Temporomandibular disorders and orthodontics: What have we learned from 1992-2022?

Evidence or else: Concerning trends and the legal risks of unsubstantiated orthodontic-surgical practices

BACKGROUND

Over the past decade, orthodontics has advanced markedly with digital methods, cutting-edge biomechanics, and 3-dimensional diagnostics. However, the rapid adoption of these innovations without rigorous evaluation of their evidential support has led to new unsubstantiated orthodontic-surgical indications.

METHODS

This article explores emerging orthodontic practices, focusing on the interpretation of orthodontic principles and the reliance on imaging-based diagnoses.

RESULTS

Strict adherence to mechanistic orthodontic principles and reliance on imaging findings can result in overzealous treatment protocols. It also emphasizes the state of knowledge regarding temporomandibular disorders (TMDs) and the lack of consensus and evidence-based guidelines.

CONCLUSIONS

There is an urgent need for the profession to integrate TMD knowledge, adopt evidence-based practices, and critically evaluate new methods before implementation.

PRACTICAL IMPLICATIONS

Orthodontists should move away from outdated mechanistic beliefs and integrate clinical knowledge from TMD research into their practices. Increased awareness and potential legal repercussions may drive a necessary reevaluation and stronger adherence to evidence-based methods.

The Role of Malocclusion and Oral Parafunctions in Predicting Signs and Symptoms of Temporomandibular Disorders-A Cross-Sectional Study

BACKGROUND

The aim of this study was to examine to what extent malocclusion and parafunctional habits contribute to the development of signs and symptoms associated with temporomandibular disorders (TMD) in schoolchildren with mixed dentition in Croatia in a sample of 338 children, aged 9 to 15 years.

METHODS

TMD signs and symptoms assessed by the clinician were joint function and pain, masticatory muscles tenderness, range of mandibular motion, and joint sounds. To evaluate subjective symptoms and parafunctions, children and parents were asked about the presence of headaches, jaw locking, temporomandibular joint (TMJ) sounds, pain during mouth opening, or bruxism, as well as parafunctions like biting pencils or nails, chewing hard candies or ice, daily gum chewing, opening bottles with teeth, engaging in jaw play, thumb-sucking, and clenching/grinding teeth.

RESULTS

At least one symptom of a TMD was pronounced in 142 participants (42.0%). The most commonly reported parafunction was pencil or nail biting, present in 25.1% of participants. Class II malocclusion increased the likelihood by 2.6 times, pencil or nail biting by 2.34 times, and clenching/grinding teeth by 8.9 times that the subject would exhibit at least one TMD symptom.

CONCLUSIONS

Every child with mixed dentition should undergo a brief examination of the TMJ, especially in cases of Class II malocclusion, pencil or nail biting, and teeth clenching or grinding, as these have all been identified as significant risk factors that increase the likelihood of experiencing TMD symptoms. This highlights the need for proactive screening and assessment by healthcare providers to reduce the risk and prevalence of TMDs in affected children and ensure timely diagnosis and treatment.

Unlocking the link between temporomandibular disorders and suicide ideation in pre-orthodontic patients: A moderated mediation model of depression and anxiety

BACKGROUND

Temporomandibular disorders (TMD) are a series of musculoskeletal diseases with high prevalence. A few studies have reported the correlation between TMD and suicide ideation (SI). However, the underlying mechanism of the relationship lacks in-depth exploration.

METHODS

A cross-sectional study was conducted among 954 pre-orthodontic patients. TMD assessment was based on the quintessential five TMD symptoms (5Ts) questionnaire. Anxiety, depression and pain catastrophizing was evaluated by Seven-item Generalized Anxiety Disorder Scale (GAD-7), Nine-item Patient Health Questionnaire (PHQ-9), and Pain Catastrophizing Scale (PCS), respectively. Correlational and moderated mediated analysis was preformed to demonstrate the relationship between TMD and SI.

RESULTS

In pre-orthodontic patients, 31.87 % reported having TMD symptoms and 6.50 % declared SI during the past two weeks. The SI prevalence was 10.53 % in participants with TMD and 4.62 % in those without TMD. Intra-articular TMD, rather than pain-related TMD were especially related with SI. Individuals with TMD had higher risk to SI (rs = 0.112, adjusted OR = 2.213, p < 0.001). The effect of TMD on SI was fully mediated through depression (β = 0.445, 95 % CI = [0.326, 0.563]). Anxiety exerted a negative moderating effect on the depression-SI relation (β = -0.033, 95 % CI = [-0.047, -0.019]).

LIMITATIONS

This study was a single-centered and cross-sectional survey. The data collection relied on self-reporting methods.

CONCLUSIONS

A positive link between TMD and SI was disclosed. The effect of TMD on SI was fully mediated through depression with anxiety as a negative moderator.

The association between orthodontic treatment and temporomandibular disorders diagnosis and disease characteristics

BACKGROUND

The association between orthodontic treatment and temporomandibular disorders (TMD) has been contentious in the literature.

