Unilateral temporomandibular disorder and asymmetry of occlusal contacts

Evaluation of the contribution of different groups of teeth to occlusion of patients with symptoms of temporomandibular disorders

PURPOSE

The purpose of this study was to analyse the distribution of occlusal forces in the dental arches released during tooth clenching in patients with symptoms of temporomandibular disorders, and to analyse the age and gender structure of the patients in the study group and the control group.

MATERIALS AND METHOD

The study was carried out on a group of 58 patients, of both genders, aged 18-40 years, with full dental arches, who presented for treatment at the Prosthodontics Clinic of the University Dental Clinic in Kraków due to symptoms of temporomandibular disorders. The patients were divided into two groups. The first group (study group) comprised 26 patients with painful temporomandibular disorders, while the second group (control group) comprised 32 patients without pain. The study only included patients over 18 years of age, with full dental arches with symptoms of temporomandibular disorders. All patients underwent a basic dental examination and a specialized functional examination of the masticatory organ. A T-Scan III-Novus instrument with electronic occlusal articulation paper was used to assess the distribution of occlusal contacts.

RESULTS

In the study, women (43) were a larger group than men (15). Statistically significant values for the percentage distribution of occlusal contacts were obtained in group of women in the study group on the right and left side, in the area of molars and premolars. In the analysis of the percentage distribution of occlusal contacts in both the study and control groups, it can be seen that the first molars (teeth 16 and 26) showed a larger percentage range of values than the other teeth. The smallest values can be observed on the second incisal teeth and on the canines.

CONCLUSIONS

The first molars are, in the majority of patients, the teeth on which the strongest occlusal contacts are generated. Excessive participation of incisal teeth in occlusion might influence the development of the pain form of TMD. In order to determine whether there is a correlation between an uneven distribution of occlusal contacts and TMD pain, studies on larger numbers of patients are needed. © 2024 Australian Dental Association.

Safety and Effects of the Rapid Maxillary Expander on Temporomandibular Joint in Subjects Affected by Juvenile Idiopathic Arthritis: A Retrospective Study

BACKGROUND

In Juvenile Idiopathic Arthritis (JIA) temporo-mandibular joints are often affected causing skeletal and dental malocclusions. The most frequent condition is mandibular hypoplasia, that may be associated with maxillary hypoplasia. The aim of this retrospective case control study is to investigate the effects and the safety of rapid maxillary expansion (RME) in growing patients affected by JIA. It was evaluated whether RME could be performed without complications on TMJs of JIA patients using DC/TMD protocol, and naso-maxillary transversal parameters were compared with the ones obtained on healthy patients.

METHODS

Twenty-five patients affected by JIA that ceased to manifest TMJ (Temporo-Mandibular Joint) symptoms in the previous year were treated with RME to solve the maxillary transverse hypoplasia. Postero-anterior cephalometric tracings were collected before and after treatment; linear measurements were obtained to study maxillary and nasal cavity modifications. Data were compared to those of a similar group of twenty-five healthy patients. Paired t-test and Independent t-test were used to evaluate changes before and after treatment in each group and to perform a comparison between the groups.

RESULTS

All patients demonstrated a statistically significant increase in nasal cavity width, maxillary width and upper and lower intermolar width. No patients presented a worsening of their TMJs condition. Intragroup comparisons revealed significant changes of cephalometric measurements, but no difference was found when comparing JIA and healthy patients.

CONCLUSIONS

Growing patients with JIA that ceased to show signs of active TMJ involvement for at least one year could be safely treated with RME, expecting similar benefits to those of healthy patients. Dentists and rheumatologists should be informed of safety and potential benefits of palatal expansion in JIA patients in order to improve the outcome of orthodontic treatment and reduce the indication for more invasive procedures (i.e., Surgical Assisted Rapid Maxillary Expansion).

Effects on the Facial Growth of Rapid Palatal Expansion in Growing Patients Affected by Juvenile Idiopathic Arthritis with Monolateral Involvement of the Temporomandibular Joints: A Case-Control Study on Posteroanterior and Lateral Cephalograms

BACKGROUND

Juvenile idiopathic arthritis (JIA) affecting temporomandibular joints (TMJ) in growing patients results in maxillofacial deformities, especially if only one condyle has been affected by the rheumatic disease. Mandibular hypoplasia is the most common issue and it may be associated with maxillary hypoplasia. The aim of this retrospective case-control study is to evaluate the effects of rapid maxillary expansion (RME) in these patients.

METHODS

25 growing patients affected by maxillary hypoplasia, currently in a quiescent phase of JIA for at least one year and monolateral involvement of the TMJs, were treated with RME. Data gathered from posteroanterior and lateral cephalograms before and after 1 year from RME were compared to those of 25 non-JIA controls.

