TMD and occlusion part II. Damned if we don't? Functional occlusal problems: TMD epidemiology in a wider context

Relationship between natural or iatrogenic malocclusions and temporomandibular disorders: A case control study

OBJECTIVE

To investigate the link between malocclusions and temporomandibular disorders (TMD) with a focus on iatrogenic malocclusion. Other etiologies of TMD (oral parafunctions) were also assessed.

METHODS

The prevalence of malocclusions was correlated in two groups: patients with TMD (case group) and patients without TMD (control group). Malocclusions involving dental care were specified. Parafunctions in the case group were assessed.

RESULTS

A statistically significant association between TMD and overbite >4 mm, interferences in laterotrusion, and absence of Angle Class I was shown. A potential deleterious effect of iatrogenic malocclusions was highlighted.

CONCLUSION

The multifactorial etiology of TMD was confirmed because an association between TMD and three malocclusions was found, and all case patients had parafunction(s). Current recommendations advising first a reversible treatment, TMD care should start with a behavioral re-education to remove parafunctions. However, it is essential to avoid creating iatrogenic malocclusion during dental care.

Effects on Sleep Bruxism Activity of Three Different Oral Appliances: One Year Longitudinal Cohort Study

BACKGROUND

Different oral appliances (OAs) have been proposed to control sleep bruxism (SB) detrimental effects on the stomatognathic system.

OBJECTIVE

The aim of the study was to evaluate the effect of different OAs on SB activity and masticatory muscle activity (sMMA) measured by EMG.

METHODS

This longitudinal cohort study was conducted on 51 patients (21 M, 30 F, mean age 26,5 ± 3,5) suffering from SB diagnosed with a validated portable EMG-ECG holter and wearing different OAs: occlusal splints, functional appliance with metallic bites and clear aligners followed after 1 week, 1 month, 3 months, 6 months and 12 months from delivery. A control group of 16 non-treated SB patients (6 M, 10 F mean age 27,1 ± 1,4) was used as a reference. A multiple regression analysis was performed to estimate the differences between groups. The level of significance was set as P value <0,05.

RESULTS

Occlusal splint reduced sleep bruxism index after 1 week, 3, 6 and 12 months from delivery while functional appliance only after 12 months. Occlusal splints reduced general phasic contractions only in the first week and sleep bruxism-related phasic contractions at 1 week, 3 and 6 months after delivery with no significant reductions after 12 months. Patients wearing clear aligners showed a reduction in general tonic contractions after 6 and 12 months.

CONCLUSION

Resin and metal bites can reduce sleep bruxism index, while resin bites can reduce sleep bruxism-related phasic contractions. Clear aligners do not influence sleep bruxism index but can reduce tonic contractions.

Changes in the distribution of occlusal forces in the course of the orthodontic retention phase : A prospective cohort study

PURPOSE

Aim of the present study was to assess the relative distribution of occlusal forces after orthodontic treatment and during the first 3 months of the retention phase using a computerized occlusal analysis system (T-Scan, Tekscan Inc., Norwood, MA, USA).

MATERIALS AND METHODS

A total of 52 patients were included in this prospective cohort study and underwent analysis of occlusal forces on the level of tooth, jaw-half, and -quadrant during a 3-month period. Furthermore, differences between three retention protocols (group I: removable appliances in both jaws; group II: fixed 3-3 lingual retainers in both jaws; group III: removable appliance in the maxilla and fixed 3-3 lingual retainer in mandible) were assessed with Wilcoxon signed-rank tests at 5%.

RESULTS

Directly after debonding, measured forces distribution were similar to published references for untreated samples. In the following, no significant difference was found between retention protocols II and III with regard to the asymmetry of the anterior occlusal forces. Both groups maintained an asymmetric force distribution in the anterior segment during the study period. There was also no difference between groups II and III in the distribution of occlusal forces for the posterior segments. Both retention concepts kept the symmetrical distribution of occlusal forces stable over the observation period. The retention concept of group I demonstrated a symmetrical distribution of occlusal forces in the anterior segment after debonding and this remained stable during the 3‑month period. In the posterior segment, no improvement of the initially asymmetric masticatory force distribution could be observed.

CONCLUSIONS

All three studied retention protocols showed stability in retaining their original symmetrical or asymmetrical occlusal force distribution posteriorly/anteriorly during the 3‑month observation period. Therefore, an even distribution of occlusal forces should be the aim of the finishing phase, as no relative benefit of any single retention scheme in terms of post-debond improvement during the retention phase was seen.

Temporomandibular Disorders and Dental Occlusion: What Do We Know so Far?

Throughout the recorded history in the literature of temporomandibular disorders (TMD) there have been a variety of opinions as to its primary cause. Those supporting an occlusal basis of TMD opined that occlusal dysfunction is either the primary cause for or a significant etiopathogenic factor in the causation of TMD. Most of the current literature, however, points to evidence in another direction and questions the causal role of occlusion and occlusal disharmony in TMD etiopathogenesis. Recognition of this evidence-based literature is paramount in eliminating and preventing the chances of overtreatment of patients with TMD.

