ABSTRACT Objective: To assess the distribution of stress produced on TMJ disc by chincup therapy, by means of the finite element method. Methods: a simplified three-dimensional TMJ disc model was developed by using Rhinoceros 3D software, and exported to ANSYS software. A 4.9N load was applied on the inferior surface of the model at inclinations of 30, 40, and 50 degrees to the mandibular plane (GoMe). ANSYS was used to analyze stress distribution on the TMJ disc for the different angulations, by means of finite element method. Results: The results showed that the tensile and compressive stresses concentrations were higher on the inferior surface of the model. More presence of tensile stress was found in the middle-anterior region of the model and its location was not altered in the three directions of load application. There was more presence of compressive stress in the middle and mid-posterior regions, but when a 50o inclined load was applied, concentration in the middle region was prevalent. Tensile and compressive stresses intensities progressively diminished as the load was more vertically applied. Conclusions: stress induced by the chincup therapy is mainly located on the inferior surface of the model. Loads at greater angles to the mandibular plane produced distribution of stresses with lower intensity and a concentration of compressive stresses in the middle region. The simplified three-dimensional model proved useful for assessing the distribution of stresses on the TMJ disc induced by the chincup therapy.

OBJECTIVE: The present research aims to evaluate the calibration of digital palpation pressure as well as to assess the inter-examiner variation and mean pressure used by a sample consisting of 56 professionals of the TMJ disorders and Orofacial Pain area. METHODS: Each participant was asked to press a digital balance to approach 1.0 kg and subsequently 0.5 kg without seeing the display, in order to obtain a blind data. The values of 1.0 kg and 0.5 kg are recommended by the Research Diagnostic Criteria for Temporomandibular Disorder in the refined Axis I, the Physical Assessment. Participants were considered calibrated when they applied the correct pressure in at least 4 of the 5 measurement taken; within a 20% variation interval (pressures between 0.4 and 0.6 kg were acceptable for the reference value of 0.5 kg and between 0.8 and 1.2 kg for the reference value of 1.0kg). The t-student test was used to analyze data (p≤0.05). RESULTS: 70% of the sample was classified as non- calibrated for the 0.5 kg pressure while 57% were not calibrated for the 1.0 kg pressure. The mean inter-examiner variations, 0.3 kg for the pressure set at 0.5kg and 0.6 kg for the pressure set at 1.0 kg, were considered high. CONCLUSION: The mean pressures applied by participants (0.7 kg for joint palpation and 1.4 kg for muscle palpation) were also considered high in comparison with those recommended by the Research Diagnostic Criteria for Temporomandibular Disorder, but acceptable according to the tendency of applying higher values of 1.0 - 1.5 kg, as proven by recent study.

The aim of this study was to evaluate the accuracy of three implant transfer impression techniques. Four groups (n = 5) were defined, according to the technique: TC - tapered copings without splint; SC - square copings without splint; SCS - square copings splinted with dental floss and acrylic resin, and CG (control group) - master model with four external hexagonal implants and a superstructure. Individual trays and polyether were used for the impression. All casts were checked for their fit into the master superstructure; for this, all four screws were placed in the implants. Digital photos were taken and images were analyzed using UTHSCSA ImageTool software. Statistical analyses were performed using one-way analysis of variance and Student’s t test (p < 0.05). The means and standard deviation were (µm): CG = 2.03 ± 0.00, TC = 14.74 ± 3.41, SC = 12.08 ± 2.56, and SCS = 6.51 ± 0.09. The control group was found to be statistically different from the TC and SC groups. Within the limitations of this study, all groups presented clinically acceptable standard gap values, and the SCS group showed no statistical difference in relation to the CG (control group), demonstrating more accuracy and fidelity to transfer implants.

