The intra- and inter-rater reproducibility of bone level measurements at strategic mini-implants using dental panoramic radiography.

OBJECTIVES: This experimental study focused on the intra- and inter-rater reproducibility of vertical bone level (VBL) measurements at strategic mini-implants (MI) using digital panoramic radiographs (PR). STUDY DESIGN: VBLs of 152 MIs for removable partial denture stabilization at 50 randomly chosen PRs from a clinical trial were digitally evaluated by three ratters. Rater deviations exceeding 0.5 mm were re-examined. The intra-class correlation coefficient (ICC) was applied to estimate reliability. The smallest detectable change (SDC) was interrelated to the minimal clinically important change of 0.2 mm. RESULTS: The first measurement round revealed intra- and inter-rater ICCs of > 0.8. However, 28 sites (9 %) were unreadable, and 97 sites (32 %) revealed differences between observers of ≥ 0.5 mm. Following a consensus session and re-training, an additional 8 sites were excluded and all remaining VBL differences were ≤ 0.5 mm. Thus, the SDCs with 95 % credibility were improved from 0.73 to 0.31 mm in the intra-rater and from 1.52 to 0.34 mm in the inter-rater statistics. Given a 50 % credibility for this special setting, both the intra- and inter-rater SDCs were 0.11 mm. CONCLUSIONS: Digital PR can be reliably utilized to determine VBLs around MIs under conditions of at least two trained observers, mutual calibration sessions, and exclusion of unquantifiable radiographs. GERMAN CLINICAL TRIALS REGISTER ID: DRKS00007589, www.germanctr.de.

Proposing a communication module to enhance dental students' attitudes towards people with dementia: Phase 1 of a curriculum revision study.

INTRODUCTION: The number of mentally altered patients a dentist meets in practice is increasing and interaction with them can be very challenging. As a baseline for an interventional study, we want to assess the attitude of dental students and identify areas of improvement in patient communication. This work compares the attitude of dental students towards people suffering from dementia to the attitudes of trained medical caregivers and the general population. Our aim is to use the results to assess the need for training in communicating with mentally altered patients. MATERIALS AND METHODS: Fourth-year dental students attended two lectures on dementia given by a psychiatrist as part of the geriatric dentistry lecture and were questioned afterwards using the Dementia Attitude Scale. In 2016 and 2017, 73 students at the University of Greifswald were interviewed. The response rate was 84%. Using a factor analysis, the Dementia Attitude Scale's validated questions were interpreted and compared with data from nursing staff from Switzerland and the USA. RESULTS: The factor analysis of the data showed the same two-factor loadings as the comparative groups, and that dental students' attitude is more comparable to the general population than to medically trained nursing staff. CONCLUSION: Given the results, we conclude that the implementation of a communication module can serve in improving the attitude of dental students towards patients with dementia.

The intra- and inter-rater reproducibility of bone level measurements at strategic mini-implants using dental panoramic radiography

Abstract Objectives: This experimental study focused on the intra- and inter-rater reproducibility of vertical bone level (VBL) measurements at strategic mini-implants (MI) using digital panoramic radiographs (PR). Study design: VBLs of 152 MIs for removable partial denture stabilization at 50 randomly chosen PRs from a clinical trial were digitally evaluated by three ratters. Rater deviations exceeding 0.5 mm were re-examined. The intra-class correlation coefficient (ICC) was applied to estimate reliability. The smallest detectable change (SDC) was interrelated to the minimal clinically important change of 0.2 mm. Results: The first measurement round revealed intra- and inter-rater ICCs of > 0.8. However, 28 sites (9 %) were unreadable, and 97 sites (32 %) revealed differences between observers of ≥ 0.5 mm. Following a consensus session and re-training, an additional 8 sites were excluded and all remaining VBL differences were ≤ 0.5 mm. Thus, the SDCs with 95 % credibility were improved from 0.73 to 0.31 mm in the intra-rater and from 1.52 to 0.34 mm in the interrater statistics. Given a 50 % credibility for this special setting, both the intra- and inter-rater SDCs were 0.11 mm. Conclusions: Digital PR can be reliably utilized to determine VBLs around MIs under conditions of at least two trained observers, mutual calibration sessions, and exclusion of unquantifiable radiographs. German Clinical Trials Register ID:DRKS00007589, www.germanctr.de

Training of the lateral pterygoid muscle in the treatment of temporomandibular joint disc displacement with reduction: A randomised clinical trial.

