Relationship between ERCC1 and XPC polymorphisms and the susceptibility to head and neck carcinoma: A systematic review, meta-analysis, and trial sequential analysis.

OBJECTIVE: This meta-analysis was conducted to investigate the relationship between ERCC1 and XPC polymorphisms and the risk of head and neck cancer (HNC), incorporating more studies and additional analyses. DESIGN: An exhaustive search of various databases, including PubMed/Medline, Web of Science, Scopus, and Cochrane Library was carried out, up until November 18, 2023, to identify pertinent studies. The Review Manager 5.3 software was employed to calculate the effect sizes, which were presented as the odds ratio (OR) along with a 95% confidence interval (CI). RESULTS: The study found that the T allele (OR = 1.11; p-value = 0.02; 95%CI: 1.02, 1.22) and the TT genotype rs2228000 polymorphism in both the homozygous model (OR = 1.61, p-value = 0.02; 95%CI: 1.07, 2.42) and the recessive model (OR = 1.53; p-value = 0.02; 95%CI: 1.06, 2.22) had statistically significant associations. However, no significant associations were found for rs11615, rs3212986, rs735482, rs2228001, and PAT polymorphisms in any genetic models. CONCLUSIONS: The meta-analysis revealed significant associations for the T allele and TT genotype rs2228000 polymorphism, but not for rs11615, rs3212986, rs735482, rs2228001, and PAT polymorphisms. The results highlight the impact of factors such as ethnicity, cancer subtype, and control source on these associations, emphasizing the intricate nature of genetic interactions in disease risk.

Relationship between XPA, XPB/ERCC3, XPF/ERCC4, and XPG/ERCC5 Polymorphisms and the Susceptibility to Head and Neck Carcinoma: A Systematic Review, Meta-Analysis, and Trial Sequential Analysis.

Background and Objectives: Nucleotide Excision Repair (NER), the most extensively researched DNA repair mechanism, is responsible for repairing a variety of DNA damages, and Xeroderma Pigmentosum (XP) genes participate in NER. Herein, we aimed to update the previous results with a meta-analysis evaluating the association of XPA, XPB/ERCC3, XPF/ERCC4, and XPG/ERCC5 polymorphisms with the susceptibility to HNC. Materials and Methods: PubMed/Medline, Web of Science, Scopus, and Cochrane Library databases were searched without any restrictions until 18 November 2023 to find relevant studies. The Review Manager 5.3 (RevMan 5.3) software was utilized to compute the effect sizes, which were expressed as the odds ratio (OR) with a 95% confidence interval (CI). Results: Nineteen articles were involved in the systematic review and meta-analysis that included thirty-nine studies involving ten polymorphisms. The results reported that the CC genotype of rs17655 polymorphism showed a significantly decreased risk of HNC in the recessive model (OR: 0.89; 95%CI: 0.81, 0.99; p-value is 0.03). In addition, the CT genotype (OR: 0.65; 95%CI: 0.48, 0.89; p-value is 0.008) of the rs751402 polymorphism was associated with a decreased risk, and the T allele (OR: 1.28; 95%CI: 1.05, 1.57; p-value is 0.02), the TT (OR: 1.74; 95%CI: 1.10, 2.74; p-value is 0.02), and the TT + CT (OR: 2.22; 95%CI: 1.04, 4.74; p-value is 0.04) genotypes were associated with an increased risk of HNC. Conclusions: The analysis identified two polymorphisms, rs17655 and rs751402, as being significantly associated with the risk of HNC. The study underscored the influence of various factors, such as the type of cancer, ethnicity, source of control, and sample size on these associations.

Association between alcohol dehydrogenase polymorphisms (rs1229984, rs1573496, rs1154460, and rs284787) and susceptibility to head and neck cancers: A systematic review and meta-analysis.

