Changes in hyoid bone and tongue position in Class I subjects after orthodontic treatment with rapid palatal expander.

OBJECTIVE: To evaluate the effects of the rapid palatal expander (RPE) on the hyoid bone and tongue position in skeletal Class I patients, compared to control groups. METHODS: Eighty-four Class I subjects, aged 6-14, were selected. Among these, 28 patients were treated with RPE, 28 with function-generating bite (FGB) appliance, and 28 were untreated. Lateral cephalograms taken before (T0) and after (T1) treatment were retrieved. Changes in the hyoid bone and tongue position were evaluated, and the area above the tongue was measured. RESULTS: No significant difference in the hyoid and tongue posture was observed across the groups. However, there were significant differences for HC3 (distance from H-point to the third cervical vertebrae), H2H (distance from H-point to SN plane), and TT-Eb (tongue length) between T0 and T1 in all groups. CONCLUSION: The results suggest that hyoid bone and tongue position changes were related to growth rather than treatment.

Effect of Class II functional treatment on facial attractiveness, as perceived by professionals and laypeople.

The literature offers different perspectives for and against two-phase treatment of skeletal Class II malocclusion. Facial attractiveness is an important aspect to take into account, given that children with skeletal Class II are often bullied by their peers and have low self-esteem and a lower social perception. The aim of the present study was to evaluate the aesthetic perception of facial profiles by a large number of observers, before and after treatment with a functional appliance, compared to untreated controls. The pre- and post-treatment cephalograms of 20 Class II subjects treated with Sander's bite-jumping appliance and 20 untreated historical controls were collected and transformed into black and white silhouettes depicting only the lower third of the face. An online questionnaire comprising the silhouettes of the two groups, three "calibration" profiles and an "ideal" profile was submitted to dentists, orthodontists, undergraduates and laypeople, asking them to rate the profile's attractiveness using a Visual Analogue Scale (VAS). The effect of treatment, and observers' age, expertise and gender were analysed. The calibration images and the ideal profiles were used to evaluate the coherence of each observer's judgement. The protocol was approved by the local Ethics Committee. Nine-hundred and ten questionnaires were collected. Treated subjects showed a larger improvement of facial attractiveness compared to controls. A significant effect of gender on the observer's ratings was observed. Some observers showed incoherent judgement, which had a significant effect on the regression model. In conclusion, early treatment with functional appliances seems to improve patients' facial aesthetics. This improvement is perceived equally by dental professionals and laypeople.

Long-term effect on adenoid dimensions and craniocervical angulation after maxillary expansion with fixed or functional appliances.

BACKGROUND: Maxillary expansion is a common orthodontic procedure that could have a positive effect also on airway patency. The aim of the present study was to evaluate the long-term effects of rapid maxillary expansion (RME) on nasopharyngeal area and cranio-cervical angulation in growing patients, compared to controls treated with a function-generating bite appliance (FGB). MATERIAL AND METHODS: Sixty patients aged 6-14 consecutively treated with RME or FGB were selected retrospectively and divided into two groups. Lateral cephalograms taken before and after treatment were retrieved, and the nasopharyngeal area, delimited superiorly by a sella-posterior nasal spine (PNS) line and inferiorly by a basion-PNS line, and the cranio-cervical angulation were measured. RESULTS: The mean observation time was 17.6 ± 8 months. No differences were present between the two groups regarding age and gender. The nasopharyngeal area increased significantly in both groups after treatment, but with no statistically significant difference between them. The cranio-cervical angulation showed no differences within or between groups. CONCLUSIONS: Maxillary deficiency treatment with either RME or FGB was followed by a comparable increase in nasopharyngeal area. Key words:Rapid maxillary expansion, Airway, Nasopharyngeal area, Adenoid.

Microtensile Bond Strength of Etch-and-Rinse Adhesives in Different Hydroabrasion Conditionings.