BACKGROUND: Disc displacement with reduction (DDwR) therapy should be performed only when pain or discomfort is presented. Data on treatment options for painful DDwR are very limited. OBJECTIVE: The aim was to investigate whether isometric training of the lateral pterygoid muscle (LPM) is equivalent to stabilisation appliance therapy with regard to the treatment of painful DDwR. The training program is based on the science of Janda. METHODS: This was a prospective, randomised study with a comparative treatment group. Sixty patients (≥18 years) with DDwR and pain were randomly assigned to two groups: (1) muscle training and (2) stabilisation appliance. The following variables were recorded at baseline examination and after 2, 4 and 6 months: changes in orofacial pain, clicking sounds of the temporomandibular joint (TMJ), force degrees for the lateral movement of the mandible and interincisal opening distance. p values of <.05 were considered statistically significant but 95% confidence intervals were also presented. RESULTS: A decrease in orofacial pain intensity was seen in both groups (p < .0001). Registered TMJ clicking disappeared after 6 months of treatment in 37% (n = 11) of the patients in the training group and in 27% (n = 8) of the appliance group (p = .0009 and p = .0047). Muscle training showed 27 improvements in Janda force degrees at the end of the study (p < .0001). CONCLUSION: Muscle training and appliance therapy improved mouth opening and reduced pain intensity in both patient groups. Muscle training might be a promising option in the treatment of patients suffering from painful DDwR.

Fused filament fabrication (FFF): influence of layer height on forces and moments delivered by aligners-an in vitro study.

OBJECTIVES: To investigate the effect of layer height of FFF-printed models on aligner force transmission to a second maxillary premolar during buccal torquing, distalization, extrusion, and rotation using differing foil thicknesses. MATERIALS AND METHODS: Utilizing OnyxCeph3™ Lab (Image Instruments GmbH, Chemnitz, Germany, Release Version 3.2.185), the following movements were programmed for the second premolar: buccal torque (0.1-0.5 mm), distalization (0.1-0.4 mm), extrusion (0.1-0.4 mm), rotation (0.1-0.5 mm), and staging 0.1 mm. Via FFF, 91 maxillary models were printed for each staging at different layer heights (100 µm, 150 µm, 200 µm, 250 µm, 300 µm). Hence, 182 aligners, made of polyethylene terephthalate glycol (PET-G) with two thicknesses (0.5 mm and 0.75 mm), were prepared. The test setup comprised an acrylic maxillary model with the second premolar separated and mounted on a sensor, measuring initial forces and moments exerted by the aligners. A generalized linear model for the gamma distribution was applied, evaluating the significance of the factors layer height, type of movement, aligner thickness, and staging on aligner force transmission. RESULTS: Foil thickness and staging were found to have a significant influence on forces delivered by aligners, whereas no significance was determined for layer height and type of movement. Nevertheless, at a layer height of 150 µm, the most appropriate force transmission was observed. CONCLUSIONS: Printing aligner models at particularly low layer heights leads to uneconomically high print time without perceptible better force delivery properties, whereas higher layer heights provoke higher unpredictability of forces due to scattering. A z-resolution of 150 µm appears ideal for in-office aligner production combining advantages of economic print time and optimal force transmission.

Survival and stability of strategic mini-implants with immediate or delayed loading under removable partial dentures: a 3-year randomized controlled clinical trial.