OBJECTIVE: Head and neck cancer (HNC) is a prevalent and complex group of malignancies with increasing incidence globally. Alcohol dehydrogenases (ADHs) play a crucial role in alcohol metabolism, and their polymorphisms have been linked to HNC risk. This systematic review and meta-analysis aims to evaluate the association between ADH polymorphisms and susceptibility to HNCs, incorporating additional analyses and adding more studies to increase power and accuracy of the results. DESIGN: Subgroup analysis, meta-regression analysis, and sensitivity analyses were conducted to explore potential differences within the data and assess the stability of pooled odds ratios (ORs). To mitigate the risk of false conclusions from meta-analyses, a trial sequential analysis was performed. RESULTS: For ADH1B rs1229984, the pooled OR (95 % confidence interval (CI)) was 0.73 (0.65, 0.82), 0.42 (0.35, 0.50), 0.57 (0.44, 0.73), 0.56 (0.50, 0.62), and 0.80 (0.73, 0.88), as well as for ADH7 rs1573496, the pooled OR was 0.72 (0.62, 0.85), 0.36 (0.17, 0.74), 0.76 (0.64, 0.91), 0.80 (0.71, 0.91), and 0.38 (0.18, 0.78) with a p < 0.05 in all allelic, homozygous, heterozygous, recessive, and dominant models, respectively. However, no significant association was found between the ADH7 rs1154460 and rs284787 polymorphisms and the risk of HNC with pooled ORs of 1.11 (p = 0.19) and 1.09 (p = 0.24) for the recessive model, respectively. The ethnicities, tumor subsites, control sources, sample sizes, quality scores, and Hardy-Weinberg equilibrium statuses were confounding factors. CONCLUSION: The ADH1B rs1229984 and ADH7 rs1573496 polymorphisms are significantly associated with a reduced risk of HNC.

A Randomized Triple-Blind Clinical Trial of the Effect of Low-Level Laser Therapy on Infiltration Injection Pain in the Anterior Maxilla

Abstract Objective: To evaluate the level of pain experienced during infiltration anesthesia of the anterior maxilla following low-level laser therapy (LLLT) with 810-980 nm wavelengths. Material and Methods: In the current triple-blind clinical trial, 84 patients received a total of 168 infiltration anesthesia injections (1.8 mL of 2% lidocaine plus 1:100,000 epinephrine) in the anterior maxilla. Each patient received two injections into the buccal mucosa of the right and left central incisors with a two-week interval. One injection was performed after LLLT, while the other injection was administered conventionally without laser. The pain level was measured immediately after injection using a visual analog scale (VAS). Results: There was a significant difference in the pain level experienced with and without LLLT, such that the mean pain score following LLLT was significantly lower than that without LLLT (p<0.05). No significant difference was found in the pain level between laser and no laser groups in males, but the difference in this regard was significant in females (p<0.05) and female patients experienced a significantly lower level of pain following LLLT. Conclusion: The low-level laser therapy can be successfully used to decrease the level of pain experienced during infiltration anesthesia of the anterior maxilla (AU).

Estimation of serum and salivary matrix metalloproteinase levels in oral squamous cell carcinoma patients: a systematic review and meta-analysis.

INTRODUCTION: Matrix metalloproteinases (MMPs) play a pivotal role in the cancer progression, invasion, and angiogenesis. AIM: This meta-analysis was conducted to evaluate the difference between oral squamous cell carcinoma (OSCC) patients and healthy controls in the serum and salivary MMP levels. MATERIAL AND METHODS: Four databases - Web of Science, PubMed, Scopus, and Cochrane Library - were searched up to March 2019. The pooled standard mean difference (SMD) and 95% confidence interval (CI) were obtained to explain the difference between the patients and controls in the salivary and serum MMP levels. Both Egger's and Begg's tests were considered as the significant publication bias. RESULTS: Thirteen case-control studies were included in the meta-analysis. Among the analyses of serum MMP levels, the serum MMP7 (SMD = 0.78; 95% CI: 0.15-1.41; p = 0.02) and MMP9 (SMD = 1.18; 95% CI: 0.51-1.84; p = 0.0005) levels were significantly higher in the OSCC patients than in the controls. In addition, the analyses of salivary MMP levels showed that the MMP1 (SMD = 0.46; 95% CI: 0.22-0.70; p = 0.0001) and MMP9 (SMD = 0.66; 95% CI: 0.19-1.12; p = 0.005) levels were significantly higher in the OSCC patients than in the controls. CONCLUSIONS: The meta-analysis showed that the serum MMP7 and MPP9 levels as well as the salivary MMP1 and MPP9 levels were significantly higher in the OSCC patients than in the controls.