Assessment of occlusion and temporomandibular joint after placing preformed metal crowns on all primary molars in children

BACKGROUND

Placing preformed metal crowns (PMCs) on all eight primary molars at one single clinical visit may disrupt a child's occlusion; the literature regarding the effects on occlusion and temporomandibular joint (TMJ) is scarce.

AIM

This study aimed to quantify the changes in occlusion using T-Scan III and to investigate whether there was TMJ dysfunction after placing eight PMCs at the same time.

DESIGN

In this study, we enrolled children with severe early childhood caries (S-ECC) and dental phobia, who needed eight PMCs to be placed under general anesthesia. The participants underwent occlusal examinations with a computed occlusal analysis system. The vertical dimension of occlusion (VDO) was measured using a dental vertical dimension gauge, TMJ dysfunction signs were recorded by the clinical dysfunction index (Di), and TMJ dysfunction symptoms were recorded using a questionnaire. The data were collected before treatment (T₀ ), 1 week after treatment (T₁ ), and 1 month (T₂ ) and 3 months (T₃ ) after treatment during follow-up visits. Repeated-measures analysis of variance and Friedman's test were used for occlusal data analysis. In addition, the Di and symptoms were compared over time using McNemar's test.

RESULTS

Forty patients (mean age = 4.25 ± 0.63 years, age range = 3-5 years, 21 boys and 19 girls) were followed up for 3 months. The occlusal contact area 3 months after treatment did not return to the pretreatment status (p = .03). The total of force at the 3-month follow-up visit increased significantly (p = .009) compared with that at the pretreatment. The asymmetric ratio of occlusal force at the 1-month follow-up visit was restored to pretreatment. Concerning the occlusion time, no significant changes were observed for any time intervals (p = .069). The VDO was recovered at the 1-month follow-up visit. The statistical analysis of TMJ dysfunction showed no significant differences in the Di and TMJ dysfunction symptoms before and after treatment (p > .05).

CONCLUSION

After undergoing eight PMC restorations under general anesthesia, occlusal re-equilibration was attained approximately after 1 month. There were no significant signs and symptoms of TMJ dysfunction after treatment.

Effects of Prosthetic Rehabilitation on Temporomandibular Disorders: Protocol for a Randomized Controlled Trial

Background

Loss of teeth or occlusal imbalance is one of the proposed dental risk factors for temporomandibular disorders (TMDs). Losing some non–free-end teeth cause the original occluding tooth/teeth to supraerupt from the original upright position and causes neighboring tooth/teeth to shift in an angle, causing biomechanical imbalance on the mandible. Based on these sequelae, rehabilitation of missing teeth is the first step in managing TMD in edentulous patients. Even though the prevalence of TMD in association with edentulism and in rehabilitated patients has been increasing, proper guidelines for the management of such cases have not been established. This study describes the protocol to analyze the effect of prosthetic rehabilitation on patients with TMD.

Objective

This study aims to determine the effectiveness of prosthetic rehabilitation in the reduction of pain in edentulous patients with TMD and to determine the effect of the span of edentulism, the number of quadrants involved, pathological migration, the type of Kennedy classification, and the prosthetic status on temporomandibular joint dysfunction signs and symptoms.

Methods

In this randomized controlled trial, 300 patients diagnosed with TMD will be grouped into one of the three interventional groups based on the type of their edentulous state. The interventional groups are (1) partially edentulous arch: Kennedy Class I and II (prosthetic rehabilitation without splint); (2) partially edentulous arch: Kennedy Class III and IV (prosthetic rehabilitation with a splint); and (3) completely edentulous arches (prosthetic rehabilitation without splint). All three of the mentioned interventional groups have corresponding control groups that will receive symptomatic treatment and comprehensive counseling. The measured primary outcomes are pain and electromyogram, and the secondary outcomes include pain drawing, Graded Chronic Pain Scale, Jaw Functional Limitation Scale, Oral Behaviours Checklist, depression, physical symptoms, and anxiety. The outcome measurements will be recorded at baseline and at the end of 24 hours, 7 days, 28 days, and 3 months.

Results

Ethical approval was obtained from the Institutional Review Board of Amrita Institute of Medical Sciences, Kochi, India. Study participants’ recruitment began in May 2021 and is expected to conclude in March 2023. This clinical trial protocol was developed based on the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) 2013 Statement.

Conclusions

The purpose of this study is to gather data on prosthetic rehabilitation as a treatment for TMD. Obtaining this goal will aid in the development of evidence-based therapy protocols for prosthetic rehabilitation in TMD management.

Trial Registration

Clinical Trials Registry - India CTRI/2020/06/026169; http://ctri.nic.in/Clinicaltrials/pdf_generate.php?trialid=42381

International Registered Report Identifier (IRRID)

DERR1-10.2196/33104

Evaluation of success of stainless steel crowns placed using the hall technique in children with high caries risk: A randomized clinical trial

Objective

This study aimed to compare the clinical efficacy and survival rates of the hall technique (HT), and conventional restoration (CR) for the management of occlusoproximal carious lesions in primary molars.