OBJECTIVES: Stability values of mini-implants (MIs) are ambiguous. Survival data for MIs as supplementary abutments in reduced dentitions are not available. The aim of this explorative research was to estimate the 3-year stability and survival of strategic MIs after immediate and delayed loading by existing removable partial dentures (RPDs). MATERIAL AND METHODS: In a university and three dental practices, patients with unfavorable tooth distributions received supplementary MIs with diameters of 1.8, 2.1, and 2.4 mm. The participants were randomly allocated to group A (if the insertion torque ≥ 35 Ncm: immediate loading by housings; otherwise, immediate loading by RPD soft relining was performed) or delayed loading group B. Periotest values (PTVs) and resonance frequency analysis (RFA) values were longitudinally compared using mixed models. RESULTS: A total of 112 maxillary and 120 mandibular MIs were placed under 79 RPDs (31 maxillae). The 1st and 3rd quartile of the PTVs ranged between 1.7 and 7.8, and the RFA values ranged between 30 and 46 with nonrelevant group differences. The 3-year survival rates were 92% in group A versus 95% in group B and 99% in the mandible (one failure) versus 87% in the maxilla (eleven failures among four participants). CONCLUSIONS: Within the limitations of explorative analyses, there were no relevant differences between immediate and delayed loading regarding survival or stability of strategic MIs. CLINICAL RELEVANCE: The stability values for MIs are lower than for conventional implants. The MI failure rate in the maxilla is higher than in the mandible with cluster failure participants. CLINICAL TRIAL REGISTRATION: German Clinical Trials Register (Deutsches Register Klinischer Studien, DRKS-ID: DRKS00007589, www.germanctr.de ), January 15, 2015.

Multicenter RCT on intensive caries prevention for children undergoing dental general anaesthesia: Intensive caries prevention for children undergoing dental general anesthesia.

OBJECTIVES: Early childhood caries is a persistent problem often leading to dental treatment under general anesthesia (GA). Thus, this study investigated the effect of two additional individual caries prevention appointments before and after GA. MATERIALS AND METHODS: In this multi-center, 2-arm randomized, controlled clinical trial, 408 children (age 2-5 years, mean 4.2 ± 1.04) intended for GA were recruited and randomly assigned to the intervention and control groups with or without two additional intensive oral hygiene appointments before and after the GA. At baseline and at 6-/12-months follow-ups, approximal plaque index (API), gingival sulcus bleeding index (SBI), caries experience (dmft/s) and initial caries were recorded. RESULTS: Participants in test group and control group (ITT; n = 161 vs. n = 147) as well as drop-outs in test and control groups (n = 40 vs. n = 58) showed no statistical significant difference in baseline characteristics. Test and control groups showed equivalent baseline oral health parameters (API: 78 and 77%, SBI: 22.6 and 23.5%, dmft: 8.5 and 8.2, respectively), which continuously improved during the study. The test group exhibited statistically significant greater improvement (API: 42%, SBI: 7%) than the control (API: 54%, OR: 0.48; P = 0.003; SBI: 12%, OR=0.44; P = 0.005). Due to the robust rehabilitation with predominantly stainless steel crowns and extractions, caries incidence was minimal and, therefore, without statistical significance (mean increase dt, test: 0.5, control: 0.6; P = 0.68), which was also true for new initial carious lesions (mean increase test: 0.8 vs. CONTROL: 0.9; P = 0.55). CONCLUSIONS: Additional preventive sessions for children undergoing treatment under GA improved their oral hygiene parameters signifiqantly. CLINICAL SIGNIFICANCE: Intensive caries prevention appointments for children receiving dental treatment under GA improved their oral hygiene and might reduce their caries risk.

Cephalometric analyses for cleft patients: a statistical approach to compare the variables of Delaire's craniofacial analysis to Bergen analysis.

OBJECTIVES: Cephalometric analyses using lateral craniofacial radiographs are common diagnostic procedures for evaluating skeletal patterns. However, in patients with pronounced abnormalities like cleft lip and palate, standard cephalometric analyses and landmarks may not be suitable. This study aims to clarify whether the inclusion of landmarks less compromised by the cleft defect or located outside the cleft area results in a different cephalometric assessment of the viscerocranium. Delaire's whole-skull analysis and Bergen analysis were examined for similarities and underlying common observations. MATERIALS/METHODS: Based on the cephalometric evaluation of 217 patients with different types of non-syndromal cleft formation, Delaire and Bergen analysis were compared using three statistical methods: correlation analysis, factor analysis, and cluster analysis. Reproducibility was assessed by Bland-Altman plots, intraclass correlation coefficients, mean absolute differences, and coefficients of variability. RESULTS: Although Delaire analysis and Bergen analysis are based on different concepts and landmarks, a majority of corresponding variables was found. Certain aspects of craniofacial base relation and craniospinal articulation are only assessed by Delaire analysis. All but one variable showed very good reproducibility. CONCLUSIONS: The inclusion of landmarks less compromised by or located outside the cleft area does not result in variables that provide a different assessment of the viscerocranial area. CLINICAL RELEVANCE: The findings contradict the concept of invalidity of landmarks compromised by the cleft defect or located within the affected cleft area. Within the scope of its viscerocranial field of view, Bergen analysis appears to be on a par with Delaire analysis in the diagnosis of cleft patients.

