attribute abnormal patterns of masticatory movements to malocclusion of the teeth. There is now convincing evidence that specific patterns of malocclusion of the teeth can alter the symmetrical bilateral function of the masticatory muscles. For example, in the unilateral posterior crossbite malocclusion of the teeth there is asymmetry between the activity of the left and right masticatory muscles, suggesting abnormality of the bilateral chewing function through abnormal coupling of the hyperneurons in the left and right cerebral hemispheres.

The phenomenon of uncoordinated masticatory movements in malocclusions of the teeth associated with occlusal interferences or premature dental contacts can be attributed to sensory deprivation of the brain (see Sect. 3.4). In addition, occlusal interferences in early age during eruption of the teeth may also affect the function of the central pattern generator through sensory deprivation of the cortex induced by the combined action of occlusal interferences and of emotional disturbance in young children.

The statistical evidence that specific patterns of muscle activity during chewing are correlated with orofacial morphology and occlusion of the teeth may be understood through the mechanosensation of bone advanced recently by Moss. See Sects. 8.20, 3.3, 4.8, and 11.