Materials and Methods

This clinical study observed 35 children (aged 4-8 years). Exclusion criteria included symptoms of pulpal or periradicular pathology or systemic conditions requiring special dental considerations. For each child, at least one tooth was treated with HT and one with CR. The primary outcome measures were minor and major clinical failure rates. Plaque and gingival scores of the teeth were also evaluated. Friedman test and Wilcoxon signed ranks test were used to compare the plaque and gingival index scores for each arm. Chi-square tests were used for comparisons of clinical outcomes, plaque-gingival index, and distribution of ICDAS categories among treatment arms (P < 0.05).

Results

Thirty-three of 35 (94.2%) participants returned for 1-year follow-up. HT showed statistically significantly higher treatment survival rate and fewer minor failures than CR (P = 0.040). The rate of major failures was minimal (2 of 84 teeth) and did not differ between treatments (P = 0.092). In both treatment groups, the gingival score and plaque score were significantly decreased at the 1-year follow-up (P < 0.05).

Conclusion

HT was a more successful method for managing caries in primary molars than CR, both for symptoms of pulpal disease and longevity of the restorations. HT is a simplified method of managing carious primary molars using SSCs cemented with no local anesthesia, caries removal, or tooth preparation.

Relationship between Pathological Occlusal Changes and the Signs and Symptoms of Temporomandibular Dysfunction

Objective

This study aimed to investigate whether there is a correlation between pathological occlusal changes and the signs and symptoms of temporomandibular dysfunction (TMD).

Methods

This cross-sectional, quantitative, non-randomized clinical trial was conducted on 150 participants. We examined adult patients of both genders with occlusal interference, malocclusion and dental absence in the posterior region of the dental arch that were associated or not associated with painful symptoms. The questionnaire was administered, and the intra- and extra-oral clinical examination was performed on each patient, including the evaluation of the temporomandibular joint (TMJ) to investigate the presence of dysfunction.

Results

The mean age of the participants was 33 years (±2.3), and 103 (68.7%) of them were women and 47 (31.3%) were men. Tooth loss and malocclusion were more prevalent in females. Tooth loss showed a statistically significant association with all the signs and symptoms of TMD (p=0.02). Patients with multiple teeth losses experienced preauricular pain during mandibular opening and closing. There was no association between malocclusion with tooth loss and the signs and symptoms of TMD in 65 patients (p>0.05).

Conclusion

Only in the patients with Class II malocclusion there was a significant association with 2 signs of TMD (crackling and bruxism). There was no association between malocclusion and tooth loss with the signs and symptoms of TMD. The signs and symptoms of TMD were more frequent in the patients who presented multiple teeth loss without malocclusion.

Professional consensus on orthodontic risks: What orthodontists should tell their patients

INTRODUCTION

Effective communication of risk is a requisite for valid consent, shared decision-making, and the provision of person-centered care. No agreed standard for the content of discussions with patients about the risks of orthodontic treatment exists. This study aimed to produce a professional consensus recommendation about the risks that should be discussed with patients as part of consent for orthodontic treatment.

METHODS

A serial cross-sectional survey design using a modified electronic Delphi technique was used. Two survey rounds were conducted nationally in the United Kingdom using a custom-made online system. The risks used as the prespecified items scored in the Delphi exercise were identified through a structured literature review. Orthodontists scored treatment risks on a 1-9 scale (1 = not important, 9 = critical to discuss with patients). The consensus that a risk should be discussed as part of consent was predefined as ≥70% orthodontists scoring risk as 7-9 and <15% scoring 1-3.

RESULTS

The electronic Delphi was completed by 237 orthodontists who reached a professional consensus that 10 risks should be discussed as part of consent for orthodontic treatment; demineralization, relapse, resorption, pain, gingivitis, ulceration, appliances breaking, failed tooth movements, treatment duration, and consequences of no treatment.

CONCLUSIONS

A professional orthodontic consensus has been reached that 10 key risks should be discussed with patients as part of consent for orthodontic treatment. The information in this evidence base should be tailored to patients' individual needs and delivered as part of a continuing risk communication process.

Hall Technique for Carious Primary Molars: A Review of the Literature

The high frequency of caries in primary teeth and its inadequate treatment are major public health problems during childhood. Nowadays, the Hall technique is one of the methods used for biological sealing in carious lesions in primary molars. Thus, the bacteria will be sealed from oral environment and the caries will be inactive. The objective of this article was to provide an updated search on the Hall technique description, indication, contraindication, advantages, concerns, success and failure, cost-effectiveness, acceptability, and preference in pediatric dentistry, and to compare the Hall technique with traditional crown preparation and conventional treatment options for carious primary molars. A discussion of the recently published articles on the Hall technique reveals that the Hall technique is considered a promising restorative option with high acceptability and longevity; with low failure rate for managing carious primary molars compared to conventional treatment modalities used in primary care settings. Furthermore, the survival rate of stainless steel crowns (SSCs) is considered high, whether provided using Hall technique or traditional preparation by a pediatric dentist. Thus, the Hall technique can be an effective addition to the clinician’s range of treatment options for carious primary molars. However, it should be chosen in restricted cases.

