Difference between revisions of "Occlusion and Posture"

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 system and peripheral neuromotor system. This is not an opinion but a proven scientific observation already reported somewhere in Masticationpedia.[[File:VEMP.jpg|thumb|200x200px|Figure 1: Vestibula Evoked Myogenic Potentials (see chapter '[[Complex Systems]]']]VEMPs, translated into Miocene Vestibular Evoked Potentials are proof of this. Acoustic stimuli can evoke EMG reflex responses in the masseter muscle called Vestibular Evoked Myogenic Potentials (VEMPs). Although these findings have previously been attributed to activation of cochlear (high-intensity sound) receptors, these may also activate vestibular receptors. Because anatomical and physiological studies in both animals and humans have demonstrated that the masseter muscles are a target for vestibular inputs, the authors of this study reevaluated the vestibular contribution for masseter reflexes. This is a typical example of a basic level 'Complex System' as it consists of only two cranial nervous systems but, at the same time, they interact by activating monosynaptic and polysynaptic circuits (Figure 1).</blockquote>Previous publications attempting to evaluate the impact of craniofacial abnormalities on posture and stability focus, among others, on the analysis of patients presenting with symptoms of temporomandibular disorders. It has been shown that changes in the temporomandibular joint (TMJ) can have a direct impact on muscle activity in terms of posture, stability and physical performance.<ref name=":2" /><ref>Moon H.J., Lee Y.K. The relationship between dental occlusion/temporomandibular joint status and general body health: Part 1. Dental occlusion and TMJ status exert an influence on general body health. J. Altern. Complement. Med. 2011;17:995–1000. doi: 10.1089/acm.2010.0739.</ref><ref>Souza J.A., Pasinato F., Correa E.A., da Silva A.M. Global body posture and plantar pressure distribution in individuals with and without temporomandibular disorder: A preliminary study. J. Manip. Physiol. Ther. 2014;37:407–414.</ref>  However, there is a lack of high-quality studies using advanced measurement tools to better understand the phenomenon under investigation.<ref>Ferrillo M., Marotta N., Giudice A., Calafiore D., Curci C., Fortunato L., Ammendolia A., de Sire A. Effects of occlusal splints on spinal posture in patients with temporomandibular disorders: A systematic review. Healthcare. 2022;10:739. doi: 10.3390/healthcare10040739.</ref> The study authors evaluated the impact of masticatory abnormalities on postural control and focuses on evaluating individuals with specific malocclusions that determine the anteroposterior position of the mandible. According to some researchers, malocclusion, like TMD, can affect the osteoarticular system of the whole body and become a source of persistent pain and favor the development and perpetuation of some postural defects. According to the cited authors, occlusal disturbances can lead to an altered stimulation of the periodontal proprioceptors, causing changes in the tension of the neck muscles and postural muscles and changes in the position of the head, followed by compensatory changes in the anatomical regions in their immediate vicinity. Over time, this can affect your posture, center of gravity position, or foot contact with the ground.<ref name=":0" /><ref name=":11" /><ref name=":12" /><ref>Saccucci M., Tettamanti L., Mummolo S., Polimeni A., Festa F., Tecco S. Scoliosis and dental occlusion: A review of the literature. Scoliosis. 2011;6:1–15. doi: 10.1186/1748-7161-6-15. </ref><ref>Sforza C., Tartaglia G.M., Solimene U., Morgan V., Kaspranskiy R.R., Ferrario V.F. Occlusion, sternocleidomastoid muscle activity, and body sway: A pilot study in male astronauts. Cranio. 2006;24:43–49. doi: 10.1179/crn.2006.008</ref><blockquote>[[File:Question 2.jpg|left|50x50px]][[File:Pz.Arc006.jpg|thumb|232x232px|'''Figure 2:'''Trigeminal electrophysiological responses.]]This could also be true but at the same time it should be demonstrable in order not to make diagnostic errors such as the one we will present in the section dedicated to 'Occlusion and Posture. Indeed, the patient we will present exclusively reported a masticatory disorder such as to require continuous rehabilitative reconstructions from his dentist. How can we demonstrate this occlusal disturbance at the neuromotor level such that it can also condition the vestibular system, the cerebellum and other brain centres? Faced with a marked asymmetry such as the one shown in Figure 2, we certainly cannot deny a trigeminal disorder which is often related to a malocclusion. In Figure 2A we can see a slight asymmetry of the interferential EMG trace between the right and left masseter as well as the MEPs of the trigeminal root (Figure 2B) as well as the absence of the action potential on the right masseter in the mandibular reflex responses (Figure 2C ). As we will see in the chapters concerning this patient, these abnormal trigeminal electrophysiological responses have nothing to do with occlusal disturbances, much less postural disturbances.</blockquote>However, there is still a gap in scientific knowledge on the relationship between craniofacial structure and spinal postural control in patients with malocclusion. Furthermore, the available documents show problems related to the small number of subjects, the small number of tested parameters or the selection of reliable measurement tools.<ref name=":8" /><ref>Michelotti A., Buonocore G., Manzo P., Pellegrino G., Farella M. Dental occlusion and posture: An overview. Prog. Orthod. 2011;12:53–58. doi: 10.1016/j.pio.2010.09.010. </ref><ref>Ishizawa T., Xu H., Onodera K., Ooya K. Weight distributions on soles of feet in the primary and early permanent dentition with normal occlusion. J. Clin. Pediatr. Dent. 2005;30:165–168. doi: 10.17796/jcpd.30.2.8x4727137678061m.</ref>