A PRISMA-compliant meta-analysis on association between X-ray repair cross complementing (XRCC1, XRCC2, and XRCC3) polymorphisms and oral cancer susceptibility.

BACKGROUND: Oral Cancer (OC) is one of the leading causes of death and the disease mainly occurs over 50 years of age. Herein, a meta-analysis aimed to assess the association between X-ray repair cross complementing (XRCC) polymorphisms and OC risk. METHODS: Four databases were searched extensively until June 5, 2020. Subgroup analysis, meta-regression, and funnel plots, as well as the quality assessment were estimated. RESULTS: Fifteen studies were entered to the analysis. With regards to allele, homozygote, heterozygote, recessive, and dominant models, the pooled ORs for XRCC1 rs1799782 polymorphism were 1.51 (P = 0.01), 1.45 (P = 0.11), 1.45 (P = 0.0003), 1.44 (P = 0.0002), and 1.29 (P = 0.26); for XRCC1 rs1799782 polymorphism were 1.65 (P = 0.11), 1.50 (P = 0.33), 1.06 (P = 0.83), 1.57 (P = 0.12), and 1.32 (P = 0.45); for XRCC1 rs25489 polymorphism were 0.01 (P = 0.19), 1.44 (P = 0.48), 1.21 (P = 0.72), 1.17 (P = 0.19), and 1.38 (P = 0.54); for XRCC2 rs2040639 polymorphism were 0.68 (P = 0.0002), 0.63 (P = 0.02), 0.95 (P = 0.92), 0.79 (P = 0.49), and 0.61 (P = 0.005); and for XRCC3 rs861539 polymorphism were 1.24 (P = 0.20), 1.28 (P = 0.48), 0.99 (P = 0.95), 1.15 (P = 0.46), and 1.52 (P = 0.15), respectively. CONCLUSIONS: The T allele and CT genotype of XRCC1 rs1799782 polymorphism had an elevated risk, whereas the G allele and GG genotype of XRCC2 rs2040639 polymorphism had a protective role in OC.

Evaluation of Serum and Plasma Interleukin-6 Levels in Obstructive Sleep Apnea Syndrome: A Meta-Analysis and Meta-Regression.

Obstructive sleep apnea syndrome (OSAS) is considered a low-grade chronic inflammatory disease. Interleukin-6 (IL-6) is one of the most significant inflammatory markers and an excellent proxy for the inflammatory/immune system. The present meta-analysis and meta-regression aimed at comparing plasma and serum levels of IL-6 between individuals (children and adults) with OSAS and healthy controls. Four databases, PubMed/Medline, Scopus, Cochrane Library, and Web of Science, were comprehensively searched to retrieve articles published up to December, 2019, with no further restrictions. RevMan 5.3 software was used to calculate the crude mean difference (MD) and 95% confidence interval (CI). The results of funnel plots and meta-regression were analyzed by the CMA 2.0 software. Sixty-three studies (57 with adults; six with children) were included in the present meta-analysis. For adults, 37 studies reported significantly higher serum IL-6 levels and 20 reported significantly higher plasma IL-6 levels for those with OSAS than for healthy controls [pooled MD of 2.89 pg/ml (P < 0.00001) and pooled MD of 2.89 pg/ml (P < 0.00001), respectively]. The pooled analysis of serum and plasma IL-6 levels in children with OSAS compared with controls revealed that only the MD of plasma IL-6 levels was significant (MD = 0.84 pg/ml, P = 0.004). Results of the meta-regression showed that greater age was associated with higher serum IL-6 levels. Egger's test revealed a publication bias across the studies for serum and plasma IL-6 levels (P = 0.00044 and P = 0.01445, respectively). In summary, the meta-analysis and meta-regression confirmed that, compared to healthy controls, individuals with OSAS (children and adults) had higher serum/plasma IL-6 levels.

