Porphyromonas gingivalis amount in the tongue biofilm is associated with erosive arthritis in systemic lupus erythematosus.

BACKGROUND: Several data have demonstrated the occurrence of erosive arthritis in Systemic Lupus Erythematosus (SLE) patients. However, a few studies have focused on the pathogenic mechanisms involved in this feature. The implication of oral pathogens has been proved in Rheumatoid Arthritis: in particular, Porphyromonas gingivalis (Pg), by inducing citrullination, could trigger autoimmune response. Here, we evaluated amount of Pg on the tongue in a cohort of SLE patients with arthritis, focusing on the association with the erosive phenotype. METHODS: SLE patients with arthritis were enrolled. DAS28 was applied to assess activity. Erosive damage was evaluated by ultrasound at level of MCP (metacarpophalangeal) and PIP (proximal interphalangeals) joints. All subjects underwent a tongue cytologic swab in order to quantify the amount of Pg (real-time PCR). The bacterium expression was obtained from the ratio between the patient's DNA amount and that obtained from healthy subjects. RESULTS: 33 patients were enrolled (M/F 3/30; median age 47 years, IQR 17; median disease duration 216 months, IQR 180): 12 of them (36.4%) showed erosive damage, significantly associated with ACPA positivity (p = 0.03) and higher values of DAS28 (p = 0.01). A mean ratio of 19.7 ± 31.1 was found for Pg amount. Therefore, we used Pg mean values as threshold, identifying two groups of patients, namely, highPg and lowPg. Erosive damage was significantly more frequent in highPg patients in comparison with lowPg (60.0% vs 26.0%, p = 0.001). Furthermore, highPg patients showed higher prevalence of skin manifestations, serositis, and neurological involvement (p = 0.005, p = 0.03, p = 0.0001, respectively). CONCLUSION: The possible contribution of oral microbiota in SLE erosive arthritis was here evaluated for the first time, finding a significant association between erosive damage and higher expression of Pg at tongue level.

Musculoskeletal disorders related to dental hygienist profession.

OBJECTIVES: Musculoskeletal disorders (MSDs) are occupational illnesses concerned with different classes of professionals; dental hygienists are among those. The aim of this trial is to evaluate MSDs prevalence and significance of the symptoms in a sample of dental hygienists. MATERIALS AND METHODS: A 20-question questionnaire was administered to a sample of dental hygienists, via social networks. The variables taken into consideration were personal data, hours of sport, working habits, years of professional activity, working hours and number of patients per week, presence or absence of pain. STATISTICAL ANALYSIS: Data were evaluated using standard statistical analysis software, and an Excel database was created. Descriptive statistics were calculated for each variable. Group comparison was assessed by the chi-square test of homogeneity and Fisher's exact test. (p-value <0.05 as significant). RESULTS: 468 questionnaires were examined: 396 females (85%) and 72 males (15%). The prevailing age was between 25 and 35. Among them, 91% referred to be suffering or have suffered MSDs. The most relevant affected muscular areas are neck (30.6%), shoulder (25.0%) and lumbosacral region (23.3%); the remaining 21.1% is divided among the other regions. Association and statistical analysis among the different variables showed how presence of MSDs negatively influences absenteeism and work performance; further research regarding ergonomics, type of seat, stretching and workout prevention would be important to strengthen the results collected. CONCLUSIONS: Musculoskeletal disorders diffusion among dental hygienists is particularly high due to lack of information; the majority of interviewees showed very little awareness of it; this led to a lack of effort in facing or possibly preventing these pathologies.

Porphyromonas gingivalis and rheumatoid arthritis.

PURPOSE OF REVIEW: To explore the pathogenic association between periodontal disease and rheumatoid arthritis focusing on the role of Porphyromonas gingivalis. RECENT FINDINGS: In the last decades our knowledge about the pathogenesis of rheumatoid arthritis substantially changed. Several evidences demonstrated that the initial production of autoantibodies is not localized in the joint, rather in other immunological-active sites. A central role seems to be played by periodontal disease, in particular because of the ability of P. gingivalis to induce citrullination, the posttranslational modification leading to the production of anticitrullinated protein/peptide antibodies, the most sensitive and specific rheumatoid arthritis biomarker. SUMMARY: The pathogenic role of P. gingivalis has been demonstrated in mouse models in which arthritis was either triggered or worsened in infected animals. P. gingivalis showed its detrimental role not only by inducing citrullination but also by means of other key mechanisms including induction of NETosis, osteoclastogenesis, and Th17 proinflammatory response leading to bone damage and systemic inflammation.