Bruxism

Bruxism is a parafunctional activity of the masticatory system, which is characterized by clenching or scraping of teeth. This condition is often accompanied by a change in the shape and size of the teeth, as well as the function of the stomatognathic system. Bruxism can occur during sleep and in the waking state. The etiology is multifactorial and all causes can be divided into peripheral and central. The clinical signs and symptoms of bruxism are primarily characterized by temporomandibular disorders, the appearance of bruxofacets and changes in the hard dental tissues, supporting apparatus of the teeth and masticatory muscles, as well as headaches. The diagnosis of bruxism is made on the basis of anamnesis and clinical signs and symptoms, while electromyography and polysomnographic analysis are used in scientific researches. Therapy is aimed at controlling etiological factors and reducing symptoms. Occlusal splints are the most commonly used in the treatment of bruxism. Medications are used in situations when other methods, including psychotherapy, do not give positive results. Given the multifactorial etiology, the therapeutic approach must be multidisciplinary. The approach to the patient must be individual in order to treat as effectively as possible.

Evaluation of Disclusion Time in Various Angle's Malocclusions by T-Scan III System

Objective  The main purpose of this article is to evaluate the disclusion time (DT) in the lateral excursions and protrusion among subjects with Angle’s malocclusions using a T-Scan III system.

Materials and Methods  One hundred subjects with malocclusions were divided into Class I, Class II division 1, Class II division 2, and Class III ( n = 25 per group). All groups’ DT of each excursion was evaluated by a T-Scan III system.

Statistical Analysis  One-way analysis of variance, followed by a post hoc test, was used to analyze the numerical data at p < 0.05.

Results  In the respective malocclusions, means ± standard deviations in second(s) of the DT were 2.08 ± 0.65, 2.13 ± 0.74, 2.12 ± 0.72, and 3.19 ± 1.34 during left excursion; 2.15 ± 0.94, 2.58 ± 1.16, 2.37 ± 1.07, and 3.28 ± 1.25 during right excursion; and 1.88 ± 0.99, 2.08 ± 1.11, 2.07 ± 0.68, and 3.01 ± 1.53 during protrusion. When compared to Class I and Class II malocclusions, Class III showed a significantly higher mean DT of each excursion ( p < 0.05).

Conclusion  Class III had the significantly highest mean DT of each excursion and the significantly longest DT in all excursions.

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.

Prevalence of dental problems in recreational SCUBA divers: a pilot survey

Objective To determine the prevalence of dental symptoms in recreational scuba divers and describe the distribution of these symptoms on the basis of diver demographics, diving qualifications and dive conditions during the episode of dental pain.Design A survey was designed and distributed through online social media platforms dedicated to scuba diving. A convenience sample of 100 recreational divers was obtained by this method.Main outcome measures The outcome measures of interest were: diver demographics, diving characteristics (level of certification, number of dives completed), occurrence of dental problems during a dive, and details of the episode.Results Forty-one percent of the respondents experienced dental symptoms during a dive. Barodontalgia was the most frequently experienced dental symptom during a dive.Conclusion Within the limits of the small sample size and online method of recruitment, the findings of this study suggest that a high proportion of recreational divers may experience dental symptoms during a dive. It would be meaningful to ensure that dental decay and damaged restorations are addressed before a dive and that the mouthpiece design be evaluated in case of complaints of temporomandibular discomfort during a dive.

A Study to Determine the Prevalence of Temporomandibular Disorders in a Young Adult Population and its Association with Psychological and Functional Occlusal Parameters

PURPOSE

To determine the prevalence of temporomandibular disorders (TMD) in medical university students and to analyze the relationship of TMD with psychological and functional occlusal parameters.

MATERIALS AND METHODS

200 students (mean age 21.81 ± 1.99) were screened for TMD with the TMD Pain Screener. Clinical examinations identified the participants with TMD. Based on their diagnostic criteria for TMD (DC/TMD) axis I diagnosis, participants were divided into three groups: group 1- non-TMD, group 2- pain related TMD and headaches, and group 3- intra-articular joint disorders. Further study was continued involving patients diagnosed with TMD as the study group, and an equal number of age- and sex-matched participants were selected in control group. Among these, emotional distress was evaluated using the "hospital anxiety and depression scale" (HADS). Occlusal evaluations were done by using the T-Scan computerized occlusal analysis system. Occlusion time, left lateral disclusion time, right lateral disclusion time, and protrusion disclusion time were measured with T-Scan III. These parameters were compared among the groups with ANOVA test at a significance level of 0.05.

RESULTS

17% of the population were affected by TMD. The mean HADSd (depression) and HADSa (anxiety) scores were significantly higher (p < 0.05) in group 2 (7.67 ± 3.68; 10.60 ± 3.33) and group 3 (6.89 ± 3.23; 9.26 ± 4.05) as compared to group 1 (3.18 ± 2.33; 5.29 ± 3.21). The mean values of occlusion time, left lateral disclusion time, right lateral disclusion time, and protrusion-disclusion time were also higher for group 2 and group 3 as compared to group 1.

