The role of occlusal factor in the etiology of temporomandibular dysfunction

Orthodontics and Temporomandibular Disorders: An Overview

The relationship between orthodontics and temporomandibular disorders (TMDs) constitutes a subject of paramount significance in dental and craniofacial health. This abstract embarks upon an in-depth examination of the intricate connection between orthodontic practices and TMD, primarily focusing on evaluating the impact of orthodontic treatment modalities on the health and functionality of the temporomandibular joint (TMJ). This exploration elucidates the multifaceted interplay between orthodontic interventions and TMD by traversing a landscape of scholarly research and empirical investigations. The review draws from a broad spectrum of studies to analyze the potential influence of orthodontic treatments, which encompass occlusal adjustments and alterations in jaw positioning, on the development and management of TMD symptoms. The inquiry delves into the diverse range of TMD conditions, considering the implications of orthodontic techniques on occlusal stability, condylar alignment, and overall TMJ function. Through a comprehensive synthesis of the available body of knowledge, this abstract aspires to equip dental practitioners, orthodontists, and researchers with a nuanced understanding of the complex dynamics that govern the relationship between orthodontics and TMD. This knowledge, in turn, offers a foundation for informed clinical decision-making and the formulation of effective treatment strategies for patients presenting with TMD symptoms. By shedding light on the intricate interactions between orthodontic procedures and TMJ health, this abstract contributes to the advancement of clinical practices, promoting improved patient outcomes and well-being in the context of both orthodontics and TMDs.

In silico approach towards neuro-occlusal rehabilitation for the early correction of asymmetrical development in a unilateral crossbite patient

Neuro-occlusal rehabilitation (N.O.R.) is a discipline of the stomatognathic medicine that defends early treatments of functional malocclusions, such as unilateral crossbite, for the correction of craniofacial development, avoiding surgical procedures later in life. Nevertheless, N.O.R.'s advances have not been proved analytically yet due to the difficulties of evaluate the mechanical response after the treatment. This study aims to evaluate computationally the effect of N.O.R.'s treatments during childhood. Therefore, bilateral chewing and maximum intercuspation occlusion were modelled through a detailed finite element model of a paediatric craniofacial complex, before and after different selective grinding-alternatives. This model was subjected to the muscular forces derived from a musculoskeletal model and was validated by the occlusal contacts recorded experimentally. This approach yielded errors below 2% and reproduced successfully the occlusal, muscular, functional and mechanical imbalance before the therapies. Treatment strategies balanced the occlusal plane and reduced the periodontal overpressure (>4.7 kPa) and the mandibular over deformation (>0.002 ε) on the crossed side. Based on the principles of the mechanostat theory of bone remodelling and the pressure-tension theory of tooth movement, these findings could also demonstrate how N.O.R.'s treatments correct the malocclusion and the asymmetrical development of the craniofacial complex. Besides, N.O.R.'s treatments slightly modified the stress state and functions of the temporomandibular joints, facilitating the chewing by the unaccustomed side. These findings provide important biomechanical insights into the use of N.O.R.'s treatments for the correction of unilateral crossbite, but also encourage the application of computing methods in biomedical research and clinical practise.

[Dental condiction of patients with temporomandibular dysfunction]

OBJECTIVE

To evaluate the dental condition and the vertical dimension in patients with TMD, and the age and origin of the DTM.

METHODS

Was performed a descriptive study, observational, cross-sectional, with a sample of thirty patients with TMD, diagnosed by Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). This sample was determined based on estimates the service thus a sample of convenience. The association between gender, age, vertical dimension and dental condition with TMD were verified using the chi-square statistical test with 95% confidence intervals.

RESULTS

It found that 26 patients were female and 4 males. Fifteen subjects presented aged below 36.5 years. How much the origin of the DTM, 19 subjects had articular disorder, and 11 muscle disorder. Has been determined that there was no statistically significant association between the independent variables with the DTM.

CONCLUSION

The etiological factors analyzed in isolation do not seem to influence in a unique way in the development of TMD, but may act together with other factors, because the cause is multifactorial.

