Malocclusion Complexity in Patients with Disc Displacement Disorders: A Case-Control Study.

This study aimed to determine the possible association between disc displacement (DD) disorders and malocclusion complexity. This cross-sectional study was carried out using a case-control design. The Research Diagnosis Criteria for Temporomandibular Disorders were used to identify cases and controls. The Index of Complexity, Outcome, and Need (ICON) was used to quantify malocclusion complexity as easy, mild, moderate, difficult, or very difficult. A total of 310 subjects were included: 130 cases and 180 controls. A binary logistic regression (p < 0.05) was used to identify associations. The odds ratio (OR) was also calculated. DD was associated with sex, age, and malocclusion complexity (p < 0.05). The malocclusion complexity comparison showed that 89.3% of the controls fell within the easy-moderate levels of the ICON, whereas 85.4% of the cases were in the moderate-very difficult levels (p ≤ 0.001). Difficult and very difficult malocclusions had high ORs (9.801 and 9.689, respectively) compared to the easy cases. In conclusion, patients with malocclusion complexity levels classified as difficult or very difficult have greater odds of presenting DD.

Malocclusion complexity as an associated factor for temporomandibular disorders. A case-control study.

OBJECTIVE: To evaluate the association between temporomandibular disorders (TMD) and malocclusion complexity using the Index of Complexity Outcome and Need (ICON) levels. METHODS: A prospective, cross-sectional, case and control study was done. Cases and controls were matched in a one-to-one relationship (179 subjects each). The Research Diagnostic Criteria was used to evaluate the presence of TMD, and the ICON was used to quantify malocclusion complexity. A binary logistic regression (p < 0.05) was used to identify associations between variables. RESULTS: TMD presence was associated with gender and malocclusion complexity (p < 0.05). The largest proportion of controls were in the lowest three levels of ICON complexity, while most cases were in the three highest levels (p < 0.001). Higher malocclusion complexity indicated a greater TMD risk. CONCLUSION: The results indicate that TMD is associated with malocclusion complexity. As malocclusion complexity increases, so do the odds of presenting with TMD.

Effects of Neutralization on the Physicochemical, Mechanical, and Biological Properties of Ammonium-Hydroxide-Crosslinked Chitosan Scaffolds.

It has been reported that chitosan scaffolds, due to their physicochemical properties, stimulate cell proliferation in different tissues of the human body. This study aimed to determine the physicochemical, mechanical, and biological properties of chitosan scaffolds crosslinked with ammonium hydroxide, with different pH values, to better understand cell behavior depending on the pH of the biomaterial. Scaffolds were either neutralized with sodium hydroxide solution, washed with distilled water until reaching a neutral pH, or kept at alkaline pH. Physicochemical characterization included scanning electron microscopy (SEM), elemental composition (EDX), Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, thermogravimetric analysis (TGA), and mechanical testing. In vitro cytotoxicity was assessed via dental-pulp stem cells' (DPSCs') biocompatibility. The results revealed that the neutralized scaffolds exhibited better cell proliferation and morphology. It was concluded that the chitosan scaffolds' high pH (due to residual ammonium hydroxide) decreases DPSCs' cell viability.

Use of Ionized Monocalcium phosphate and enameline derivatives to reduce dentin hypersensitivity after periondontal therapy / Uso de Fostato Monocálcio y derivados en Enamelina para reducir la hipersensibilidad dentaria después de terapia periodontal

Abstract This study aimed to evaluate the effectiveness of using an ionized monocalcium phosphate and enamelin derivatives (IMP+ED) based mouthwash for the treatment of dentin hypersensitivity (DH) after scaling and root planing (SRP). 47 patients who reported DH after SRP treatment were included in this prospective cohort study. The Schiff Cold Air Sensitivity Scale (SCASS) was applied to classify their degree of pain in mild, moderate or intense at two times: after SRP (T0), and after one month of using a IMP+ED-based mouthwash (T1). The McNemar-Bowker test was used to compare the correlated proportions between both times (p<0.05). After the SRP therapy (T0), all the sample members reported pain distributed in the following manner: 12.8% were mild, 27.6% moderate, and 59.6% intense. At one month since treatment and with the use of the IMP+ED-based mouthwash (T1), the distribution of pain levels changed to 83% mild, 12.8% moderate, and 4.3% intense, this change was statistically significant (p<0.001). IMP+ED-based mouthwash produces a positive effect in reducing painful responses caused by exposure of the dentin tubules to the oral environment after SRP therapy.