OBJECTIVES

To analyse the associations between orthodontic treatment and TMD diagnosis and diseases characteristics.

METHODS

This case-control study included 291 individuals, 192 TMDs and 99 controls. All patients underwent assessment based on a questionnaire and a clinical examination according to Axis I of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). Differences in orthodontic treatment between TMDs and controls, as well as across different TMD diagnoses within the TMD group were analysed. Patients who underwent orthodontic treatment were compared to those who did not, regarding their trauma history, bruxism, aggressive teeth brushing, level of oral hygiene, pain scores, muscle tenderness scores and subjective sleep quality.

RESULTS

Of the 291 participants, 119 (40.9%) underwent orthodontic treatment and 172 (59.1%) had no orthodontics experience. Orthodontic treatment included: mandibular orthodontic treatment (102 subjects) and maxillary orthodontic treatment (113 subjects) of those 47 used a headgear. Following multivariate analysis among TMDs, orthodontic treatment was associated with a good level of oral hygiene versus poor (Odds ratio [OR]: 5.17 [1.04-25.59]), lower number of tender muscles [OR = 0.84 (0.74-0.96)] and lower (better) Pittsburgh Sleep Quality Index (PSQI) scores (OR = 0.86 [0.76-0.97]). None of the studied parameters maintained a statistically significant association with orthodontic treatment in the multivariate analysis among the entire study population.

CONCLUSIONS

Utilising a holistic approach, this study supports the main hypothesis that orthodontic treatment is not associated with TMD diagnosis and disease characteristics.

Application of panoramic radiographs in the diagnosis of temporomandibular disorders

To evaluate the feasibility of temporomandibular disorder (TMD) diagnosis with panoramic radiography, and provide standardized data for artificial intelligence-assisted diagnosis by measuring the differences in the condylar and mandibular ramus heights. A total of 500 panoramic radiographs (219 male and 281 female participants) of healthy individuals were examined. The panoramic machine compatible measurement software, SCANORA 5.2.6, was used to measure the bilateral condylar height and mandibular ramus height, and SPSS 27.0 was used to calculate the left- and right-side differences in condylar height and mandibular ramus height of healthy individuals. Magnetic resonance images of the temporomandibular joint region obtained from 46 outpatients in the Stomatology Department were selected along with their corresponding panoramic radiographs. The left- and right-sided differences were measured and compared with the magnetic resonance imaging results. The measurement data are expressed as mean ± standard deviation (mm). t Tests were used to analyze data from healthy male and healthy female groups. The findings revealed that while there was no significant difference (P > .05) in the height of the condyle between men and women, there was a significant difference (P  < .05) in the height of the mandibular ramus. In healthy population, the difference in height between the left and right condyle was 1.09 ± 0.99 mm. The difference in height of mandibular ramus in men was 1.26 ± 0.85 mm and that in women was 1.19 ± 0.87 mm. For the diagnosis of TMD, the sensitivity of panoramic radiographs was 94.74% (36/38), specificity was 75.00% (6/8), and diagnostic accuracy was 91.30% (42/46). The height of the right and left lateral condyles was not identical in healthy individuals, resulting in a discernible height discrepancy. In addition, the height of the mandibular ramus varied. By considering the left-right lateral height differences identified in this study along with clinical examination, it is possible to employ this metric as a preliminary screening tool for patients with TMD. Further, the use of panoramic radiographs for initial TMD screening is both viable and significant.

Impact of occlusal contact pattern on dental stability and oromandibular system after orthodontic tooth movement in rats

How to ensure dental stability in new positions and reduce the likelihood of relapse is a major clinical concern in the orthodontic field. Occlusal contacts between arches may affect the transmission of masticatory forces, thereby influencing the biological response of the periodontal and the oromandibular system. Occlusion factors that may influence the stability after orthodontic tooth movement (OTM) remain largely unknown. Hence, this research was conducted in order to investigate the influence of different occlusal contact patterns on tooth stability and oromandibular system including the masseter muscle and the temporomandibular joint following OTM. By modifying the occlusal surfaces, in vivo animal study models with distinct occlusal patterns corresponding to clinical circumstances were established. The relapse distance of teeth and the level of inflammatory factors in the gingival cervical fluid were analyzed. We also closely observed the histological remodeling of periodontal tissue, masseter tissue, and joint tissue after one week of relapse. Moreover, genes expression in the alveolar bone was analyzed to illustrate the potential biological mechanisms of relapse under the influence of different occlusal contact patterns following OTM. Different occlusal contact patterns after OTM in rats were established. The intercuspation contact between cusp and fossa group exhibited the lowest level of relapse movement, inflammatory factors and osteoclast activity (P < 0.05). On the other hand, groups with interferences or inadequate contacts exhibited more relapse movement, and tend to promote inflammation of periodontal tissue and activate bone resorption (P < 0.05). Adequate occlusal contacts without interference may enhance tooth stability and reduce the likelihood of relapse. After active orthodontic treatment, necessary occlusal adjustment should be made to achieve the desired intercuspation contact relationship and ensure adequate contact between the arches. The elimination of occlusal interferences is crucial to achieving optimal stability and promoting overall healthy condition of the oromandibular system.