Serum and Plasma Tumor Necrosis Factor Alpha Levels in Individuals with Obstructive Sleep Apnea Syndrome: A Meta-Analysis and Meta-Regression.

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is associated with a variety of inflammatory factors. Specifically, proinflammatory cytokines appear to be associated with the pathogenesis of OSAS. METHODS: For the present meta-analysis and meta-regression on serum and plasma tumor necrosis factor alpha (TNF-α) levels in individuals with and without OSAS, we performed a systematic search without any restrictions of the PubMed/Medline, Scopus, Cochrane Library, and Web of Science databases to find relevant articles published up to February 1, 2020. RESULTS: Fifty-five (adults: 29 studies on serum and 17 studies on plasma; children: 4 studies on serum and 5 studies on plasma) were included and analyzed. Always compared to age-matched healthy controls, the pooled MDs were as follows: adults, serum: 10.22 pg/mL (95% CI = 8.86, 11.58; p < 0.00001); adults, plasma: 5.90 pg/mL (95% CI = 4.00, 7.80; p < 0.00001); children, serum: 0.21 pg/mL (95% CI = 0.05, 0.37; p = 0.01); children, plasma: 5.90 pg/mL (95% CI = 4.00, 7.80; p < 0.00001). CONCLUSIONS: Compared to healthy and age-matched controls, adult individuals with OSAS had significantly higher serum/plasma TNF-α levels. For children with OSAS, significantly higher levels were observed for TNF-α in serum but not in plasma.

Patterns of Mandibular Third Molar Impaction in an Iranian Subpopulation

Abstract Objective: To assess the patterns of mandibular third molar impaction in an Iranian subpopulation. Material and Methods: This retrospective descriptive study evaluated 1000 panoramic radiographs retrieved from the archives of a private radiology clinic in Kermanshah city, Iran. Depth of impaction, position of impacted mandibular third molar relative to the mandibular ramus according to Pell and Gregory's classification and angle of impacted tooth according to Winter's classification were determined. Data were analyzed using the Chi-square and Wilcoxon tests. Results: Of 1000 radiographs, 230 (23%) showed an impaction of at least one mandibular third molar. Mandibular third molar impaction was more common in females (60%). Mesioangular (35.9%) and vertical (34.8%) impactions were the most common angles of impaction in the right and left sides, respectively. Level C (40.3%) and Class I (63.7%) were the most common types of impaction in terms of depth of impaction and position relative to ramus, respectively. No significant difference was observed between the right and left sides of the mandible in terms of patterns of mandibular third molar impaction (p>0.05). Conclusion: Mandibular third molar impaction was relatively common in the studied population. The mesioangular, level C and Class I impaction patterns were the most frequent.

Effect of Experience in Landmark Identification on 2D Lateral Cephalograms on Performance of Dental Students Concerning Landmark Identification on 3D Cone Beam Computed Tomography Scans

Abstract Objective: To assess the effect of experience in landmark identification on two-dimensional (2D) lateral cephalograms on performance of dental students concerning landmark identification on three-dimensional (3D) cone-beam computed tomography (CBCT) scans. Material and Methods: This quasi-experimental study evaluated 40 dental students in two groups (n=20). Group 1 included senior dental students who had experience in landmark identification on 2D lateral cephalograms and Group 2 included third-year dental students with no such experience. Both groups received instructions on identification of eight landmarks on 3D CBCT scans. The coordinates of the landmarks were determined in x, y and z axes. One orthodontist determined the mean coordinates of each landmark as a reference by twice measurements with a one-week interval. The mean distance from the identified points to the reference points was reported as the mean consistency (MC), and the standard deviation of the mean was considered as precision of landmark identification. Data were analyzed using independent samples t-test. Results: The mean distances from the points identified as nasion, point B, orbitale, anterior nasal spine (ANS), menton, coronoid process and pogonion in x, y and z axes and point A in x and z axes (p<0.001) to the reference points in Group 1 were greater than those in Group 2 with no such experience. Conclusion: Previous experience in landmark identification on 2D cephalograms does not help in landmark identification on 3D CBCT scans and may even adversely affect the results.