CONCLUSIONS

This study found that the prevalence of TMD in this university student population was 17%. There were significant associations of TMD with psychological parameters and functional occlusal parameters.

Evaluation of the relationship between the occlusion parameters and symptoms of the temporomandibular joint disorder

Background.

The aetiology of temporomandibular joint disorders (TMD) is multifactorial, whereas occlusal disharmony is one of the predisposing factors. Researchers still discuss the relation between occlusion and TMD.

Objective.

The study aims to investigate the relation between static occlusal parameters and TMD clinical symptoms using T-Scan II analysis system.

Material and methods.

The sample consisted of 44 persons divided into the treatment group of 20 TMD patients and the control group of 24 subjects without TMD. The main task of T-Scan II computerized occlusal analysis system was to record every patient’s occlusion and estimate static occlusal parameters: centre of occlusal force, asymmetry index of maximum occlusal force and occlusion time. These results were compared between groups, data related to patients’ complaints and clinical symptoms. The analysis was carried out using Mann-Whitney U, Kruskal-Wallis and Chi-square tests.

Results.

Averages of the centre of occlusal force in TMD subjects were 6.55 ± 0.99 mm, in the control group – 5.88 ± 0.69 mm; the asymmetry index of maximum occlusal force averages: 15.90 ± 2.71 and 12.93 ± 1.88; occlusion time: 0.281 ± 0.036 s and 0.236 ± 0.022 s, respectively. There were no statistically significant differences between two groups but they were found in the centre of occlusal force and the asymmetry index in the two groups (p < 0.05).

Conclusions.

There exists a relation between complaints of patients with TMD and static occlusion parameters. Values of the centre of the occlusal force distance and the asymmetry index of occlusal force in TMD patients with pain in the temporomandibular joint (TMJ) were significantly higher than in the control group.

Do patients with malocclusion have a higher prevalence of temporomandibular disorders than controls both before and after orthognathic surgery? A systematic review and meta-analysis

PURPOSE

The aim of this study was to identify, through meta-analysis, whether patients who require orthognathic surgery have a higher prevalence of temporomandibular disorders (TMDs) than controls, both before treatment and after.

MATERIAL AND METHODS

A systematic review and meta-analysis were conducted based on PRISMA guidelines, to address the study purposes. A search of major databases through PubMed, EMBASE, and Cochrane CENTRAL was performed to locate all pertinent articles published from inception to June 2016. Inclusion criteria were controlled clinical studies, either prospective or retrospective, and case-control studies comparing preoperative and postoperative signs and symptoms of TMDs in patients who undergo orthognathic surgery to those of a healthy volunteer population with no dentofacial deformities. The predictor variables were patients with dentofacial deformities who underwent orthognathic surgery and patients with no dentofacial deformities and with good maxillomandibular relations and normal occlusion. The outcomes variables were the weighted, prevalence rate (proportion) in signs and symptoms of TMDs in patients with dentofacial deformities and risk ratio (RR) of signs and symptoms of TMDs before and after orthognathic surgery, compared to the control group.

RESULTS

A total of 542 patients enrolled in 6 studies were included in this analysis. The overall pooled weighted rate or prevalence of TMDs for orthognathic surgery patients preoperatively was 32.5% (95% CI = 26.7%-38.9%). There was a significant difference between the 2 groups with respect to TMDs before surgery, but no significant difference in TMDs after surgery. The RR for patients who had dentofacial deformities before orthognathic surgery compared with a control group was 1.634 (95% CI = 1.216-2.194; P = 0.001). The RR for patients after orthognathic surgery compared with a control group was 1.262 (0.718; 95% CI = 0.805-1.979; P = 0.311).

CONCLUSION

The results of this study show that patients who are going to have a correction of their malocclusion by orthodontics and orthognathic surgery have a significant incidence of TMDs when compared to a control population, but that after treatment, the incidence of TMDs does not differ from a control population. The reasons for these findings are not clear.

Adults seeking orthodontic treatment: expectations, periodontal and TMD issues

The growth in adult orthodontics presents new challenges to both the general dental practitioner and the orthodontist. Although many of the main objectives of orthodontic treatment are similar for adults, young adults and children, adult patients frequently bring significant challenges in several areas not often seen in the younger patient group. In areas such as planning realistic treatment outcomes, it is paramount that the patient's expectations are identified, respected and managed where appropriate. The adult patient's dental health often dictates deviation from the ideal treatment plan and periodontal problems are a common example. Based on current evidence, this paper presents an overview of some of the difficulties in the management of these issues, as well as highlighting developments with regard to pain conditions and their relevance to orthodontic treatment and its effects on temporomandibular joint disorders (TMD) management.

