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.

Optimal gingival display on smiling based on different facial vertical patterns in Iranians.

INTRODUCTION: This study aimed to determine the optimal gingival display on smiling on the basis of different facial vertical patterns in Iranians from the perspective of laypeople, maxillofacial surgeons, and orthodontists. METHODS: Photographs were obtained from short-faced, normal-faced, and long-faced males and females (1 male and 1 female from each group) aged 18-30 years. The original photographs were then modified to have 6, 4, 2, 0, -2, -4, and -6 mm gingival display. Three groups of raters (n = 40), including laypeople, orthodontists, and maxillofacial surgeons, were requested to score each photograph regarding smile attractiveness using a 5-point Likert scale. Data were analyzed using analysis of variance and the Kruskal-Wallis test. RESULTS: Regarding the photographs of the normal-faced female model, all 3 rater groups gave the highest score to a 2 gingival display. In the normal-faced male model, all 3 rater groups gave the highest and lowest scores to 0 and 6 mm gingival display, respectively. In the long-faced female model, all 3 rater groups gave the same score to 0, 4, and 6 gingival display. In the long-faced male model, the 3 rater groups gave the same score to 0, 2, 4, and 6 gingival display. In the short-faced female model, all 3 rater groups gave the highest score to 0 gingival display. In the short-faced male model, the 3 rater groups gave the same score to all values of gingival display except -4 mm. CONCLUSIONS: The laypeople, maxillofacial surgeons, and orthodontists all gave the highest score to the photograph of a short-faced Iranian female model with 0 gingival display.

Association of Blood MCP-1 Levels with Risk of Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis.

Background and objective: Among the broad variety of chemokines, monocyte chemoattractant protein-1 (MCP-1) is considered to be one of the most important chemokines. Among others, MCP-1 activates monocytes and other immune cells highly involved in inflammation. In the present systematic review and meta-analysis, we evaluated the relationship between serum/plasma MCP-1 levels and the risk of obstructive sleep apnea (OSA) in adults as a disease related to inflammation. Materials and methods: Four databases were systematically investigated until 12 July 2022. We used the Review Manager 5.3 software (Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark) to extract and calculate the standardized mean difference (SMD) and its 95% confidence interval (CI) of plasma/serum levels of MCP-1 between adults with and without OSA. Results: Eight articles including eleven studies in adults were entered into the meta-analysis. The serum/plasma MCP-1 levels in adults with OSA were higher than that in the controls (SMD = 0.81; p = 0.0007) and as well as for adults with severe OSA compared to those with mild and moderate OSA (SMD = 0.42; p < 0.0001). The subgroup analysis showed that ethnicity was an effective factor in the pooled analysis of blood MCP-1 levels in adults with OSA compared to the controls (Asians: (p < 0.0001), mixed ethnicity: (p = 0.04), and Caucasians: (p = 0.89)). The meta-regression showed increasing serum/plasma MCP-1 levels in adults with OSA versus the controls, publication year, age of controls, body mass index (BMI) of controls, and sample size reduced, and also BMI and the apnea−hypopnea index of adults with OSA increased. Conclusions: The meta-analysis showed that compared to the controls, serum/plasma levels of MCP-1 in adults with OSA were significantly more, as well as adults with severe OSA having more serum/plasma MCP-1 levels compared to the adults with mild to moderate OSA. Therefore, MCP-1 can be used as a diagnostic and therapeutic factor in adults with OSA.

Evaluation of Blood Intercellular Adhesion Molecule-1 (ICAM-1) Level in Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis.

Background and objective: Intercellular adhesion molecule-1 (ICAM-1) appears to be an active and important biomarker for decreasing the risk of cardiovascular issues among individuals with obstructive sleep apnea (OSA). Herein, a systematic review and meta-analysis was designed to probe whether plasma/serum ICAM-1levels are different in adults with OSA compared to adults with no OSA, as well as adults with severe OSA compared to adults with mild/moderate OSA. Materials and methods: A thorough and systematic literature search was performed in four databases (PubMed/Medline, Web of Science, Scopus, and Cochrane Library) until 17 July 2022, without any age and sample size restrictions to retrieve the relevant articles. The standardized mean difference (SMD) along with a 95% confidence interval (CI) of plasma/serum of ICAM-1 levels was reported. Analyses, including sensitivity analysis, subgroup analysis, trial sequential analysis, meta-regression, and a funnel plot analysis, were performed in the pooled analysis. Results: A total of 414 records were identified in the databases, and 17 articles including 22 studies were entered into the meta-analysis. The pooled SMD of serum/plasma ICAM-1 levels in adults with OSA compared to controls was 2.00 (95%CI: 1.41, 2.59; p < 0.00001). The pooled SMD of serum/plasma ICAM-1 levels in adults with severe compared to mild/moderate OSA was 3.62 (95%CI: 1.74, 5.51; p = 0.0002). Higher serum/plasma ICAM-1 levels were associated with a higher mean age of controls, higher scores for the apnea-hypopnea index, and with a lower mean age of adults with OSA and with smaller sample sizes. Conclusions: Th results of the present meta-analysis showed that serum/plasma ICAM-1 levels in adults with OSA was higher than serum/plasma ICAM-1 levels in controls. Similarly, serum/plasma ICAM-1 levels in adults with severe OSA were higher compared to serum/plasma ICAM-1 levels of adults with mild or moderate OSA. Therefore, ICAM-1 may be used as an additional diagnostic and therapeutic biomarker in adults with OSA.