Oral health related quality of life of patients with class III skeletal malocclusion before and after orthognathic surgery.

BACKGROUND: Orthognathic surgery includes improvement of morphology and function of occlusion as well as psychological perception and oral health-related quality of life (OHRQoL) of patients. The aim of this study was to determine the OHRQoL of patients with class III skeletal malocclusion before and after orthognathic surgery. MATERIALS AND METHODS: A total of 112 skeletal class III patients including 39 (34.8%) males and 73 (65.2%) females participated in this descriptive quasi-experimental study in three groups: "prior to orthodontic treatment" (n = 25); "under orthodontic treatment and prior to surgery" (n = 65), and "after surgery" (n = 25). All patients filled out a demographic information questionnaire, the oral health impact profile-14 (OHIP-14), and the orthognathic quality of life questionnaire (OQLQ) under the supervision of the examiner. Data were analyzed using ANOVA, independent samples t-test, Mann Whitney test, and Kruskal-Wallis test. RESULTS: OHRQoL summary score changed from 14.5 prior to orthodontic treatment to 23.4 prior to surgery and during orthodontic treatment to 5.4 after surgery. These OHRQoL changes were statistically significant (P < 0.001). CONCLUSIONS: Orthognathic surgery matters to patients with class III skeletal malocclusion and significantly improves their OHRQoL.

Association between cystathionine beta-synthase c.844ins68 polymorphism and risk of non-syndromic cleft lip/palate: A meta-analysis of family-based and case-control studies.

OBJECTIVE: Both genetics and environmental factors play a role in the occurrence of non-syndromic cleft lip/palate (NSCL/P). This meta-analysis evaluated the association between cystathionine beta-synthase (CBS) c.844ins68 polymorphism and risk of NSCL/P in family-based and case-control studies. MATERIALS AND METHODS: The PubMed, Web of Science, Scopus, and Cochrane Library databases were searched for articles published until September 2018. RevMan 5.3 software was used to calculate the odds ratio (OR) for the association between CBS c.844ins68 polymorphism and risk of NSCL/P by using five genetic models in the studies. The transmission disequilibrium test (TDT) was conducted for family-based studies. RESULTS: Three case-control and three family-based studies were evaluated. Based on the analysis of five genetic models, risk of NSCL/P was not related to CBS c.844ins68 polymorphism in case-control studies. The results of family-based studies did not show any association between the CBS c.844ins68 allele and NSCL/P either. CONCLUSIONS: The results of this meta-analysis showed that there was no association between CBS c.844ins68 polymorphism and risk of NSCL/P; therefore, this polymorphism does not play a role in susceptibility to NSCL/P.

Polymorphic Variants of V-Maf Musculoaponeurotic Fibrosarcoma Oncogene Homolog B (rs13041247 and rs11696257) and Risk of Non-Syndromic Cleft Lip/Palate: Systematic Review and Meta-Analysis.

