title: Can short-term oral fine motor training affect precision of task performance and induce cortical plasticity of the jaw muscles?
abstract: The aim was to test the hypothesis that short-term oral sensorimotor training of the jaw muscles would increase the precision of task performance and induce neuroplastic changes in the corticomotor pathways, related to the masseter muscle. Fifteen healthy volunteers performed six series with ten trials of an oral sensorimotor task. The task was to manipulate and position a spherical chocolate candy in between the anterior teeth and split it into two equal halves. The precision of the task performance was evaluated by comparing the ratio between the two split halves. A series of "hold-and-split" tasks was also performed before and after the training. The hold force and split force along with the electromyographic (EMG) activity of jaw muscles were recorded. Motor-evoked potentials and cortical motor maps of the right masseter muscle were evoked by transcranial magnetic stimulation. There was a significant effect of series on the precision of the task performance during the short-term oral sensorimotor training (P < 0.002). The hold force during the "hold-and-split" task was significantly lower after training than before the short-term training (P = 0.011). However, there was no change in the split force and the EMG activity of the jaw muscles before and after the training. Further, there was a significant increase in the amplitude of the motor-evoked potentials (P < 0.016) and in the motor cortex map areas (P = 0.033), after the short-term oral sensorimotor training. Therefore, short-term oral sensorimotor task training increased the precision of task performance and induced signs of neuroplastic changes in the corticomotor pathways, related to the masseter muscle.
authors.affiliation: Department of Prosthodontics, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, 210008, China.|Section of Orofacial Pain and Jaw Function, Department of Dentistry, Aarhus University, Aarhus C, Denmark.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Scandinavian Center for Orofacial Neuroscience (SCON), Aarhus C, Denmark.|Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Hammel Neurorehabilitation Center and University Research Clinic, Aarhus C, Denmark.
authors.forename: Mohit
authors.initials: M
authors.lastname: Kothari
authors.affiliation: Department of Prosthodontics, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, 210008, China. l_xiaoping@yahoo.com.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Luo
authors.affiliation: Scandinavian Center for Orofacial Neuroscience (SCON), Aarhus C, Denmark.|Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden.
authors.forename: Mats
authors.initials: M
authors.lastname: Trulsson
authors.affiliation: Scandinavian Center for Orofacial Neuroscience (SCON), Aarhus C, Denmark.|Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden.
authors.forename: Krister G
authors.initials: KG
authors.lastname: Svensson
authors.affiliation: Section of Orofacial Pain and Jaw Function, Department of Dentistry, Aarhus University, Aarhus C, Denmark.|Scandinavian Center for Orofacial Neuroscience (SCON), Aarhus C, Denmark.|Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Svensson
mesh_terms: D000328:Adult; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D008406:Masseter Muscle / Q000502:physiology*; D009044:Motor Cortex / Q000502:physiology*; D009048:Motor Skills / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D013647:Task Performance and Analysis; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult
keywords: Masseter training; Motor learning; Periodontal mechanoreceptors; Precision task; Transcranial magnetic stimulation