The aim of the present study was to in vitro evaluate the effect of dentin conditioning with hydroabrasion on the microtensile bond strengths of three adhesive systems, compared to the standard etch-and-rinse technique. Sixty extracted human third molars were collected, and their midcoronal occlusal dentin was used for the microtensile bond strength test. Teeth were randomly assigned to three groups according to the adhesive system used: ExciTE F DSC, ENA Bond, and Scotchbond Universal. Specimens from each group were further divided into four subgroups: control specimens were treated with standard adhesive procedures; hydroabraded (HA) specimens were subjected to preventive hydroabrasion with three different intensity levels. After bonding procedures, composite crowns were incrementally built up. After thermocycling, specimens were subsequently sectioned into 1 × 1 mm sticks, and microtensile bond strengths were measured. Data were statistically analyzed. Failure mode analysis was performed. There were no significant differences in terms of bond strength between standard adhesion protocols and adhesion with HA preconditionings. On the other hand, the type of adhesive used had a significant effect on the tensile bond strength. Subgroups treated with hydroabrasion at higher intensity showed a slightly increased frequency of cohesive fractures. In conclusion, hydroabrasion can be used for dentin cavity preparation or finishing, since it does not seem to affect the bonding effectiveness.

In Vitro Shear Bond Strength of Orthodontic Brackets after Enamel Conditioning with Acid Etching and Hydroabrasion.

The purpose of this study was to evaluate the shear bond strength and adhesive remnant index ARI) of orthodontic brackets following enamel conditioning with acid etching, hydroabrasion, and with both procedures. Thirty extracted human premolars were divided into three groups and received either acid etching, hydroabrasion or both procedures. Orthodontic brackets were bonded with composite resin. Shear bond strength was tested with a tensile machine, then the teeth were observed under a stereomicroscope to evaluate ARI scores. The enamel morphology after each conditioning method was evaluated with scanning electron microscope imaging. A one-way ANOVA and a Kruskal-Wallis H test were used to compare the bond strength and the ARI scores among the three groups. Hydroabrasion alone produced shear bond strength values below clinical acceptability, while the combination of acid etching and hydroabrasion produced the highest values. The ARI scores in the hydroabrasion group were significantly different from the other groups. Hydroabrasion followed by acid etching was effective in increasing the shear bond strength of orthodontic brackets. Further in vivo studies are needed to confirm the cost and benefits of this technique.

Dimensional variability of orthodontic slots and archwires: an analysis of torque expression and clinical implications.

BACKGROUND: The loss of third-order information in pre-adjusted brackets due to torsional play is a problem in clinical orthodontics. The aim of this study was to evaluate the impact of slot height, archwire height, width and edge bevel's radius on the torsional play for three brackets/archwire systems. METHODS: Ninety brackets with a 0.022 × 0.028 in. slot with McLaughlin-Bennett-Trevisi prescription from three different manufacturers were selected, and the slot's height and depth were measured using a profile projector. Sixty stainless-steel rectangular archwires from three different manufacturers were sectioned and observed with a SEM to measure their height, width, and radius of edge bevel. The recorded data were used to calculate the theoretical torsional play between different slot-archwire combinations. One-way ANOVA was used to compare the measurements within different bracket types and among different manufacturers. RESULTS: Slot height was usually oversized. Archwire's height was usually undersized, but oversized wires were also observed. The radius edge bevel was the most variable parameter. A certain degree of torsional play is always present that differs from one bracket type to another of the same producer and that can even be doubled from one manufacturer to another. CONCLUSIONS: Due to production tolerance, differences between the nominal values and the real dimensions of any components of a slot/archwire system are common. This results in a torsional play that limits torque expression. The archwire's edge bevel plays an important role in torque expression, and clearer information should be provided by the manufacturers regarding this aspect.

Condylar long axis and articular eminence in MRI in patients with temporomandibular disorders.

OBJECTIVE: To compare morphologic findings in MRI and skeletal divergence of a group of patients with temporomandibular joint disorders (TMD) subdivided into condylar symmetric and asymmetric. METHODS: Fifty-nine adults (26.7 years old) with TMD were retrospectively recruited. Condylar height symmetry was evaluated by orthopantomography (Habets's method) and used to divide patients into Symmetric and Asymmetric groups; skeletal divergence was assessed on lateral cephalograms. MRI was used to evaluate the condylar long axis' angle, the glenoid fossa morphology, and the degree of disc displacement. RESULTS: Asymmetric subjects showed a hyperdivergent skeletal pattern (p = 0.036), asymmetric condylar long axis (p = 0.018), and deeper (p = 0.025) and asymmetric (p = 0.001) glenoid fossa compared to symmetric subjects. CONCLUSION: Patients with TMD and condylar asymmetry diagnosed with orthopantomography are more likely to show hyperdivergent skull in cephalometry, condylar asymmetry of both height and major axis, and a steeper glenoid fossa in MRI.

Enamel preservation during composite removal after orthodontic debonding comparing hydroabrasion with rotary instruments.