Dental Cone Beam Computed Tomography in Children: Clinical Effectiveness and Cancer Risk due to Radiation Exposure.

Firstly used in the early 90s to generate 3-dimensional projections of X-ray images, cone beam computed tomography (CBCT) has resulted in a large application in dentomaxillofacial imaging, even in children. CBCT uses ionizing radiation that may cause damage to the DNA, and children are at the greatest carcinogenesis risk due to their higher tissue radiosensitivity and their longer life expectancy compared to adults. The questions of whether the cancer risk is really increased after repeated dental CBCT in childhood and of what the underlying biological basis is have become hot topics in the field of dentistry and radiobiology. We performed an overview of the current literature to assess an acceptable role of CBCT in pediatric dentistry.

Enamel remineralization and repair results of Biomimetic Hydroxyapatite toothpaste on deciduous teeth: an effective option to fluoride toothpaste.

BACKGROUND: Dental caries is a recognized worldwide public health problem. Despite being one of the most effective strategies against dental caries, the excessive use of fluorine may result in a potential risk of developing dental fluorosis especially in children under age of six. The purpose of this work is to analyze a fluorine-free toothpaste containing Biomimetic Hydroxyapatite to assess enamel re-mineralizing and repairing properties. RESULTS: The study was performed in vitro and in vivo, comparing the hydroxyapatite toothpaste with two others toothpaste containing different fluorine concentrations. The coating effect of the micro-structured Hydroxyapatite nanoparticles reintegrates the enamel with a biomimetic film reproducing the structure and the morphology of the biologic Hydroxyapatite of the enamel. As demonstrated, the coating is due to the deposit of a new layer of apatite, which presents fewer particles than the natural enamel, not based on the chemical-physical changes occurring in fluorinated toothpastes. Moreover, it shows resistance to brushing as a consequence of chemical bonds between the synthetic and natural crystals of the enamel. CONCLUSIONS: The use of Biomimetic Hydroxyapatite toothpastes has proven to be a valuable prevention measure against dental caries in primary dentition since it prevents the risk of fluorosis.

Periodontitis and Rheumatoid Arthritis: The Same Inflammatory Mediators?

The strict link between periodontitis (PD) and rheumatoid arthritis (RA) has been widely demonstrated by several studies. PD is significantly more frequent in RA patients in comparison with healthy subjects: this prevalence is higher in individuals at the earliest stages of disease and in seropositive patients. This is probably related to the role of P. gingivalis in inducing citrullination and leading to the development of the new antigens. Despite the many studies conducted on this topic, there is very little data available concerning the possibility to use the same biomarkers to evaluate both RA and PD patients. The aim of the review is to summarize this issue. Starting from genetic factors, data from literature demonstrated the association between HLA-DRB1 alleles and PD susceptibility, similar to RA patients; moreover, SE-positive patients showed simultaneously structural damage to the wrist and periodontal sites. Contrasting results are available concerning other genetic polymorphisms. Moreover, the possible role of proinflammatory cytokines, such as TNF and IL6 and autoantibodies, specifically anticyclic citrullinated peptide antibodies, has been examined, suggesting the need to perform further studies to better define this issue.

Assessing risk factors for dental caries: a statistical modeling approach.

The problem of identifying potential determinants and predictors of dental caries is of key importance in caries research and it has received considerable attention in the scientific literature. From the methodological side, a broad range of statistical models is currently available to analyze dental caries indices (DMFT, dmfs, etc.). These models have been applied in several studies to investigate the impact of different risk factors on the cumulative severity of dental caries experience. However, in most of the cases (i) these studies focus on a very specific subset of risk factors; and (ii) in the statistical modeling only few candidate models are considered and model selection is at best only marginally addressed. As a result, our understanding of the robustness of the statistical inferences with respect to the choice of the model is very limited; the richness of the set of statistical models available for analysis in only marginally exploited; and inferences could be biased due the omission of potentially important confounding variables in the model's specification. In this paper we argue that these limitations can be overcome considering a general class of candidate models and carefully exploring the model space using standard model selection criteria and measures of global fit and predictive performance of the candidate models. Strengths and limitations of the proposed approach are illustrated with a real data set. In our illustration the model space contains more than 2.6 million models, which require inferences to be adjusted for 'optimism'.