Background: Non-syndromic cleft lip/palate (NSCL/P) has an etiology, including both genetic and environmental factors. Herein, we evaluated the association of rs13041247 and rs11696257 v-maf musculoaponeurotic fibrosarcoma oncogene homolog B (MAFB) polymorphisms with the risk of NSCL/P in a meta-analysis. Methods: The PubMed/Medline, Scopus, Cochrane Library, Web of Science, and HuGE Navigator databases were systematically searched to retrieve relevant articles published up to January 2019. The Newcastle-Ottawa scale was applied for quality evaluation of retrieved articles. The 95% confidence interval (CI) and crude odds ratio (OR) were calculated for each study using the Review Manager 5.3 software to show the association between MAFB polymorphisms and risk of NSCL/P. The comprehensive meta-analysis 2.0 software was used to calculate the publication bias. In addition, sensitivity analysis was carried out to show the stability of results. Results: Of 102 articles retrieved from the databases, 10 articles were analyzed in this meta-analysis. Ten articles, including eleven studies reporting rs13041247 MAFB polymorphism, included 3082 NSCL/P patients and 4104 controls. Three studies that reported rs11696257 MAFB polymorphism involved 845 NSCL/P patients and 927 controls. The rs11696257 MAFB polymorphism was not associated with the risk of NSCL/P, but the CC and TC genotypes of rs13041247 polymorphism were associated with the risk of NSCL/P. Nevertheless, the C allele and CC and TC genotypes were associated with a significant decline in the risk of NSCL/P in population-based studies. Conclusions: The results of this meta-analysis demonstrated that the risk of NSCL/P was related to rs13041247 polymorphism, not rs11696257 MAFB polymorphism. Well-designed studies are required to assess the interaction of MAFB and other genes with environmental factors in different ethnic groups.

Assessment of hair nickel and chromium levels in patients with a fixed orthodontic appliance: a systematic review and meta-analysis of case-control studies.

INTRODUCTION: The metals nickel (Ni) and chromium (Cr) can cause immunological sensitivity and adverse biological and cytotoxic effects. AIM: To evaluate hair levels of these metals in patients undergoing fixed orthodontic treatment compared with controls. MATERIAL AND METHODS: Five databases - PubMed, Web of Science, Scopus, Cochrane Library, and ScienceDirect - were searched up to January 2018 for evaluation of the hair levels of nickel and/or chromium in patients undergoing fixed orthodontic treatment. To assess the study quality, the Newcastle-Ottawa Scale was used (NOS), and to compare hair Ni and Cr levels in the cases compared with the controls, a random-effects meta-analysis was performed by Review Manager 5.3 using standard mean differences (SMDs) and 95% confidence intervals (CIs). RESULTS: Out of 38 studies in the databases searched, 6 studies were included in the meta-analysis. The pooled SMD of hair Ni levels between the cases and controls was 0.95 µg/g (95% CI: -0.09, 1.99; p = 0.07), which showed that the Ni level was similar in the cases compared with the controls, and that for hair Cr levels was 0.88 µg/g (95% CI: -0.45, 2.21; p = 0.20), so the Cr level was similar in the cases compared with the controls. CONCLUSIONS: The slightly elevated hair levels of Ni and Cr in patients undergoing fixed orthodontic treatment suggest that changing the components of fixed orthodontic appliances can be considered as an acceptable solution in the future.

Evaluation of Serum and Salivary Interleukin-6 and Interleukin-8 Levels in Oral Squamous Cell Carcinoma Patients: Systematic Review and Meta-Analysis.

This meta-analysis aimed to assess the salivary and serum concentrations of IL-6 and IL-8 in oral squamous cell carcinoma (OSCC) patients compared to the controls. Four electronic databases (Scopus, PubMed, Cochrane Library, and Web of Science) were searched up to January 2019. The study quality was checked according to the Newcastle-Ottawa Scale. The mean difference (MD) plus 95% confidence interval (95%CI) were calculated using RevMan 5.3 software. The publication bias and sensitivity analysis were done using CMA 2.0 software. Out of 309 studies retrieved from the 4 databases, 26 studies were analyzed in the present meta-analysis. In this meta-analysis, the pooled MD in the OSCC patients compared to the controls was 19.06 pg/mL (95%CI: 14.78-23.33) for the serum IL-6 level, 199.14 pg/mL (95%CI: 47.39-350.89) for the serum IL-8 level, 122 pg/mL (95%CI: 64-179) for the salivary IL-6 level, and 958 pg/dL (95%CI: 718-1197) for the salivary IL-8 level. All values in this meta-analysis were statistically significant. In conclusion, according to the meta-analysis results, the serum and salivary IL-6 and IL-8 levels in OSCC patients were significantly elevated compared to the controls, and both cytokines can be useful as potential biomarkers in early OSCC diagnosis.

Serum and salivary interleukin-4 levels in patients with oral lichen planus: A systematic review and meta-analysis.