The aim of the present study was to evaluate how hydroabrasion performs during composite removal. A standardized amount of composite was bonded to 40 enamel surfaces of extracted third molars, then removed with either a tungsten carbide bur mounted on a micro-motor handpiece without irrigation, a tungsten carbide bur mounted on a micro-motor handpiece with irrigation, a tungsten carbide bur mounted on an air-rotor handpiece, or hydroabrasion. The four treatment methods were compared using the enamel-surface-index and the adhesive-remnant-index and performing a Kruskal-Wallis statistical test to detect differences between each method' scores. Hydroabrasion produced significantly less damage to the enamel surface compared to the other three methods. Hydroabrasion was the cleaning method that produced less damages to the enamel surface, at a cost of a less efficient composite removal than tungsten carbide burs on micro-motor handpiece.

Morphometric analysis of sella turcica in growing patients: an observational study on shape and dimensions in different sagittal craniofacial patterns.

The aim of this study was to evaluate the differences in sella dimensions and shape between growing patients with Class I, Class II, and Class III skeletal malocclusions, evaluated through morphometric analysis. Seventy-eight subjects aged between 9 and 13 years were selected and assigned to either the Class I, Class II, or Class III groups according to the measured ANB angle (the angle between the Nasion, skeletal A-point and skeletal B-point). Six landmarks were digitised to outline the shape of the sella turcica. Linear measurements of the sella length and depth were also performed. Procrustes superimposition, principal component analysis, and canonical variate analysis were used to evaluate the differences in sella shape between the three groups. A one-way MANOVA and Tukey's or Games-Howell tests were used to evaluate the presence of differences in sella dimensions between the three groups, gender, and age. The canonical variate analysis revealed a statistically significant difference in sella shape between the Class I and the Class II groups, mostly explained by the CV1 axis and related to the posterior clinoidal process and the floor of the sella. No differences were found regarding linear measurements, except between subjects with different age. These differences in sella shape, that are present in the earlier developmental stages, could be used as a predictor of facial growth, but further studies are needed.

Biomarkers in the gingival crevicular fluid used to detect root resorption in patients undergoing orthodontic treatment: A systematic review.

OBJECTIVES: To evaluate whether changes in the concentration of different biomarkers in the gingival crevicular fluid (GCF) can be used to detect the root resorption process in adult or adolescent patients undergoing treatment with a fixed appliance, in comparison with untreated subjects or treated patients not showing signs of root resorption. MATERIAL AND METHODS: The following databases were analysed in the period between June 2017 and March 2018, without any language and initial date restrictions: PubMed, EMBASE, Scopus, Web of Science and Cochrane Library. A quality assessment instrument (QAI) was developed to establish the risk of bias. RESULTS: A total of 1127 articles were analysed. Based on the inclusion and exclusion criteria, seven studies qualified for the final review. The QAI tool revealed that five articles were at a moderate risk of bias and two articles were at a low risk of bias. CONCLUSION: Dentine phosphoprotein (DPP) may be considered a relatively useful marker for root resorption. Dentinal sialoprotein (DSP) could be a potential biomarker but is not highly helpful at detecting root shortening. Inflammatory cytokines (pro- and anti-resorption), osteopontin (OPN), osteoprotegerin (OPG), RANKL and alkaline phosphatase (ALP) are useful biomarkers to explain the biological mechanisms that occur during orthodontic movement but are not specific enough. Further studies are required to clarify the role of GM-CSF as a potential biomarker to distinguish subjects at a risk of severe root resorption in the early phase.

Soft-tissue changes after Class II malocclusion treatment using the Sander bite-jumping appliance: a retrospective study.

BACKGROUND: The soft tissue profile outcome after functional treatment of Class II malocclusion is important for a patient's aesthetic and psychosocial results. The soft tissue effects of the Sander bite-jumping appliance (BJA), which is the device that produces the greatest mandibular advancement according to a systematic review, have never been investigated. The aim of the present study was to assess the soft tissue effects of the BJA in comparison to matched untreated controls. METHODS: A total of 19 patients treated with BJA during puberty were retrospectively recruited, and 15 untreated controls were retrieved from a previous growth study to match the treated group. Lateral cephalograms were used to evaluate the pre- and post-treatment differences in the ANB angle, the inclination of the upper and lower incisors, facial convexity, the nasolabial angle and the sagittal position of the skeletal and soft tissue at points A and B. Independent t-tests or Mann-Whitney U tests were used to detect differences between the two groups. RESULTS: Statistically significant differences were found for the ANB angle, the inclination of the upper incisors and facial convexity. CONCLUSIONS: Functional treatment of Class II patients with the Sander BJA during puberty was effective at improving the profile and reducing the facial convexity angle in the short term.