Effect of periodontal treatment on preclinical Alzheimer's disease-Results of a trial emulation approach.

INTRODUCTION: We investigated the relationship between periodontal treatment and pre-clinical Alzheimer's disease (AD). METHODS: In this quasi-experimental design, 177 periodontally treated patients from the "Greifswald Approach to Individualized Medicine" cohort, which used the same protocols as the population-based Study of Health in Pomerania TREND (SHIP-TREND), and 409 untreated subjects from SHIP-TREND were analyzed. Subjects were younger than 60 years at the magnetic resonance imaging examination, with a median observation period of 7.3 years. Imaging markers for brain atrophy in late-onset AD and brain aging were used as the outcomes. RESULTS: Robust to sensitivity analyses, periodontal treatment had a favorable effect on AD-related brain atrophy (-0.41; 95% confidence interval: -0.70 to -0.12; P = .0051), which corresponds to a shift from the 50th to the 37th percentile of the outcome distribution. For brain aging, the treatment effect was uncertain. CONCLUSION: Periodontitis is related to pre-clinical AD in our population.

Randomized trial in split-mouth design to evaluate the effectiveness of manual and machine-aided cleaning of removable partial dentures.

PURPOSE: To evaluate the efficacy of manual and machine-aided cleaning to remove matured plaque from removable partial dentures (RPD). MATERIALS AND METHODS: A total of 32 patients with bilateral free-end saddle RPDs were included. The plaque was stained, and the RPD was photographed on all sides. One saddle was randomly allocated to manual cleaning, while the other was allocated to no cleaning. The patient manually cleaned the saddle by applying a denture brush and gel. The whole RPD was then cleaned with the aide of a machine using a rotating needle device. After each step, plaque dyeing and photographing were repeated. The plaque proportions (% pixel) were measured using special software. For statistical analysis, mixed models were used to adjust for baseline covariates, including plaque and surfaces, and to cover all time points. RESULTS: The mean plaque area without cleaning at the fitting surface was higher than at the buccal/lingual surfaces (32.8% [95% CI: 28.1% to 36.4%] vs 15.3% [13.1% to 17.4%], respectively). Manual cleaning was not substantially better than no cleaning (4.6% [-0.1% to 9.2%] for the difference at fitting surfaces; disclaiming a substantial difference of > 10%; the difference found was even smaller at buccal/lingual surfaces). Machine-aided cleaning was substantially better than manual cleaning (16.1% [12.0% to 20.2%] for the difference at fitting surfaces and 7.3% [4.6% to 10.0%] at buccal/lingual surfaces). The combination of manual and machine-aided cleaning was not better than machine-aided cleaning alone (-0.2% [-2.6% to 2.1%] difference at fitting surface). CONCLUSION: Manual cleaning is insufficient in removing matured denture plaque. Machine-aided cleaning is clearly superior to manual cleaning, especially at fitting surfaces.

SHIP-MR and Radiology: 12 Years of Whole-Body Magnetic Resonance Imaging in a Single Center.

The Study of Health in Pomerania (SHIP), a population-based study from a rural state in northeastern Germany with a relatively poor life expectancy, supplemented its comprehensive examination program in 2008 with whole-body MR imaging at 1.5 T (SHIP-MR). We reviewed more than 100 publications that used the SHIP-MR data and analyzed which sequences already produced fruitful scientific outputs and which manuscripts have been referenced frequently. Upon reviewing the publications about imaging sequences, those that used T1-weighted structured imaging of the brain and a gradient-echo sequence for R2* mapping obtained the highest scientific output; regarding specific body parts examined, most scientific publications focused on MR sequences involving the brain and the (upper) abdomen. We conclude that population-based MR imaging in cohort studies should define more precise goals when allocating imaging time. In addition, quality control measures might include recording the number and impact of published work, preferably on a bi-annual basis and starting 2 years after initiation of the study. Structured teaching courses may enhance the desired output in areas that appear underrepresented.