Correlação entre sinais e sintomas da Disfunção Temporomandibular (DTM) e severidade da má oclusão

Introdução O papel da oclusão como fator etiológico das disfunções temporomandibulares (DTMs) tem sido um assunto polêmico e ainda controverso. Objetivo Avaliar a correlação entre sinais e sintomas da disfunção temporomandibular e a severidade da má oclusão. Método Foram avaliados 135 estudantes de Odontologia da UFPB. A presença de DTM foi estimada através do Índice Anamnésico de Fonseca (DMF) e de questões objetivas sobre seus sintomas. Os estudantes também foram submetidos a um protocolo resumido de avaliação clínica de DTM. A avaliação dos fatores oclusais foi realizada através do Índice de Prioridade de Tratamento (IPT) aplicado a modelos de gesso dos arcos dentários superior e inferior. As diferenças entre as médias do IPT relacionadas aos sinais e sintomas de DTM foram determinadas por meio dos testes t e One-way ANOVA. As correlações entre os fatores oclusais e a DTM foram determinadas a partir de correlação de Pearson. Resultado A severidade da má oclusão, segundo o IPT, não influenciou no surgimento de DTM e de sinais clínicos musculares ou articulares, e na necessidade de tratamento. A má oclusão de classe II, trespasse vertical acentuado e dentes girados foram estatisticamente correlacionados à necessidade de tratamento e aos sinais clínicos de DTM. Conclusão Em modelos multifatoriais, como na fisiopatologia da DTM, a oclusão pode desempenhar um papel de cofator na predisposição ou perpetuar as diferentes formas de DTM, não devendo ser considerada fator principal.

Longitudinal study on TMJ disk status and its effect on mandibular growth

OBJECTIVE

This longitudinal study assessed the potential contribution of temporomandibular joint (TMJ) disk status over mandibular linear and angular changes.

DESIGN

Cohort study.

SETTING

Edmonton, Alberta, Canada.

PARTICIPANTS

Seventy-three adolescent subjects attending TMJ or orthodontic clinics with or without TMJ disk abnormality were followed during a mean 3 years 7 months. From this sample 39 subjects underwent orthodontic treatment.

METHODS

Disk displacement and disk length measurements taken from MRIs were utilized to evaluate the TMJ disk status. Mandibular changes were quantified from cephalometric radiographs by superimposing the mandible around the internal cortex of the posterior wall of the mandibular symphysis. Fishman's skeletal maturation system was used to calculate the percentage of mandibular growth remaining during the follow-up. This expected mandibular growth was factored out through a statistical normalization process applied to the actual difference between the initial and final mandibular measurements. In addition, previous orthodontic treatment was also considered for the analysis. A multiple analysis of variance (MANOVA) was used to evaluate interaction between the independent variables (TMJ disk status and previous orthodontic treatment) over the dependent variables (mandibular ramus, mandibular body, mandibular length and gonial angle measurements).

RESULTS

No significant contribution was found of any of the evaluated variables or its interactions over the mandibular measurements.

CONCLUSIONS

No evidence was found of TMJ disk abnormality as an associated significant factor with mandibular dimensional changes. The findings have to be evaluated with caution because of some limitations identified in this study.

Evaluation of occlusal factors in patients with temporomandibular joint disorder

OBJECTIVE: The aim of this study was to determine the prevalence and the relation between the main occlusal factors and the temporomandibular disorder (TMD). METHODS: We analyzed 100 patients (50 diagnosed with TMD and 50 asymptomatic volunteers, control group) through a questionnaire that classified TMD as absent, mild, moderate and severe. Then, an evaluation was made of intraoral occlusal factors: Absence of posterior teeth, wear facets, overjet, overbite, open bite, posterior crossbite, sagittal relationship (Class I, II and III), centric relation discrepancy for maximum intercuspation, anterior guidance and balancing occlusal interference. The c² examined the association between TMD and considered occlusal variables. RESULTS: The prevalence of studied occlusal factors was higher in patients with moderate and severe TMD. Statistically significant results were found on: Absence of five or more posterior teeth, overbite and overjet greater than 5 mm, edge-to-edge bite, posterior crossbite, Class II and III, the absence of effective anterior guide and balancing side interferences. CONCLUSIONS: Indeed, it is concluded that there is a relationship between TMD and occlusal factors, however it can not be told to what extent these factors are predisposing, precipitating or perpetuating the disease. Therefore, despite its multifactorial etiology, one can not neglect the occlusal analysis of these patients.

A review of the oral health-related evidence that supports the orthodontic treatment need indices

BACKGROUND AND OBJECTIVES

To date, there is no evidence-based method of quantification for malocclusion. Consequently, how deviant occlusal traits should be scored and weighted relative to one another is a matter of serious debate. Orthodontic Treatment Need Indices (OTNI) use the subjective opinion of the experts, as their foundation, to define the pathological boundaries (cut-offs) of occlusal traits. This paper reviews the evidence relating malocclusions or deviated occlusal traits to oral health problems, and investigates if this evidence supports the cut-off points and the rationale used for OTNI.

MATERIALS AND METHODS

The relevant cited studies and reviews from the MEDLINE, Web of Science, Scopus, Cochrane databases, and scientific textbooks were used. The citation rate was confirmed by using the Google Scholar.

