An Approach to Improve Specimen Processing for the Flexural Strength Testing of Zirconia.

Measuring the flexural strength of restorative materials such as zirconia is crucial for providing proper indications for clinical applications and predicting performance. Great variations in specimen preparation for flexural strength measurements exist among laboratories. The aim was to evaluate how the processing method, surface treatment, and test method of the specimens affect the flexural strength of zirconia. Zirconia specimens (VITA YZ HT) (n = 270) were processed using CAD/CAM or were conventionally milled with three different surface treatments (machined, ground, polished) and were measured with three-point bending (non-chamfered/chamfered) or biaxial flexural strength test. Weibull statistics were conducted. The mean flexural strength values ranged from 612 MPa (conventional, machined, three-point bending non-chamfered) to 1143 MPa (CAD/CAM, polished, biaxial flexural strength). The highest reliability is achieved when specimens are prepared using thoroughly controllable processing with CAD/CAM and subsequently polished. Higher strength values are achieved with the biaxial flexural strength test method because the stress concentration in relation to the effective volume is smaller. Polishing reduces surface microcracks and therefore increases the strength values.

Epidemiology of burns in a humanitarian setting: A national study among refugees in Lebanon.

INTRODUCTION: Burns represent one of the leading causes of morbidity worldwide and disproportionately impact women, children, and socioeconomically disadvantaged individuals. Syrian refugees who fled conflict to land in overcrowded informal settlements across Lebanon are a particularly vulnerable population. This study aims to assess the etiology and risk factors for burns in this population. METHODS: This cross-sectional, cluster-based population study adopted the Surgeons Overseas Assessment of Surgical Need (SOSAS) version 3.0 to capture data from refugees residing in informal settlements in multiple regions across Lebanon. The tool was contextualized and used to collect detailed information on burn cases sustained by refugees during the last 12 months prior to data collection. Univariate logistic regression models were performed to assess the relationship between burns and associated risk factors. RESULTS: From the 1468 households surveyed, a total of 223 households experienced a burn in the last 12 months. Over 63% of burns occurred in children under the age of ten years and almost 57% of burns occurred in females. More than 70% of burns resulted from hot liquid, while 17% were caused by direct heat contact. Over 3/4ths of burns occurred while preparing food (77.4%). Approximately 32% of those burned did not seek healthcare, of which almost 85% noted the cause was mainly due to financial limitations. CONCLUSION: Burns are a common injury in the Syrian refugee population living in Lebanon. Children and women are particularly impacted, often during cooking. Multi-level interventions are necessary to reduce burn injuries and improve care for those affected by burns. Community kitchens can be used to separate cooking and living environments and get stoves and hot liquids off the floor. Importantly, policies should allow for refugees to receive medical care when necessary without a major financial burden.

Dental caries and associated factors in 7-, 12- and 15-year-old schoolchildren in the canton of Basel-Landschaft, Switzerland: Changes in caries experience from 1992 to 2021.

BACKGROUND: Epidemiological surveys in schoolchildren are used to assess the current status of oral health. AIM: To investigate the changes in caries experience among schoolchildren in the canton of Basel-Landschaft, Switzerland, over a period of three decades. Secondary objectives were to evaluate the impact of various personal and demographic factors such as age group, place of residence or dental hygiene awareness on caries prevalence as well as the history of orthodontic treatment in the year 2021. DESIGN: A random sampling of school classes from first, sixth and ninth grades, that is schoolchildren aged 7, 12 and 15 years, was performed. Children's dmft and DMFT scores were determined according to the WHO methodology while information on oral hygiene habits and dental prophylaxis awareness was collected by means of a questionnaire directed to the legal guardians of the children. Individual logistic regressions were performed to identify possible influencing factors for caries. RESULTS: A total of 1357 schoolchildren could be included in the study. In the year 2021, the youngest age group had an average of 0.68 primary teeth that needed treatment, whereas the 12- and 15-year-olds each had approximately 0.3 permanent teeth requiring treatment. While these numbers remained constant over the examination period of three decades, most of the other caries indices improved. Younger children (p = .001) and children with a migrant background (p < .001) were found to be risk groups. Orthodontic treatment was more frequent in females, schoolchildren of Swiss nationality and children attending higher secondary schools at ninth grade. CONCLUSION: This study demonstrated that even in a country with a low prevalence of caries experience, untreated carious lesions remain a problem as their prevalence remained unchanged over the examination period of three decades.

