A systematic review and meta-analysis of the prevalence and global distribution of middle mesial canals in mandibular molars identified by CBCT.

OBJECTIVES: This systematic review and meta-analysis aimed to evaluate the prevalence of middle mesial canal (MMC) in permanent mandibular molars of different populations and regions based on cone-beam computed tomography (CBCT) studies. MATERIALS AND METHODS: PubMed, Scopus, Embase, Web of Science, and Open-Grey were searched up to October 2023 according to specific keywords. A hand search was conducted on the references of the included studies and articles from three peer-reviewed journals in endodontics. The main variable of interest was the prevalence of MMC. Additional data such as the total number of included cases, age and country of the population, CBCT device information, voxel size, and field of view details were also extracted. Extracted data were analyzed qualitatively with the JBI quality assessment checklist and quantitatively with STATA software. RESULTS: Of 32,793 studied teeth, the cumulative prevalence of MMC in both mandibular 1st and 2nd molars was 3.11% (95% CI: 2.00-4.44%). The subgroup analysis reveals a prevalence of 4.15% (95% CI: 2.69-5.89%) for mandibular 1st molars and 1.2% (95% CI: 0.2-2.83%) for mandibular 2nd molars. The highest prevalence of MMC in 1st molar was attributed to South Asia (11.24%) and Africa (6.61%). CONCLUSIONS: The prevalence of MMC varies among regions. Clinicians should be aware of the potential prevalence of MMC, particularly in mandibular first molars, as a missed MMC could result in endodontic failure. CLINICAL RELEVANCE: The presence of MMCs varies in different geographic regions (0% to 29.7%). Clinicians should always look for MMC when doing an endodontic treatment on mandibular molars, as the presence of this canal is not uncommon. We suggest searching for this canal as if searching for the second mesiobuccal canal of maxillary 1st molars.

The prevalence of helmet use in motorcyclists around the world: a systematic review and meta-analysis of 5,006,476 participants.

Road traffic injuries present a significant public health burden, especially in developing countries. This systematic review and meta-analysis synthesized global evidence on motorcycle helmet use prevalence by including 299 records across 249 articles involving 5,006,476 participants from 1982 to 2022. The findings revealed a declining trend in helmet use prevalence over the past four decades, with an overall prevalence of 48.71%. The meta-regression analysis did not find any statistically significant change in the overall prevalence. Subgroup analysis showed higher helmet use prevalence in observation/survey records (54.29%) compared to crashed patient records (44.84%). Riders/Motorcyclists demonstrated a higher likelihood of wearing helmets than passengers in both observation/survey records (62.61 vs. 28.23%) and crashed patient records (47.76 vs. 26.61%). Countries with mandatory helmet use laws had higher helmet usage prevalence compared to those without (52.26 vs. 37.21%). The African continent had the lowest helmet use rates, while Latin America and the Caribbean regions had higher rates. This study provides a comprehensive overview of global helmet use prevalence, emphasizing disparities between high and low-income countries, variations in law enforcement, and trends over four decades. Targeted interventions are necessary to improve helmet-wearing habits, especially among passengers and regions with low usage rates. Effective legislation and awareness campaigns are crucial for promoting helmet use and reducing road traffic injuries burden.

Changes in the Maxillary Sinus Membrane Thickness and Sinus Health Following Lateral Sinus Floor Elevation: Comparing Preoperative Mucosal Thicknesses of Less than and Greater than 5 Millimeters.

PURPOSE: To investigate the effect of lateral sinus floor elevation (LSFE) on sinus membrane (SM) thickness and sinus health in mucosa thickness less and more than 5 mm. MATERIALS AND METHODS: LSFE was performed in a prospective controlled clinical trial on two groups with less than and more than 5 mm (group A & B) SM thickness and followed for 6 months. Using preoperative and 6-month postoperative CBCT and clinical evaluation, SM thickness changes (primary outcome variable), sinus health, augmented bone height, and length (augmentation adequacy), membrane-related variables, and operation time were measured. RESULTS: Forty unilateral sinus augmentations (A:20, B:20) with simultaneous installation of 52 fixtures were performed on 40 subjects (72.5% males, mean age of 48.8±7.6). The mean preoperative and 6- month SM thicknesses in group A and group B were 1.4±0.9 and 1.3±0.6 mm, and 6.8±1.0 and 3.4±1.7 mm, respectively. The mean postoperative SM thickness significantly decreased (P<0.001) only in group B. The mean SM thickness changes also revealed a noticeable difference between the two groups (P<0.001). Augmentation adequacy and membrane perforation rate were similar in both groups. Clinical and radiographic rhinosinusitis was not detected in any of the patients. Bleeding during separation and resistance to elevation in group B were significantly higher than in group A (P=0.003, P=0.001). Surgical time in group B (12.08 ± 8.26 minutes) was longer than in group A (8.64 ± 3.70 minutes), without reaching a significant level (P=0.097). CONCLUSIONS: LSFE in thickened mucosa (≤10 mm) and thinner mucosa (≤5 mm) does not cause abnormal changes in the sinus membrane and sinus health. LSFE in thickened mucosa results in adequate sinus augmentation. Thickened SM also shows a significant thickness reduction. The thickened membrane does not appear to be a contraindication to SFE.

