title: Optimization of jaw muscle activity and fine motor control during repeated biting tasks.
abstract: OBJECTIVE
  To investigate if repeated holding and splitting of food morsel change the variability of force and jaw muscle activity in participants with natural dentition.
  
  
  METHODS
  Twenty healthy volunteers (mean age=26.2±3.9 years) participated in a single session divided into six series. Each series consisted of ten trials of a standardized behavioural task (total 60 trials) involving holding and splitting a flat-faced tablet (8mm, 180mg) placed on a bite force transducer with the anterior teeth. The hold and split forces along with the electromyographic (EMG) activity of the left and right masseter (MAL and MAR), left anterior temporalis (TAL) and digastric (DIG) muscles were recorded. A series (ten trials) of natural biting tasks was also performed before and after the six series of the behavioural task.
  
  
  RESULTS
  The mean hold force (P<0.001) but not the mean split force (P=0.590) showed significant effect of number of series. No significant effect of series was seen on the variability of hold and split force and the EMG activity except for the variability of EMG activity for MAL during the hold phase (P=0.021) and DIG during the split phase (P<0.001). The behavioural task had no effect on the EMG activity of the natural biting task.
  
  
  CONCLUSIONS
  There was no evident optimization of jaw motor function in terms of reduction in the variability of bite force values and muscle activity, when this simple task was repeated up to sixty times in participants with normal intact periodontium.
authors.affiliation: Section of Clinical Oral Physiology, Department of Dentistry, Aarhus University, Denmark; Scandinavian Center for Orofacial Neuroscience (SCON). Electronic address: a.kumar@odont.au.dk.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Section for Oral Rehabilitation, Department of Dental Medicine, Karolinska Institute, Sweden; Scandinavian Center for Orofacial Neuroscience (SCON).
authors.forename: Krister G
authors.initials: KG
authors.lastname: Svensson
authors.affiliation: Section of Clinical Oral Physiology, Department of Dentistry, Aarhus University, Denmark; Scandinavian Center for Orofacial Neuroscience (SCON).
authors.forename: Lene
authors.initials: L
authors.lastname: Baad-Hansen
authors.affiliation: Section for Oral Rehabilitation, Department of Dental Medicine, Karolinska Institute, Sweden; Scandinavian Center for Orofacial Neuroscience (SCON).
authors.forename: Mats
authors.initials: M
authors.lastname: Trulsson
authors.affiliation: Section of Prosthetic Dentistry, Department of Dentistry, Aarhus University, Denmark.
authors.forename: Flemming
authors.initials: F
authors.lastname: Isidor
authors.affiliation: Section of Clinical Oral Physiology, Department of Dentistry, Aarhus University, Denmark; Scandinavian Center for Orofacial Neuroscience (SCON).
authors.forename: Peter
authors.initials: P
authors.lastname: Svensson
mesh_terms: D000328:Adult; D001732:Bite Force; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008409:Mastication / Q000502:physiology*; D008410:Masticatory Muscles / Q000502:physiology*; D008465:Mechanoreceptors / Q000502:physiology; D009048:Motor Skills / Q000502:physiology*; D012984:Software; D014159:Transducers
keywords: Behavioural learning; Neuroplasticity; Periodontal mechanoreceptors