Fast and Early Mandibular Osteodistraction: The Long-Term Follow-Up of Mandibular Distraction Osteogenesis on Teeth Position.

Pierre Robin Sequence is a congenital pathology defined by the triad micrognathia, glossoptosis and often a U-shaped cleft of soft palate. Newborns affected by airways obstruction may necessitate more invasive options: tongue-lip adhesion, tracheostomy and mandibular distraction osteogenesis. The authors analyzed the effect of fast and early mandibular osteodistraction on deciduous dental development in patients affected by Pierre Robin Sequence. Analysis of the patients treated for severe form was performed by a team composed by maxillofacial surgeons and dentists. Five patients were included for the analysis: before and long term clinical and radiological assessments were considered. All patients underwent fast and early mandibular osteodistraction; two years follow up computed tomography and panorex reconstructions showed bone consolidation, 33 of 35 teeth analyzed before ostedistraction are present after distraction protocol; no positional changes were detected at the follow up analysis either deciduous teeth and molar permanent buds. No deformities regarding molar buds were detected. In conclusion external mandibular distractor devices have been associated with dental injuries and facial scaring. Even though, the dental complications identified can not be unambiguously connected to the external distractor devices.

Survival of dental implants in patients with oral cancer treated by surgery and radiotherapy: a retrospective study.

BACKGROUND: The aim of this retrospective study was to evaluate the survival of dental implants placed after ablative surgery, in patients affected by oral cancer treated with or without radiotherapy. METHODS: We collected data for 34 subjects (22 females, 12 males; mean age: 51 ± 19) with malignant oral tumors who had been treated with ablative surgery and received dental implant rehabilitation between 2007 and 2012. Postoperative radiation therapy (less than 50 Gy) was delivered before implant placement in 12 patients. A total of 144 titanium implants were placed, at a minimum interval of 12 months, in irradiated and non-irradiated residual bone. RESULTS: Implant loss was dependent on the position and location of the implants (P = 0.05-0.1). Moreover, implant survival was dependent on whether the patient had received radiotherapy. This result was highly statistically significant (P < 0.01). Whether the implant was loaded is another highly significant (P < 0.01) factor determining survival. We observed significantly better outcomes when the implant was not loaded until at least 6 months after placement. CONCLUSIONS: Although the retrospective design of this study could be affected by selection and information biases, we conclude that a delayed loading protocol will give the best chance of implant osseointegration, stability and, ultimately, effective dental rehabilitation.

Analysis of human alveolar osteoblast behavior on a nano-hydroxyapatite substrate: an in vitro study.

BACKGROUND: Nano-hydroxyapatite (nHA) is a potential ideal biomaterial for bone regeneration. However, studies have yet to characterize the behavior of human osteoblasts derived from alveolar bone on nHA. Thus, the aim of the present study was to evaluate the influence of nHA on the adhesion, proliferation and differentiation of these alveolar bone-derived cells. METHODS: Primary human alveolar osteoblasts were collected from the alveolar ridge of a male periodontal patient during osseous resective surgery and grown on culture plates coated with either polylysine or polylysine with nano-hydroxyapatite (POL/nHA) composite. The cells were grown and observed for 14 days, and then assessed for potential modifications to osteoblasts homeostasis as evaluated by quantitative reverse transcriptase-polymerase chain reaction (real time RT-PCR), scanning electron microscopy and atomic force microscopy. RESULTS: Real time PCR revealed a significant increase in the expression of the selected markers of osteoblast differentiation (bone morphogenetic protein (BMP)-2,-5,-7, ALP, COLL-1A2, OC, ON) in cells grown on the POL/nHA substrate. In addition, as compared with the POL surface, cells grown on the POL/nHA substrate demonstrated better osteoconductive properties, as demonstrated by the increase in adhesion and spreading, likely as a result of the increased surface roughness of the composite. CONCLUSIONS: The increased expression of BMPs and osteoinductive biomarkers suggest that nano-hydroxyapatite may stimulate the proliferation and differentiation of local alveolar osteoblasts and thus encourage bone regeneration at sites of alveolar bone regeneration.

Biomechanical Multipurpose Miniscrew Strategy for Simultaneous Distalization in Class II Patients-The BiGa System.

