Apparatus, recorded signals and phases of chewing cycles. (A) Electromyographic signals (EMG) from the masseter muscle were recorded by bipolar surface electrodes. Jaw movements were monitored by tracking the position of a small magnet attached to the labial surfaces of the lower incisors, with magnetic sensors in a lightweight frame mounted on the head. (B) Vertical position of the mandible and EMG activity (r.m.s. processed) during representative masticatory sequences, performed by a dentate and an implant participant. The grey boxes indicate the beginning (B), middle (M) and end (E) of this sequence. (C) Expansion of the middle segment in (B) illustrating the opening, closing and occlusal phases of one cycle.