Sagittal Plane Kinematics of the Jaw and Hyolingual Apparatus During Swallowing in Macaca mulatta

Abstract

Studies of mechanisms of feeding behavior are important in a society where aging- and disease-related feeding disorders are increasingly prevalent. It is important to evaluate the clinical relevance of animal models of the disease and the control. Our present study quantifies macaque hyolingual and jaw kinematics around swallowing cycles to determine the extent to which macaque swallowing resembles that of humans. One female and one male adult Macaca mulatta were trained to feed in a primate chair. Videofluoroscopy was used to record kinematics in a sagittal view during natural feeding on solid food, and the kinematics of the hyoid bone, thyroid cartilage, mandibular jaw, and anterior-, middle-, and posterior-tongue. Jaw gape cycles were defined by consecutive maximum gapes, and the kinematics of the swallow cycles were compared with those of the two consecutive non-swallow cycles preceding and succeeding the swallow cycles. Although there are size differences between macaques and humans, and macaques have shorter durations of jaw gape cycles and hyoid and thyroid upward movements, there are several important similarities between our macaque data and human data reported in the literature: (1) The durations of jaw gape cycles during swallow cycles are longer than those of non-swallow cycles as a result of an increased duration of the jaw-opening phase; (2) Hyoid and thyroid upward movement is linked with a posterior tongue movement and is faster during swallow than non-swallow cycles; (3) Tongue elevation propagates from anterior to posterior during swallow and non-swallow cycles. These findings suggest that macaques can be a useful experimental model for human swallowing studies.

Dynamic Musculoskeletal Functional Morphology: Integrating diceCT and XROMM

“…Swallow (N 5 24) and chew (N 5 39) cycles defined from maximum gape to maximum gape were included in the analysis. The swallows digitized in this study were intercalated between chewing cyclesalthough they do not come at the end of the sequence, these types of swallows have been shown to be fundamentally similar to human swallowing kinematics reported in the literature (Nakamura et al, 2017). Gape cycle phases (fast close, slow close, slow open, fast open) were determined by analyzing the acceleration of mandibular pitch using a modified version of the method described by Reed and with the addition of an intercuspal phase (Palmer et al, 1992;Hiiemae et al, 1995) (Fig.…”

“…The data presented here were collected as part of an on ongoing research program to develop a nonhuman primate model of human swallowing biomechanics (Nakamura et al, 2017). Previous studies have measured hyolingual kinematics (Franks et al, 1984;German et al, 1989;Hiiemae et al, 1995;Steele and Van Lieshout, 2008;Matsuo and Palmer, 2010;Nakamura et al, 2017), individual muscle activity (Inokuchi et al, 2014(Inokuchi et al, , 2016, muscle length (Okada et al, 2013;Feng et al, 2015), and simultaneous skeletal kinematics and EMG (Palmer et al, 1992;Park et al, 2017), but this is the first study to integrate EMG with in vivo 3D measures of both hyolingual kinematics and muscle length, orientation, and velocity. Specifically, this article demonstrates how integration of these techniques can be used to evaluate the mechanisms underlying hyoid elevation during chewing and swallowing ( Fig.…”

XROMM and diceCT reveal a hydraulic mechanism of tongue base retraction in swallowing

“…In primates, swallow jaw gape cycles consist of fast close, slow close, slow open, and fast open phases and are longer in duration than chewing cycles, primarily because of longer slow open and fast open phases 20,31 (Fig. 2a).…”

“…2a). We defined tongue base retraction (TBR) onset as the start of posterior displacement of the posterior superficial tongue marker, and our data show that this began during slow open, in the intercuspal phase (IP), and was complete prior to or around the end of slow open 31 (Fig. 2b).…”

Jaw sensorimotor control in healthy adults and effects of ageing

“…As modification to the dental occlusion such as tooth extraction or trimming in rodents , as well as in humans , can affect muscle activities and patterns of jaw movements during mastication, and as adaption to an altered pattern of mastication conceivably requires repetition of novel movements somewhat analogous to learning a novel motor skill, it is possible that the reorganisation of motor representations within oM1 and oS1 including the co‐activation of jaw and tongue muscles play a role also in motor learning and adaptation to an altered oral state such as occur following injury or dental treatment . Indeed, training monkeys in a novel tongue or biting task can induce short‐term (<1 h) and long‐term (days) neuroplastic changes within both the oM1 and oS1 although there are differences between the oM1 and oS1 neuroplastic changes, pointing to differences in the way oM1 and oS1 neurons may contribute to motor control parameters as training progresses .…”