An efficient treatment plan using a temporary anchorage device should be built following the principle of reducing the number of tads to obtain a multiple biomechanical advantage. The following case report concerns the Biga system, a strategy that supports orthodontists during class II corrections and vertical control through treatment. A 12-year-old girl with a high angle of skeletal class II was selected. A novel biomechanical strategy was effectively applied using two tads on the upper arch to obtain sequential distalization of the upper teeth and to correct the lower arch spee curve using third-class elastics. Eventually, on the same tads, a double cantilever was applied to control the overbite and intrusion during incisors' retraction. The Biga system is an easy biomechanical strategy that ensures the three-dimensional control of treatment mechanics in class II patients.

Clinical association between teeth malocclusions, wrong posture and ocular convergence disorders: an epidemiological investigation on primary school children.

BACKGROUND: As the various systems in the body are inter-connected to form a single structural unit, a pathological condition in one area can also affect other areas. There are many known correlations between the visual and motor system. The importance of visual function, particularly the paracentral peripheral field of view, in motor coordination, ambulation and the maintenance of balance has been amply demonstrated.In line with current medical principles, which are moving towards a more holistic view of the human body, this study aims to investigate, in an interdisciplinary manner, the incidence of dental malocclusions together with posture and eye convergence disorders. METHODS: Six hundred and five children attending at the 3rd, 4th and 5th years of seven Genoa primary schools were examined. Each child underwent the following examinations: (i) dental/occlusal; (ii) orthoptic; and (iii) postural. Occlusal data concerned the presence of cross-bite, midline deviation with a mandibular shift, bad habits and deep or open bite.Postural assessment involved frontal and lateral inspection, investigation during trunk flexion and ambulation, and note of any asymmetry in the lower limbs. The recorded orthoptic data included those pertaining to ocular dominance, a cover test, convergence and the Brock string test. RESULTS: A prevalence of cases with an unphysiological gait was found in patients with overjet (14.70%) or overbite (14.87%), while the percentage of patients with normal occlusion that showed an unphysiological gait was 13.08%. Also, about 93.8%-94.2% of children showed normal legs without dysmetry, with no difference in respect to the type of occlusion. Subjects with an open bite or deep bite showed a slightly different distribution of right or left dominant eyes. CONCLUSION: About 13% of children showed a pathological gait and, among them, vertical anomalies of occlusion (deep bite or open bite) were prevalent with respect to the other occlusal defects. The vertical dimension of occlusion revealed a slight relationship with the proper dominant eye. Postural, orthoptic, osteopathic and occlusal variables were often clinically associated, and therefore these disorders appear to request a multidisciplinary medical approach for their treatment.

Current knowledge on the association between cardiovascular and periodontal disease: an umbrella review.

INTRODUCTION: Periodontal disease (PD) and cardiovascular diseases (CVD) are among the most common pathologies in the world and their relationship has long been studied. Both conditions lead to a chronic inflammatory process with degenerative characteristics and their biunivocal correlation is now well established. The aim of this umbrella review on cardiovascular and periodontal disease was to evaluate the real degree of association between these two pathological conditions. EVIDENCE ACQUISITION: We conducted a comprehensive literature search on PubMed/Medline and in the Cochrane Library for systematic reviews focused on clinical evidence regarding the relationship between PD and CVD. The internal validity of systematic reviews and meta-analyses was formally analyzed using the Overview Quality Assessment Questionnaire (OQAQ) Tool. The umbrella review was planned in accordance with current international recommendations and was described as specified by the PRISMA Guidelines. EVIDENCE SYNTHESIS: Thirty-one systematic reviews, including 8 meta-analyses for a total of 507 clinical studies and over 3,549,966 patients were included. PD resulted to be associated with a higher risk of developing CVD (acute coronary syndrome, acute myocardial infarction) and cerebrovascular diseases (ischemic stroke); however, if the treatment of periodontitis reduces the risk of CVD events related is yet to be investigated. CONCLUSIONS: To date, the relationship between CVD and PD provides heterogeneous data. There is an association between PD and CVD, but a causal relationship cannot be established. Further research with properly designed long-term follow-up studies are needed in order to examine various physiopathological aspects of their association.

Impact of Stress on Periodontal Health: Literature Revision.

