The effect of musculoskeletal facial pain on registration of maxillomandibular relationships and treatment planning: a synthesis of the literature

Evaluation of accuracy between extraoral Gothic arch tracing and various other methods assessing horizontal condylar guidance angle in completely edentulous patients: A systematic review and meta-analysis

Aim

The aim of this systematic review and meta-analysis was to determine the accuracy of different methods of measuring horizontal condylar guidance (HCG) angle in comparison with extraoral Gothic arch tracing for completely edentulous patients.

Settings and Design

This was a systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

Materials and Methods

Two reviewers searched the EBSCOhost, Cochrane Library, and PubMed/MEDLINE databases and the Google Scholar search engine for in vivo studies, randomized controlled trials, cross-sectional studies, and quasi-experimental studies published from January 2005 to December 2022 on various other methods of determining HCG angle in completely edentulous patients compared with extraoral Gothic arch tracing method.

Statistical Analysis Used

Meta-analysis was conducted from the reported quantitative data.

Results

A total of 513 articles were obtained from different electronic databases, of which 22 studies were included for qualitative synthesis and 20 studies were included for meta-analysis. For the right side, a statistically significant difference was observed for panoramic radiograph (P < 0.05, pooled mean difference = 5.08 [2.17, 7]) and cephalogram (P < 0.05, pooled mean difference = 10.65 [8.81, 12.49]), whereas no statistically significant difference was observed for cone-beam computed tomography (CBCT) (P = 0.41, pooled mean difference = 4.39 [-6.10, 14.87]) and protrusive interocclusal wax record (P = 0.92, pooled mean difference = -0.45 [-9.62, 8.72]) as compared with extraoral Gothic arch tracing method. For the left side, a statistically significant difference was observed for panoramic radiograph (P < 0.05, pooled mean difference = 5.07 [1.95, 8.18]) and cephalogram (P < 0.05, pooled mean difference = 10.24 [8.65, 11.83]), whereas no statistically significant difference was observed for CBCT (P = 0.31, pooled mean difference = 4.05 [-3.74, 11.84]) and protrusive interocclusal wax record (P = 0.72, pooled mean difference = -1.21 [-7.86, 5.43]) as compared with extraoral Gothic arch tracing method.

Conclusion

The cephalogram and panoramic radiograph obtained higher HCG angles in completely edentulous patients than extraoral Gothic arch tracing.

Osteoarthritis of the temporomandibular joint: A review of aetiology and pathogenesis

The aim of this review was to assess the level of evidence for genetic, biological, and functional predictive and predisposing factors for end-stage temporomandibular joint arthritis within the published literature. A comprehensive review based upon PRISMA guidelines was performed from all literature relevant to the topic. Case series and animal studies were included given the rare nature of the disease and goal of finding root-cause predictive factors. Clinical and radiographic measures were used specifically to identify factors which may have contributed to disease onset and progression. A total of 249 abstracts were identified based on search terms of major databases. After application of exclusion and inclusion criteria, 63 full-text articles were included in the analysis of this paper. There were few factors that could be reliably used to predict end-stage temporomandibular joint disease. Limited evidence is available to adequately predict end-stage temporomandibular joint osteoarthritis. No descriptive process exists that explains how and why this process can occur in younger adults. A better understanding of the aetiology and pathogenesis of TMJ-OA may lead to prevention and more effective management strategies that may reduce the need for drastic surgical intervention, particularly in young adults.

Centric relation critically revisited-What are the clinical implications?

PURPOSE OF THE ARTICLE

Centric relation is a dental term that has undergone many alterations over the years, which in turn have led to significant clinical controversies. These continuing changes in the meaning of the term CR have not only led to confusion, but they also have resulted in a variety of unnecessary diagnostic and therapeutic procedures. Analysis of the dental literature reveals ongoing misunderstanding and disagreement regarding that term among both clinicians and academic dentists.

MATERIALS AND METHODS

A search of the PubMed database was performed with the following search terms: "centric relation", "masticatory muscles", "maxillomandibular relationship" and "condylar position." Relevant literature from the past 70 years until the present day was meticulously scrutinised.

