Journal of Craniomandibular Function, 01/2018

Bruxism is a common phenomenon involving repetitive activation of the masticatory muscles. Muscle-stretching exercises are a recommended part of several international guidelines for musculoskeletal disorders. They may be effective in the management of the jaw-muscle activity that gives rise to bruxism. However, most studies of muscle-stretching exercises have mainly focused on their influence on the performance (eg, range of motion, coordination, and muscle strength) of the limb or trunk muscles of healthy individuals or individuals with sports-related injuries. Very few studies have investigated stretching of the human masticatory muscles, and none have investigated muscle-stretching exercises in the management of sleep bruxism (SB). This article reviews the literature on muscle-stretching exercises and their potential role in the management of SB or its consequences in the musculoskeletal system. Keywords: bruxism, muscle stretching, jaw muscle stretching protocol

Background: Sleep bruxism (SB) and obstructive sleep apnea (OSA) are closely associated. Scores of occlusal splints are prescribed around the world for the management of bruxism and the symptoms associated with it. This prompted Gagnon et al1 to conduct a pilot study in 2004 investigating the effects of an occlusal splint adjusted in centric occlusion on different OSA variables. The investigators observed some differences in OSA variables, but none were statistically significant. Furthermore, the study had a low level of evidence. Aim: The objective of this review, conducted as part of a Master's thesis, was to systematically evaluate the national and international literature on this subject and derive conclusions for dental practice. Methods: Systematic searches of the Cochrane, PubMed, LIVIVO (formerly MEDPILOT), and TRIP medical databases and of various publishing company databases and national and international sleep medicine association journal databases were conducted and supplemented by manual searches of the cited references to identify potentially suitable studies. The identified studies were analyzed for design, methodological quality, and level of evidence (Oxford Centre for Evidence-Based Medicine criteria), and were evaluated and discussed. Results: Currently, there is insufficient evidence to support the hypothesis that the use of a monomaxillary occlusal splint provokes the aggravation of clinical symptoms and the escalation of diagnostically relevant parameters in OSA patients. In addition to design weaknesses and methodological differences, another main limitation of the three thematically relevant and hitherto published studies is that the number of cases studied was too small to draw any statistically reliable conclusions. Conclusions: In view of the close association between SB and OSA and the trends identified in the available studies, it still seems wise to review the medical history before prescribing an occlusal splint to determine whether the patient has OSA. A positive history of snoring, pauses in breathing during sleep, daytime tiredness, micro-sleep, sleep laboratory testing or the use of a positive airway pressure (PAP) device for respiratory ventilation should prompt the dentist to refer the patient to a sleep laboratory for polysomnography (PSG) to test for OSA. If the diagnosis is confirmed by a sleep medicine specialist, it is recommended that a portable device is used to monitor sleep-related parameters with the occlusal splint in place. Keywords: apnea/hypopnea index (AHI), history, occlusal splint therapy, sleep bruxism (SB), obstructive sleep apnea (OSA)

A model for the simulation of temporomandibular joint (TMJ) function was developed by our group based on human TMJ measurements and computer-aided design/computer-aided manufacture (CAD/CAM) as a tool for the visualization of TMJ function. We found that only a few parameters are needed to visualize both temporal bone and condylar surfaces as subregions of rotation bodies. With condyle and temporal bone specimens, we found that it was possible to match practically all points of interest, vary the condylar axes to simulate all types of functional movement, and produce near-natural models of the TMJ discs as well as pathological variations using the developed model. It proved to be a good visualization tool suitable for teaching purposes. It can also be used for the comparison and analysis of various functional scenarios in scientific research. The model can be used to study TMJ disc function and variation, rotation, displacement and torsion, and the results can be analyzed in relation to magnetic resonance imaging (MRI) findings and pathological manifestations. Keywords: temporomandibular joint, simulation, biomechanics, temporomandibular joint function, temporomandibular joint model

The occlusal splint as a tried and tested treatment method for temporomandibular dysfunction (TMD) can pose a challenge to dentists in clinical practice in the case of certain positional anomalies of the jaw and teeth, especially with regard to the correct functional design. This article describes a case-based reasoning approach, which, via simple adjustments made to the occlusal splint in a patient with Angle Class II Division 2 malocclusion, resulted in the rapid success of treatment. In this article, possible factors for the occurrence and successful treatment of TMD with joint sounds are briefly discussed in the context of this dysgnathia case. Keywords: occlusal splint, Angle Class II Division 2 malocclusion, malocclusion, joint sounds, case-based reasoning

The functional analysis of mandibular movement patterns based on electronic records (electronic axiography or condylography) is not covered by the 2012 revision of the German Dental Fee Schedule (GOZ). The only change from GOZ 1988 is that the old service item 806 was renumbered 8060 and limited to the application of mechanical recording systems. The description was otherwise left unchanged. A separate service item, 8065, was added with a similar description, but intended to cover the use of electronic registration systems. Apart from the distinction between mechanical and electronic recording systems, both services thus remain almost unchanged in the revised GOZ 2012 compared to the GOZ 1988. Furthermore, the descriptions of both service items unequivocally limit the scope of the items to the movement record intended for programming articulators. This is sufficient and useful for restorative applications. However, the methods for the functional evaluation of mandibular movement patterns that have arisen in recent years are not reflected in these two items. At the same time, however, these methods are well founded in the scientific literature and have now also been described in the Guideline (S2k) "Instrumental Functional Analysis in Dentistry"1. Dentists in Germany are required by law to practice dentistry according to the current state of the art, but they cannot do so based solely on the service items listed in the GOZ. § 6.1 of GOZ 2012 therefore explicitly stipulates that those dental services not listed as independent service items can be billed according to the type, cost, and time input involved and the degree of difficulty of comparable services (referred to as "analogous services"). With reference to the example of functional mandibular movement analysis, the present article describes the legal and technical background of the GOZ items as well as the consequences for their implementation in clinical practice. Keywords: temporomandibular dysfunction (TMD), analysis of mandibular movements, recording of mandibular movement, clinical functional analysis, Dental Fee Schedule (GOZ), analogous billing