Effect of the posterior stop on temporomandibular disorders: A systematic review

Background. Temporomandibular disorders have common signs and symptoms, including pain in the masticatory muscles, limitation or deviation in a mandibular range of motion, and other common patient complaints, such as headache and earache. The main focus of this study was to collect comprehensive and integrated data on the effect of the posterior stop on temporomandibular joint disorders, as well as prevention, treatment, and follow-up care for the patients. Methods. The authors conducted the search in PubMed, SCOPUS, Web of Science, Cochrane Library, CINHAL, Medline, ProQuest, Google Scholar, Magiran, IranDoc, SID, and Iranmedex databases for relevant articles. A list of selected study sources, related conferences, and grey literature were manually searched in addition to the databases mentioned above. A 21-year time limit was imposed (2000-2021). Results. Finally, 16 articles were selected to be reviewed in this systematic review. The designs of the included studies were heterogeneous, and due to the low number of studies covered, the authors could not carry out a meta-analysis. Conclusion. The causes of temporomandibular disorders are multifactorial and complex. Therefore, it is difficult to investigate the relationship between this disorder and predictors. The results of the present study indicate that to determine the effect of the posterior stop on temporomandibular joint disorders, more clinical trials and case-control studies should be conducted.

Awareness to consequences of teeth missing and prosthodontics treatment options among people of Aseer region, Saudi Arabia

Background:

Good teeth play a significant role in keeping a healthy personality and a decent quality of life. Loss of tooth is listed among the top hundred health condition affecting the world population, resulting not only in aesthetic and functional damage but also has negative social impact thus affecting the overall quality of life. It has been estimated to cause 7.6 million disability adjusted life years (DALY). Tooth loss has negative consequences on oral health as it may cause drifting of adjacent teeth or over eruption of opposing teeth, further loss of adjacent tooth and temporomandibular diseases (TMDs).

Methods:

This cross sectional study was performed in the clinics of Aseer Dental Centre and King Khalid University during the period from February 2020 to April 2020. In the current study, we kept a 95% level of confidence, precision error of 5%, and we anticipated the awareness among targeted population to be 85%. The sample size for our study was 200. Patients attending the Prosthodontic department for any dental consultation with a prosthetically unrestored partial edentulous areas in oral cavity were the target population.

Results:

Out of total 200 patients 50% of them were male while 50% of them were female. Mean Age ± S.D = 57.8 ± 22.5. We have observed that demographical variables have significant relationship regarding teeth awareness and treatment.

Conclusion:

Although tooth loss has a high prevalence, the common causes found were dental caries and loosing of teeth. As both these conditions can be prevented, repeated awareness campaign should be carried out in order to increase the awareness regarding oral hygiene..

Effect of deprogramming splint and occlusal equilibration on condylar position of TMD patients - A CBCT assessment

Objective: Assessment of clinical symptoms and condylar position of TMD patients using CBCT imaging with deprogramming splint therapy and occlusal equilibration. The hypothesis tested was the alleviation of symptoms of TMD with possible changes in condylar position occurs with this treatment.Methods: The condylar position of 12 TMD patients was observed from CBCT images, and clinically, symptom severity score, mouth opening, and range of motion were compared pre- and post-treatment.Results: All patients reported a statistically significant decrease in the symptom severity score and increase in mouth opening and range of motion (p < .05). A significant decrease was only achieved in the left anterior joint space (p < .05).Conclusion: Deprogramming splint therapy and occlusal equilibration benefitted patients with a reduction in clinical symptoms, and minor changes in condylar position were observed.

Efficacy of Selective Grinding Guided by an Occlusal Splint in Management of Myofascial Pain: A Prospective Clinical Trial

BACKGROUND

For patients whose centric relation (CR) has not been considered at the start and during treatment, the task of achieving an occlusal scheme that works together with the temporomandibular joint, the muscles, and the structures of the stomatognathic apparatus becomes a major concern.

OBJECTIVE

This study aims to describe a reproducible, predictable and to date unreported procedure of selective grinding guided by an occlusal splint and to analyze condylar position (CP) based on the skeletal pattern.

METHODS

A total of 72 symptomatic patients (38 females and 34 males) were classified into three groups: hyperdivergent, intermediate and hypodivergent. CP was quantified by mounted casts on a measures condyle displacement (MCD) device. Helkimo index was also performed in order to assess the severity of the temporomandibular joint (TMJ) disorders attending to clinical dysfunction, occlusal state and anamnestic dysfunction. Once the stability had been obtained, the splint was progressively reduced until the maximum intercuspation (MIC) was achieved.