Does muscular activity related to vertical facial divergence influence the time needed for orthodontic extrusion of palatally impacted maxillary canines? A retrospective study.

BACKGROUND: The aim of the present study was to evaluate if the different muscular activity correlated to different degrees of facial divergence has an effect on the time needed to extrude a palatally impacted maxillary canine. MATERIAL AND METHODS: Twenty-six patients were retrospectively selected, all treated with a specific cantilever appliance that allows extrusion of the impacted canine applying a physiologic amount of force below 0.6 N in a predictable way. For all the patients, pre-treatment cephalometric tracings were used to evaluate facial divergence through the FMA angle, the angle between the maxillary and mandibular plane, and the angles between the occlusal plane and either the maxillary and mandibular plane. Linear bivariate regression was calculated to evaluate if facial divergence can predict the time needed for canine extrusion. RESULTS: The linear regression model was not able to predict extrusion time from variables explaining the facial divergence. CONCLUSIONS: Palatally impacted maxillary canines can be treated with the application of physiologic extrusion force regardless of patients' facial divergence and muscular activity. Key words:Impacted canines, cantilever, facial divergence, muscular activity.

Correlation between tooth size-arch length discrepancy and interradicular distances measured on CBCT and panoramic radiograph: an evaluation for miniscrew insertion.

INTRODUCTION: The selection of appropriate sites for miniscrew insertion is critical for clinical success. OBJECTIVES: The aim of the present study was to evaluate how interradicular spaces measured on panoramic radiograph compare with Cone-Beam Computed Tomography (CBCT), and how crowding can influence the presence of available space for miniscrew insertion, in order to define a new "safe zones" map. METHODS: A total of 80 pre-treatment panoramic radiographs and 80 CBCT scans with corresponding digital models were selected from the archives of the department of Dentistry, Aarhus University. Crowding was measured on digital models, while interradicular spaces mesial to the second molars were measured on panoramic radiographs and CBCTs. For panoramic radiographs, a magnification factor was calculated using tooth widths measured on digital models. Statistical analyses were performed to investigate the correlation between the amount of crowding and the available interradicular space. Visual maps showing the amount of interradicular spaces measured were drawn. RESULTS: The most convenient interradicular spaces are those between the second molar and the first premolar in the mandible, and between the central incisors in the maxilla. However, some spaces were revealed to be influenced by crowding. CONCLUSIONS: Calibration of panoramic radiographs is of utmost importance. Generally, panoramic radiographs underestimate the available space. Preliminary assessment of miniscrew insertion feasibility and the related selection of required radiographs can be facilitated using the new "safe zone" maps presented in this article.

Correlation between tooth size-arch length discrepancy and interradicular distances measured on CBCT and panoramic radiograph: an evaluation for miniscrew insertion

Abstract Introduction: The selection of appropriate sites for miniscrew insertion is critical for clinical success. Objectives: The aim of the present study was to evaluate how interradicular spaces measured on panoramic radiograph compare with Cone-Beam Computed Tomography (CBCT), and how crowding can influence the presence of available space for miniscrew insertion, in order to define a new "safe zones" map. Methods: A total of 80 pre-treatment panoramic radiographs and 80 CBCT scans with corresponding digital models were selected from the archives of the department of Dentistry, Aarhus University. Crowding was measured on digital models, while interradicular spaces mesial to the second molars were measured on panoramic radiographs and CBCTs. For panoramic radiographs, a magnification factor was calculated using tooth widths measured on digital models. Statistical analyses were performed to investigate the correlation between the amount of crowding and the available interradicular space. Visual maps showing the amount of interradicular spaces measured were drawn. Results: The most convenient interradicular spaces are those between the second molar and the first premolar in the mandible, and between the central incisors in the maxilla. However, some spaces were revealed to be influenced by crowding. Conclusions: Calibration of panoramic radiographs is of utmost importance. Generally, panoramic radiographs underestimate the available space. Preliminary assessment of miniscrew insertion feasibility and the related selection of required radiographs can be facilitated using the new "safe zone" maps presented in this article.