Less Invasive Window Repositioning Technique for Sinus Floor Elevation: A Clinical and Radiographic Study

PURPOSE: To determine whether a less invasive window repositioning technique could provide a feasible, safe, and reliable lateral sinus augmentation. MATERIALS AND METHODS: The less-invasive window repositioning technique using a piezoelectric saw was performed on adult patient candidates for lateral sinus floor elevation. The augmented bone height (primary outcome variable), bone length, and posthealing outcome variables were evaluated to determine the augmentation adequacy, safety, and reliability of this technique overall and in one- and two-implant groups with different window dimensions. Data were analyzed using descriptive statistics, chi-square test, and Pearson correlation analysis. P < .05 was considered significant. RESULTS: A total of 50 consecutive sinus floor elevations with simultaneous placement of 66 implants (one-implant: 34, two-implant: 16) were performed on 44 subjects (72% men) with a mean age of 46.7 ± 10.3 years and followed for a mean of 13.28 ± 3.5 months. The overall, one-implant, and two-implant group mean window sizes were 31.38 ± 6.78 mm2, 28.38 ± 4.2 mm2, and 37.75 ± 6.88 mm2, respectively. The mean overall augmented bone height and length were 12.3 ± 1.04 mm and 19.67 ± 2.01 mm, respectively. The mean window size was significantly smaller in the one-implant group versus the two-implant group (P < .001). However, there was no correlation between window size and augmented bone height (r = -0.9, P = .54) and length (r = 0.05, P = .68). The posthealing outcome variables showed perfect window integration without soft tissue ingrowth. Six sinus perforations (12%) during membrane elevation that were not related to window osteotomy were observed and were appropriately managed. CONCLUSION: The less-invasive window repositioning technique is feasible, safe, and reliable for appropriate sinus augmentation in height and length. The reduction of window dimension does not influence the feasibility, augmentation adequacy, and surgical safety and does not increase surgical risks or membrane perforation. The repositioned window showed proper integration. Also, sinus floor elevation through this technique is an experience-based surgery that requires delicate instruments.

Topical Mentha piperita Effects on Cutaneous Wound Healing: A Study on TGF-ß Expression and Clinical Outcomes.

BACKGROUND: Wound healing is a critical clinical concept. We aimed to evaluate the effects of topical Mentha piperita essence on cutaneous wound healing. METHODS: This randomized controlled trial was conducted in Tehran University of Medical Sciences, Tehran, Iran in 2019. Square-shaped 1.5×1.5 cm wounds were made on the neck of 60 male Wistar rats in a sterile condition. Samples were randomly divided into a control group and three experimental groups. Group A treated with M. piperita essence and Vaseline. The second group received the M. piperita essence, and the third group received Vaseline. Histological specimens were obtained in 4th, 7th, and 14th days and were explored for fibroblasts, epithelial cells, inflammatory cells, and vessels. RT-PCR was performed for molecular and gene expression evaluation of TGF-ß. RESULTS: The M. piperita essence increases TGF-ß gene expression as an important factor in wound healing. After 14 d, group A, who received M. piperita and Vaseline, had 99.73% of wound healing with the mean wound size of 0.006 cm2 while wound healing in the control group was only 52%. Samples treated with M. piperita have 74.58% wound healing following by group treated with Vaseline, which was 67.02% (P<0.05), respectively. CONCLUSION: The application of the M. piperita essence for wound healing accelerates the process and improves outcomes.

Adverse Impacts of Imposing International Economic Sanctions on Health.