RESULTS

As expected, the literature review on the topic of CR revealed a problematic pattern of changing definitions and clinical disagreements, all of which have had a significant impact on the practice of dentistry.

CONCLUSION

There are semantic, conceptual and practical reasons for concluding that the term 'centric relation' is flawed. Those flaws have a significant impact on dental practice. Based on our analysis, argumentation is provided to conclude that the term 'centric relation' should be abandoned. Instead, it appears that every individual has a unique temporomandibular joint relationship which cannot be described by any singular term. In healthy dentate patients, this relationship is determined by the maximum intercuspation of the teeth and should therefore be considered as biologically acceptable.

Comparative evaluation of the depth of curve of Spee between individuals with normal dentition and individuals with occlusal wear using conventional and digital software analysis techniques: An in vivo study

Objectives:

The objective of this study is to evaluate and compare the depth of curve of Spee in normal dentitions and dentitions with occlusal wear using conventional and digital software techniques.

Materials and Methods:

A total of 70 healthy human subjects were selected for this study in an age group of 20–50 years. Group A includes the stone models (dental casts) of 35 individuals with healthy (nonattrited) dentition. Group B includes stone models of 35 individuals with occlusal wear (generalized attrited) dentition. Two methods were used for measuring the curve of Spee, i.e., conventional method and three-dimensional digital analysis method.

Results:

Depth of the curve of Spee between these two groups was statistically the same. The Digital software analysis (Method II) gives more accurate readings when compared with the Conventional (Method I) of measuring the depth of the curve of Spee.

Conclusion:

Depth of curve of Spee is maintained through the life. There is no statistical difference in depth of curve of Spee between the two groups and digital method give more accurate measurements.

Occlusal stability

Occlusion is the foundation for clinical success in fixed, removable, and implant prosthodontic treatment. Understanding those principles is critical when restoring a patient's occlusion. Many philosophies, devices, and theories of occlusion have evolved based on anecdotal clinical observations and applied geometric perceptions. The literature has reported these classic and contemporary occlusal concepts. As evidence-based dentistry emerged, it championed scrutiny of previously held beliefs, resulting in the abandonment of many pragmatic, yet beneficial occlusal procedures. The impetus toward scientific discovery, whereby factual information might be universally applied in dental education and clinical practice, has renewed interest in occlusal studies.

Reproducibility of condyle position and influence of splint therapy on different registration techniques in asymptomatic volunteers

The current study aims to analyze and quantify the effects of different registration techniques on the reproducibility of condyle position and the influence of stabilization splint therapy on the technique's reproducibility. Three-dimensional electronic-condylar-position analysis (EPA) with an ultrasound-based jaw-tracking system was recorded during intermaxillary registration of manually guided centric relation (CR), maximal intercuspation (MI), and clenching-force-dependent Gothic arch tracing guided centric relation (DIR method) before (T0) and after (T1) splint therapy. Patients were supplied with a stabilization splint for three months on the basis of the DIR registration. Participants were 26 asymptomatic volunteers with a mean age of 30.6 +/- 9.5 years. The registration technique was found to have a significant (p = 0.001) effect on condylar displacement in all axes before, and in X- and Y-axes after splint therapy. Condyles during DIR were found to be in a more anterior-inferior position compared with CR and MI, with the condyles in the latter position being likewise more anterior than in CR. There were significant (p < 0.03) differences in reproducibility of the condyle position dependent on the technique, both at T0 and T1. The DIR method showed the highest reproducibility, followed by MI and CR. There was no significant effect of time of investigation on the technique's reproducibility.