What German dentists choose for their teeth: A Web-based survey of molar restorations and their longevity.

STATEMENT OF PROBLEM: Which restorative material is best suited for treating the posterior molar region is unclear. As dentists presumably choose the most appropriate restoration, German dentists were asked how their own molars were treated. PURPOSE: The purpose of this survey study was to examine molar restorations and their durability in German dentists. MATERIAL AND METHODS: In the official journal of the Federal Dental Association, German dentists were asked to participate in an online survey that gathered demographic data and information on the type and durability of their molar restorations. To reduce selection bias, the data were weighted for region, sex, and age of the dentist. RESULTS: The data set consisted of 1719 molars from 288 dentists. Restorations included gold inlays (25%), composite resin (24.3%), amalgam (11.8%), ceramic inlays (5.4%), glass ionomer cement or compomer (0.8%), gold crowns (21.8%), ceramic crowns (6.6%), and metal-ceramic crowns (4.3%). Notable differences were identified based on the sex, age, and region of the dentist. Women selected increased esthetic options, as did young dentists. Restorations made of gold, amalgam, and base metal had the highest longevity, at more than 20 years CONCLUSIONS: Among German dentists, restorations with metallic materials dominated in molars, with gold accounting for the largest share. In recent years, the proportion of tooth-colored restorations has increased, and in particular, young dentists use composite resin and ceramics.

Association between coronal caries and malocclusion in an adult population.

PURPOSE: Only a few but conflicting results have been reported on the association between malocclusions and caries. We investigated this association using data from the population-based cross-sectional Study of Health in Pomerania (SHIP). METHODS: Sagittal, vertical and transversal intermaxillary relationship, space conditions and sociodemographic parameters of 1210 dentate subjects (median age 30 years, interquartile range 25-35 years) were collected. Caries was assessed with the Decayed-Missing-Filled Surfaces index but analyzed as ordered outcome (four levels: sound, enamel caries, caries, tooth loss) in ordinal multilevel models, taking into account subject, jaw, and tooth level simultaneously. RESULTS: Anterior open bite ≤3 mm (odds ratio [OR] = 2.08, 95% confidence interval [CI]: 1.19-3.61), increased sagittal overjet of 4-6 mm (OR = 1.31, CI: 1.05-1.64), distal occlusion of ½ premolar width (OR = 1.27, CI: 1.05-1.53) and distal 1 premolar width (OR = 1.31, CI: 1.06-1.63) were associated with adjusted increased odds for a higher outcome level (caries). Anterior spacing (OR = 0.24, CI: 0.17-0.33), posterior spacing, (OR = 0.69, CI: 0.5-0.95), posterior crowding (OR = 0.57, CI: 0.49-0.66) and buccal nonocclusion (OR = 0.54, CI: 0.33-0.87) were associated with a lower outcome level (caries). CONCLUSION: The results from this population-based study suggest that a connection between caries and malocclusion exists to a limited extent in young adults. The associations with caries are contradictory for several malocclusion variables. Distal occlusion (OR = 1.31, CI: 1.06-1.63) and related skeletal anomalies displayed positive associations with caries whereas crowding did not. Orthodontic treatment of anterior crowding would probably not interfere with caries experience. These aspects should be considered for patient information and in treatment decisions.

New insights in the reproducibility of visual and electronic tooth color assessment for dental practice.

BACKGROUND: The aim of the study was to compare a 2D and 3D color system concerning a variety of statistical and graphical methods to assess validity and reliability of color measurements, and provide guidance on when to use which system and how to interpret color distance measures, including ΔE and d(0M1). METHODS: The color of teeth 14 to 24 of 35 patients undergoing regular bleaching treatment was visually assessed and electronically measured with the spectrophotometer Shade Inspector™. Tooth color was recorded before bleaching treatment, after 14 days, and again after 6 months. VITAPAN® Classical (2D) and VITA-3D-Master® (3D) served as reference systems. RESULTS: Concerning repeated measurements, the 2D system was superior to the 3D system, both visually and electronically in terms of ΔE and d(OM1), for statistics of agreement and reliability. All four methods showed strong patterns in Bland-Altman plots. In the 3D system, hue was less reliable than lightness and chroma, which was more pronounced visually than electronically. The smallest detectable color difference varied among the four methods used, and was most favorable in the electronic 2D system. Comparing the methods, the agreement between the 2D and 3D system in terms of ΔE was not good. The reliability of the visual and electronic method was essentially the same in the 2D and 3D systems; this comparability is fair to good. CLINICAL RELEVANCE: The 3D system may confuse human raters and even electronic devices. The 2D system is the simple and best choice.

