Mediotrusive Occlusal Contacts: Best Evidence Consensus Statement

Abstract

Purpose The impact of mediotrusive (MT) occlusal contacts has been a topic of controversy and confusion in both clinical practice and in the dental literature. The purpose of this Best Evidence Consensus Statement was to explore whether MT interferences are harmful in the natural or therapeutic occlusion directed by 4 focus questions relating to prevalence, jaw function, jaw dysfunction and biomechanical models. Materials and Methods An electronic search in October 2020 sought evidence in MEDLINE (Ovid) using (mediotrus* OR nonworking side OR nonworking contact OR balancing side OR interfer* side OR premature contact) in the multipurpose (.mp) search field; and in Google Scholar using permutations of the above. Supplementary articles were sourced from the associated reference lists. There was no language restriction. The search yield was reviewed in duplicate. Results The electronic search identified 420 articles. Following screening, 164 were selected for eligibility assessments. Of these, 47 were included in the current paper. Conclusions Non‐standardized nomenclature and methodology is used to identify MT interferences in patient populations, with resultant prevalence varying from 0% to 77%, (median = 16%). MT interferences may alter the biomechanics of mandibular function. Together with the presence of repeated high loads resultant strain can manifest as pathophysiology of the temporomandibular joint and associated muscle structures. MT interferences should be avoided in any therapeutic occlusal scheme to minimize pulpal, periodontal, structural and mechanical complications or exacerbation of temporomandibular disorders (TMDs). Naturally occurring molar MT interferences should be eliminated only if signs and symptoms of TMDs are present. Literature supports there being a biomechanical basis which can explain how MT interferences may affect temporomandibular joint morphology and jaw function.

The effect of tooth cusp morphology and grinding direction on TMJ loading during bruxism

“…More specifically, our study focused on the investigation of potential differences between MT and LT guidance. While the topic of MT guidance is still controversially discussed in literature, generally anterior LT guidance seems to be preferred, when redesigning occlusal contacts ( Walton and Layton, 2021 ). Due to the changes in the direction of movement, differences in muscle excitation patterns can be seen.…”

“…Recently, a consensus statement on MT occlusal contacts stated that “MT interferences may alter the biomechanics of mandibular function. In the presence of repeated high loads this can possibly lead to pathophysiology of the temporomandibular joint and associated muscle structures” ( Walton and Layton, 2021 ). Accordingly, the investigation of MT interferences during bruxing is important to better understand the potential connection of TMD and bruxism.…”

Treatment protocol for temporomandibular joint derangement using an anterior repositioning splint with modification (one year prospective study).

“…Tow examiners used "Form 2", that was designed according to TMD research diagnostic criteria (RDC/ TMD) (58) , the form consists of 3 parts as follows; A) first part help to assess pain and disability in terms of a Modified Chronic Pain Disability Scale (MCPS) in which (0= no pain & no disability, 1= low pain & no/ low disability, 2= moderate pain & no/ low disability, 3= moderate pain & low/ moderate disability, 4= high intensity pain & high disability or even severely limiting situation) (57) , B) second part helps to assess secondary myalgia in terms of a pain site scale (MYS), in which (0= no pain, 1= local pain at palpation site, 2= pain spreading beyond palpation site within the palpated muscle, 3= pain spreading beyond palpation site and beyond the palpated muscle) (59) , C) third part is used to assess the opening deviation from mid line (OD) or the mediolateral shift that deviates the mandibular closing path, the measurements indicated the deviation of the lower incisors midline in relation to upper incisors mid line from maximum intercuspation and maximum opening.. The difference in millimeters were recorded in terms of (0= no shift, 1 = 1-2mm, 2 = 3-4mm, 3 = 5mm, 4= more than 5mm) (60,61) .…”

Risk factors for temporomandibular disorders in young people

“…Основными этиологическими факторами заболеваний ВНЧС считаются окклюзионные нарушения, травмы челюстно-лицевой области, эмоциональный стресс и парафункциональная активность мышц челюстно-лицевой области [6]. При этом ведущим этиологическим фактором дисфункции ВНЧС традиционно считают окклюзионные нарушения, при которых выявляют преждевременные межзубные контакты, изменяющие функциональное состояние мышц челюстнолицевой области [7,8,9,10]. Также многие авторы, изучая психоэмоциональное состояние пациентов с заболеваниями ВНЧС, отмечают значимость эмоционального стресса в усилении парафункциональной активности мышц и возникновении симптомов дисфункции [11,12].…”