Resumo Introdução: a seleção de locais apropriados para a inserção de mini-implantes é crítica para o sucesso clínico. Objetivo: os objetivos do presente estudo foram avaliar as medições de espaços inter-radiculares feitas em radiografias panorâmicas e compará-las com as medições feitas com tomografia computadorizada de feixe cônico (TCFC), além de avaliar como o apinhamento pode influenciar na disponibilidade de espaços para inserção dos mini-implantes, no intuito de definir um novo mapa de "áreas seguras". Métodos: foram selecionadas, nos arquivos do departamento de Ortodontia da Aarhus University, 80 radiografias panorâmicas pré-tratamento e 80 imagens de TCFC com os modelos digitais correspondentes. O apinhamento foi medido nos modelos digitais, enquanto os espaços inter-radiculares mesiais aos segundos molares foram medidos nas radiografias panorâmicas e na TCFC. O fator de magnificação das radiografias panorâmicas foi calculado utilizando-se as larguras dentárias medidas nos modelos digitais. Análises estatísticas foram realizadas para investigar a correlação entre a quantidade de apinhamento e o espaço inter-radicular disponível. Foram desenhados mapas visuais mostrando a quantidade dos espaços inter-radiculares medidos. Resultados: os espaços inter-radiculares mais adequados são aqueles entre o segundo molar e o primeiro pré-molar inferior, e entre os incisivos centrais superiores. Porém, verificou-se que alguns espaços são influenciados pelo apinhamento. Conclusões: A calibração das radiografias panorâmicas é de suma importância, pois, geralmente, as radiografias panorâmicas subestimam o espaço disponível. A avaliação preliminar da viabilidade de inserção dos mini-implantes e a seleção das radiografias necessárias para isso podem ser facilitadas utilizando-se os novos mapas de "áreas seguras" aqui apresentados.

Retrospective evaluation of treatment time and efficiency of a predictable cantilever system for orthodontic extrusion of impacted maxillary canines.

INTRODUCTION: Orthodontic extrusion of impacted maxillary canines requires careful biomechanical planning and the use of physiologic force. The aim of this study was to evaluate the time needed for orthodontic extrusion of impactions of different severities, using a device that can predictably apply forces under 0.6 N. METHODS: Twenty-two patients who were consecutively treated were selected retrospectively, and a total of 30 impacted canines were studied. Indexes of impaction were used to measure severity on pretreatment panoramic radiographs. Statistical analysis was used to detect interactions between treatment time, complexity of impaction, age, and sex. RESULTS: Treatment time was highly dependent on the patient's age; the shortest treatment time was observed in 11- to 12-year old patients. On the other hand, the severity of impaction had no effect on treatment time. CONCLUSIONS: Applying physiologic force with the proposed device resulted in a short treatment time, which depended on the patient's age more than the impaction complexity. Few complications were associated with use of this device. Future prospective studies are needed to replicate these findings and confirm the recommended use of this device.

Post-orthodontic lower incisor inclination and gingival recession-a systematic review.

BACKGROUND: The present systematic review was carried out to determine the correlation between gingival recession/bone height and incisor inclination in non-growing post-orthodontic patients compared to adult untreated subjects or patients treated with different methodologies. MATERIALS AND METHODS: PubMed, EMBASE, Web of Science, Scopus, Cochrane, and OpenGrey databases were searched without time and language restriction. Search terms included orthodontic, incisor, inclination, angulation, proclination, and gingival. Articles involving human participants and adult subjects receiving orthodontic treatment with fixed appliance, having incisors position, bone height and/or gingival recessions evaluated pre- and post-treatment were included. Two authors independently extracted data using predefined forms. Risk of bias in individual studies was assessed with the Newcastle-Ottawa Scale. RESULTS: Two observational studies were included in the qualitative analysis. The heterogeneity in outcome assessment among the studies did not allow performing a meta-analysis. The two studies, while observing some effects of orthodontic treatment on the development of gingival recession, reported that these effects were not statistically or clinically significant. CONCLUSIONS: There is no strong scientific evidence concluding that proclination of incisors by means of fixed orthodontic appliances can affect periodontal health. Further prospective studies are required to elucidate this statement. PROTOCOL: PROSPERO database registration number CRD42016042369 .

Expansion of permanent first molars with rapid maxillary expansion appliance anchored on primary second molars.