Angle suggested a classification of occlusion and malocclusion based on the anteroposterior position of the first molar and the position of the canines.<ref>Bernabé E., Sheiham A., de Oliveira C.M. Condition-specific impacts on quality of life attributed to malocclusion by adolescents with normal occlusion and Class I, II and III malocclusion. Angle Orthod. 2008;78:977–982. doi: 10.2319/091707-444.1</ref><ref name=":13">Okeson J.P.  Management of Temporomandibular Disorders and Occlusion.Mosby; Maryland Heights, MO, USA: 2019.</ref>Malocclusion is often a congenital condition, resulting from hereditary or environmental factors. It is also caused by local factors, such as an abnormal pattern of breathing or postural defects, as well as oral parafunctions such as nail biting or teeth grinding (bruxism).<ref name=":13" />According to Lombardo's analyses, occlusal anomalies occur on average in 56% of the general population.<ref name=":14">Lombardo G., Vena F., Negr P., Pagano S., Barilotti C., Paglia L., Colombo S., Orso M., Cianetti S. Worldwide prevalence of malocclusion in the different stages of dentition: A systematic review and meta-analysis. Eur. J. Paediatr. Dent. 2020;21:115–122.</ref> Their prevalence increases with age. Given their increasing prevalence in later age groups and the consequences they entail, it is reasonable to expect a large number of adult patients who will require complex and expensive multidisciplinary treatment.<ref name=":14" /><ref>Kawala B., Szumielewicz M., Kozanecka A. Are orthodontists still needed? Epidemiology of malocclusion among polish children and teenagers in last 15 years. Dent. Med. Probl. 2009;46:273–278</ref><blockquote>[[File:Question 2.jpg|left|50x50px]][[File:Recovery cycle.jpeg|thumb|150x150px|Figura 3: _rcMIR in paziente bruxista]]Regarding bruxism<ref name=":13" /> we certainly cannot speak of scientific certainties or take into consideration the incidence of bruxism in the population because, as described in the specific chapter concerning our patient '[[Encrypted code: Hyperexcitability of the trigeminal system|Bruxer]]', he had a perfect occlusion and neuromuscular responses apparently up to standard if it hadn't been for the study of the case and have highlighted a neuronal hyperexcitability with the test of the crMIR masseter inhibitory recovery cycle (Figure 3). Although the patient was in a state of neuronal hyperexcitability which affected the entire left leg with stiffness of the upper limbs, he never accused postulated problems. With this we want to underline that although there are correlations between different cerebral association areas such as the vestibular, the trigeminal, the midbrain and so on, this does not give the clinician the right to base the diagnosis on these certainties. As, of course, we will repeat repeatedly throughout the 'Normal Science' section to justify the next section which will focus on the aspect of the anomalies and therefore the crisis of the paradigm.</blockquote>

==== Contents to refute the correlation ====

#dental intercuspid position (ICP).