OBJECTIVE: to analyze the pattern of disocclusion during excursive mandibular movements and presence or absence of occlusal interferences and occlusal pathologies (gingival recession and abfraction). METHOD: examination of 120 individuals divided into two groups, as follows: Group 1 - 90 patients with complete cleft lip and palate (study group), subdivided into 30 patients with complete left unilateral cleft lip and palate, 30 patients with complete right unilateral cleft lip and palate and 30 patients with complete bilateral cleft lip and palate; Group 2 - 30 individuals without clefts (control group). RESULTS: 58.8% of patients in Group 1 presented unilateral or bilateral canine guidance, 26.6% presented unilateral or bilateral group function and 54.4% presented lateral movements through the posterior teeth. Regarding protrusive movements, 80% presented anterior guidance and 20% presented posterior guidance. In Group 2, 69.6% of individuals presented unilateral or bilateral canine guidance, 43.2% presented unilateral or bilateral group function and only 13.3% presented lateral movements through the posterior teeth; 3.4% presented protrusion through the posterior teeth. CONCLUSIONS: there was no difference in the pattern of disocclusion between subgroups of patients with clefts. Group 2 presented predominance of bilateral group function, whereas Group 1 presented a higher prevalence of posterior guidance during lateral movements. Protrusion occurred primarily through anterior guidance in Group 2 and through the posterior teeth in Group 1. There was high prevalence of occlusal interferences at the molar area for both groups, yet with no correlation with occlusal pathologies (recession and abfraction).

OBJECTIVE: to analyze the pattern of disocclusion during excursive mandibular movements and presence or absence of occlusal interferences and occlusal pathologies (gingival recession and abfraction). METHOD: examination of 120 individuals divided into two groups, as follows: Group 1 - 90 patients with complete cleft lip and palate (study group), subdivided into 30 patients with complete left unilateral cleft lip and palate, 30 patients with complete right unilateral cleft lip and palate and 30 patients with complete bilateral cleft lip and palate; Group 2 - 30 individuals without clefts (control group). RESULTS: 58.8% of patients in Group 1 presented unilateral or bilateral canine guidance, 26.6% presented unilateral or bilateral group function and 54.4% presented lateral movements through the posterior teeth. Regarding protrusive movements, 80% presented anterior guidance and 20% presented posterior guidance. In Group 2, 69.6% of individuals presented unilateral or bilateral canine guidance, 43.2% presented unilateral or bilateral group function and only 13.3% presented lateral movements through the posterior teeth; 3.4% presented protrusion through the posterior teeth. CONCLUSIONS: there was no difference in the pattern of disocclusion between subgroups of patients with clefts. Group 2 presented predominance of bilateral group function, whereas Group 1 presented a higher prevalence of posterior guidance during lateral movements. Protrusion occurred primarily through anterior guidance in Group 2 and through the posterior teeth in Group 1. There was high prevalence of occlusal interferences at the molar area for both groups, yet with no correlation with occlusal pathologies (recession and abfraction).

OBJECTIVE: To evaluate the marginal misfit between intermediate and micro-unitmetal cylinder, by varying the angle of the implants, using two different types of material and different molding techniques. METHODS: A model was made with three implants (one perpendicular to the horizontal plane and two inclined) using micro-unit intermediates. A rod attached to the master model served as a control condition to evaluate the suitability of the twenty specimens, carried out with the help of an optical stereomicroscope (Pantec, Brazil; Materials Testing Laboratory, São Leopoldo Mandic, Campinas, São Paulo). RESULTS: Evaluator reliability was assessed using theIntraclass Correlation Coefficient, obtaining 99.6% (excellent). There were significant differences between groups, and the Mann-Whitney test compared groups in pairs for a more accurate result. CONCLUSION: The group which presented the best behavior was open tray and condensation silicone and the worst result, that needed to be cast several times, was closed tray and condensation silicone.