BACKGROUND: International economic sanctions (IES) influence a country's economic development and the overall welfare of a nation's population. METHODS: An electronic search of PubMed, Embase and Web of Science was conducted until July 31, 2019. Additionally, a list of references to related articles was reviewed. Key search terms were "Economics", "Health", "Sanction", and their equivalents with no language or time restriction. RESULTS: Totally, 8624 records were identified of which 2869 duplicates were deleted. Finally, 24 papers met the inclusion criteria and were selected for drafting. The number of papers included for evaluating each factor included healthcare (n=16) and pharmaceutical industry (n=10). Nine and eight studies examined the effect of sanctions imposed on Iran and Iraq, respectively. France, Haiti, Serbia, Cuba, Syria, and other areas such as Africa were also evaluated. Sanctions lead to a decrease in immunization rates and government health care expenditures. Sanctions increase infant and under-five mortality rate, road traffic injuries and fatalities, severe malnutrition, infective diseases, neurologic and visual disorders, as well as shortage of medical or dental instruments and a variety of medicines. Sanctions have adverse impacts on female labor and are associated with disabling hospitals, dispersing medical workers, and facilities for radiation therapy. CONCLUSION: The health status of sanctioned nations in terms of healthcare, and pharmaceutical industry was adversely affected in targeted countries.

Does Minimal-Invasive Envelope Flap Reduce Side Effects Compared to Conventional Envelope Flap Following Impacted Third Molar Surgery? A Split-Mouth Randomized Clinical Trial.

PURPOSE: The surgical removal of impacted third molars can lead to various postoperative consequences, which can be influenced by modifiable factors such as flap design. The present study aimed to determine whether a minimal-invasive envelope flap (MIEF) can reduce surgical consequences and improve life quality compared to conventional envelope flap (CEF) after removing impacted mandibular third molars. MATERIAL AND METHODS: This single-blinded, cross-over randomized clinical trial was conducted on adult patients with bilateral, symmetrically impacted mandibular third molars. The flap design for surgical removal of the third molar was the primary predictor variable. The primary outcome (pain) and secondary outcome variables (swelling, mouth opening limitation [MOL]) were recorded daily and on the second and seventh days after the surgery, respectively. Wound dehiscence and patients' postoperative quality-of-life scores (PPOQL) were recorded on the seventh day. The data were analyzed by Kolmogorov-Smirnov and paired sample t test using SPSS version 22. The P value < .5 was considered significant. RESULTS: Sixty-eight impacted third molars of 34 subjects with a mean age of 22 ± 12.9 years (35% females) were followed. The postoperative pain level in the MIEF group at rest (0.80 ± 0.53) and chewing (2.10 ± 1.32) up to fifth day was significantly (P value < .01) lower than CEF group (2.40 ± 1.12 and 3.05 ± 1.13, respectively). The difference did not reach a significant level at rest and chewing on the sixth and seventh days (P value > .05). On the seventh day, the subjects in the MIEF group showed a significantly (P value < .001) lower level of swelling (1.13 ± 0.11) and MOL (8.28 ± 4.17) than the CEF group (3.2 ± 2.1 and 12.67 ± 4.92, respectively). Based on the PPOQL scale, patients in the MIEF group (1.82 ± 1.31) expressed a better recovery period than the CEF group (3.5 ± 2.1) (P value < .001). CONCLUSIONS: Considering the reduction of pain, swelling, MOL, and wound dehiscence in MIEF cases, the application of MIEF in surgical removal of impacted mandibular third molars can lead to a significant reduction in postoperative consequences and also a noticeable improvement in PPOQL compared to CEF.

Impact of COVID-19 on Dentistry.

The coronavirus disease 2019 (COVID-19) pandemic has affected the health-care system drastically, including dental care practice. COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is thought to spread via close contact through respiratory droplets and aerosols. Owing to specific characteristics of dental care such as aerosol generation as well as close proximity to patients, dentistry is thought to be associated with the nosocomial spread of infection. The risk of bidirectional spread of infection between patient and dental care providers makes it critical to take additional precautionary measures to mitigate the spread of COVID-19. It is essential to understand that the guidelines for providing dental treatment during the COVID-19 pandemic will vary across the globe, and dental practices should be in compliance with their regional guidelines. This chapter aims to present an overview of the dynamics of COVID-19 transmission and its impact on dentistry and discuss measures to provide dental care during the time of the COVID-19 outbreak effectively.

Are saliva and deep throat sputum as reliable as common respiratory specimens for SARS-CoV-2 detection? A systematic review and meta-analysis.

