Difference between revisions of "Occlusion and Posture"

  }}[[File:VEMP.jpg|Figure 1: Vestibula Evoked Myogenic Potentials (see chapter '[[Complex Systems]]'|left|300x300px]]In this section of Masticationpedia we will deal with a much discussed topic in the field of prosthetic rehabilitation and in the diagnosis of Orofacial disorders including Temporomandibular dysfunctions. As we shall see, there is a line between proponents of the correlation between posture and the trigeminal system and those who refute the correlation. To confirm or deny this correlation, it would be enough to focus the attention on the VEMPs (Myogenic Vestibular Evoked Potentials) to understand the neuronal synergism but it would be necessary to pay equal attention to the synaptic modulations that occur in this phenomenon to understand how much we still know about the aforementioned trigeminal/vestibular correlation. Just think of the roll effect and evaluate the click-evoked cervical vestibular myogenic potentials (VEMPS) during the visual roll motion that elicited an illusory sensation of self-movement (i.e., vection). During vetion, there is an increase in cVEMP amplitude that is positively correlated with subjective reports of vection strength. The experimental conclusion is, therefore, that the simple subjective sensation of section is able to modulate the response of VEMPs and that this higher-level cortical phenomenon can also extend to short-lasting vestibulospinal responses. Therefore, regardless of who will be right over time, one must always be very careful in evaluating the symptoms and clinical signs reported by patients and not be influenced by more or less fashionable axioms which can generate even serious errors in the differential diagnosis such as in clinical case that we will present below.  

Posture is understood as the position of the human body and its orientation in space which requires the analysis and integration of stimuli from three systems: vision, vestibular and proprioception.<ref>Guez G. The Posture. In: Kandel E., Schwartz J., editors. Principles of Neural Science. Elsevier; Amsterdam, The Netherlands: 1991. pp. 612–623.</ref><ref>Czaprowski D., Stoliński L., Tyrakowski M., Kozinoga M., Kotwicki T. Non-structural misalignments of body posture in the sagittal plane. Scoliosis Spinal Disord. 2018;13:6. doi: 10.1186/s13013-018-0151-5.</ref> Over the years, numerous observations have been made on the factors influencing postural stability. <ref>Iwanenko J., Gurfinkel V. Human postural control. Front. Neurosci. 2018;12:17. </ref><ref>Guerraz M., Bronstein A.M. Ocular versus extraocular control of posture and equilibrium. Neurophysiol. Clin. 2008;38:391–398. doi: 10.1016/j.neucli.2008.09.007.</ref><ref>Hamaoui A., Frianta Y., Le Bozec S. Does increased muscular tension along the torso impair postural equilibrium in a standing posture? Gait Posture. 2011;34:457–461. doi: 10.1016/j.gaitpost.2011.06.017.</ref><ref>Kolar P., Sulc J., Kyncl M., Sanda J., Neuwirth J., Bokarius A.V., Kriz J., Kobesova A. Stabilizing function of the diaphragm: Dynamic MRI and synchronized spirometric assessment. J. Appl. Physiol. 2010;109:1064–1071. doi: 10.1152/japplphysiol.01216.2009.</ref><ref>Szczygieł E., Fudacz N., Golec J., Golec E. The impact of the position of the head on the functioning of the human body: A systematic review. Int. J. Occup. Med. Environ. Health. 2020;33:559–568. doi: 10.13075/ijomeh.1896.01585.</ref> The role of the craniomandibular system is now being increasingly analyzed in relation to it. <ref>Tardieu C., Dumitrescu M., Giraudeau A., Blanc J.L., Cheynet F., Borel L. Dental occlusion and postural control in adults. Neurosci. Lett. 2009;450:221–224. doi: 10.1016/j.neulet.2008.12.005.</ref><ref>Munhoz W.C., Hsing W.T. Interrelations between orthostatic postural deviations and subjects’ age, sex, malocclusion, and specific signs and symptoms of functional pathologies of the temporomandibular system: A preliminary correlation and regression study. Cranio. 2014;32:175–186. doi: 10.1179/0886963414Z.00000000031.</ref><ref>Pérez-Belloso A.J., Coheña-Jiménez M., Cabrera-Domínguez M.E., Galan-González A.F., Domínguez-Reyes A., Pabón-Carrasco M. Influence of dental malocclusion on body posture and foot posture in children: A cross-sectional study. Healthcare. 2020;8:485. doi: 10.3390/healthcare8040485.</ref><ref>Amaricai E., Onofrei R.R., Suciu O., Marcauteanu C., Stoica E.T., Negruțiu M.L., David V.L., Sinescu C. Do different dental conditions influence the static plantar pressure and stabilometry in young adults? PLoS ONE. 2020;15:e0228816. doi: 10.1371/journal.pone.0228816.</ref> Many theories attempt to explain the association between the masticatory organ and posture, including myofascial chains, trigeminal nerve activation or deactivation, and subsequent interaction in the brainstem.<ref name=":0">Cabrera-Domínguez M.E., Domínguez-Reyes A., Pabón-Carrasco M., Pérez-Belloso A.J., Coheña-Jiménez M., Galán-González A.F. Dental malocclusion and its relation to the podal system. Front. Pediatr. 2021;9:654229. doi: 10.3389/fped.2021.654229.</ref><ref>Myers T.  Anatomy Trains: Myofasziale Leitbahnen (für Manual- und Bewegungstherapeuten) Elsevier Health Sciences; Berlin, Germany: 2015.</ref><ref>Pinganaud G., Bourcier F., Buisseret-Delmas C., Buisseret P. Primary trigeminal afferents to the vestibular nuclei in the rat: Existence of a collateral projection to the vestibulo-cerebellum. Neurosci. Lett. 1999;264:133–136. doi: 10.1016/S0304-3940(99)00179-2. [PubMed] [CrossRef] [Google Scholar] [Ref list]</ref> However, this is a controversial topic in the scientific community. There is both evidence to support that relationship<ref name=":1">Bracco P., Deregibus A., Piscetta R. Effects of different jaw relations on postural stability in human subjects. Neurosci. Lett. 2004;356:228–230. doi: 10.1016/j.neulet.2003.11.055.</ref><ref name=":2">Manfredini D., Castroflorio T., Perinetti G., Guarda-Nardini L. Dental occlusion, body posture and temporomandibular disorders: Where we are now and where we are heading for. J. Oral Rehabil. 2012;39:463–471. doi: 10.1111/j.1365-2842.2012.02291.x. </ref><ref name=":3">Sakaguchi K., Mehta N.R., Abdallah E.F., Forgione A.G., Hirayama H., Kawasaki T., Yokoyama A. Examination of the relationship between mandibular position and body posture. Cranio. 2007;25:237–249. doi: 10.1179/crn.2007.037. </ref><ref name=":4">Cuccia A., Caradonna C. The relationship between the stomatognathic system and body posture. Clinics. 2009;64:61–63. doi: 10.1590/S1807-59322009000100011.</ref><ref name=":5">Marchena-Rodríguez A., Moreno-Morales N., Ramírez-Parga E., Labajo-Manzanares M.T., Luque-Suárez A., Gijon-Nogueron G. Relationship between foot posture and dental malocclusions in children aged 6 to 9 years. A cross-sectional study. Medicine. 2018;97:e0701. doi: 10.1097/MD.0000000000010701</ref><ref name=":6">Iacob S.M., Chisnoiu A.M., Buduru S.D., Berar A., Fluerasu M.I., Iacob I., Objelean A., Studnicska W., Viman L.M. Plantar pressure variations induced by experimental malocclusion—A pilot case series study. Healthcare. 2021;9:599. doi: 10.3390/healthcare9050599.</ref> and to refute it.<ref name=":7">Michelotti A., Buonocore G., Farella M., Pellegrino G., Piergentili C., Altobelli S., Martina R. Postural stability and unilateral posterior crossbite: Is there a relationship? Neurosci. Lett. 2006;392:140–144. doi: 10.1016/j.neulet.2005.09.008.</ref><ref name=":8">Perinetti G., Contardo L., Silvestrini-Biavati A., Perdoni L., Castaldo A. Dental malocclusion and body posture in young subjects: A multiple regression study. Clinics. 2010;65:689–695. doi: 10.1590/S1807-59322010000700007.</ref><ref name=":9">Scharnweber B., Adjami F., Schuster G., Kopp S., Natrup J., Erbe C., Ohlendorf D. Influence of dental occlusion on postural control and plantar pressure distribution. Cranio. 2017;35:358–366. doi: 10.1080/08869634.2016.1244971.</ref><ref name=":10">Isaia B., Ravarotto M., Finotti P., Nogara M., Piran G., Gamberini J., Biz C., Masiero S., Frizziero A. Analysis of dental malocclusion and neuromotor control in young healthy subjects through new evaluation tools. J. Funct. Morphol. Kinesiol. 2019;4:5. doi: 10.3390/jfmk4010005.</ref>  