Association between orthodontic treatment and the occurrence of temporomandibular disorders: smoke and mirrors in the form of a systematic review?

QUESTION

To investigate the association between orthodontic treatment and incidence of temporomandibular joint disorders (TMD) as a revision to the existing literature.

DATA SOURCES

Electronic searches were performed in the following databases: PubMed/Medline, Scopus, Scielo, Google Scholar and Web of Science. Hand search of the references of the included studies was also conducted.

STUDY SELECTION

Two authors performed database search independently using the keywords to include case control and cohort studies in English or Spanish language. Systematic reviews and Randomized controlled trials (RCTs) were excluded.

DATA EXTRACTION AND SYNTHESIS

From the studies that met the inclusion criteria, investigators extracted the following data: authors, year, study title, number of patients, male/female ratio, mean age (range), follow up time, groups, number of patients per group, country and results. The Newcastle Ottawa scale was used for risk of bias assessment. All disagreements were resolved by consulting with a third reviewer.

RESULTS

A total of 686 articles were found in the search and 28 duplicates were removed. After title and abstract screening, 648 articles remained. Ten articles were analyzed for full text and four studies were excluded in the process, leaving six articles that met all inclusion and exclusion criteria. Out of six studies, four were case control, one cohort and one prospective cohort. Authors found good quality on all categories of risk of bias assessment in the selected studies. For the meta-analysis, they considered Odds Ratio (OR) because of its presence in every included study. An association between orthodontic treatment and the occurrence of TMD was demonstrated with an odds ratio of 1.84.

CONCLUSIONS

The review authors conclude that the results of their systematic review indicate association between the orthodontic treatment and incidence of TMJ disorders.

CMD und Kieferorthopädie

Die Craniomandibuläre Dysfunktion (CMD) ist mit einer Prävalenz von über 30% die häufigste chronische Schmerzerkrankung im Kiefer- Gesichtsbereich. Die Therapie erfordert einen interdisziplinären, individuell angepassten Behandlungsansatz. Diese Fallvorstellung soll einen Einblick über das Behandlungskonzept eines posterior-lateralen Zwangsbisses mit Oberkiefer- Okklusionsschiene und OK/UK Alignern (Invisalign) geben.

Prevalence of temporomandibular disorders and its association with malocclusion in children: A transversal study

This study investigated the prevalence of temporomandibular disorders (TMDs) in a sample of children and adolescents and evaluated the correlation with occlusal variables. TMD signs and symptoms were recorded in 411 subjects (age range 7-15 years), divided into two groups: 214 subjects treated in Chieti (Italy) CG group and 197 in Murcia (Spain) MG group. Once the Angle dental class was identified, it was recorded if there were signs and symptoms of temporomandibular disorders (TMDs) and occlusal interferences. The percentages of signs and symptoms were compared to determine the differences among the groups for TMDs, bruxism, joint sounds, deviation during the opening, reduced opening/lateral/protrusive movements, malocclusions, and myofascial pain. There is no statistically significant difference between the two groups (χ² = 1.057, p > 0.05). Subjects with Angle Class I (37.37%), deep bite (43.43%), and increased overjet (41.41%) showed a higher prevalence of TMD symptoms.

Associations among Orthodontic History, Psychological Status, and Temporomandibular-Related Quality of Life: A Cross-Sectional Study

OBJECTIVES

This cross-sectional study aimed to evaluate the associations among orthodontic history, psychological status, and temporomandibular-related quality of life.

METHODS

A questionnaire was developed and distributed to students in a local college, containing questions about demographic information, the Patient Health Questionnaire-4 (PHQ-4), the Fonseca anamnestic index, and the Oral Health Impact Profile for Temporomandibular Disorders (OHIP-TMD). The respondents were divided into with orthodontic history (OS) group and without OS group. Binary logistic regression and multiple linear regression were performed for statistical analysis.

RESULTS

A total of 531 valid questionnaires were collected, covering 161 participants with OS and 370 participants without OS. No statistically significant differences were observed in the scores of PHQ-4 between the two groups. There was statistical difference in the prevalence of TMD (with OS group, 54.66%; without OS group, 40.81%) and the mean value ( ± standard deviations) of the scores of OHIP-TMD (with OS group, 9.64 ± 12.36; without OS group, 6.64 ± 10.79) (p < 0.05). After adjusting confounding factors, participants with OS have worse temporomandibular-related quality of life and a higher risk of having TMD than the participants without OS.

CONCLUSIONS

Orthodontic history was related with the higher prevalence of TMD and worse temporomandibular-related quality of life, but not related with psychological distress, and the cause-and-effect relationship needs further exploration.