An evaluation of horizontal jaw relations during standing and sitting with open or closed eyes

When determining the horizontal jaw relation and mandibular movements, a question arises as to the appropriate choice of registration positions. The current study was carried out using 22 adults with full dentition who did not have any discomfort in their skeletal and craniomandibular systems. Occlusion and mandibular movements were investigated with open and closed eyes in standing and sitting positions using an electronic, central-bearing tracing device. The coordinates of the measured parameters are presented using a two-dimensional computer vector diagram. The non-parametric Friedman test was used for statistical data analysis. The measured data obtained for the initial habitual centric relation record (HR), centric relation record (CR), final habitual centric relation record (HR), and protrusion (P) did not significantly differ in the sitting and standing positions or with opened and closed eyes (p = 1.00). With closed eyes, the differences in the average values between the two condylar positions (initial HR/final HR, initial HR/CR, and final HR/CR) decreased in a manner that was independent of the registration position. The CR that was measured in a sitting position with closed eyes was 2.26 mm more retrusive than that measured with open eyes. Before and after CR measurements, only laterotrusion showed significant differences (p=0.02) in patients who were standing with closed eyes. It was concluded that the registration position and visual system could individually influence the measurements of condylar position and mandibular movements. From a clinical perspective, these measurements exhibited the smallest differences when they were conducted with patients in a sitting position with closed eyes.

The influence of different registration techniques on condyle displacement and electromyographic activity in stomatognathically healthy subjects: a prospective study

STATEMENT OF PROBLEM

It is unclear whether different intermaxillary registration techniques are related to a physiological condylar position that permits neuromuscular equilibrium.

PURPOSE

This study analyzes and quantifies the effects of different registration techniques on the condyle position and how the registration technique modulates bilateral masseter and anterior temporalis muscle electromyographic activity.

MATERIAL AND METHODS

Three-dimensional electronic condylar position analysis (EPA) with an ultrasound-based jaw-tracking system and surface electromyographic activity (sEMG) was recorded during the registration of a manually guided centric relation (CR), maximal intercuspation (MI), and Gothic arch tracing guided centric relation (DIR method). Participants were 26 stomatognathically healthy volunteers (mean age, 30.6 ±9.5 years). Data were analyzed by 1-way ANOVA and post hoc Bonferroni correction (α=.05).

RESULTS

EPA showed significant differences (P<.001) for CR, MI, and DIR in the vertical, sagittal, and horizontal axes. The condyle position during DIR was found to be significantly more anteriorly and inferiorly located than with CR (P<.001) and MI (P<.04). There were no significant differences in the mean muscle activity among CR, MI, and DIR. Muscular symmetry ranged from 63.87 to 81.47%. Significantly higher symmetry for the anterior temporalis (P=.03) and the masseter (P=.03) was found during the DIR than with CR. Torque coefficients (potential laterodeviating effect) were between 88.02% (CR) and 89.94% (MI).

CONCLUSIONS

Registration technique significantly influenced the condyle position, while mean muscular activity was minimally affected. With respect to muscular balance and activation, the DIR position proved to be capable of inducing the greatest motor unit activity when compared with manually guided CR and MI.

Comparative study of intermaxillary relationships of manual and swallowing methods

This study compared the mandibular displacement from three methods of centric relation record using an anterior jig associated with (A) chin point guidance, (B) swallowing (control group) and (C) bimanual manipulation. Ten patients aged 25-39 years were selected if they met the following inclusion criteria: complete dentition (up to the second molars), Angle class I and absence of signs and symptoms of temporomandibular disorders and diagnostic casts showing stability in the maximum intercuspation (MI) position. Impressions of maxillary and mandibular arches were made with an irreversible hydrocolloid impression material. Master casts of each patient were obtained, mounted on a microscope table in MI as a reference position and 5 records of each method were made per patient. The mandibular casts were then repositioned with records interposed and new measurements were obtained. The difference between the two readings allowed measuring the displacement of the mandible in the anteroposterior and lateral axes. Data were analyzed statistically by ANOVA and Tukey's test at 5% significance level. There was no statistically significant differences (p>0.05) among the three methods for measuring lateral displacement (A=0.38 +/- 0.26, B=0.32 +/- 0.25 and C=0.32 +/- 0.23). For the anteroposterior displacement (A=2.76 +/- 1.43, B=2.46 +/- 1.48 and C=2.97 +/- 1.51), the swallowing method (B) differed significantly from the others (p<0.05), but no significant difference (p>0.05) was found between chin point guidance (A) and bimanual manipulation (C). In conclusion, the swallowing method produced smaller mandibular posterior displacement than the other methods.