RESULTS

So far, the evidence for harmful effects of deviated occlusal traits on oral health is either lacking or exists as cross-sectional (mostly) and longitudinal (a few and primarily short-term) studies. When an association was reported between a deviated occlusal trait and an oral health problem, either the strength of that association was weak, or due to methodological issues, findings were not conclusive. Consequently, establishing a cause and effect relationship is difficult. Further, commonly used OTNI do not record a full spectrum of occlusal traits, and relating their ranking or scoring systems to the available evidence is difficult. Therefore, there is little evidence to suggest that individuals with a high need (high score), as measured by OTNI, will necessarily put at risk their oral health if they turn down orthodontic therapy.

CONCLUSION

OTNI have a role in the epidemiology and can be used for resource planning, but their predictive value to detect the future objective functional deficits or oral health problems is questionable. OTNI will need revalidation over time with emerging research findings.

Short communication: Influence of preformed metal crowns (Hall technique) on the occlusal vertical dimension in the primary dentition

AIM

This was to investigate the measure of propping, or occlusal interference and opening the bite after placement of preformed metal crowns (PMC) using the Hall technique and in how many days it took for the open bite to return to normal.

METHODS

For this study school children living in the rain forest of Suriname were selected. The distance between the tip of the mandibular and maxillary primary canines was measured just before and after treatment with PMCs and again after 15 and 30 days.

RESULTS

In 48 children the mean distance between the canine tips reduced from 2.45 mm before to 0.54 mm directly after treatment. After 15 days the distance increased again to 1.96 mm and after 30 days (with the remaining 8 patients) to 2.75 mm. The reduction of the overbite seems to be caused by intrusion of the crowned molar and its antagonist.

CONCLUSION

Although the overbite had equilibrated after 30 days, additional research is necessary in a larger study to draw more decisive conclusions.

Pharmacological interventions for pain in patients with temporomandibular disorders

BACKGROUND

Temporomandibular disorders (TMD) are a group of disorders affecting the temporomandibular joints and the muscles of mastication. TMDs are treated with a wide range of drugs. The extent to which the use of these drugs is based upon evidence is unknown.

OBJECTIVES

To assess the effectiveness of pharmacological interventions both alone and in combination with non-pharmacological therapy in relieving pain in patients with chronic TMD.

SEARCH STRATEGY

Electronic searches of the Cochrane Oral Health Group's Trials Register (2 August 2010), CENTRAL (The Cochrane Library 2010, Issue 3), MEDLINE via OVID (1950 to 2 August 2010), EMBASE via OVID (1980 to 2 August 2010) and CINAHL via EBSCO (1981 to 2 August 2010) were conducted. Reference lists of articles and previous reviews were scanned for relevant articles and authors were contacted for further information where appropriate.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in which a pharmacological agent was compared with placebo for the management of pain in patients with TMD. Parenteral routes of administration were excluded.

DATA COLLECTION AND ANALYSIS

Duplicate data extraction and assessment of risk of bias in included studies was performed.

MAIN RESULTS

Eleven studies were included with a total of 496 participants. The primary outcome of most of the studies was pain. The risk of bias in the included studies was variable. Whilst four studies showed significant pain relief for the active treatment, three were of poor quality. Most adverse effects were mild to moderate in severity. Four studies reported withdrawals due to severe adverse reactions, but insufficient information was provided regarding the trial groups from which the withdrawals occurred. No meta-analysis was conducted due to lack of similarities across the included studies.

AUTHORS' CONCLUSIONS

There is insufficient evidence to support or not support the effectiveness of the reported drugs for the management of pain due to TMD. There is a need for high quality RCTs to derive evidence of the effectiveness of pharmacological interventions to treat pain associated with TMD.

Mandibular condylar cartilage response to moving 2 molars in rats

INTRODUCTION

The purpose of this study was to investigate the responses of mandibular condylar cartilage to moving 2 molars in different combinations.

METHODS

Rats were assigned to male and female control and experimental groups (each, n = 5). Elastic rubber bands were used to move medially the maxillary left and the mandibular right first molars in experimental group I. The same method was used to distally move the maxillary left and the mandibular right third molars, 2 mandibular third molars, and 2 maxillary third molars in experimental groups II, III, and IV, respectively. At the end of the eighth week, all condyles were examined histologically. The areas of histologic change as a percentage of total cartilage area were compared by using the Mann-Whitney U test.

RESULTS

Cartilage degenerative remodeling was observed in experimental groups II, III, and IV. The percentage areas of degenerative remodeling were higher in female experimental groups II and III than in the female control group, and in female experimental group II than in female experimental group IV and male experimental group II (all, P <0.05).

CONCLUSIONS

The mandibular condylar cartilage of female rats responded variously to different combinations of molar movement; the most obvious remodeling was observed in groups in which the maxillary left and mandibular right third molars were moved.

Twenty-year cohort study of health gain from orthodontic treatment: temporomandibular disorders

INTRODUCTION

Temporomandibular disorder (TMD) is a common condition. Studies of TMD in relation to orthodontic treatment did not show an association, but longitudinal studies from adolescence to adulthood are lacking. The aim of this study was to investigate the relationship between orthodontic treatment and TMD with a longitudinal study design.

METHODS

This prospective cohort study was conducted in South Wales, United Kingdom. The baseline investigation was carried out in 1981 and involved children aged 11 to 12 years (n = 1018). Follow-up investigations were done in 1984 (n = 792), 1989 (n = 456), and 2000 (n = 337).

