The efficacy of manual toothbrushes in patients with fixed orthodontic appliances: a randomized clinical trial.

OBJECTIVE: This study aims to evaluate three types of manual toothbrushes [Cross action (CA), Flat trim (FT), and orthodontic type (OT)] in terms of efficacy in plaque removal in patients undergoing fixed orthodontic treatment. BACKGROUND: Manual toothbrushes are an essential part of oral hygiene for primary prevention. Plaque control, however, can be influenced by a number of individual and material-related factors. Individual factors include the presence of fixed orthodontic appliances on tooth surfaces, such as brackets and bands, which create difficulties with oral hygiene and lead to plaque formation. The evidence for the effectiveness of advanced bristle designs (multilevel, criss-cross) of the manual toothbrush alone in removing plaque in patients undergoing orthodontic therapy is limited. METHODS: The experiment followed the Consolidated Standards of Reporting Trials (CONSORT) guidelines. This was a three treatment, three-period crossover clinical trial with a single brushing exercise. Thirty subjects were randomized to one of the three treatment sequences of different bristle designs: (CA, FT, and OT). The primary outcome measure was the difference in the plaque scores (baseline minus post-brushing) at each study period, as determined by the Turesky-Modified Quigley-Hein Plaque Index. RESULTS: Of the thirty-four subjects enrolled in the study, thirty of the subjects met the inclusion criteria and completed all three periods of the study. The mean age was 19.5 ± 1.52 years, with a range of 18-23 years. The differences between treatments in plaque score reduction after brushing were statistically significant (p-value < .001). The treatment differences were statistically significant (p-value < .001) favoring the FT toothbrush over the OT and CA types of toothbrush designs. On the contrary, the difference between the OT and CA types was not statistically significant. CONCLUSIONS: Plaque was significantly removed by the conventional FT toothbrush after a single brushing compared to the OT and CA types.

Rapid morphologic changes to microglial cells and upregulation of mixed microglial activation state markers induced by P2X7 receptor stimulation and increased intraocular pressure.

BACKGROUND: The identification of endogenous signals that lead to microglial activation is a key step in understanding neuroinflammatory cascades. As ATP release accompanies mechanical strain to neural tissue, and as the P2X7 receptor for ATP is expressed on microglial cells, we examined the morphological and molecular consequences of P2X7 receptor stimulation in vivo and in vitro and investigated the contribution of the P2X7 receptor in a model of increased intraocular pressure (IOP). METHODS: In vivo experiments involved intravitreal injections and both transient and sustained elevation of IOP. In vitro experiments were performed on isolated mouse retinal and brain microglial cells. Morphological changes were quantified in vivo using Sholl analysis. Expression of mRNA for M1- and M2-like genes was determined with qPCR. The luciferin/luciferase assay quantified retinal ATP release while fura-2 indicated cytoplasmic calcium. Microglial migration was monitored with a Boyden chamber. RESULTS: Sholl analysis of Iba1-stained cells showed retraction of microglial ramifications 1 day after injection of P2X7 receptor agonist BzATP into mouse retinae. Mean branch length of ramifications also decreased, while cell body size and expression of Nos2, Tnfa, Arg1, and Chil3 mRNA increased. BzATP induced similar morphological changes in ex vivo tissue isolated from Cx3CR1+/GFP mice, suggesting recruitment of external cells was unnecessary. Immunohistochemistry suggested primary microglial cultures expressed the P2X7 receptor, while functional expression was demonstrated with Ca2+ elevation by BzATP and block by specific antagonist A839977. BzATP induced process retraction and cell body enlargement within minutes in isolated microglial cells and increased Nos2 and Arg1. While ATP increased microglial migration, this required the P2Y12 receptor and not P2X7 receptor. Transient elevation of IOP led to microglial process retraction, cell body enlargement, and gene upregulation paralleling changes observed with BzATP injection, in addition to retinal ATP release. Pressure-dependent changes were reduced in P2X7-/- mice. Death of retinal ganglion cells accompanied increased IOP in C57Bl/6J, but not P2X7-/- mice, and neuronal loss showed some association with microglial activation. CONCLUSIONS: P2X7 receptor stimulation induced rapid morphological activation of microglial cells, including process retraction and cell body enlargement, and upregulation of markers linked to both M1- and M2-type activation. Parallel responses accompanied IOP elevation, suggesting ATP release and P2X7 receptor stimulation influence the early microglial response to increased pressure.