RESULTS

The vertical displacement was found to be significantly different between the hyperdivergent and other two groups (p<0.01). Comparisons of MCD analysis before and after the selective grinding procedure identified a statistically significant difference in the horizontal and vertical CP (p<0.01) between the different groups whereas the Helkimo Index showed a clear improvement of TMJ disorders.

CONCLUSION

All facial types, specially the hyperdivergent face type, showed a reduction in condylar displacement (CD) and less craniomandibular symptoms using this procedure, making it an excellent technique for clinicians.

Average chewing pattern improvements following Disclusion Time reduction

OBJECTIVES

Studies involving electrognathographic (EGN) recordings of chewing improvements obtained following occlusal adjustment therapy are rare, as most studies lack 'chewing' within the research. The objectives of this study were to determine if reducing long Disclusion Time to short Disclusion Time with the immediate complete anterior guidance development (ICAGD) coronoplasty in symptomatic subjects altered their average chewing pattern (ACP) and their muscle function.

METHODS

Twenty-nine muscularly symptomatic subjects underwent simultaneous EMG and EGN recordings of right and left gum chewing, before and after the ICAGD coronoplasty. Statistical differences in the mean Disclusion Time, the mean muscle contraction cycle, and the mean ACP resultant from ICAGD underwent the Student's paired t-test (α = 0.05).

RESULTS

Disclusion Time reductions from ICAGD were significant (2.11-0.45 s. p = 0.0000). Post-ICAGD muscle changes were significant in the mean area (p = 0.000001), the peak amplitude (p = 0.00005), the time to peak contraction (p < 0.000004), the time to 50% peak contraction (p < 0.00001), and in the decreased number of silent periods per side (right p < 0.0000002; left p < 0.0000006). Post-ICAGD ACP changes were also significant; the terminal chewing position became closer to centric occlusion (p < 0.002), the maximum and average chewing velocities increased (p < 0.002; p < 0.00005), the opening and closing times, the cycle time, and the occlusal contact time all decreased (p < 0.004-0.0001).

CONCLUSION

The average chewing pattern (ACP) shape, speed, consistency, muscular coordination, and vertical opening improvements can be significantly improved in muscularly dysfunctional TMD patients within one week's time of undergoing the ICAGD enameloplasty. Computer-measured and guided occlusal adjustments quickly and physiologically improved chewing, without requiring the patients to wear pre- or post-treatment appliances.

Correlation analysis of craniomandibular index and gothic arch tracing in patients with craniomandibular disorders

BACKGROUND/AIM

Complex etiology and symptomatology of craniomandibular dysfunction make the diagnosing and therapy of this disorder more difficult. The aim of this work was to assess the value of clinical and instrumental functional analyses in diagnosing of this type of disorders.

METHODS

In this study 200 subjects were examined, 15 with temporomandibular joint disorder. They were subjected to clinical functional analysis (Fricton-Shiffman) and instrumental functional analysis by using the method of gothic arch. The parameters of the gothic arch records were analyzed and subsequently compared among the subjects of the observed groups.

RESULTS

In the examined group of the population 7.5% of them were with craniomandibular dysfunction. The most frequent symptoms were sound in temporomandibular joint, painful sensitivity of the muscles on palpation and lateral turning of the lower jaw while opening the mouth. By analyzing the gothic arch records and comparing the obtained values between the observed groups it was assessed that: lateral and protrusion movements, lateral amplitude and the size of gothic arch were much bigger in the healthy subjects, and latero-lateral asymmetry was larger in the sick subjects. Latero-lateral dislocation of apex was recorded only in the sick subjects with average values of 0.22 +/- 0.130 mm. The correlation between the values of Fricton-Shiffman craniomandibular index and the parameters of the gothic arch records and latero-lateral amplitude and dislocation of apex records were established by correlative statistical analysis.

CONCLUSION

Functional analysis of orofacial system and instrumental analysis of lower jaw movements (gothic arch method) can be recommended as precise and simple methods in diagnosing craniomandibular dysfunctions.