RESULTS

Nasal cavity width, maxillary width and upper and lower intermolar width statistically increased. Maxillary and mandibular symmetry indexes presented a statistically significant increase, so did the skeletal class. No signs or symptoms of TMJ activity of JIA occurred according to Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) criteria. No difference was found when comparing JIA and non-JIA patients apart from the better improvement of several mandibular symmetry indexes in the affected TMJ side of JIA patients. This event is allegedly due to a worse baseline asymmetry in JIA patients that underwent a bigger relative improvement after treatment.

CONCLUSIONS

Results suggest that solving maxillary hypoplasia and, therefore, premature contacts are likely to have allowed mandibular repositioning and condylar growth. RME is a safe and effective solution that can substantially improve maxillary and mandibular symmetry in growing patients affected by JIA with TMJ involvement.

Vertical contact tightness of occlusion comparison between orofacial myalgia patients and asymptomatic controls: a pilot study

OBJECTIVE

The association between occlusal contact and orofacial pain remains unclear. The aim of this study was to detect occlusal contact tightness by using a new method and to compare differences between patients and asymptomatic controls.

METHODS

Fifteen female patients with orofacial myalgia and fifteen age- and sex-matched asymptomatic controls were enrolled. Occlusal contacts were recorded by making bite imprints. The numbers, sizes, and distributions of the contacts were detected by making photos of bite imprints after biting. The Mann-Whitney U test and ANOVA were used for statistical analysis.

RESULTS

In myalgia patients, impact contacts at the molar regions were more frequent, larger in number and area size, and were distributed more on guiding cusps, compared with impact contacts in asymptomatic controls.

CONCLUSION

Our new method revealed more prevalent and more severe impact contacts in orofacial myalgia patients, compared with asymptomatic controls.

Digital evaluation of occlusal forces: comparison between healthy subjects and TMD patients

Aim

Continuous technological innovation has provided the clinicians to access to a computerized device that can analyse the different characteristics of occlusal contacts. The purpose of this research was to use this device to study the occlusal forces comparing healthy subjects and TMD patients.

Materials and methods

The study was conducted by following specific criteria to select participants; the sample was divided into two homogeneous groups: control group (CG) comprising healthy subjects, and dysfunctional group (DG) comprising TMD patients. The occlusal force analysis was performed using the computerized system T-Scan III V 5.20 T. The data were analysed with statistical methods.

Results

The most significant differences emerged between the groups in the average occlusal load distribution and in the location of the centre of occlusal forces (COF). In particular, compared with the CG and the functional standard, reductions in the molar field forces on the second and first molars of 27% and 6.9%, respectively, were observed in the DG. The COF was located in the most forward position in TMD patients compared with healthy subjects.

Conclusions

Although the differences in the distribution of the occlusal forces and the location of the occlusal centre of gravity were significant, the relationship between occlusal contacts and TMD remains to be fully clarified. Further research is needed to investigate whether studying occlusal force distributions in both healthy subjects and TMD patients.

Computerized analysis of the distribution of occlusal contacts in individuals with Parkinson's disease and temporomandibular disorder

OBJECTIVES

The aims of the present study were to determine the prevalence of temporomandibular disorder (TMD) in a sample of patients with Parkinson's disease (PD) and to analyze the distribution of occlusal contacts.

METHOD

The sample was composed of patients with PD aged 50-75 years. Temporomandibular disorder was evaluated using the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The distribution of occlusal contacts was determined using the portable T-Scan III^® occlusal analysis system during maximum voluntary clenching. Fisher's exact test was used to test the association between TMD and occlusal contact symmetry.

RESULTS

Forty-two individuals with PD were analyzed. The prevalence of TMD was 23.8%. No statistically significant association was found between TMD and occlusal contact symmetry. Moreover, no significant difference in the distribution of occlusal contacts was found between the groups with and without TMD.

DISCUSSION

The present data suggest no association between TMD and occlusal contact asymmetry in individuals with PD.

CONCLUSION

The results of this study identified a prevalence of 23.8% of TMD signs in subjects with PD and a high frequency of occlusal asymmetry in this sample.

Prosthodontic management of temporomandibular disorders

Temporomandibular disorders (TMD) are examined from a biopsychosocial or illness perspective. It is considered that TMD share features with many common chronic pain conditions. Functional disturbances of the masticatory system can be as complicated as the system itself. Although numerous treatments have been advocated, the complex nature of TMD requires a multidisciplinary team. Effective treatment selection begins with a thorough understanding of the disorder & its etiology. However, the multifactorial nature of this malady places some aspects of the disease beyond the traditional education of a Prosthodontist. The management goals for the Prosthodontist as a member of a TMD team are patient comfort, occlusal stability & the complex restoration of the teeth.

Occlusal adjustment using the bite plate-induced occlusal position as a reference position for temporomandibular disorders: a pilot study

Background

Many researchers have not accepted the use of occlusal treatments for temporomandibular disorders (TMDs). However, a recent report described a discrepancy between the habitual occlusal position (HOP) and the bite plate-induced occlusal position (BPOP) and discussed the relation of this discrepancy to TMD. Therefore, the treatment outcome of evidence-based occlusal adjustments using the bite plate-induced occlusal position (BPOP) as a muscular reference position should be evaluated in patients with TMD.

