Generation of the central masticatory pattern and its modification by sensory feedback.

Mammalian mastication results from the interaction of an intrinsic rhythmical neural pattern and sensory feedback generated by the interaction of the effecter system (muscles, bones, joints, teeth, soft tissues) with food. The main variables that explain variation in the pattern of human mastication are the subjects themselves, their age, the type of food being eaten, and time during a sequence of movements. The intrinsic pattern of mastication is generated by a central pattern generator (CPG) located in the pons and medulla. The output of the CPG is modified by inputs that descend from higher centers of the brain and by feedback from sensory receptors. Intraoral touch receptors, muscle spindles in the jaw-closing muscles, and specialized mechanoreceptors in the periodontal ligament have especially powerful effects on movement parameters.