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Vision and masticatory muscle function

Contents

Influence of vision on masticatory muscles function: surface electromyographic evaluation (1)

  • A study was conducted on patients who were troubled by pain from jaw muscles and also near-sightedness (13 persons). This group was compared to a control group (15 persons) with neither of these two symptoms
  • The results showed that there was a significant difference in muscle activation of the temporalis and masseter muscle in the group who were short sighted and had jaw pain, compared to the control group with eyes open. Little to no difference was found with eyes closed
  • The test was conducted with surface electromyography
  • The healthy group had no significant change in activation with eyes open or closed, with values of 3.200 μV open and 2.600 μV closed
  • The group with myopia and jaw pain had values of 23.85 μV in eyes open for temporalis and 3.538 μV for eyes closed. The masseter muscle for the same group showed 24.46 μV in eyes open and 4.923 μV in eyes closed

This study shows that the amount of muscular activity with eyes open is up to 8 times higher in people with both short-sightedness (myopia) and muscular jaw pain.

Visual input effect on EMG activity of masticatory and postural muscles in healthy and in myopic children (2)

  • This study measured the activity level of Anterior Temporal, Masseter, Sternocleidomastoid and Anterior Digastric muscles in children aged 7-13 with eyes open and closed
  • The analysis was between a group of 10 children with normal vision, and a group of children with myopic defects
  • The results showed that the group with myopic defects had marked difference from normal vision group in that the Anterior Temporal muscles had a higher tonic activity in myopic group with eyes open according to EMG
  • The authors of the study concludes that there should be paid attention to vision defects in patients with high masticatory tenderness

Effects of myogenous facial pain on muscle activity of head and neck. (3)

  • This study was conducted to evaluate the effects of visual input on activity in the jaw and neck muscles (Anterior Temporalis, Masseter, Anterior Digastric, and Sternocleidomastoideus) in patients with myogenous facial pain compared to healthy volunteers
  • In the study group, left and right anterior temporalis and right digastric with open eyes showed higher values than sEMG with closed eyes. In the control group no significant differences were observed between closed and open eyes.
  • In patients with myogenous facial pain, visual input appears to be associated with a significant increase in the sEMG activity of the Temporalis and Digastric muscles
  • Also, the group with myogenous pain also had higher activity levels of the Anterior Temporalis, Masseter, and Sternocleidomastoideus with closed eyes than the control group.

Clinical association between teeth malocclusions, wrong posture and ocular convergence disorders: an epidemiological investigation on primary school children (4)

  • Because of its position, misalignment of the mandible can also cause the position of the pupillary line to be momentarily altered, provoking the intervention of ocular muscles to keep the gaze straight.
  • There are many known correlations between the visual and motor systems, and the importance of visual function, particularly the paracentral peripheral field of view, in motor coordination, ambulation and the maintenance of balance has been amply demonstrated. In fact, to follow an object in motion, the eye needs to be able to coordinate the movement of the head and neck. The musculature controlling eye movement is closely connected to the stomatognathic system.

Relationship between mandibular deviation and ocular convergence (5)

  • Recent studies have confirmed the relationship between head posture, mandibular position and visual focusing
  • These results seemed to confirm that in mandibular latero-deviation subjects ocular convergence defects occurred in greater frequency than in controls underlining the importance of role of pediatric dentistry among interdisciplinary cooperation.

Sources:

  1. Influence of vision on masticatory muscles function: surface electromyographic evaluation Pubmed link
  2. Visual input effect on EMG activity of masticatory and postural muscles in healthy and in myopic children. Pubmed link

  3. Effects of myogenous facial pain on muscle activity of head and neck. Pubmed link

  4. Clinical association between teeth malocclusions, wrong posture and ocular convergence disorders: an epidemiological investigation on primary school children. PubMed

  5. Relationship between mandibular deviation and ocular convergence. PubMed