Parent's Experiences During Orthodontic Treatment of Their Children With Cleft Lip and Palate: Phenomenological Study.

OBJECTIVES: Cleft lip and palate (CLP) is a congenital anomaly that affects not only the patients but also their family members and companions. Identifying the problems encountered by patients with CLP and their families can greatly help clinicians in efficient treatment planning to obviate the treatment needs and promote the quality of life of patients. This study aimed to determine the experiences of the parents of children with CLP undergoing orthodontic treatment. METHODS: This study was conducted based on descriptive phenomenology using the Colaizzi's 7-step analysis method of phenomenological data. The private orthodontic clinics of Kermanshah city were evaluated in this study. The participants included the parents of children with CLP younger than 15 years who had presented to the clinics seeking orthodontic treatment. In-depth semistructured interviews with open-ended questions were used to collect information regarding the experiences of parents in this process. The collected data were analyzed using the Colaizzi's 7-step analysis. RESULTS: Qualitative analysis of the interviews yielded 271 codes, 18 subthemes, 7 themes, and 3 main themes including fatigue (exhaustion, helplessness, and incompetence), self-reliance (mutual support and empathy), and the need for social support (counseling services and citizenship rights). CONCLUSION: In general, the results revealed that parents of children with CLP under orthodontic treatment are vulnerable due to their previous adverse experiences in the course of treatment of their children and need support in several physical, psychological, social and spiritual domains.

Tooth alignment and pain experience with A-NiTi versus Cu-NiTi: a randomized clinical trial.

BACKGROUND: Nickel-titanium (NiTi) archwires are routinely used for initial leveling and alignment of teeth in orthodontic treatment. This study aimed to clinically compare the level of pain and tooth alignment in orthodontic treatment with A-NiTi versus Cu-NiTi archwires. METHODS: In this parallel randomized clinical trial, 88 orthodontic patients (12-25 years) with an irregularity index > 2 mm in the anterior site of the lower dental arch who required non-extraction orthodontic treatment of the lower arch were randomized into two age- and sex-matched groups (n = 44) for treatment with A-NiTi and Cu-NiTi initial archwires. Each archwire was used for 6 weeks. After 6 weeks, the irregularity index was measured, and the level of pain was scored using the Modified McGill pain questionnaire (MPQ) and visual analog scale (VAS) according to the time of onset and duration of pain, and analgesic intake. Data were analyzed by paired t test, independent samples t test, and Chi-square test (P < 0.05). RESULTS: The irregularity index significantly decreased in both groups after 6 weeks of treatment (P < 0.001). However, the difference in this respect was not significant between the two groups (P > 0.05). Pain perception (P = 0.487), duration of pain (P = 0.546), and analgesic intake (P = 0.102) were not significantly different between the two groups either. CONCLUSION: Both A-NiTi and Cu-NiTi archwires are equally effective for tooth alignment in the anterior site of the lower dental arch and have no significant difference with regard to the level of pain experienced by patients. TRIAL REGISTRATION NUMBER: IRCT20190705044102N1 and Name of the registry: Iranian registry of clinical trials (https://irct.ir/) Date of registration: September, 26, 2019.

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.

The effect of obstructive sleep apnea syndrome on serum S100B and NSE levels: a systematic review and meta-analysis of observational studies.

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is a common disorder that is accompanied by structural brain changes. This meta-analysis aimed to evaluate the effect of OSAS on the serum levels of astrocytic protein (S100B) and neuron-specific enolase (NSE) in observational studies. METHODS: A comprehensive search was performed in the PubMed/Medline, Web of Science, Scopus, ScienceDirect, and Cochrane Library databases to assess the serum level of S100B and/or NSE in patients with OSAS and/or controls. The quality of the study was evaluated by the Newcastle-Ottawa Scale (NOS). A random-effects model was performed using RevMan 5.3 with the mean difference (MD) and 95% confidence intervals (CIs). RESULTS: Out of 63 studies found in the mentioned databases and one identified by a manual search, nine studies were included and analyzed in this meta-analysis (three cross-sectional and six case-control studies). The analysis showed that the S100B [MD = 53.58 pg/ml, 95%CI: 1.81, 105.35; P = 0.04] and NSE levels [MD = 3.78 ng/ml, 95%CI: 2.07, 5.48; P < 0.0001] were significantly higher in patients than the controls. However, there were no significant differences between the S100B [MD = -28.00 pg/ml, 95%CI: - 79.48, 23.47; P = 0.29] and NSE levels [MD = 0.49 ng/ml, 95%CI: - 0.82, 1.80; P = 0.46]. CONCLUSIONS: This meta-analysis found elevated serum S100B and NSE levels in OSAS patients compared to the controls, which suggests that these markers may be used as peripheral indicators of brain damage in OSAS.