Resumen El objetivo de este estudio fue evaluar la efectividad de un enjuague bucal a base de fosfato monocálcico ionizado y derivados de enamelina (FCI+DE) para el tratamiento de hipersensibilidad dentinaria (HD) posterior al tratamiento de raspado y alisado radicular (RAR). 47 pacientes que reportaron tener HD posterior al tratamiento de RAR fueron incluidos en este estudio prospectivo de cohorte. Con el fin de clasificar la HD de los pacientes en leve, moderada o intensa se utilizó la Escala de Sensiblidad al Aire Frío de Schiff (ESAFS). Los pacientes fueron evaluados después del tratamiento de RAR (T0) y posterior al uso de un enjuague bucal basado en FCI+DE (T1). Para comparar las proporciones correlacionadas se utilizó la prueba de McNemar-Bowker (p<0.05). La distribución del dolor de los pacientes posterior al tratamiento de RAR (T0) fue la siguiente: 12.8% fueron leves, 27.6% moderado, and 59.6% intenso. Un mes después del uso del enjuague buccal basado en FCI+DE (T1) la distribución en los niveles de dolor cambio a 83% leve, 12.8% moderado, and 4.3% intenso, este cambio fue estadísticamente significativo (p<0.001). El uso del enjuague bucal basado en FCI+DE produce una reducción significativa a la respuesta de dolor causada por la exposición de la dentina al ambiente oral como consecuencia del tratamiento de RAR.

Dental anomalies in cleft lip and palate: A case-control comparison of total and outside the cleft prevalence.

This study's objective was to compare the total and outside the cleft prevalence of dental anomalies (DA) between patients with cleft lip and palate (CLP) and a control group. This retrospective cross-sectional study was done under a case-control design. The case group consisted of 192 non-syndromic patients with complete CLP, while the control group included 411 patients. All subjects had orthopantomography, intra, and extraoral photographs. The prevalence of dental agenesis, supernumerary teeth, impacted teeth, dental transposition, and microdontia were compared using a chi-squared test (P < .05). Next, a second test was made, but only the anomalies outside the cleft were considered for this study. Total prevalence was 89.1% for cases, and 20.9% for controls (P < .01). The prevalence of each DA was significantly higher for the case group. In the analysis of DAs outside the cleft, the total prevalence was still significantly associated (P < .01); however, only dental agenesis was statistically significant (P < .01). Further analysis found that a high rate of upper premolar absence (P < .01) could explain this event. Patients with CLP have a higher prevalence of DAs compared to controls. After considering only the DAs outside the cleft, the total prevalence remains significantly higher. However, this phenomenon is explained mainly by the elevated prevalence of upper premolars' agenesis. This study's results suggest that environmental factors are behind the high prevalence of DAs in subjects with CLP.

Malocclusions in Pediatric Patients with Asthma: A Case-Control Study.

Asthma is a public health problem that has been widely described, but little has been reported about its effects on dental occlusions. The aim of this study was to compare the alterations of normal occlusions in asthmatic children and those without the disease. The study included 186 patients between 5 and 12 years old, divided into two groups. The first group included patients with a previous diagnosis of asthma given by a specialist, which was confirmed by using the International Study of Asthma and Allergies in Childhood questionnaire. The second group included patients without the disease. All patients underwent a clinical examination to determine the presence of occlusion alterations in the sagittal, transverse, and vertical planes. Subsequently, chi-squared tests were performed to compare the variables between the groups. A significant association was found between asthma and the variables studied here: alterations in the sagittal plane (chi2 = 7.839, p = 0.005), alterations in the vertical plane (chi2 = 13.563, p < 0.001), alterations in the transverse plane (Fisher's F p < 0.001), and oral habits (chi2 = 55.811, p < 0.001). The results suggest that asthmatic patients are more likely to develop malocclusions, especially anterior open bite and posterior crossbite. These conditions are typically related to mouth breathing, which is common in asthmatic patients.

Malocclusion Complexity in Patients with Myofascial Pain with or without Mouth-Opening Limitation: A Case-Control Study.