Linear and angular measurement using cone-beam computed tomography to enhance safety in Le Fort I osteotomy with tuberosity cut.

OBJECTIVE: The study aimed to evaluate surgical angles for tuberosity cut and linear and angular measurements for all horizontal cuts in Le Fort I osteotomy using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: This study included 189 CBCT scans to assess the surgical angles on 3 different sites distal to maxillary second molars relative to the midsagittal plane (MSP) and the buccal cortical plane (BCP) in relation to the descending palatine foramen for tuberosity cut. The linear and angular measurements for all horizontal cuts in Le Fort I osteotomy were also evaluated. RESULTS: The mean surgical angles for tuberosity cut varied from 58.90 to 95.28° and 74.85 to 100.93° according to the MSP and the BCP, respectively. For the horizontal cuts, mean lengths (angles) for posterior buccal and lateral nasal wall osteotomies were 27.44 mm (13.62°) and 33.20 mm (9.60°), respectively, and a mean length of 47.12 mm was measured for nasal septum osteotomy. Additionally, the presence of impacted third molar resulted in significantly higher mean surgical angles than those with fully erupted or without third molars (p < 0.01). CONCLUSIONS: Overall, angles running through the buccal midpoint of the third molars relative to the MSP (76.56°) or the BCP (92.31°) might be the most appropriate in clinical practice. Furthermore, some caution seems warranted when performing tuberosity cuts with the impacted third molars. CLINICAL RELEVANCE: To avoid potential damage to the descending palatine artery for tuberosity cut in Le Fort I osteotomy.

Assessment of the prevalence and length of the anterior and caudal loops of the mental nerve as anatomical variants of exiting the mandible at the mental foramen using cone-beam computed tomography: a systematic review and meta-analysis.

OBJECTIVES: This systematic review aimed to identify the studies that performed cone-beam computed tomography analysis of the prevalence and length of the anterior loop (AL) and caudal loop (CL) of the mental nerve. MATERIALS AND METHODS: An electronic database search was performed across PubMed, EMBASE, Web of Science, Scopus, the Cochrane library, and Google Scholar. Original studies reporting the frequency and length of the AL and CL were selected. Qualitative synthesis and meta-analysis were then conducted to assess the prevalence and length of the AL and CL and their associations with age, gender, sides, and dentition status. RESULTS: A total of 21 studies were included in this review. The pooled prevalence of the AL (95% confidence interval) of the mental nerve at the patient and side level was 51% (31-71%) and 53% (37-69%) while the mean anterior loop length was 2.08 (1.46-2.70) mm. The pooled prevalence of the CL and mean caudal loop length were 100% and 4.73 (3.44-6.01) mm. No significant associations were found between the prevalence and length of the AL and CL and age, gender, sides, and dentition status. CONCLUSIONS: Overall, the pooled prevalence and mean length of AL of the mental nerve varied among different populations while CL seems to be a constant anatomical landmark with a longer CL than AL. CLINICAL RELEVANCE: Surgeons performing inter-foraminal oral surgeries like dental implant placement and genioplasty should be aware of the possible distance of the AL and CL to avoid iatrogenic mental nerve injury.

Evaluation of the relationship between malar projection and lower facial convexity in terms of perceived attractiveness in 3-dimensional reconstructed images.

BACKGROUND: This study aimed to investigate dental student's perception of facial attractiveness with regard to different combinations of anteroposterior malar-jaw positions using 3-dimensional (3-D) reconstructed images of subjects. METHODS: Two Chinese young adults (1 male and 1 female) with straight profiles and average malar projections were selected for the study. 3-D facial images and cone-beam computed tomography images of these two subjects were superimposed using 3-D imaging software. Lateral and oblique views of nine different images were created by moving the maxillomandibular complex and/or zygomatic bone by 4 mm either forward or backward along the sagittal plane. One hundred three undergraduate dental students (n = 24, 33, and 46 students from the Year 3, 4, and 5, respectively) then scored lateral and 45° oblique view images of the newly reconstructed faces. RESULTS: In the present study, images with a neutral malar and retruded jaws were found to be the most attractive in both male and female subjects. In addition, the Protruded malar (PM) group (p < 0.001), and the Retruded Jaws (RJ) group were rated more attractive (p < 0.001). Furthermore, the Relatively Prominent malar (RP) group was rated more attractive (p < 0.001) when malar-jaw relative positions were compared. CONCLUSION: This study shows that a neutral or a protruded malar favours facial attractiveness in both Chinese male and female subjects. Therefore, an appropriate relationship between malar projection and lower facial convexity should be taken into consideration while designing the orthodontic/orthognathic treatment plans for enhanced aesthetic outcomes.