The P2X7 receptor links mechanical strain to cytokine IL-6 up-regulation and release in neurons and astrocytes.

Mechanical strain in neural tissues can lead to the up-regulation and release of multiple cytokines including interleukin 6 (IL-6). In the retina, the mechanosensitive release of ATP can autostimulate P2X7 receptors on both retinal ganglion cell neurons and optic nerve head astrocytes. Here, we asked whether the purinergic signaling contributed to the IL-6 response to increased intraocular pressure (IOP) in vivo, and stretch or swelling in vitro. Rat and mouse eyes were exposed to non-ischemic elevations in IOP to 50-60 mmHg for 4 h. A PCR array was used to screen cytokine changes, with quantitative (q)PCR used to confirm mRNA elevations and immunoblots used for protein levels. P2X7 antagonist Brilliant Blue G (BBG) and agonist (4-benzoyl-benzoyl)-ATP (BzATP) were injected intravitreally. ELISA was used to quantify IL-6 release from optic nerve head astrocytes or retinal ganglion cells. Receptor identity was confirmed pharmacologically and in P2X7-/- mice, acute elevation of IOP altered retinal expression of multiple cytokine genes. Elevation of IL-6 was greatest, with expression of IL1rn, IL24, Tnf, Csf1, and Lif also increased more than twofold, while expression of Tnfsf11, Gdf9, and Tnfsf4 were reduced. qPCR confirmed the rise in IL-6 and extracellular ATP marker ENTPD1, but not pro-apoptotic genes. Intravitreal injection of P2X7 receptor antagonist BBG prevented the pressure-dependent rise in IL-6 mRNA and protein in the rat retina, while injection of P2X7 receptor agonist BzATP was sufficient to elevate IL-6 expression. IOP elevation increased IL-6 in wild-type but not P2X7R knockout mice. Application of mechanical strain to isolated optic nerve head astrocytes increased IL-6 levels. This response was mimicked by agonist BzATP, but blocked by antagonists BBG and A839977. Stretch or BzATP led to IL-6 release from both astrocytes and isolated retinal ganglion cells. The mechanosensitive up-regulation and release of cytokine IL-6 from the retina involves the P2X7 receptor, with both astrocytes and neurons contributing to the response.

Correlation of Dental and Skeletal Malocclusions in Sagittal Plane among Saudi Orthodontic Patients.

AIM: Whether or not the dental relationship correlates with skeletal relationship in the sagittal plane is an area of interest for orthodontic diagnosis and treatment planning. Thus, the aim of this study was to investigate the correlation of the dental malocclusion and the skeletal malocclusion in the sagittal plane among Saudi orthodontic patients. MATERIALS AND METHODS: Orthodontic dental casts and cephalometric radiographs of 124 patients were investigated and analyzed. The dental casts were classified in relation to the molar relationship according to Angle's classification and to the incisal relationship according to the British Standards Institution (BSI) classification. The sagittal relation in the cephalometric radiographs was analyzed according to ANB angle and WITS appraisal. RESULTS: The results show that the incisal relation had a very high significant association with WITS appraisal (p = 0.0045), whereas with ANB, the association was marginally significant (p =0.0528). No significant associations were found with molar relation neither at ANB (p = 0.2075) nor at the WITS (p = 0.4794) appraisal. Significant positive correlations between ANB and WITS appraisal were found at the three incisal classification classes (class I, r = 0.73; class II, r = 0.64; class III, r = 0.75) and no significant correlation was observed in all classes with the Angle's (molar) classification. CONCLUSIONS: The incisal classification had a significant association with WITS appraisal, whereas with ANB the association was marginally significant. No correlation was found between Angle's (molar) classification and ANB or WITS appraisal. CLINICAL SIGNIFICANCE: The incisal relation could be considered as a good indicator of the skeletal malocclusion in the sagittal plane in the orthodontic practice.

The application of zebrafish model in the study of cleft lip and palate development: A systematic review.

