Unbalanced occlusion modifies the pattern of brain activity during execution of a finger to thumb motor task
Front. Neurosci.. 2019-05-17; 13:
DOI: 10.3389/fnins.2019.00499
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Tramonti Fantozzi MP(1), Diciotti S(2), Tessa C(3), Castagna B(4), Chiesa D(5), Barresi M(6), Ravenna G(1), Faraguna U(1)(7), Vignali C(3), De Cicco V(1), Manzoni D(1).
Author information:
(1)Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Pisa, Italy.
(2)Department of Electrical, Electronic and Information Engineering “Guglielmo Marconi,” University of Bologna, Cesena, Italy.
(3)Department of Radiology, Versilia Hospital, Azienda USL Toscana Nord Ovest, Camaiore, Italy.
(4)Orthopedics Unit, St. Barth Hospital, Sarzana, Italy.
(5)Department of Orthopedics, University of Genoa, Genoa, Italy.
(6)Institut des Maladies Neurodégénératives, Université de Bordeaux, Bordeaux, France.
(7)Department of Developmental Neuroscience, IRCCS Fondazione Stella Maris, Pisa, Italy.
In order to assess possible influences of occlusion on motor performance, we
studied by functional magnetic resonance imaging (fMRI) the changes in the blood
oxygenation level dependent (BOLD) signal induced at brain level by a finger to
thumb motor task in a population of subjects characterized by an asymmetric
activation of jaw muscles during clenching (malocclusion). In these subjects,
appropriate occlusal correction by an oral orthotic (bite) reduced the
masticatory asymmetry. The finger to thumb task was performed while the subject’s
dental arches were touching, in two conditions: (a) with the teeth in direct
contact (Bite OFF) and (b) with the bite interposed between the arches (Bite ON).
Both conditions required only a very slight activation of masticatory muscles.
Maps of the BOLD signal recorded during the movement were contrasted with the
resting condition (activation maps). Between conditions comparison of the
activation maps (Bite OFF/Bite ON) showed that, in Bite OFF, the BOLD signal was
significantly higher in the trigeminal sensorimotor region, the premotor cortex,
the cerebellum, the inferior temporal and occipital cortex, the calcarine cortex,
the precuneus on both sides, as well as in the right posterior cingulate cortex.
These data are consistent with the hypothesis that malocclusion makes movement
performance more difficult, leading to a stronger activation of (a) sensorimotor
areas not dealing with the control of the involved body part, (b) regions
planning the motor sequence, and (c) the cerebellum, which is essential in motor
coordination. Moreover, the findings of a higher activation of temporo-occipital
cortex and precuneus/cingulus, respectively, suggest that, during malocclusion,
the movement occurs with an increased visual imagery activity, and requires a
stronger attentive effort.
DOI: 10.3389/fnins.2019.00499
PMCID: PMC6533560
PMID: 31156377