OBJECTIVE: The COVID-19 pandemic raises an urgent need for large-scale control through easier, cheaper, and safer diagnostic specimens, including saliva and sputum. We aimed to conduct a systemic review and meta-analysis on the reliability and sensitivity of SARS-CoV-2 detection in saliva and deep throat sputum (DTS) compared to nasopharyngeal, combined naso/oropharyngeal, and oropharyngeal swabs. METHODS: This systematic review and meta-analysis was performed according to the PRISMA statement. The inclusion criteria were studies that specifically assessed a sample of saliva or DTS with at least one other respiratory specimen in patients with COVID-19 infection, based on RT-PCR tests. The DerSimonian-Laird bivariate random-effects model analysis performed using STATA software with the "metaprop" package. RESULTS: From 1598 studies, we retrieved 33 records, of which 26 studies were included for quantitative analysis. We found an overall sensitivity of 97% (95% confidence interval [CI], 86-100) for bronchoalveolar lavage fluid, 92% (95% CI, 80-99) for double naso/oropharyngeal swabs, 87% (95% CI, 77-95) for nasopharyngeal swabs, 83% (95% CI, 77-89) for saliva, 82% (95% CI, 76-88) for DTS, and 44% (95% CI, 35-52) for oropharyngeal swabs among symptomatic patients, respectively. Regardless of the type of specimens, the viral load and sensitivity in the severe patients were higher than mild and in the symptomatic patients higher than asymptomatic cases. CONCLUSIONS: The present review provides evidence for the diagnostic value of different respiratory specimens and supports saliva and DTS as promising diagnostic tools for first-line screening of SARS-CoV-2 infection. However, the methods of sampling, storing, and laboratory assay need to be optimized and validated before introducing as a definitive diagnosis tool. Saliva, DTS, and nasopharyngeal swab showed approximately similar results, and sensitivity was directly related to the disease severity. This review revealed a relationship between viral load, disease severity, and test sensitivity. None of the specimens showed appropriate diagnostic sensitivity for asymptomatic patients.

The effectiveness of different types of motorcycle helmets - A scoping review.

BACKGROUND: Protective helmets may reduce the risk of death and head injury in motorcycle collisions. However, there remains a large gap in knowledge regarding the effectiveness of different types of helmets in preventing injuries. OBJECTIVE: To explore and evaluate the effectiveness of different types of motorcycle helmets; that is the association between different helmet types and the incidence and severity of head, neck, and facial injuries among motorcyclists. Also, to explore the effect of different helmet types on riders. METHODS: A systematic search of different scientific databases was conducted from 1965 to April 2019. A scoping review was performed on the included articles. Eligible articles were included regarding defined criteria. Study characteristics, helmet types, fixation status, retention system, the prevention of injury or reduction of its severity were extracted. RESULTS: A total of 137 studies were included. There was very limited evidence for the better protection of full-face helmets from head and facial injury compared to open-face and half-coverage helmets. There was however scarce evidence for the superiority of a certain helmet type over others in terms of protection from neck injury. The retention system and the fixation status of helmets were two important factors affecting the risk of head and brain injury in motorcyclists. Helmets could also affect and limit the riders in terms of vision, hearing, and ventilation. Multiple solutions have been discussed to mitigate these effects. CONCLUSION: Full-face helmets may protect head and face in motorcycle riders more than open-face and half-coverage helmets, but there is not enough evidence for better neck protection among these three helmet types. Helmets can affect the rider's vision, hearing, and ventilation. When designing a helmet, all of these factors should be taken into account.

The Trend of Interpersonal Violence Mortality at National and Provincial Levels in Iran From 1990 to 2015.

Interpersonal violence (IPV) is a major public health concern with a significant impact on physical and mental health. This study was designed to evaluate age-sex-specific IPV mortality trends and the assault mechanisms (firearm, sharp objects, and other means), at national and provincial levels, in Iran. We used the Iranian Death Registration System (DRS) and the population and housing censuses in this analysis. Spatio-temporal and Gaussian Process Regression methods were used to adjust for inconsistencies at the provincial level and to integrate data from various sources. After assessing their validity, all records were reclassified according to the International Classification of Diseases, 10th Revision (ICD-10). All ICD-10 codes were then mapped to Global Burden of Disease (GBD) 2013 coding. More than 700 individuals died due to IPV in 1990 and more than twice this number in 2015. The IPV mortality age-standardized rate, per 100,000, increased from 1.62 (95% Uncertainty Interval [UI] = [0.96, 2.75]) in 1990 to 1.81 [1.15, 2.89] in 2015. Among females, the age-standardized mortality rate at national level per 100,000 due to IPV was 1.27 [0.66, 2.43] in 1990 and decreased to 1.08 [0.60, 1.96] in 2015. Among males, the age-standardized mortality rate was 1.96 [1.25, 3.09] in 1990 rising to 2.54 [1.70, 3.82] in 2015. Data from provinces revealed that during the period of our study, Hormozgan province had the largest increase of IPV among females, and Fars province had the largest increase of IPV among males. Conversely, the largest decrease was detected in West Azarbaijan and Qom provinces in females and males, respectively. This study showed a wide variation in the incidence and trends of IPV in Iran by age, sex, and location. The study has provided valuable information to reduce the burden of IPV in Iran and a means to monitor future progress through repeated analyses of the trends.