Objective: Craniofacial growth and development are more than a scientific curiosity; it is of tremendous interest to clinicians. Insights into the genetic etiology of cleft lip and palate development are essential for improving diagnosis and treatment planning. The purpose of this systematic review was to utilize a zebrafish model to highlight the role of the IRF6 gene in cleft lip and palate development in humans. Data: This review adhered to the guidelines outlined in the PRISMA statement. Nine studies were included in the analysis. Sources: This study used major scientific databases such as MEDLINE, EMBASE, Web of Science, and the Zebrafish Information Network and yielded 1275 articles. Two reviewers performed the screening using COVIDENCE™ independently, and a third reviewer resolved any conflicts. Study selection: After applying the inclusion and exclusion criteria and screening, nine studies were included in the analysis. The Systematic Review Center for Laboratory Animal Experimentation's (SYRCLE's) risk-of-bias tool was used to assess the quality of the included studies. Results: The main outcome supports the role of the IRF6 gene in zebrafish periderm development and embryogenesis, and IRF6 variations result in cleft lip and palate development. The overall SYRCLE risk of bias was low-medium. Conclusion: In conclusion, this review indicated the critical role of the IRF6 gene and its downstream genes (GRHL3, KLF17, and ESRP1/2) in the development of cleft lip and palate in zebrafish models. Genetic mutation zebrafish models provide a high level of insights into zebrafish craniofacial development. Clinical relevance: this review provides a productive avenue for understanding the powerful and conserved zebrafish model for investigating the pathogenesis of human cleft lip and palate.

Performance of Artificial Intelligence Models Designed for Automated Estimation of Age Using Dento-Maxillofacial Radiographs-A Systematic Review.

Automatic age estimation has garnered significant interest among researchers because of its potential practical uses. The current systematic review was undertaken to critically appraise developments and performance of AI models designed for automated estimation using dento-maxillofacial radiographic images. In order to ensure consistency in their approach, the researchers followed the diagnostic test accuracy guidelines outlined in PRISMA-DTA for this systematic review. They conducted an electronic search across various databases such as PubMed, Scopus, Embase, Cochrane, Web of Science, Google Scholar, and the Saudi Digital Library to identify relevant articles published between the years 2000 and 2024. A total of 26 articles that satisfied the inclusion criteria were subjected to a risk of bias assessment using QUADAS-2, which revealed a flawless risk of bias in both arms for the patient-selection domain. Additionally, the certainty of evidence was evaluated using the GRADE approach. AI technology has primarily been utilized for automated age estimation through tooth development stages, tooth and bone parameters, bone age measurements, and pulp-tooth ratio. The AI models employed in the studies achieved a remarkably high precision of 99.05% and accuracy of 99.98% in the age estimation for models using tooth development stages and bone age measurements, respectively. The application of AI as an additional diagnostic tool within the realm of age estimation demonstrates significant promise.

Association of Electronic Cigarette Usage with the Subsequent Initiation of Combustible Cigarette Smoking among Dental Students in Riyadh, Saudi Arabia: A Longitudinal Study.

The use of electronic cigarettes, or "e-cigarettes", among youths has sparked worries about the possibility of nicotine dependence as a serious public health issue. Dental practitioners play a critical role in helping their patients quit smoking. Dental schools across the globe have policies encouraging their students to help patients quit smoking. Current research, however, indicates that a significant portion of dental students smoke combustible cigarettes and use e-cigarettes. According to studies, using e-cigarettes has resulted in the subsequent initiation of combustible cigarette smoking among its users. The aim of this study was to determine the association between the use of electronic cigarettes and the subsequent initiation of combustible cigarette smoking among dental students who were not attitudinally susceptible to smoking combustible cigarettes. A longitudinal cohort study was conducted among 121 study participants who were never combustible cigarette users and were attitudinally non-susceptible to smoking at baseline. At baseline, 66 (54.6%) study participants were categorized as e-cigarette users who were attitudinally non-susceptible to combustible cigarette smoking, and 55 (45.4%) study participants were categorized as non-users who were attitudinally non-susceptible to combustible cigarette smoking. The initiation of combustible cigarette smoking was assessed at 6- and 12-month intervals. Binomial regression analysis of the outcome at the end of one-year follow-up, when analyzed with independent variables, revealed a significant influence of e-cigarette use on taking up combustible cigarette smoking [Relative Risk: 9.395; 95% CI: 3.03-29.04]. Chi-squared analysis of independent variables revealed e-cigarette use to be significantly associated with fathers' education level (p = 0.00), parental cigarette smoking status (p = 0.00), cigarette smoking among friends (p = 0.00), and family income (p = 0.00). E-cigarette users are more likely to believe it to be healthier (p = 0.00) than combustible smoking. In the present study, e-cigarette usage demonstrated a significant influence on taking up combustible cigarette smoking among its users. Educational institutions should implement stringent policies and regulations to prevent health professionals from using these products.