Facial attractiveness of cleft patients: a direct comparison between artificial-intelligence-based scoring and conventional rater groups.

OBJECTIVES: To evaluate facial attractiveness of treated cleft patients and controls by artificial intelligence (AI) and to compare these results with panel ratings performed by laypeople, orthodontists, and oral surgeons. MATERIALS AND METHODS: Frontal and profile images of 20 treated left-sided cleft patients (10 males, mean age: 20.5 years) and 10 controls (5 males, mean age: 22.1 years) were evaluated for facial attractiveness with dedicated convolutional neural networks trained on >17 million ratings for attractiveness and compared to the assessments of 15 laypeople, 14 orthodontists, and 10 oral surgeons performed on a visual analogue scale (n = 2323 scorings). RESULTS: AI evaluation of cleft patients (mean score: 4.75 ± 1.27) was comparable to human ratings (laypeople: 4.24 ± 0.81, orthodontists: 4.82 ± 0.94, oral surgeons: 4.74 ± 0.83) and was not statistically different (all Ps ≥ 0.19). Facial attractiveness of controls was rated significantly higher by humans than AI (all Ps ≤ 0.02), which yielded lower scores than in cleft subjects. Variance was considerably large in all human rating groups when considering cases separately, and especially accentuated in the assessment of cleft patients (coefficient of variance-laypeople: 38.73 ± 9.64, orthodontists: 32.56 ± 8.21, oral surgeons: 42.19 ± 9.80). CONCLUSIONS: AI-based results were comparable with the average scores of cleft patients seen in all three rating groups (with especially strong agreement to both professional panels) but overall lower for control cases. The variance observed in panel ratings revealed a large imprecision based on a problematic absence of unity. IMPLICATION: Current panel-based evaluations of facial attractiveness suffer from dispersion-related issues and remain practically unavailable for patients. AI could become a helpful tool to describe facial attractiveness, but the present results indicate that important adjustments are needed on AI models, to improve the interpretation of the impact of cleft features on facial attractiveness.

Randomized assessor-blinded controlled trialon the efficacy and safety of virgin coconut oil versus mineral oil as a therapeutic moisturizer for Senile Xerosis

Background@#Xerosis is one of the most common dermatologic complaints in the elderly. People in the tropics, including the Philippines, have effectively used coconut oil as a traditional moisturizer for centuries. Its film-forming qualities allow it to act as a skin moisturizer and as a protectant against moisture loss. To date, only one randomized clinical trial has proven the efficacy and safety of coconut oil as a skin moisturizer for xerosis. With the increasing number of VCO products in the market, this study aimed to validate the use of an indigenous agricultural product, virgin coconut oil, for senile xerosis. With its moisturizing, antioxidant, and antiseptic effects, VCO may be superior and more cost-effective compared to the frequently used synthetic mineral oil.@*Objective@#This study aimed to determine the efficacy and safety of virgin coconut oil compared to mineral oil for the treatment of senile xerosis.@*Methods@#This was a community-based assessor-blinded, randomized controlled trial, which included elderly patients with mild to moderate senile xerosis of the legs. Participants were instructed to apply the test oil twice daily to the legs for 2 weeks. The following primary outcomes were measured at baseline and 2-weeks post treatment: skin dryness (over-all dry skin score, ODSS), skin hydration (corneometer readings), skin lipid content (sebumeter readings), and quality of life (Dermatology Life Quality Index). Secondary outcomes like patient-assessed clinical efficacy and adverse effects were also measured.@*Results@#A total of 148 participants (59 males, 89 females) with mean age of 68 years (SD 6.02) were included in the study. Eighty-one (81) were assigned under the VCO group and 67 under the mineral oil group. There was a total of 25 dropouts, 7 in the virgin coconut oil group, and 18 in the mineral oil group. The distribution of the patients’ ODSS after treatment with VCO and mineral oil showed a trend towards improvement: 43% in the VCO group had no visible signs of leg xerosis versus 22.4% in the mineral oil group. The proportion of participants with>1 point decrease in ODSS, was statistically greater in the VCO group at 74% (60/81) compared to the mineral oil group, 34% (23/67) (p<0.0001). VCO showed significantly greater skin hydration at 74% (60/81) as compared to 46% (31/67) in the mineral oil group (p<0.0010). Improvement in the skin lipid content using the sebumeter showed 82.7% (67/81) in the VCO group compared to 61.2% (41/67) in the mineral oil group (p=0.6591). Moreover, the patients’ perceived efficacy of the oil applied on their skin was 29.6% (24/81) in the VCO group compared to 5.9% (4/67) in the mineral oil group (p=0.0030). Baseline DLQI scores showed no significant difference in the assessed quality of life of the patients between the two treatments (p=0.0161).Over all, the VCO group showed 32.1% (26/81) treatment success compared to 8.9% (6/67) in the mineral oil group (p=0.004614). Adverse events in the 2 groups were all mild and transient with 8% (6/74) patients in the VCO group and 26.5% (13/49) in the mineral oil group (p=0.089).@*Conclusion@#Among elderly patients with mild to moderate xerosis, 2-week topical application of VCO was superior to mineral oil in the immediate improvement of leg xerosis based on primary outcome measures of the Over-all Dry Skin Score (ODSS), corneometer, sebumeter readings, and the Dermatology Life Quality Index.