Does Dynamic Intermaxillary Fixation With Elastics Improve Outcomes Following Unilateral Condylar Fracture?

PURPOSE: The use of rigid versus semi-rigid intermaxillary fixation (IMF) following subcondylar fractures is controversial. This study aims to investigate whether the "dynamic" elastic fixation technique improves the outcomes, compared to the rigid fixation technique for the treatment of displaced subcondylar fractures in adults. MATERIALS AND METHODS: This nonblinded randomized clinical trial was performed on adult patients with unilateral displaced mandibular subcondylar fractures. Patients were randomly allocated into two groups (n = 17). The primary predictor variable was wire versus elastic IMF. Changes in primary (mouth opening) and secondary (other clinical and radiological) outcomes were recorded. Data were analyzed with the t test and Mann-Whitney test with SPSS software version 20. P-value < .05 considered as significant. RESULTS: In this study 34 patients (with mean age of 33.03 ± 1.79, 23.5% females & 76.5% males) in two groups (Elastics & Wire) followed up to 6 months. The Elastics group showed significant improvement in mouth opening (primary outcome) after 1 month of follow-up, but the differences were not significant at the end of the study. In terms of secondary outcomes, the ramus height shortening compared to the opposite side revealed favorable improvement in the Elastics group in the period of study. The differences between the two groups in the lateral movement and protrusive movement were significant in favor of the Elastics group. The differences in pain, fracture displacement, and midline deviation between study groups were not significant at the end of the study. Just 1 case with malocclusion was observed in the Wire group. Patients were more satisfied with dynamic nonrigid IMF with elastics. CONCLUSIONS: The results of this study showed that using the dynamic IMF technique is more tolerable, and patients have better functional and clinical outcomes during and at the end treatment.

The trend of fall-related mortality at national and provincial levels in Iran from 1990 to 2015.

Falls are one of the major causes of unintentional injuries. Understanding the epidemiology of fall-related mortality helps to identify the root causes of this event and planning preventive strategies to inhibit falls. The aim of this study was to assess the trend of fall-related mortality rate and its epidemiological patterns based on sex and age-groups at national and subnational levels in Iran during the years 1990 to 2015. All data were gathered from Death Registration Systems, cemetery databases of Tehran and Isfahan, the Demographic and Health Survey of 2000 and three rounds of national population and housing censuses. The age-standardized death rate (ASDR) due to falls per 100,000 people decreased from 2.61 (95% Uncertainty Interval (UI): 1.94-3.51) in 1990 to 2.13 (1.62-2.80) in 2015 at national level. Males were at higher risk of death due to falls than females. Our data showed that the elderly population was at higher risk of death due to falls and individuals less than 4-year old had the highest fall-related mortality rate among children and adolescents. Our data should be used to accelerate interventions to reduce fall-related mortality.

The trend of burn mortality in Iran - A study of fire, heat and hot substance-related fatal injuries from 1990 to 2015.

INTRODUCTION: Burn injuries are a major cause of preventable mortality worldwide. To implement preventive strategies, a detailed understanding of the rate and trend of fatal burn injuries is needed. The aim of this study was to determine the rate and trend of burn mortality at national and province level in Iran from 1990 to 2015. MATERIALS AND METHODS: The data were retrieved from various sources: the Death Registration System, cemetery databases, the Demographic and Health Survey and three national population and housing censuses. ICD-10 codes were converted to Global Burden of Disease (GBD) codes for comparability. After addressing the incompleteness of death data, statistical methods such as spatio-temporal modelling and Gaussian Process Regression (GPR) were applied to estimate the levels and trend of death and cause specific mortality. RESULTS: The number of deaths due to burning across Iran was 80,625, with a male to female ratio of 0.88, 0.94 and 1.14 in 1990, 1995 and 2015, respectively. The annual percentage change of age-standardized death rate from 1990 to 2015 was -5.42% and -4.22% in women and men, respectively. The burn-related age-standardized mortality rate decreased considerably from 5.97 in 1990 to 1.74 per 100,000 in 2015. The mortality rate due to burns was highest among those aged more than 85 years, especially in Ilam province. CONCLUSION: This study showed a decline in burn mortality in Iran from 1990 to 2015. Continued efforts to reduce the burden of burns are needed to accelerate this progress and prevent injuries.