Stress is a physiological response of the body to stressful life events but may not be when the individual is persistently exposed to the stress trigger, and it negatively affects certain physiological functions, thus triggering psychosomatic diseases. In literature, chronic stress and inadequate coping strategies are found to mediate the risk and development of periodontitis; mechanisms have therefore been proposed to explain the effects of stress on the periodontium. Since stress is a prevalent problem in modern life and given the importance of maintaining oral health, the present literature review aimed to estimate the association between stress and periodontal disease. The research question adopted is the following: "Are psychological stress and periodontal disease related?" The search was conducted in August 2022 and limited to articles in electronic databases from 2017 to 2022 in English, excluding reviews and literature reviews. From the electronic databases, a total of 532 articles were identified and became 306 after reviews and duplicates were removed. An additional bibliographic search was conducted through the same electronic databases, controlled terms and keywords including only systematic reviews, which were previously excluded. Through the bibliography cited in the systematic reviews, an additional 18 articles were identified, with a new total of 324. As a result of reading the title and abstract of these 324 articles, an additional 295 were excluded. Reading the full text of the remaining 29 studies, 2 articles were excluded due to non-adherence to the eligibility criteria. The remaining 27 results were included in our literature review. It has been suggested in the literature that adverse socioeconomic conditions elicit a stress response, which can trigger periodontal inflammation. Most of the 27 articles included in the study confirm and demonstrate a positive association between psychological stress and periodontal disease. Numerous studies have shown the mechanisms through which chronic stress negatively affects periodontal tissues. Therefore, in the light of the results obtained from this review, it is important that oral health professionals, also for general health purposes, consider stress factors among the risk factors of periodontal disease, its severity and decreased efficacy of treatments. It is therefore advisable to act preventively through the interception of chronic stress.

Orbital volume and surface after Le Fort III advancement in syndromic craniosynostosis.

There are no quantitative standards for the volumetric measurements of the orbital cavity after Le Fort III advancement. Computed tomography (CT) scan images have given the opportunity to compare with accuracy the real anatomic changes and potentially the functional improvements that resulted after a surgical treatment.Three-dimensional CT scan images processed by DICOM files in Dolphin 3D Software were used to assess orbital volume and surface in 12 subjects affected by craniofacial syndromic malformations treated with Le Fort III advancement. The preoperative (T0) and postoperative (T1: 6 months after surgery) three-dimensional craniofacial CT scans of the subjects were collected and retrospectively analyzed. Image segmentation of the anatomic orbital cavity and the three-dimensional graphic rendering were done by using the Dolphin Imaging Plus 11.0 software.The orbital volume was increased after surgery, with statistical significance, from 22,267 to 22,706.3 mm(3) in the right eye and from 26,511 mm(3) to 26,256.4 mm(3) in the left eye. The surface of both bony orbits had an expansion, which is statistically significant. In conclusion, this study showed that the orbital advancement in white subjects after Le Fort III advancement was significant and produced a significant augmentation of the orbital volume and surface area with correction of the ocular bulb proptosis.

The Validity of Machine Learning Procedures in Orthodontics: What Is Still Missing?

Artificial intelligence (AI) models and procedures hold remarkable predictive efficiency in the medical domain through their ability to discover hidden, non-obvious clinical patterns in data. However, due to the sparsity, noise, and time-dependency of medical data, AI procedures are raising unprecedented issues related to the mismatch between doctors' mentalreasoning and the statistical answers provided by algorithms. Electronic systems can reproduce or even amplify noise hidden in the data, especially when the diagnosis of the subjects in the training data set is inaccurate or incomplete. In this paper we describe the conditions that need to be met for AI instruments to be truly useful in the orthodontic domain. We report some examples of computational procedures that are capable of extracting orthodontic knowledge through ever deeper patient representation. To have confidence in these procedures, orthodontic practitioners should recognize the benefits, shortcomings, and unintended consequences of AI models, as algorithms that learn from human decisions likewise learn mistakes and biases.

Diet Implications and Oral Health Status of Women in Central Italy.