BACKGROUND: To evaluate how the amount of expansion of the primary second molars, the patient's age, and the skeletal maturation stage influence the amount of expansion at the level of the permanent first molars. MATERIAL AND METHODS: Fifty-five patients aged between 6 and 11 years with a cervical vertebral maturation stage of CS1 or CS2 were retrospectively selected. The intermolar width was measured before and after expansion to evaluate the amount of expansion achieved at the level of the primary second molars and the permanent first molars. Stepwise multiple linear regression was used to evaluate how the amount of primary molars expansion, the patient's age, and the cervical vertebral maturation stage predict the amount of permanent molar expansion. RESULTS: A significant regression equation was found, and for every 1 mm of primary molar expansion, 0.91 mm of permanent molar expansion can be expected. An age between 6 and 11 years and the CS1 or CS2 skeletal maturation stage were not significant predictors of permanent molar expansion. CONCLUSIONS: A rapid maxillary expansion appliance anchored on primary second molars is effective in expanding the permanent molars to correct a transverse maxillary deficiency in prepubertal patients, transferring the risks associated with the large forces used to the primary teeth. Key words:Maxillary expansion, transversal deficiency, primary molars.

Movement of anterior teeth using clear aligners: a three-dimensional, retrospective evaluation.

BACKGROUND: Clear aligner treatment offers several advantages, but the available literature shows that some kind of tooth movements are unpredictable. In addition, the majority of the studies are focused on one clear aligner system, while different characteristics of various systems can provide different treatment outcomes. The aim of the present retrospective cohort study was to evaluate the predictability of Nuvola® aligner system in achieving torque movements of anterior teeth. METHODS: Thirty-nine adult patients, who were consecutively treated with clear aligners, were retrospectively selected, and digital models pre-treatment (T0), post-treatment (T1) and the digital setup models (TS) were collected. Only the first phase of treatment made of 12 aligners was considered for the present study. Torque of anterior teeth was measured as labiolingual inclination on digital models at T0, T1, and TS using VAM software. Any difference between the predicted and achieved torque movements was evaluated using Wilcoxon signed-rank test or paired sample t test. First-type error was set as p < 0.008. RESULTS: No statistically significant difference was found for all the anterior teeth between predicted and achieved torque movements. CONCLUSIONS: The studied clear aligner system was able to produce clinical outcomes comparable to the planning of the digital setup relative to torque movements of the anterior teeth.

Correlation between body mass index and obstructive sleep apnea severity indexes - A retrospective study.

PURPOSE: To evaluate if Body Mass Index (BMI) is correlated to Apnea-Hypopnea Index (AHI), mean arterial oxygen saturation (SaO2) and Nadir SaO2, which are all indexes defining the severity of the respiratory stress associated with Obstructive Sleep Apnea (OSA). MATERIALS AND METHODS: Seventy-five adult patients (mean age 51.4) referred for polysomnography were retrospectively recruited. BMI was calculated for each patient, as well as AHI, SaO2, and Nadir SaO2 recorded during polysomnography. Spearman's Rho test was used to evaluate if OSA severity was correlated to BMI values. First type error was set as p < 0.025. RESULTS: No correlation was observed between BMI and AHI, and between BMI and SaO2. A statistically significant negative correlation (r2 = 0.424; p < 0.001) was found between the BMI index and the Nadir SaO2. CONCLUSIONS: Higher BMI values were correlated with lower Nadir SaO2 during overnight polysomnography. Since hypoxia stress is a risk factor for cardiovascular diseases and alters the lipid metabolism, dietary consulting should be recommended in association with other treatment modalities for OSA.

Swallowing and Temporomandibular Disorders in Adults.

INTRODUCTION: Temporomandibular disease (TMD) etiology is multifactorial and is related to many perpetuating, predisposing, and initiating factors. The daytime parafunctions may have an important role in TMD pathogenesis. The most frequent parafunctions analyzed were the static parafunction (ie, clenching) and the dynamic parafunction (ie, grinding). In the present paper, the authors evaluated the swallowing (an oral function/parafunction) with the surface electromyography in patients with TMD. MATERIALS AND METHODS: Twenty patients with TMD problems (nonhealthy patients, NHP) (mean age: 33 ±â€Š1.994; 8 men and 12 women) and 20 healthy matched subjects (HP) (34.4 ±â€Š2.782; 6 men and 14 women) were selected and examined. On each patient, an 8-channel surface electromyography was done during saliva swallowing. RESULTS: Nonhealthy patients presented higher masseter and temporalis activation (P < 0.05) and an unbalancing of temporalis and submental muscles activation (P < 0.05) than the HP. DISCUSSION: Nonhealthy patients presented a time of swallow higher than HP (P < 0.001). Nonhealthy patients presented a higher muscles activation and time of swallow than HP and a decrease of muscles balancing activation.