Unveiling the Impact of Electronic Cigarettes (EC) on Health: An Evidence-Based Review of EC as an Alternative to Combustible Cigarettes.

Cigarette smoking has been considered a major public health concern due to its serious impact on health. However, smokers intending to quit may find long-term abstinence challenging. When smoking an electronic cigarette (EC), users can experience a sensation and taste similar to that of smoking a combustible cigarette. Therefore, manufacturers promote these products as a viable substitute for combustible cigarettes. However, several researchers report the serious health impacts experienced by EC users. Therefore, this review aims to examine the health impacts of EC use. Based on the findings of the research papers reported in the literature, the role of EC as a smoking cessation tool is unclear. Several researchers have also reported a significant association between EC usage among non-smokers at baseline and the future initiation of combustible cigarette smoking. EC use significantly impacts user health. The nicotine that is present in EC e-liquids can elevate blood pressure, resulting in blood vessel constriction and an increase in heart rate, ultimately leading the body to an ischemic condition, resulting in myocardial infarction (MI), stroke, and increased arterial stiffness. Researchers report a higher likelihood of prediabetes among EC users; its usage was associated with higher OR of having asthma attacks and higher OR of reporting depression and has an impact on birth outcomes among pregnant women. Men using EC are more likely to report erectile dysfunction than non-users. EC also has a significant impact on oral health, which includes periodontal diseases, mucosal lesions, irritation in the mouth and throat, reduced salivary flow, and an increased risk of developing cancer. The physical injury resulting from exploding EC is another health concern. The frequently burned areas included the hands, face, genitalia, and thighs. Marketers promote EC as an alternative to combustible cigarettes and a tool for quitting smoking. However, the Food and Drug Administration has not approved them for smoking cessation. EC can have a serious impact on the health of their users; hence, the findings of this paper have several implications, including the need for regulation of the sales and marketing of these products and educating the users on the impact of these products on their health and safety.

Prevalence and Patterns of Orofacial Clefts among Children from Different Regions of Saudi Arabia: A Systematic Review.

Aim and objective: To report on the prevalence and patterns of orofacial clefts (OFC) among Saudi Arabian children by analyzing the results of the studies that have been reported in the literature. Materials and methods: A data search was carried out for the articles that had reported on the prevalence of OFC among the Saudi Arabian population in databases like Web of Science, PubMed, Google Scholar, Scopus, and Saudi Digital Library. Articles that were published over the last 15 years were included in this study, following which 13 studies were assessed for qualitative data. Newcastle-Ottawa Quality Assessment Scales for cross-sectional studies were used for analyzing the methodological quality of these studies. Results: The prevalence of OFC was within the range of 0.65-1.9/1,000 live births. The highest was witnessed in the Medina region. Parent's consanguinity was the most common risk factor in OFC cases in the included studies. OFC was found to be higher among the male population in comparison with the female. Conclusion: The prevalence of OFC in Saudi Arabian children follows the global patterns of OFC. Isolated cleft lip (CL) and cleft palate (CP) are the most common forms of OFC. The prevalence of orofacial anomalies was reported more among children born to parents who had consanguineous marriages. Considering the higher rate of consanguinity among this population, there is an urgent need of developing educational and counseling programs to address the genetic consequences. How to cite this article: Albalawi F Alsaeed S, Alalola B, et al. Prevalence and Patterns of Orofacial Clefts among Children from Different Regions of Saudi Arabia: A Systematic Review. Int J Clin Pediatr Dent 2023;16(1):124-130.