OBJECTIVE: Cytokines have an important role in keratinocyte immune damage and can act in the pathogenesis of different cutaneous diseases. Accordingly, in the literature, interleukin 4 (IL-4) concentration has been previously investigated in patients affected by oral lichen planus (OLP). STUDY DESIGN: The present meta-analysis evaluated the serum and salivary levels of IL-4 in connection with several OLP variants. The search was performed from 1995 in Cochrane Library and 1983 in Scopus, PubMed, and Web of Science to September 2018. The quality of the studies included in the meta-analysis was assessed using the Newcastle-Ottawa Scale assessment. The analyses were done by Review Manager 5.3 using mean difference (MD) and 95% confidence intervals (CIs). RESULTS: Out of 108 studies retrieved in the databases, only 10 were included and analyzed in quantitative synthesis. The pooled MD of the serum and salivary IL-4 levels in OLP patients compared with the controls was 6.36 picograms/milliliter (pg/mL) (95% CI: 1.47, 11.24; P = .01) and 2.67 pg/mL (95% CI: 2.66, 2.68; P < .00001), respectively. In addition, the pooled MD of serum and salivary IL-4 level was 1.30 pg/mL (95% CI: -0.35, 2.95; P = .12) and 1.83 pg/mL (95% CI: 0.26, 3.40; P = .02), respectively, in patients with erosive, erythematous, bullous, and ulcerative variants of OLP compared with patients with reticular OLP. CONCLUSIONS: This meta-analysis found that OLP patients present elevated serum and salivary IL-4 levels, thus indicating that IL-4 may represent a potential salivary biomarker for the disease. By contrast, clinicians must be aware that even other factors (e.g., secondary infection) may influence its concentration.

Effect of Fixed Orthodontic Treatment on Salivary Nickel and Chromium Levels: A Systematic Review and Meta-Analysis of Observational Studies.

Nickel and chromium ions released from fixed orthodontic appliances may act as allergens. This study aimed to systematically review the effect of fixed orthodontic treatment on salivary levels of these ions by doing a meta-analysis on cross-sectional and cohort studies. The Web of Science, Scopus, Cochrane Library, and PubMed databases were searched for articles on salivary profile of nickel or chromium in patients under fixed orthodontic treatment published from January 1983 to October 2017. A random-effect meta-analysis was done using Review Manager 5.3 to calculate mean difference (MD) and 95% confidence interval (CI), and the quality of questionnaire was evaluated by the Newcastle⁻Ottawa scale. Fourteen studies were included and analyzed in this meta-analysis. Salivary nickel level was higher in periods of 10 min or less (MD = -11.5 µg/L, 95% CI = -16.92 to -6.07; P < 0.0001) and one day (MD = -1.38 µg/L, 95% CI = -1.97 to -0.80; P < 0.00001) after initiation of treatment compared to baseline (before the insertion of appliance). Salivary chromium level was higher in periods of one day (MD = -6.25 µg/L, 95% CI = -12.00 to -0.49; P = 0.03) and one week (MD = -2.07 µg/L, 95% CI = -3.88 to -0.26; P = 0.03) after the initiation of treatment compared to baseline. Corrosion of fixed orthodontic appliances leads to elevated salivary nickel and chromium concentrations early after initiation of orthodontic treatment. Randomized clinical trials controlling for factors affecting the saliva composition are recommended on a higher number of patients and among different ethnicities.

Applying the Taguchi Method to the Optimization of Anticancer Activity of Bacterial Alginate-CuO Bionanocomposite.