Background: This study is aimed at determining the association between myofascial pain with or without mouth-opening limitation and malocclusion complexity. Methods: A prospective, cross-sectional, case-control study was conducted. The Research Diagnostic Criteria were used to evaluate the presence of myofascial pain, chronic pain, and depression. The Index of Complexity, Outcome, and Need (ICON) was applied to quantify malocclusion complexity. A total of 96 patients with myofascial pain were grouped into two: subjects without mouth-opening limitation (n = 76, group A) and subjects with mouth-opening limitation (group B, n = 20). Both groups were compared with 231 controls (group C). A Chi-squared test and a multinomial logistic regression (p ≤ 0.05) were used to identify associations between the variables. Results: Statistically significant associations were found between myofascial pain and the variables gender, malocclusion complexity, and depression (p ≤ 0.05). Age was not significantly associated (p = 0.327). Concerning malocclusion complexity, 77.9% of the controls were distributed in the first three ICON levels; however, 76.5% of group A subjects and 90% of group B were in the last three (p < 0.001). The multinomial logistic regression showed a significant association between malocclusion complexity in group A (p < 0.05) and an association between depression and group B (p < 0.05). Group B had the highest grades of chronic pain. Conclusions: Females had greater risk of myofascial pain without mouth-opening limitation. As the complexity of the malocclusion increases, so do the odds of presenting myofascial pain without mouth-opening limitation. Myofascial pain with mouth-opening limitation frequently coexists with depression and chronic pain.

Correlation between dental enamel chemical composition and bracket debonding, comparing adhesive systems through a scanning electron microscope.

Literature reports indicate that during bracket removal there can be enamel damage. We compare the shear bond strength (SBS) and tooth enamel loss of four adhesive systems and identify the Ca/P ratio. Then a total of 20 premolars were divided into four groups of five each. After prophylaxis, photographs were taken at 35× with a scanning electron microscope (SEM) and analyzed with X-ray spectroscopy (EDS) at 250×. Brackets were bonded with Transbond™ MIP(G1), Transbond™ PLUS SEP(G2), Enlight(G3) and Stylus®(G4) adhesives, 24 h after were debonded with a Instron universal testing machine at 1 mm/min. All the brackets were photographed with the SEM. The amount of lost enamel was measured with AutoCad. All the results were measured with a significance level p < .05. The SBS general average at debonding was 7.94 ± 2.26 MPa, meanwhile the SBS for G1, G2, G3 and G4 was 9.38 ± 1.46, 6.28 ± 0.69, 9.08 ± 2.45 and 7.04 ± 2.64 MPa respectively. 90% of the samples had no enamel loss, 10% had enamel loss. Only two samples in G1 presented an enamel loss area of 0.34mm2 and 0.80mm2 respectively. From EDS analysis, the Ca/P ratio was 1.6 ± 0.05, 1.61 ± 0.03, 1.64 ± 0.83 and 1.59 ± 0.07 for G1, G2, G3 and G4 respectively; no statistically significant differences were found. We conclude that no association was found between the Ca/P ratio and enamel damage when brackets are removed. HIGHLIGHTS: Where enamel is lost, we observe fractures, steps, horizontal and vertical enamel loss. There is a loss of tooth enamel from 0.34 to 0.80 mm2 with Transbond PLUS SEP. Structural loss of enamel is almost inevitable during the separation of the bracket.

Zinc Oxide and Copper Chitosan Composite Films with Antimicrobial Activity.

The role of the oral microbiome and its effect on dental diseases is gaining interest. Therefore, it has been sought to decrease the bacterial load to fight oral cavity diseases. In this study, composite materials based on chitosan, chitosan crosslinked with glutaraldehyde, chitosan with zinc oxide particles, and chitosan with copper nanoparticles were prepared in the form of thin films, to evaluate a new alternative with a more significant impact on the oral cavity bacteria. The chemical structures and physical properties of the films were characterized using by Fourier transform infrared spectroscopy (FTIR,) Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), elemental analysis (EDX), thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and contact angle measurements. Subsequently, the antimicrobial activity of each material was evaluated by agar diffusion tests. No differences were found in the hydrophilicity of the films with the incorporation of ZnO or copper particles. Antimicrobial activity was found against S. aureus in the chitosan film crosslinked with glutaraldehyde, but not in the other compositions. In contrast antimicrobial activity against S. typhimurium was found in all films. Based on the data of present investigation, chitosan composite films could be an option for the control of microorganisms with potential applications in various fields, such as medical and food industry.