A Correlation Analysis between Arch Width and Molar Inclination Using Cone-Beam Computed Tomography Transverse Measurements: A Cross-Sectional Study.

A new era in 3-dimensional analysis has begun with the use of cone-beam computed tomography (CBCT) in orthodontics, which promises to provide a more thorough understanding of the craniofacial skeletal architecture. This study aimed to investigate the correlation between the transverse basal arches discrepancy and dental compensation by utilizing CBCT width analysis. An observational study was conducted to retrospectively review 88 CBCT scans of patients presented to dental clinics from 2014 to 2020 obtained from the Planmeca Romexis x-ray system at three centers. Dental compensation data across normal and narrow maxillae were analyzed and a Pearson correlation was used to find the relationship between molar inclination and width difference. Significant maxillary molar compensation differences were observed between the normal maxilla and narrow maxilla group, where the amount of dental compensation (164.73 ± 10.15) was higher in the narrow maxilla group. A significant negative correlation (r = -0.37) was observed between width difference and maxillary molar inclination. Maxillary molars were tipped buccally to compensate for the reduced maxillary arch width. These findings are important to determine the amount of needed maxillary expansion taking into account the buccal inclination while treating cases.

What Is the Most Effective Frictionless Method for Retracting Anterior Teeth When Using Buccal Fixed-Appliance Therapy? A Systematic Review.

There are various techniques and designs for springs used in orthodontic treatment, including frictionless methods for closing spaces. However, there is limited explicit evidence to support the superiority of one method over another. This review aims to investigate the available evidence and highlight the advantages of these different methods. This review contained six papers, and information such as study design, spring design, applied force systems, variables studied, follow-up period, and records were extracted. All of the studies focused on canine retraction with the Ladanyi spring showing the highest rate of movement (1.8 mm per month) among all springs for upper canine retraction. The Gjessing and T-loop springs outperformed the Reverse Closing Loop and Ricketts spring, respectively, substantially. In terms of tip control, the T-loop spring showed a clear advantage over the modified Marcotte spring with a difference of 1.2° vs. 6.6° per 3 months. Additionally, it was observed that the Reverse Closing Loop caused a significant loss of anchorage during canine retraction with a medial movement of 2.4 mm. When comparing wire types, no significant differences were found between TMA and Nitinol, while stainless steel was found to be less effective in terms of movement rate and tip control. However, the results indicated that there was no clear evidence that one specific technique was definitively preferable to another; therefore, there is an urgent need for more studies with proper study designs to produce more robust conclusions.

Efficacy of Er, Cr: YSGG laser phosphoric acid gel and Riboflavin activated by Photodynamic therapy on enamel reconditioning rebonded to metallic brackets: An Invitro study.

AIM: To evaluate the shear bond strength (SBS) and failure percentage of rebonded metallic brackets after employing various enamel-reconditioning methods (37% phosphoric acid, sandblasting, Er, Cr: YSGG laser, and Riboflavin (RF). MATERIAL AND METHODS: After sample size calculation, a sum of 40 non-carious, non-traumatically extracted and sound human premolar teeth were collected and the enamel surface was prepped by etching, washing, and drying. The enamel surface was primed with a bonding agent and light cured, later brackets were bonded via composite. After bonding, bracket debonding was begun using a Weingart plier and the enamel surface was reconditioned before rebonding. Samples were divided into four (n=10) reconditioning groups at random and subjected to SB with 90-µm alumina particles group 1, Er, Cr: YSGG laser group 2, 37% PA (control) group 3, and RF group 4 respectively. After reconditioning, brackets were rebonded to the enamel surface via an adhesive system and composite. Later, samples were exposed to the universal testing machine for SBS analysis, and bond failure analysis was performed by using an adhesive remnant index (ARI). Statistical analysis was executed by one-way ANOVA and Post Hoc Tukey multiple comparison tests at a statistically significant level of p ˂ 0.05. RESULTS: The SBS analysis showed that the highest SBS of rebounded brackets was exhibited by 37% phosphoric acid (control) and the lowest SBS by sandblasting enamel surface with 90-µm alumina particles for enamel prior rebonding. However, Er, Cr: YSGG laser and RF activated by PDT validated comparable SBS results to control (p>0.05). Contrarily, sandblasting with 90-µm alumina particles showed a statistically significant difference from other analyzed reconditioning groups (p<0.05). Deliberating failure rate analysis by ARI index, the most eminent failures predicted among groups were scored between 0 and 1 except for sandblasting which majorly resulted in a score of 2 showing cohesive type failure. CONCLUSION: Chromium-doped erbium, yttrium-scandium-gallium-garnet (Er, Cr: YSGG) laser, and Riboflavin activated by photodynamic therapy have the potential to be used as an alternative to 37% phosphoric acid for enamel surface reconditioning before the rebonding metallic bracket.