Methods

The BPOP was defined as the position at which a patient voluntarily closed his or her mouth while sitting in an upright posture after wearing an anterior flat bite plate for 5 minutes and then removing the plate. Twenty-one patients with TMDs underwent occlusal adjustment using the BPOP. The occlusal adjustments were continued until bilateral occlusal contacts were obtained in the BPOP. The treatment outcomes were evaluated using the subjective dysfunction index (SDI) and the Helkimo Clinical Dysfunction Index (CDI) before and after the occlusal adjustments; the changes in these two indices between the first examination and a one-year follow-up examination were then analyzed. In addition, the difference between the HOP and the BPOP was three-dimensionally measured before and after the treatment.

Results

The percentage of symptom-free patients after treatment was 86% according to the SDI and 76% according to the CDI. The changes in the two indices after treatment were significant (p < 0.001). The changes in the mean HOP-BPOP differences on the x-axis (mediolateral) and the y-axis (anteroposterior) were significant (p < 0.05), whereas the change on the z-axis (superoinferior) was not significant (p > 0.1).

Conclusion

Although the results of the present study should be confirmed in other studies, a randomized clinical trial examining occlusal adjustments using the BPOP as a reference position appears to be warranted.

Electromyographic activity of sternocleidomastoid and masticatory muscles in patients with vestibular lesions

This study evaluated the electromyographic characteristics of masticatory and neck muscles in subjects with vestibular lesions. Surface electromyography of the masseter, temporalis and sternocleidomastoid muscles was performed in 19 patients with Ménière's disease, 12 patients with an acute peripheral vestibular lesion, and 19 control subjects matched for sex and age. During maximum voluntary clenching, patients with peripheral vestibular lesions had the highest co-contraction of the sternocleidomastoid muscle (analysis of covariance, p=0.02), the control subjects had the smallest values, and the patients with Ménière's disease had intermediate values. The control subjects had larger standardized muscle activities than the other patient groups (p=0.001). In conclusion, during maximum voluntary tooth clenching, patients with vestibular alterations have both more active neck muscles, and less active masticatory muscles than normal controls. Results underline the importance of a more inclusive craniocervical assessment of patients with vestibular lesions.

Is there such a thing as a 'healthy occlusion'?: lessons from history

Opinions on occlusion and its link to oral health could not be more diverse. These opinions are used as justification for an equally diverse range of treatments for so-called occlusally related problems, from heavy wear to chronic orofacial pain. Many claim to have evidence to back up their opinions, although much of it appears to be from a very weak source or based on clinical experience. The strongest case appears to be made by those who believe there is no link, by virtue of a lack of evidence to support its existence. Yet for many clinicians, it is a self-evident truth that occlusion must be related in some way to the function and dysfunction of the stomatognathic system. This article uses historical research to highlight where the pro-occlusionists may be going wrong. It also offers a new concept, based on anthropological studies, that indicates occlusion's link to oral health, and explains why most patients appear to have no occlusal problems for most of the time. This theory needs to be tested by researchers to establish its validity. In the meantime, dentists who feel the need to treat occlusal problems will find it supports a very conservative approach to care.

Occlusal contact patterns – Population-based data

The reconstruction of functionally appropriate contacts between antagonistic teeth substantially determines the quality of prosthetic-restorative work. In a population-based sample comprising 2597 subjects, static occlusal contacts were registered and analysed using the GEDAS (Greifswald Digital Analyzing System), which digitally represents the contact point situation by means of silicone bite impressions. The number of contacting teeth is approximately equal on the Left- and right-hand side amounting to 8.3 on the left and 8.4 on the right. Furthermore, it was shown that 39% of the maxillary bridge pontics and 33% of the mandibular bridge units are not in contact. Antagonistic contacts are missing in 41% of the maxillary and 39% of the mandibular removable denture teeth. These results show that the fabrication of fixed dentures, particularly in bridge pontics, and the inspection of removable dentures needs to be done with more care to this detail.

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.

Aktualisierung der Empfehlungen zur standardisierten Diagnostik und Klassifikation von Kaumuskel- und Kiefergelenkschmerzen

BACKGROUND

In 2000, the interdisciplinary Working Group of Orofacial Pain within the German Chapter of the IASP (German Association for the Study of Pain) published recommendations for the standardized evaluation and diagnostic classification of patients with painful masticatory muscles and/or temporomandibular joints. The purpose of the present study was to critically review and update these recommendations.

RESULTS

Appraisal of the relevant literature published after the release of the recommendations (up to December 2005) shows that the two-axis approach for the assessment of the somatic and psychosocial parameters of the orofacial pain experience has found wide support. Single aspects of the recommendations have been substantiated by additional scientific evidence.

CONCLUSIONS

The recommendations reflect the current state of pain medicine. Therefore, they should be considered among practitioners who diagnose and manage patients suffering from temporomandibular disorders.