Evaluation of enamel loss by scanning electron microscopy after debonding brackets place with four different adhesives.

The clinically adequate shear bond strengths (SBS) should be from 2.8 to 10 MPa. The aim of this research is to observe tooth enamel loss through a scanning electron microscope (SEM) during the debonding of braces of four adhesive systems. Then, 100 premolars were used in 4 groups of 25 specimens each, for Transbond MIP (G1), Enlight (G2), Stylus (G3), and Transbond Plus SEP (G4). The research was done under the NOM ISO/TS 11405:2015. Gemini 3M were placed under the manufacturer's recommendations. The SBS test was done at 24 hr in an Instron electromechanical universal testing machine at 1 mm/1 min. Adhesive remnant index (ARI) was measured, all of the brackets where examined in the SEM. For the shear bonding strength G1 = 10.09 ± 2.73 MPa, G2 = 9.27 ± 3.99 MPa, G3 = 7.83 ± 4.46 MPa, and G4 = 6.40 ± 2.85 MPa statistically significant differences were found when comparing the four groups (p = .002). In the Tukey post hoc test, G1 versus G4 and G2 versus G4, statistically significant differences were found. For the ARI a value of 1 in 46%, followed by a value of 2 in 38%, a value of 3 in 13% and a value of 0 in 3% of the total samples, finding statistically significant differences (p < .001). In relation to the tooth enamel loss due to SBS, statistically significant differences were found (p = .326). G1 and G4 had not statistically significant differences. Even though our results concur with the appropriate clinical values, we observed tooth enamel loss with Transbond Plus SEP and Stylus.

Evaluation of diagnostic agreement among cephalometric measurements for determining incisor position and inclination / Evaluación de la concordancia diagnóstica entre mediciones cefalométricas para la determinación de la posición e inclinación de los incisivos

SUMMARY: The incisors are a key factor in dental occlusion and dentofacial aesthetics; therefore, the sagittal position and inclination of the incisors is a key parameter in diagnosis and orthodontic treatment planning. In some cases, the orthodontist will use more than one cephalometric analysis, and thus different results can be obtained. The aim of this study was to establish the diagnostic agreement among the different cephalometric measurements used to determine the anteroposterior position and the inclination of the incisors. Lateral cephalometric radiograms of patients between 18 and 59 years old were measured (n=260). Digital cephalometric measurements were made with Dolphin Imaging software, by a single calibrated operator. Here, a specific cephalometric analysis was designed in the software analysis editor. The results for each variable and each measurement were registered and compared. Fleiss's Kappa statistical tests, Cohen's Kappa, and Kendall's coefficient were used to determine the strength of agreement using the Minitab software. The results showed diagnostic strength agreement between slight and moderate among measurements of the same variable. This indicates that same diagnosis might not be obtained when using different approaches to measure the anteroposterior position and inclination of the incisors. It was concluded that there is a difference in the diagnosis between one measurement and another because the results showed slight or moderate strength of agreement. However, in some cases, better agreement was found when the measurements were compared as a function of the diagnostic response.

RESUMEN: Los incisivos son un factor clave en la oclusión dental y la estética dentofacial; por lo tanto, la posición sagital y la inclinación de los incisivos es un parámetro clave en el diagnóstico y la planificación del tratamiento de ortodoncia. En algunos casos, el ortodoncista utilizará más de un análisis cefalométrico y, por lo tanto, se pueden obtener resultados diferentes. El objetivo de este estudio fue establecer el acuerdo de diagnóstico entre las diferentes mediciones cefalométricas utilizadas para determinar la posición anteroposterior y la inclinación de los incisivos. Se midieron radiografías cefalométricas laterales de pacientes entre 18 y 59 años (n = 260). Las mediciones cefalométricas digitales se realizaron con el software Dolphin Imaging, por un solo operador calibrado. Aquí, se diseñó un análisis cefalométrico específico en el editor de análisis de software. Los resultados para cada variable y cada medición se registraron y compararon. Las pruebas estadísticas Kappa de Fleiss, Kappa de Cohen y el coeficiente de Kendall se usaron para determinar la fuerza del acuerdo utilizando el software Minitab. Los resultados mostraron un acuerdo de fuerza diagnóstica entre leve y moderado entre las mediciones de la misma variable. Esto indica que no se puede obtener el mismo diagnóstico cuando se utilizan diferentes enfoques para medir la posición anteroposterior y la inclinación de los incisivos. Se concluyó que existe una diferencia en el diagnóstico entre una medición y otra porque los resultados mostraron una fuerza de acuerdo leve o moderada. Sin embargo, en algunos casos, se encontró un mejor acuerdo cuando se compararon las mediciones en función de la respuesta de diagnóstico.