Treatment of Obstructive Sleep Apnea Using Oral Appliances in Saudi Arabia: Are We following the Guidelines?

BACKGROUND: This study aimed to assess sleep medicine physicians' knowledge and attitudes toward the role of oral appliances (OAs) in managing obstructive sleep apnea (OSA) in Saudi Arabia. METHODS: An online questionnaire was administered to the registered physicians practicing sleep medicine (otolaryngology, internal medicine, pulmonology, and family medicine) in Saudi Arabia. The questionnaire included 26 questions under five domains. All the collected data were analyzed using descriptive statistics and Chi-square tests. RESULTS: One hundred sleep physicians (43% Saudi, 75% male) from Saudi Arabia participated in this study. Almost 43% of participants reported inadequate knowledge of the treatment of OSA patients using OAs. Half of the participants were unaware of how OAs work in managing OSA. Most physicians (62%) never referred the patient for treatment of OSA using OAs, whereas 4% referred at least one patient every month. The majority (60%) believed that there are barriers to referring a case for OA treatment, mainly the lack of knowledge of the suitable cases (60%) and the lack of qualified dentists in this area (43%). CONCLUSION: Most sleep physicians reported poor knowledge of OA indications and mechanism of use, with most never referring a case for OA therapy.

Application and Performance of Artificial Intelligence Technology in Detection, Diagnosis and Prediction of Dental Caries (DC)-A Systematic Review.

Evolution in the fields of science and technology has led to the development of newer applications based on Artificial Intelligence (AI) technology that have been widely used in medical sciences. AI-technology has been employed in a wide range of applications related to the diagnosis of oral diseases that have demonstrated phenomenal precision and accuracy in their performance. The aim of this systematic review is to report on the diagnostic accuracy and performance of AI-based models designed for detection, diagnosis, and prediction of dental caries (DC). Eminent electronic databases (PubMed, Google scholar, Scopus, Web of science, Embase, Cochrane, Saudi Digital Library) were searched for relevant articles that were published from January 2000 until February 2022. A total of 34 articles that met the selection criteria were critically analyzed based on QUADAS-2 guidelines. The certainty of the evidence of the included studies was assessed using the GRADE approach. AI has been widely applied for prediction of DC, for detection and diagnosis of DC and for classification of DC. These models have demonstrated excellent performance and can be used in clinical practice for enhancing the diagnostic performance, treatment quality and patient outcome and can also be applied to identify patients with a higher risk of developing DC.

The Posterior Extension of the Palatal Rugae as an Anatomical Constraint for Soft Tissue Grafts in a Saudi Arabian Population.

Background The purpose of this study was to investigate the distal extension of the palatal rugae area as an anatomical constraint on the harvesting of palatal soft tissue grafts in a Saudi Arabian population. Additionally, factors that could affect or predict the extension were considered. Methods Three hundred seventy-four (374) dental casts from Saudi nationals currently residing in Riyadh (170 males and 204 females) were included. Two independent observers used a standardized probe to measure the posterior extent of the rugae on each stone cast bilaterally on a horizontal base. A sharp graphite pencil was used to mark the measurements from the origin of the rugae to their terminal ends on the cast, and a magnification lens was used to identify them. Using this technique, the most posterior extension of the rugae was marked and then analyzed. The normal approximation test for binomial distribution was used to determine the proportion of the subjects with rugael extensions beyond the mesial end of the upper second premolar, and logistic regression was used to see the association of this extension with other factors. Results The asymptotic chi-squared (p = 0.0002) McNemar tests revealed that the posterior distal extension of the rugae was not the same on both sides. A normal approximation test for the left side with 95% confidence intervals (CIs) with the "rugael extension proximal to the mesial end of the upper second premolar" category considered "success" found that the proportion of upper second premolars with rugael extensions proximal to the mesial end was not significantly different to the proportion of rugael extensions beyond the mesial end of the upper second premolars (95% CI: 48.69%-58.79%, p = 0.147). Conversely, the proportion of the upper second premolars with rugael extensions proximal to the mesial end was significantly lower than that beyond the mesial end on the right (95% CI: 35.92%-45.89%, p = 0.00004). Gender, age, and palatal shape did not significantly affect the posterior extension of palatal rugae. Conclusions The palatal rugae on the left side of a sample of the Saudi Arabian population do not considerably extend beyond the upper second premolar mesial aspect, which may provide reliable soft tissue grafts for esthetic mucogingival surgery.