The authors of the scientific reports, who recognize the associations between the systems in question, give two indications for the possible interactions. The first, i.e. ascending disturbances, refers to the situation in which bad posture and disturbances of the peripheral structures (e.g. lower limbs), through myofascial neuromotor activities and the dura mater, functionally condition the cranio-mandibular structures. Conversely, a chain of descending disorders is present when anomalies of the craniomandibular region affect posture and body areas located more distally, including the pelvis and lower extremities.<ref name=":0" /><ref name=":11">Michalakis K.X., Kamalakidis S.N., Pissiotis A.L., Hirayama H. The Effect of clenching and occlusal instability on body weight distribution, assessed by a postural platform. BioMed Res. Int. 2019;2019:7342541. doi: 10.1155/2019/7342541.</ref><ref name=":12">Julià-Sánchez S., Álvarez-Herms J., Cirer-Sastre R., Corbi F., Burtscher M. The influence of dental occlusion on dynamic balance and muscular tone. Front. Physiol. 2020;10:1626. doi: 10.3389/fphys.2019.01626.</ref><ref>Pacella E., Dari M., Giovannoni D., Mezio M., Caterini L., Costantini A. The relationship between occlusion and posture: A systematic review. Orthodontics. 2017;8:WMC005374.</ref><blockquote>[[File:Question 2.jpg|left|50x50px]]And on this nothing to say because no one can deny an anatomical-functional correlation between vestibular systems, cerebellum, trigeminal and peripheral neuromotor system. This is not an opinion but a proven scientific observation already reported somewhere in Masticationpedia.