AIM: In recent decades, despite various types of cancer inflicting many people worldwide, the existing therapies are not satisfactory and have many side effects. The present study was conducted to optimise the synthesis of novel alginate-CuO nanocomposite with utmost anticancer activity. METHODS: In this study, 9 nanocomposites were designed using Taguchi method and three factors including copper oxide nanoparticles, alginate biopolymer and stirring times were assessed at three different levels. The anticancer activity of the synthesised nanocomposites was evaluated on the MCF-7 cell line using the MTT method. Using the Qulitek-4 software, we determined the optimum conditions for the synthesis of alginate-CuO nanocomposite with the highest anticancer activity. RESULTS: The results indicated that all three factors (copper oxide, alginate and stirring time) were effective on the anticancer activity of the alginate-CuO nanocomposite. Also, the nanocomposite produced under the conditions of experiment 9 (8 mg/ml of copper oxide, 2 mg/ml of alginate and 60 min of stirring time) provided the highest growth inhibition rate as 75.63% against cancer cells. CONCLUSION: The synthesised alginate-copper oxide nanocomposites in this study showed a significant anticancer effect. Therefore, the synthesised nanocomposite under optimal conditions can be used in the design of new anticancer drugs.

Evaluation of serum and salivary interferon-γ levels in patients with oral lichen planus: a systematic review and meta-analysis of case-control studies.

OBJECTIVE: Cytokines have regulatory and leading roles in the immunopathogenesis of oral lichen planus (OLP). Here, we present the findings of a meta-analysis that evaluated serum and salivary interferon-γ (IFN-γ) levels in patients with OLP compared with those in controls and the correlation of this cytokine with the progression of OLP. STUDY DESIGN: Four databases-PubMed, Web of Science, Scopus, and Cochrane Library-were searched, from their start dates to November 2017, for reports in all languages on the effect of OLP on salivary and serum IFN-γ. RESULTS: Eleven studies were included and analyzed in this meta-analysis. The pooled mean difference (MD) values were estimated to be 3.60 pg/mL (P = .23) and -0.02 pg/mL (P = 1.00) for serum and salivary levels of IFN-γ, respectively, in the patients with OLP compared with controls. The pooled MD values were -2.52 pg/mL (P = .03) and -2.01 pg/mL (P = .20) for serum and salivary IFN-γ levels in the erosive type, respectively, compared with the nonerosive type. CONCLUSIONS: According to the results of meta-analysis, there was no statistically significant differences in IFN-γ levels between the OLP group and the control group both in serum and salivary levels and also between erosive and nonerosive types of OLP at the salivary level; so this cytokine is not considered to have an important role in the pathogenesis or severity of OLP.

Esthetic preferences of orthodontists, oral surgeons, and laypersons for Persian facial profiles.

INTRODUCTION: The patient's perception of facial esthetics is not necessarily consistent with that of the practitioner. The aim of this study was to compare the perceptions of Persian orthodontists, oral surgeons, and laypersons with regard to facial profile attractiveness and the most favorable mandibular position. METHODS: Software (Dolphin Imaging and Management Systems, Chatsworth, Calif) was used to alter the mandibular position depicted on profile photographs of a young man and a young woman. Nine construction profile photos were produced with incremental changes of the G'-Sn-Pg' angle at 2° intervals (6° to 22°). Thirty-two orthodontists, 32 maxillofacial surgeons, and 32 laypersons were asked to score all 18 profiles on a 1-to-10 visual analog scale. They also evaluated whether each profile needed orthognathic surgery for improvement of facial esthetics. Actual agreement and intraclass correlation coefficient tests were used to assess reliability. The data were analyzed using 2-way repeated measures analysis of variance and Wilcoxon signed-rank tests. RESULTS: The intraparticipant reliability was acceptable (intraclass correlation coefficient >72%; actual agreement, >79%). The sex of the participants was not a significant factor influencing the scores, although the sex of the models was a discriminating factor for the most acceptable mandibular horizontal position. The scores given by the 3 groups were different, especially for the female model. The orthodontists had similar opinions and preferred a slightly more protrusive mandible (G'-Sn-Pg', 12°-14°). Laypersons' scores were the most inconsistent, and they generally preferred a retrusive profile (G'-Sn-Pg', 14°-18°). There was no significant correlation with regard to the necessity of orthognathic surgery for G'-Sn-Pg' angles over 20° in men and below 8° in women. CONCLUSIONS: Although the laypersons' perceptions were slightly different from those of the clinicians, most participants preferred a more protrusive mandible for male models compared with female models.