Dental occlusion: a critical reflection on past, present and future concepts

For nearly a century, the diversity of concepts about 'normal' and 'ideal' dental occlusal relationships has led to confusion in trying to describe the occlusion of any individual patient. In addition, a similar controversy arises when trying to formulate treatment plans for patients who need extensive dental restorations or orthodontic treatment. And finally, the application of occlusal concepts to patients with temporomandibular pain and dysfunction has created a third area of debate. Over the past few decades, however, an appreciable part of the tenacious dogmatic heritage of this topic has been challenged. As a result, the acceptance of morphological and functional variability of the stomatognathic system has gained increasing support, and this change has important consequences for modern dental practice. In this article, the past, present and future of the subject of occlusion will be considered.

Therapie bei Schmerzen der Kaumuskulatur

Myalgias of the masticatory muscles are the most frequent noninfectious complaints in the orofacial region. After summarizing the current knowledge on the physiology, etiology, pathophysiology, diagnosis, and differential diagnosis of masticatory muscle pain, we specifically focus on management recommendations. Results of an extensive literature search show that for the majority of patients pain reduction or pain relief can be achieved with noninvasive reversible methods. Longitudinal short- and long-term studies have revealed that different therapeutic measures are similarly effective. In patients with chronic masticatory myalgias associated with psychosocial impairment, however, additional involvement of a psychotherapist is crucial.

Report on the determination of occlusal vertical dimension and centric relation using swallowing in edentulous patients

When constructing a complete denture, the correct vertical dimension of occlusion (VDO) and centric relation (CR) can be difficult to determine. The aim of this study was to compare the swallowing technique used to determine the maxillomandibular relationship with a conventional technique. Fifteen edentulous patients were selected, each having a complete denture. The VDO and CR were assessed using acrylic base plates and a Boley gauge. First, the VDO was established by means of the vertical dimension of rest (VDR) and interocclusal rest space, and the CR was obtained by mandibular manipulation. Secondly, the VDO and the antero-posterior mandibular position were determined using swallowing. All measurements were repeated three times and the average was calculated. The results showed that (i). the VDO determined by means of the swallowing method was reproducible and significantly higher than the one established from the VDR (P < 0.01), and (ii). the swallowing position was located 2 mm anterior to CR (P < 0.01) and was moderately reproducible. This study suggests that swallowing can be used to determine the vertical position but no as a reference position in the sagittal plane.

Regulation of mandibular postures: mechanisms and clinical implications

This review argues that (1) the habitual mandibular position is constantly variable and so cannot be considered as a craniomandibular reference point, (2) there is no unique centric relation, (3) mandibular posture greatly depends on head posture, (4) clinical evaluation of the occlusal vertical dimension is mostly empirical, and (5) neither the vertical dimension at rest nor the centric relation can be determined by means of existing instrument-based clinical methods. However, some physiological conditions exist that facilitate the recording of craniomandibular position.

Overview of articulation materials and methods for the prosthodontic patient

STATEMENT OF PROBLEM

Many methods and materials are available for registering the centric relation position, with various degrees of accuracy. Once the centric relation position is recorded, many instruments are available for cast articulation. These articulators range from simple to complex devices that generate different mandibular movements depending on the sophistication of the instrument.

PURPOSE

This review evaluated the methods and materials used to record the centric relation position and eccentric maxillomandibular relations, and to compare the articulators available for mounting casts.

METHODS

A MEDLINE search was completed (from 1966-present) along with personal searches of selected journals to find additional publications that addressed these materials, methods of registration, and available instrumentation.

CONCLUSION

Potential applications of this review are as follows: (1) to allow the reader to examine the various methods for recording the centric relation position that have been studied and described, and (2) to observe how the accuracy of recording materials have changed over time. The reader will also realize the types of simple and complex articulators that exist, along with the different degrees of simulated mandibular movements that may be accomplished.