OBJECTIVE: The relationships between oral health habits, dietary practices, and oral health status, as well as general health status, in the population of Italian women, are complex, with many mutual and interrelating factors. The purpose of this study is to investigate oral habits, oral status, and dietary habits of a sample of women in Italy, highlighting the links between nutrition and oral health and discussing how oral health care professionals can integrate nutrition counseling that aimed at improving the oral health of their patients into their practices. MATERIALS AND METHODS: In the period between February 2020 and July 2020, an anonymous questionnaire made up of 20 questions was administered to a randomized sample of 120 Italian women. RESULTS: Most of women declare good manual skills in oral hygiene (50%) but just less than half of them brushes their teeth more than three times a day. Statistically significant correlations were found between frequency of dental checkups and dental mobility (p = 0.036), and halitosis (p = 0.006), as well as between frequency of flossing and gum bleeding. Correlation between the type of diet and oral health status showed more halitosis (∼21%), sensitivity (∼26%), and xerostomia (∼53.3%) for vegetarian and vegan women. CONCLUSION: More awareness need to be raised concerning oral hygiene habits, and regarding the importance of regular dental checkups. Brushing at least twice or three times a day needs to be encouraged and the valid support of dental aids has to be in the everyday domestic oral hygiene protocol, as scientific evidence demonstrates. Future clinical studies need to be performed on a more consistent number of vegetarian and vegan patients, to obtain more statistically significant results and support future research that will compare omnivorous, vegetarian, and vegan diets and their influence on oral health status.

Assessment of Enamel Color Stability of Resins Infiltration Treatment in Human Teeth: A Systematic Review.

(1) The evolution of techniques and materials used in dentistry has led to the introduction of a technique known as micro-infiltration, using ICON infiltrating resin. The purpose of this study was to evaluate whether the resin infiltrant can remain stable in the enamel color of human teeth over time or if it causes discoloration and review current knowledge on color stability based on the literature selected solely on studies performed on human teeth and to provide a perspective on the methods proposed by clinicians in the infiltration procedure; (2) Methods: This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement; (3) Results: Twelve studies were selected for this review. The study results suggest that the device content is sufficiently comprehensive. The reviewers expressed strong support for the device's content for assessing the quality of reviews. The paper summarizes current reports regarding the color stability assessment of enamel treated by in- filtration resin confirmed in in vitro and in vivo studies; (4) Conclusions: Based on these considerations, the resin infiltration method can be recommended to improve the appearance of enamel lesions. The infiltrated lesions remained chromatically stable, showing no significant color changes in the long term.

Endosseous Dental Implant Materials and Clinical Outcomes of Different Alloys: A Systematic Review.

In recent years, implantology has made significant progress, as it has now become a safe and predictable practice. The development of new geometries, primary and secondary, of new surfaces and alloys, has made this possible. The purpose of this review is to analyze the different alloys present on the market, such as that in zirconia, and evaluate their clinical differences with those most commonly used, such as those in grade IV titanium. The review, conducted on major scientific databases such as Scopus, PubMed, Web of Science and MDPI yielded a startling number of 305 results. After the application of the filters and the evaluation of the results in the review, only 10 Randomized Clinical Trials (RCTs) were included. Multiple outcomes were considered, such as Marginal Bone Level (MBL), Bleeding on Probing (BoP), Survival Rate, Success Rate and parameters related to aesthetic and prosthetic factors. There are currently no statistically significant differences between the use of zirconia implants and titanium implants, neither for fixed prosthetic restorations nor for overdenture restorations. Only the cases reported complain about the rigidity and, therefore, the possibility of fracture of the zirconium. Certainly the continuous improvement in these materials will ensure that they could be used safely while maintaining their high aesthetic performance.

Signs and symptoms of temporomandibular joint disorders in Caucasian children and adolescents.

This study investigated the prevalence of the signs and symptoms of temporomandibular disorders (TMD) in a population of children and adolescents. TMD signs and symptoms were recorded in 1134 subjects (593 males and 541 females; age range 5-15 years), divided into various groups according to the: (i) Angle dental class; (ii) presence and type of crossbite; (iii) gender; and (iv) age (ages 5-11 and 12-15 years). The percentages of signs and symptoms were compared using the chi2-test to determine the differences among the groups for the rates of TMD symptoms, bruxism, joint sounds, deviation during opening, reduced opening/lateral/protrusive movements, and myofascial pain. Subjects who were 12-15 years old showed a significantly higher prevalence of myofascial pain than those who were 5-11 years old (chi2 = 4.263; p < 0.05). Females showed a significantly higher prevalence of myofascial pain than males (chi2 = 3.882; p < 0.05). Subjects with posterior, unilateral crossbite showed a significantly higher prevalence of TMD symptoms (chi2 = 33.877; p < 0.001) and reduction of functional movements (chi2 = 10.800; p < 0.05) than those with no crossbite, or with anterior or posterior bilateral crossbite. TMD's signs and symptoms seem to be associated to some definite characteristics of the patient, such as female gender, young age, and presence of posterior unilateral crossbite.