Stabilizing Removable Partial Dentures by Immediate or Delayed Loading of Mini-implants: Chewing Efficiency in a Randomized Controlled Clinical Trial.

PURPOSE: The aim of this investigation was to compare the chewing efficiency after immediate and delayed loading of mini-implants that served as supplementary support for removable partial dentures (RPDs). MATERIALS AND METHODS: In this four-center randomized trial, patients who had RPDs in arches with unfavorable tooth distributions, ie, no canine and at most two posterior teeth in one or both quadrants, received strategic mini-implants with ball abutments. The mini-implants in group A were loaded immediately either by housings with O-rings (insertion torque ≥ 35 Ncm) or by soft relining material (insertion torque < 35 Ncm). In group B, the RPDs were only hollowed over the balls. After 4 months, the soft relined RPDs and all RPDs of group B received the housings. Masticatory efficiency was evaluated with a validated mixing ability test of two-colored chewing gum before surgery and 14 days, 4 months (before housing pickup), 4.5 months, and 12 months after surgery. The circular variance of hue was the measure of mixing. RESULTS: From 76 participants with 79 RPDs, 38 each were randomly allocated to group A or B. In group A, the housings in six participants were picked up immediately, and the remaining RPDs were primarily soft relined. There was a significant group difference only after 4 months. The mixing ability was better after immediate loading than after delayed loading (P < .0001). In group B, the chewing efficiency was notably deteriorated after the RPDs were hollowed over the ball abutments. However, immediately after all housings were picked up, the chewing efficiency in both groups was substantially improved, and the variance of hue values after 1 year were very similar in the groups. CONCLUSION: The chewing performance can be improved by inserting supplementary mini-implants under existing RPDs with unfavorable tooth support. This improvement occurred faster by immediate loading than by delayed loading.

New insights in the link between malocclusion and periodontal disease.

AIM: We aimed to investigate associations between malocclusions and periodontal disease by comparing it to that of smoking in subjects recruited from the population-based cross-sectional study "Study of Health in Pomerania." MATERIALS AND METHODS: Sagittal intermaxillary relationship, variables of malocclusion and socio-demographic parameters of 1,202 dentate subjects, 20-39 years of age, were selected. Probing depth (PD) and attachment loss (AL) were assessed at four sites by tooth in a half-mouth design. Analyses were performed with multilevel models on subject, jaw and tooth level. RESULTS: Distal occlusion determined in the canine region, ectopic position of canines, anterior spacing, deep anterior overbite and increased sagittal overjet were associated with AL (p-value <0.05). Associations between malocclusions and PD: deep anterior overbite with gingival contact (odds ratio [OR] = 1.40, 95% CI: 1.08-1.82; p-value = 0.0101) and anterior crossbite (OR = 1.75, 95% CI: 1.29-2.38; p-value = 0.0003). Regarding crowding, only severe anterior crowding was compatible with a moderate to large association with PD (OR = 1.93, 95% CI: 0.89-4.20). Compared to smoking, the overall effect of malocclusions was about one half for AL and one-third for PD. CONCLUSION: Malocclusions or morphologic parameters were associated with periodontal disease.

Association Between Symptoms of Posttraumatic Stress Disorder and Signs of Temporomandibular Disorders in the General Population.