This study evaluated the stress distribution on an implant-supported zirconia crown of a mandibular first molar subjected to oblique loading by occlusal contact with the natural maxillary first molar by using the 3D finite element method. Two virtual models were made to simulate the following situations: (1) occlusion between maxillary and mandibular natural first molars; (2) occlusion between zirconia implant-supported ceramic crown on a mandibular first molar and maxillary natural first molar. The models were designed virtually in a modeling program or CAD (Computer Aided Design) (Rhinoceros). An oblique load of 100 N was uniformly applied to the zirconia framework of the crown. The results were obtained by the Von Mises criterion of stress distribution. Replacement of the mandibular tooth by an implant caused a slight increase in stress on portions of the maxillary tooth roots. The crown of the maxillary model in occlusion with natural antagonist tooth showed 12% less stress when compared with the maxillary (model in occlusion with the) implant-supported crown. The mandibular crown of the implant show 35% more stress when compared with the mandibular antagonist crown on the natural tooth. The presence of the implant to replace the mandibular tooth increased the stresses on the maxillary tooth, especially in the region of the mesial and distal buccal roots.

O objetivo deste estudo foi avaliar a densidade mineral óssea (DMO), a resistência final à compressão (RFC), e a eventual correlação entre os valores dessas variáveis, de quatro blocos ósseos xenógenos comercialmente disponíveis no Brasil para aplicações em implantodontia. Trinta e dois espécimes dos materiais de enxertia analisados foram divididos em 4 grupos de estudo (n = 8): Grupo 1 (G1), Biocollagen (Bioteck, Arcugnano, Itália); Grupo 2 (G2), Bio-Graft, (Geistilich, Wolhusen, Suíça); Grupo 3 (G3), OrthoGen (Baumer, Mogi Mirim, SP, Brasil); e Grupo 4 (G4), Bonefill (Bionnovation, Bauru, SP, Brasil). A DMO foi determinada por meio da análise da densidade óptica dos materiais, observada em imagens tomográficas de alta definição, e expressa em unidades Hounsfield (HU). A RFC foi determinada por meio de um ensaio mecânico de compressão e expressa em Newton (N). Os valores de DMO encontrados para os grupos G1, G2, G3 e G4 foram significativamente diferentes, a saber, 354,3 HU, 317,7 HU, 206,5 HU e 145,6 HU, respectivamente (p ? 0,05). Os valores de RFC encontrados para os grupos G1, G2, G3 e G4 também foram significativamente diferentes, a saber, 685,18 N, 563,18 N, 915,20 N e 1399,70 N, respectivamente (p ? 0,05). Observou-se uma correlação positiva e moderada entre a DMO e a RFC apenas no G4 (p = 0,015; r2 = 0,655). A análise dos resultados demonstrou que os blocos de enxerto ósseo xenógenos com uma menor DMO tendem a ter uma maior RFC.

Abstract: The lack of guidelines for bone augmentation procedures might compromise decision making in implantology. The objective of this study was to perform a retrospective study to verify the outcomes of horizontal bone reconstruction in implant dentistry with different types of materials and amounts of native bone in the recipient bed to allow for a new guideline for horizontal bone reconstruction. One hundred preoperative CT scans were retrospectively evaluated and categorized in accordance to horizontal bone defects as presence (Group P) or absence (Group A) of cancellous bone in the recipient bed. Different approaches were used to treat the edentulous ridge and the outcomes were defined either as satisfactory or unsatisfactory regarding the possibility of implant placement. The percentage distribution of the patients according to the presence or absence of cancellous bone was 92% for Group P and 8% for Group A. In Group P, 98% of the patients had satisfactory outcomes, and the use of autografts had 100% of satisfactory outcomes in this group. In Group A, 37.5% of the patients had satisfactory outcomes, and the use of autografts also yielded 100% of satisfactory outcomes. The use of allografts and xenografts in Group A had 0% and 33.3% of satisfactory outcomes, respectively. Therefore, it seems reasonable to speculate that the presence of cancellous bone might be predictive and predictable when the decision includes bone substitutes. In cases of absence of cancellous bone in the recipient bed, the use of a vitalized graft seems to be mandatory.