RESULTS

Overall TMD prevalence increased from the baseline (3.2%) to age 19 to 20 (17.6%) and decreased by age 30 to 31 (9.9%). TMD prevalence was higher in females at all follow-up points, except the baseline. Overall, incidences of TMD were 11.9%, 11.5%, and 6.0% at the first, second, and last follow-ups, respectively. Females were more likely to develop TMD than males (hazard ratio [HR], 2.1; 95% CI, 1.3 and 3.3), and those with high self-esteem were less likely to develop TMD (HR, 0.6; 95% CI, 0.4 and 0.8). There was no association between orthodontic treatment and new TMD onset. The incidences of persistent TMD were 20.0%, 34.9%, and 28.0% at the first, second, and last follow-ups, respectively. Females were more likely to have persistent TMD than males (HR, 2.5; 95% CI, 1.0 and 6.1). There was no association between orthodontic treatment and persistent TMD. The only significant predictors of TMD in adults aged 30 to 31 were female sex (odd ratio, 3.0; 95% CI, 1.1 and 8.2) and TMD in adolescence (odds ratio, 4.5; 95% CI, 2.0 and 10.0).

CONCLUSIONS

Orthodontic treatment neither causes nor prevents TMD. Female sex and TMD in adolescence were the only predictors of TMD in young adulthood.

TMD in Consecutive Patients Referred for Orthognathic Surgery

Objective: To answer the question whether temporomandibular disorders (TMD) were more common in a group of individuals referred for orthognathic surgery than in a control group. The null hypothesis was that neither the frequency of signs and symptoms of TMD or diagnosed TMD would differ between the patient group and a control group.

Materials and Methods: A sample of 121 consecutive patients referred for orthognathic surgery at the Department of Oral Maxillofacial Surgery, Malmö University Hospital, Sweden, was interviewed and examined regarding signs and symptoms of TMD and headaches. A control group was formed by 56 age- and gender-matched individuals attending the Department of Oral Diagnosis, Faculty of Odontology, Malmö University, Sweden, and Public Dental Health Clinic in Oxie, County of Skane, Sweden. TMD diagnoses were used according to Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD).

Results: The patient group showed more myofascial pain without limited opening, disc displacement with reduction, and arthralgia according to RDC/TMD than the control group. The patient group also had more symptoms and signs of TMD in general.

Conclusions: The null hypothesis was rejected because patients who were to be treated with orthognathic surgery had more signs and symptoms of TMD and higher frequency of diagnosed TMD compared with the matched control group.

The Hall Technique; a randomized controlled clinical trial of a novel method of managing carious primary molars in general dental practice: acceptability of the technique and outcomes at 23 months

Background

Scotland has high levels of untreated dental caries in primary teeth. The Hall Technique is a simplified method of managing carious primary molars using preformed metal crowns (PMCs) cemented with no local anaesthesia, caries removal or tooth preparation. This study compared the acceptability of the Hall Technique for children, their carers, and dentists, and clinical outcomes for the technique, with conventional restorations.

Methods

General dental practice based, split mouth, randomized controlled trial (132 children, aged 3–10). General dental practitioners (GDPs, n = 17) in Tayside, Scotland (dmft 2.7) placed conventional (Control) restorations in carious primary molars, and Hall Technique PMCs on the contralateral molar (matched clinically and radiographically). Dentists ranked the degree of discomfort they felt the child experienced for each procedure; then children, their carers and dentists stated which technique they preferred. The teeth were followed up clinically and radiographically.

Results

128 conventional restorations were placed on 132 control teeth, and 128 PMCs on 132 intervention teeth. Using a 5 point scale, 118 Hall PMCs (89%) were rated as no apparent discomfort up to mild, not significant; for Control restorations the figure was 103 (78%). Significant, unacceptable discomfort was recorded for two Hall PMCs (1.5%) and six Control restorations (4.5%). 77% of children, 83% of carers and 81% of dentists who expressed a preference, preferred the Hall technique, and this was significant (Chi square, p < 0.0001). There were 124 children (94% of the initial sample) with a minimum follow-up of 23 months. The Hall PMCs outperformed the Control restorations:

a) 'Major' failures (signs and symptoms of irreversible pulpal disease): 19 Control restorations (15%); three Hall PMCs (2%) (P < 0.000);

b) 'Minor' failures (loss of restoration, caries progression): 57 Control restorations (46%); six Hall PMCs (5%) (P < 0.000)

c) Pain: 13 Control restorations (11%); two Hall PMCs (2%) (P = 0.003).

Conclusion

The Hall Technique was preferred to conventional restorations by the majority of children, carers and GDPs. After two years, Hall PMCs showed more favourable outcomes for pulpal health and restoration longevity than conventional restorations. The Hall Technique appears to offer an effective treatment option for carious primary molar teeth.

Trial registration number

Current Controlled Trials ISRCTN47267892 – A randomized controlled trial in primary care of a novel method of using preformed metal crowns to manage decay in primary molar teeth: the Hall technique.