Neuroscience Letters 450 (2009) 221–224 Contents lists available at ScienceDirect Neuroscience Letters journal homepage: www.elsevier.com/locate/neulet Dental occlusion and postural control in adults Corinne Tardieu a , Michel Dumitrescu b , Anne Giraudeau a , Jean-Luc Blanc b , Franc ¸ ois Cheynet c , Liliane Borel b,∗ a Faculté d’Odontologie, Université de la Méditerranée, 27, Boulevard Jean Moulin, 13385 Marseille Cedex 5, France b Laboratoire de Neurosciences Intégratives et Adaptatives, UMR 6149, Université de Provence/CNRS, Pôle 3C, Case B, 3, Place Victor Hugo, 13331 Marseille Cedex 3, France c Service de Chirurgie Maxillo-faciale, Stomatologie, Hôpital de la Timone, 163 rue Saint Pierre, 13385 Marseille Cedex 5, France article info Article history: Received 29 July 2008 Received in revised form 1 December 2008 Accepted 2 December 2008 Keywords: Occlusion status Crossbite Balance control Head stabilization Motion analysis Static and dynamic posturography abstract We studied the influence of a dental occlusion perturbation on postural control. The tests were performed in three dental occlusion conditions: (Rest Position: no dental contact, Maximal Intercuspal Occlusion: maximal dental contact, and Thwarted Laterality Occlusion: simulation of a dental malocclusion) and four postural conditions: static (stable platform) and dynamic (unstable platform), with eyes open and eyes closed. A decay of postural control was noted between the Rest Position and Thwarted Laterality Occlusion conditions with regard to average speed and power indexes in dynamic conditions and with eyes closed. However, the head position and stabilization were not different from those in the other experimental conditions, which means that the same functional goal was reached with an increase in the total energetic cost. This work shows that dental occlusion differently affects postural control, depending on the static or dynamic conditions. Indeed, dental occlusion impaired postural control only in dynamic postural conditions and in absence of visual cues. The sensory information linked to the dental occlusion comes into effect only during difficult postural tasks and its importance grows as the other sensory cues become scarce. © 2008 Elsevier Ireland Ltd. All rights reserved. Postural control is usually described as being based on the visual, proprioceptive, and vestibular systems. Hence, mandible position could have an impact on postural control since it affects the head position. Mandibular proprioception, assisted by the trigeminal nerve and provided by the masticatory muscles and the periodontal ligament [22], contributes to head postural control via the sterno- cleido-mastoidian muscle [14]. Several studies have focused on the relation between dental occlusion proprioceptive information and upright stance some of them reporting postural control is influenced by dental occlusion. The laterotrusive occlusal position and the lack of balance between the antagonist left and right masticatory muscles may cause a devi- ation of the cervical spine [23]. This human modeling study was supported by results on the rat [5]. These authors reported verte- brae alignment changed after dental occlusion modification. Also, changes in the mandibular position could influence gait stabiliza- tion [8] and postural stability [3]. Starting from observations of increases of the spinal curve, it was shown that a cervical hyper lordosis is often linked to a class II angle malocclusion and that a scoliosis and a torticolis augment the risk of anterior crossbite [13]. This reciprocal link between postural deficits and dental mal- ∗ Corresponding author. Tel.: +33 4 88 57 68 38; fax: +33 4 88 57 68 18. E-mail address: liliane.borel@univ-provence.fr (L. Borel). occlusion suggests that mandibular position or dental occlusion may influence static and dynamic posture and even cause postural pathologies. However, other studies reported that dental malocclusion or temporo-mandibular disorders have no influence on postural con- trol [7]. Finally, as shown by a systematic review [11], contradictory results are still reported concerning the influence of dental occlu- sion on posture. We hypothesized that such contradictions could originate in the nature of the postural task (static versus dynamic) and the sensory cues available to stabilize body in space (light ver- sus darkness). The present study focused on the influence of dental occlusion on postural control in young, healthy adults. The main issue was to specify the weight of dental occlusion on postural control according to the task difficulty (static and dynamic upright stance) and to the presence or absence of visual cues (eyes open, eyes closed). Ten young healthy subjects were included, six men and four women, aged from 25 to 28 years (mean: 21 ± 0.73). They were selected after evaluation of their plaster dental cast and ques- tionnaire assessment. The selecting criteria were bilateral angle I of molars and canines; absence of anterior and lateral crossbite; absence of oral pathology (malocclusion or articular disorders), oro- facial pain, temporary restorative dental treatment or periodontal healing tissues; and absence of neuropathology, postural and gait disorders or vestibular disorders. The subjects gave their written 0304-3940/$ – see front matter © 2008 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.neulet.2008.12.005