Growth differences in patients with dental agenesis, how its location impacts facial morphology.

BACKGROUND/PURPOSE: Non-formation of a tooth impacts the morphology of the alveolar bone, which may, in turn, generate an imbalance in facial growth. This retrospective case-control study aimed to determine whether observable differences exist in the facial growth of patients with dental agenesis relative to complete dentition controls. MATERIALS AND METHODS: The sample comprised 75 patients with dental agenesis, and each case was paired with two controls of the same age and gender (n = 150). All patients were measured cephalometrically (31 variables), and both groups were compared with student's t- or Z-test (P < 0.05). Subsequently, ANOVA or Kruskal-Wallis tests (P < 0.05) were used to compare facial growth depending on the missing tooth's sagittal location in the dental arch (anterior or posterior agenesis); as well as its location in the affected bone (maxillary, mandibular, or both). RESULTS: Four measurements with significant differences were found, whereas ten were found in the sagittal location in the dental arch analysis. Regarding the affected bone, there were no affected variables. CONCLUSION: it was found that patients with dental agenesis show differences in the sagittal growth of the upper jaw and in the position of the lower incisor. In the studied population, these changes are strongly influenced by the sagittal location of the missing tooth, while its location in the jaws does not affect facial growth.

Titanium - castor oil based polyurethane composite foams for bone tissue engineering.

Polyurethanes (PU) foams with titanium particles (Ti) were prepared with castor oil (CO) and isophorone diisocyanate (IPDI) as polymeric matrix, and 1, 3 and 5 wt.% of Ti. Composites were physicochemically and mechanically characterized and their biocompatibility assessed using human dental pulp stem cells (HDPSC). PU synthesis was confirmed by FTIR, but the presence of Ti was detected by RAMAN, X-ray diffraction (peak at 2θ = 40.2°) and by EDX-mapping. Materials showed three decomposition temperatures between 300 °C and 500 °C and their decomposition were not catalyzed by Ti particles. Compressive modulus (164-846 kPa), compressive strength (12.9-116.7 kPa) and density (128-240 kg/m3) tend to increase with Ti concentration but porosity was reduced (87% to 80%). Composites' foams were fully degraded in acid and oxidative media while remained stable in distilled water. HDPSC viability on all composites was higher than 80% up to 14 days while proliferation dropped up to 60% at 21 days. Overall, these results suggest that these foams can be used as scaffolds for bone tissue regeneration.

Preparation and characterization of titanium-segmented polyurethane composites for bone tissue engineering.

Segmented polyurethanes were prepared with polycaprolactone diol as soft segment and 4,4-methylene-bis cyclohexyl diisocyanate and l-glutamine as the rigid segment. These polyurethanes were filled with 1 wt.% to 5 wt.% titanium particles (Ti), physicochemically characterized and their biocompatibility assessed using human dental pulp stem cells and mice osteoblasts. Physicochemical characterization showed that composites retained the properties of the semicrystalline polyurethane as they exhibited a glass transition temperature (Tg) between -35°C and -45°C, melting temperature (Tm) at 52°C and crystallinity close to 40% as determined by differential scanning calorimetry. In agreement with this, X-ray diffraction showed reflections at 21.3° and 23.6° for polycaprolactone diol and reflections at 35.1°, 38.4°, and 40.2° for Ti particles suggesting that these particles are not acting as nucleating sites. The addition of up to 5 wt.% of Ti reduced both, tensile strength and maximum strain from 1.9 MPa to 1.2 MPa, and from 670% to 172% for pristine and filled polyurethane, respectively. Although there were differences between composites at low strain rates, no significant differences in mechanical behavior were observed at higher strain rate where a tensile stress of 8.5 MPa and strain of 223% were observed for 5 wt.% composites. The addition to titanium particles had a beneficial effect on both human dental pulp stem cells and osteoblasts viability, as it increased with the amount of titanium in composites up to 10 days of incubation.