Validity of SC-StepRx pedometer-derived moderate and vigorous physical activity during treadmill walking and running in a heterogeneous sample of children and youth.

BACKGROUND: The purpose of this study was to determine the validity of the SC-StepRx pedometer to assess moderate and vigorous physical activity during treadmill walking and running in a heterogeneous sample of children and youth aged 10-17 years. METHODS: Physical activity intensity assessed via indirect calorimetry served as the criterion standard. A convenience sample of 40 participants (20 boys, 20 girls) wore 6 SC-StepRx pedometers, 2 ActiGraph GT3X accelerometers, 2 Actical accelerometers, 1 Walk4Life MVP pedometer and 1 NL-1000 pedometer while walking/running at speeds approximating 2, 3, 4, 6 and 7 METs. Associations between indirect calorimetry and each activity monitor were assessed using linear regression analyses in SAS 9.2. RESULTS: Estimates of moderate and vigorous physical activity from all monitors were significantly associated with the criterion standard of indirect calorimetry. The strongest associations with the criterion measure were observed for the SC-StepRx with moderate/vigorous thresholds of 110/130 steps•minute(-1), and the NL-1000 (R2 = 0.82, p <0.05). The SC-StepRx with moderate/vigorous thresholds of 110/130 steps•minute(-1) also exhibited the highest combined sensitivity (92.9%) and specificity (96.5%) for correctly identifying a bout of moderate-to-vigorous physical activity. CONCLUSIONS: This study demonstrates that the SC-StepRx pedometer is a valid tool for the measurement of moderate and vigorous physical activity in children and youth.

The mystery of missing female children in the Caucasus: an analysis of sex ratios by birth order.

CONTEXT: Official data on sex ratios at birth suggest a rise in sex-selective abortions in some post-Soviet states following the introduction of ultrasonography. However, questions remain about the validity of official data in these nations as well as whether the high sex ratios at birth are a statistical artifact. METHODS: Trends in sex ratios at birth from 1985 to 2009 for 12 post-Soviet states were examined using vital registration data. For the three countries that had had a Demographic and Health Survey (DHS) in 2005-2010 (Armenia, Azerbaijan and Moldova), survey data were used to calculate sex ratios at birth according to birth order, and vital registration data for 2010 were used to estimate the number of "missing" female births (if any). RESULTS: Official data revealed elevated sex ratios at birth in Armenia (117), Azerbaijan (116) and Georgia (121), but not in other post-Soviet states. According to DHS data, sex ratios were high in Armenia and Azerbaijan for first births (138 and 113, respectively); if the first child was a girl, the sex ratio in Armenia was even higher for the second birth (154). Overall, the number of girls born in these countries in 2010 was 10% lower than expected, consistent with 1,972 sex-selective abortions in Armenia and 8,381 in Azerbaijan. Sex ratios did not vary by birth order in Moldova. CONCLUSION: Sex-selective abortion appears to be common in Azerbaijan and Armenia. Family planning and legal interventions are needed to address this issue.