A Morphometric Analysis of Palatal Rugae Patterns in a Saudi Arabian Population.

Background Palatal rugae patterns are useful in the field of forensic dentistry. Ethnicity has a significant effect on the development and final morphological pattern of palatal rugae. This study focused on a morphological analysis of the palatal rugae in a Saudi population to determine if any differences based on age and gender could support identifying an individual. Materials and methods This cross-sectional study conducted at the College of Dentistry, King Saud bin Abdul Aziz University for Health Sciences, was undertaken to evaluate 496 dental casts from the participant database of Saudi nationals from Riyadh. The rugae were delineated using a sharp graphite pencil under adequate light and magnification. The rugae patterns were classified based on the length, shape, and direction of the rugae by two observers as per Thomas and Kotze's criteria. Results The asymptotic chi-square McNemar test indicated bilateral symmetry for all the characteristics of the palatal rugae, except for the backward and forward directions of the rugae. Two-way analysis of variance (ANOVA) revealed a statistically significant interaction between the effects of age group and gender on the primary rugae count (F(3, 488) = 7.466, p <0.05)). In addition, age had a statistically significant effect on the fragmentary rugae (p <0.05), and gender had a statistically significant effect on the circular and backward patterns of the rugae (p<0.05). The females had a higher incidence of backward-directed rugae and the males had more circular rugae. No other significant difference was evident, based on gender. The logistic regression analyses showed a significant association between the circular (OR=1.298; 95% CI= 1.061-1.588) and backward (OR= 0.898; 95% CI= 0.828-0.975) palatal rugae and gender. Also, there was a significant association of the fragmentary palatal rugae (PR) (OR=1.274; 95% CI= 1.084-1.498) with the age group younger than 16 years. Conclusion In a Saudi Arabian ethnic group, the varying type of length of the palatal rugae patterns can be used to identify the age group while the direction and shape can be used to determine gender, although with limited accuracy. Post-mortem identification may benefit from using them along with other reliable forensic tools. There is a need to conduct continued research on diverse populations and ethnic groups in order to evaluate the PR potential in forensic dentistry.

Effects of Lidocaine and Articaine on Neuronal Survival and Recovery.

The local anesthetics lidocaine and articaine are among the most widely used drugs in the dentist's arsenal, relieving pain by blocking voltage-dependent Na+ channels and thus preventing transmission of the pain signal. Given reports of infrequent but prolonged paresthesias with 4% articaine, we compared its neurotoxicity and functional impairment by screening cultured neural SH-SY5Y cells with formulations used in patients (2% lidocaine + 1:100,000 epinephrine or 4% articaine + 1:100,000 epinephrine) and with pure formulations of the drugs. Voltage-dependent sodium channels Na(v)1.2 and Na(v)1.7 were expressed in SH-SY5Y cells. To test the effects on viability, cells were exposed to drugs for 5 minutes, and after washing, cells were treated with the ratiometric Live/Dead assay. Articaine had no effect on the survival of SH-SY5Y cells, while lidocaine produced a significant reduction only when used as pure powder. To determine reversibility of blockage, wells were exposed to drugs for 5 minutes and returned for medium for 30 minutes, and the calcium elevation induced by depolarizing cells with a high-potassium solution was measured using the calcium indicator Fura-2. High potassium raised calcium in control SH-SY5Y cells and those treated with articaine, but lidocaine treatment significantly reduced the response. In conclusion, articaine does not damage neural cells more than lidocaine in this in vitro model. While this does not question the safety of lidocaine used clinically, it does suggest that articaine is no more neurotoxic, at least in the in vitro setting.