AIMS: To estimate the association between signs of temporomandibular disorders (TMD) and symptoms of posttraumatic stress disorder (PTSD) in a representative sample from the general population of northeastern Germany. METHODS: Signs of TMD were assessed with a clinical functional analysis that included palpation of the temporomandibular joints (TMJs) and masticatory muscles. PTSD was assessed with the PTSD module of the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, ed 4. The change-in-estimate method for binary logistic regression models was used to determine the final model and control for confounders. RESULTS: After the exclusion of subjects without prior traumatic events, the sample for joint pain consisted of 1,673 participants with a median age of 58.9 years (interquartile range 24.8), and the sample for muscle pain consisted of 1,689 participants with a median age of 59.1 years (interquartile range 24.8). Of these samples, 84 participants had pain on palpation of the TMJ, and 42 participants had pain on palpation of the masticatory muscles. Subjects having clinical PTSD (n = 62) had a 2.56-fold increase in joint pain (odds ratio [OR] = 2.56; 95% confidence interval [CI]: 1.14 to 5.71, P = .022) and a 3.86-fold increase (OR = 3.86; 95% CI: 1.51 to 9.85, P = .005) in muscle pain compared to subjects having no clinical PTSD. CONCLUSION: These results should encourage general practitioners and dentists to acknowledge the role of PTSD and traumatic events in the diagnosis and therapy of TMD, especially in a period of international migration and military foreign assignments.

Alexithymia and temporomandibular joint and facial pain in the general population.

BACKGROUND: Associations of alexithymia with temporomandibular pain disorders (TMD), facial pain, head pain and migraine have been described, but the role of the different dimensions of alexithymia in pain development remained incompletely understood. OBJECTIVES: We sought to investigate the associations of alexithymia and its subfactors with signs of TMD and with facial pain, head pain and migraine in the general population. METHODS: A total of 1494 subjects from the general population completed the Toronto Alexithymia Scale-20 (TAS-20) and underwent a clinical functional examination with palpation of the temporomandibular joint and masticatory muscles. Facial pain, migraine and head pain were defined by questionnaire. A set of logistic regression analyses was applied with adjustment for age, sex, education, number of traumatic events, depressive symptoms and anxiety. RESULTS: Alexithymia was associated with TMD joint pain (Odds Ratio 2.63; 95% confidence interval 1.60-4.32 for 61 TAS-20 points vs the median of the TAS-20 score) and with facial pain severity (Odds Ratio 3.22; 95% confidence interval 1.79-5.79). Differential effects of the subfactors were discovered with difficulties in identifying feelings as main predictor for joint, facial, and head pain, and externally oriented thinking (EOT) as U-shaped and strongest predictor for migraine. CONCLUSION: Alexithymia was moderately to strongly associated with signs and symptoms of TMD. These results should encourage dental practioners using the TAS-20 in clinical practice, to screen TMD, facial or head pain patients for alexithymia and could also help treating alexithymic TMD, facial or head pain patients.

Genome-wide association reveals contribution of MRAS to painful temporomandibular disorder in males.

Painful temporomandibular disorders (TMDs) are the leading cause of chronic orofacial pain, but its underlying molecular mechanisms remain obscure. Although many environmental factors have been associated with higher risk of developing painful TMD, family and twin studies support a heritable genetic component as well. We performed a genome-wide association study assuming an additive genetic model of TMD in a discovery cohort of 999 cases and 2031 TMD-free controls from the Orofacial Pain: Prospective Evaluation and Risk Assessment (OPPERA) study. Using logistic models adjusted for sex, age, enrollment site, and race, we identified 3 distinct loci that were significant in combined or sex-segregated analyses. A single-nucleotide polymorphism on chromosome 3 (rs13078961) was significantly associated with TMD in males only (odds ratio = 2.9, 95% confidence interval: 2.02-4.27, P = 2.2 × 10). This association was nominally replicated in a meta-analysis of 7 independent orofacial pain cohorts including 160,194 participants (odds ratio = 1.16, 95% confidence interval: 1.0-1.35, P = 2.3 × 10). Functional analysis in human dorsal root ganglia and blood indicated this variant is an expression quantitative trait locus, with the minor allele associated with decreased expression of the nearby muscle RAS oncogene homolog (MRAS) gene (beta = -0.51, P = 2.43 × 10). Male mice, but not female mice, with a null mutation of Mras displayed persistent mechanical allodynia in a model of inflammatory pain. Genetic and behavioral evidence support a novel mechanism by which genetically determined MRAS expression moderates the resiliency to chronic pain. This effect is male-specific and may contribute to the lower rates of painful TMD in men.