Stimulation of TLR3 triggers release of lysosomal ATP in astrocytes and epithelial cells that requires TRPML1 channels.

Cross-reactions between innate immunity, lysosomal function, and purinergic pathways may link signaling systems in cellular pathologies. We found activation of toll-like receptor 3 (TLR3) triggers lysosomal ATP release from both astrocytes and retinal pigmented epithelial (RPE) cells. ATP efflux was accompanied by lysosomal acid phosphatase and beta hexosaminidase release. Poly(I:C) alkalinized lysosomes, and lysosomal alkalization with bafilomycin or chloroquine triggered ATP release. Lysosomal rupture with glycyl-L-phenylalanine-2-naphthylamide (GPN) eliminated both ATP and acid phosphatase release. Secretory lysosome marker LAMP3 colocalized with VNUT, while MANT-ATP colocalized with LysoTracker. Unmodified membrane-impermeant 21-nt and "non-targeting" scrambled 21-nt siRNA triggered ATP and acid phosphatase release, while smaller 16-nt RNA was ineffective. Poly(I:C)-dependent ATP release was reduced by TBK-1 block and in TRPML1-/- cells, while TRPML activation with ML-SA1 was sufficient to release both ATP and acid phosphatase. The ability of poly(I:C) to raise cytoplasmic Ca2+ was abolished by removing extracellular ATP with apyrase, suggesting ATP release by poly(I:C) increased cellular signaling. Starvation but not rapamycin prevented lysosomal ATP release. In summary, stimulation of TLR3 triggers lysosomal alkalization and release of lysosomal ATP through activation of TRPML1; this links innate immunity to purinergic signaling via lysosomal physiology, and suggests even scrambled siRNA can influence these pathways.

The P2X7 Receptor Primes IL-1ß and the NLRP3 Inflammasome in Astrocytes Exposed to Mechanical Strain.

Inflammatory responses play a key role in many neural pathologies, with localized signaling from the non-immune cells making critical contributions. The NLRP3 inflammasome is an important component of innate immune signaling and can link neural insult to chronic inflammation. The NLRP3 inflammasome requires two stages to contribute: priming and activation. The priming stage involves upregulation of inflammasome components while the activation stage results in the assembly and activation of the inflammasome complex. The priming step can be rate limiting and can connect insult to chronic inflammation, but our knowledge of the signals that regulate NLRP3 inflammasome priming in sterile inflammation is limited. This study examined the link between mechanical strain and inflammasome priming in neural systems. Transient non-ischemic elevation of intraocular pressure increased mRNA for inflammasome components IL-1ß, NLRP3, ASC, and CASP1 in rat and mouse retinas. The elevation was greater 1 day after the insult, with the rise in IL-1ß most pronounced. The P2X7 receptor was implicated in the mechanosensitive priming of IL-1ß mRNA in vivo, as the antagonist Brilliant Blue G (BBG) blocked the increased expression, the agonist BzATP mimicked the pressure-dependent rise in IL-1ß, and the rise was absent in P2X7 knockout mice. In vitro measurements from optic nerve head astrocytes demonstrated an increased expression of IL-1ß following stretch or swelling. This increase in IL-1ß was eliminated by degradation of extracellular ATP with apyrase, or by the block of pannexin hemichannels with carbenoxolone, probenecid, or 10panx1 peptide. The rise in IL-1ß expression was also blocked by P2X7 receptor antagonists BBG, A839977 or A740003. The rise in IL-1ß was prevented by blocking transcription factor NFκB with Bay 11-7082, while the swelling-dependent fall in NFκB inhibitor IκB-α was reduced by A839977 and in P2X7 knockout mice. In summary, mechanical trauma to the retina primed NLRP3 inflammasome components, but only if there was ATP release through pannexin hemichannels, and autostimulation of the P2X7 receptor. As the P2X7 receptor can also trigger stage two of inflammasome assembly and activation, the P2X7 receptor may have a central role in linking mechanical strain to neuroinflammation.