Efficacy of smartphone-based Mobile learning versus lecture-based learning for instruction of Cephalometric landmark identification.

BACKGROUND: Considering the increasing popularity of electronic learning, particularly smartphone-based mobile learning, and its reportedly optimal efficacy for instruction of complicated topics, this study aimed to compare the efficacy of smartphone-based mobile learning versus lecture-based learning for instruction of cephalometric landmark identification. METHODS: This quasi-experimental interventional study evaluated 53 dental students (4th year) in two groups of intervention (n = 27; smartphone instruction using an application) and control (n = 26, traditional lecture-based instruction). Two weeks after the instructions, dental students were asked to identify four landmarks namely the posterior nasal spine (PNS), orbitale (Or), articulare (Ar) and gonion (Go) on lateral cephalograms. The mean coordinates of each landmark identified by orthodontists served as the reference point, and the mean distance from each identified point to the reference point was reported as the mean consistency while the standard deviation of this mean was reported as the precision of measurement. Data were analyzed using SPSS version 18 via independent sample t-test. RESULTS: No significant difference was noted between the two groups in identification of PNS, Ar or Go (P > 0.05). However, the mean error rate in identification of Or was significantly lower in smartphone group compared with the traditional learning group (P = 0.020). CONCLUSIONS: Smartphone-based mobile learning had a comparable, and even slightly superior, efficacy to lecture-based learning for instruction of cephalometric landmark identification, and may be considered, at least as an adjunct, to enhance the instruction of complicated topics. TRIAL REGISTRATION NUMBER: This is not a human subject research. https://ethics. RESEARCH: ac.ir/ProposalCertificateEn.php?id=33714&Print=true&NoPrintHeader=true&NoPrintFooter=true&NoPrintPageBorder=true&LetterPrint=true .

Smile attractiveness of Persian women after orthodontic treatment.

INTRODUCTION: Achieving a balanced, attractive smile is an important goal in contemporary orthodontics. This study aimed to assess the smile attractiveness of Persian women after orthodontic treatment. METHODS: In this descriptive-analytical study, frontal-view photographs were taken of posed smiles of 100 Persian women 3 months after completion of their orthodontic treatment. A total of 153 laypeople aged over 15 years were requested to score each smile in terms of attractiveness using a visual analogue scale (1-10). Next, 25 photographs that acquired the lowest score (group A) and 25 photographs that acquired the highest score (group B) were chosen and evaluated by 3 orthodontists regarding parameters related to an attractive smile. Data were analyzed using SPSS version 18. RESULTS: The mean buccal corridor space in group A was significantly greater than that in group B (P = 0.004). The correlation of lip line and study group was significant such that 60% of patients in group B had a moderate lip line (P = 0.005). The difference in other parameters was not significant between the 2 groups (P >0.05). CONCLUSIONS: The buccal corridor space and lip line are important factors affecting smile attractiveness of Persian women. According to the opinion of the laypeople, smaller buccal corridor space and moderate lip line yield a more attractive smile. Thus, these parameters should be taken into account in the orthodontic treatment of Persian women.

Association of LTF, ENAM, and AMELX polymorphisms with dental caries susceptibility: a meta-analysis.

BACKGROUND: This meta-analysis evaluated the association of LTF, ENAM, and AMELX polymorphisms with dental caries susceptibility. METHODS: We searched the Scopus, PubMed/Medline, Web of Science, and Cochrane Library databases to retrieve articles published by October 2019. Review Manager 5.3 software was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs). The results of publication bias tests were retrieved by Comprehensive Meta-Analysis 2.0 software. RESULTS: A total of 150 relevant records were identified; out of which, 16 were entered into the analysis (4 studies assessed LTF, 11 ENAM, and 11 AMELX polymorphisms). Of all polymorphisms, there was a significant association only between ENAM rs3796704 polymorphism and dental caries susceptibility. Both ENAM rs3796704 and AMELX rs17878486 polymorphisms had a significant association with dental caries risk in the Caucasian ethnicity and the studies including caries-free control group. CONCLUSIONS: The results of this meta-analysis showed that the G allele and the GG genotype of ENAM rs3796704 were associated with an increased risk of caries in the case group compared with the control group. But there was no association between LTF rs1126478, ENAM (rs1264848 and rs3796703), and AMELX (rs946252, rs17878486, and rs2106416) polymorphisms and dental caries susceptibility.

Effect of virtual versus traditional education on theoretical knowledge and reporting skills of dental students in radiographic interpretation of bony lesions of the jaw.

BACKGROUND: This study aimed to compare the effect of virtual and traditional education on theoretical knowledge and reporting skills of dental students in radiographic interpretation of bony lesions of the jaw. METHODS: This experimental study evaluated 39 dental students who had not received any instruction regarding radiographic interpretation of bony lesions of the jaw. They were randomly divided into two groups of virtual (n = 20) and traditional education (n = 19) and matched in terms of their grade point average (GPA). The virtual group received a virtual learning package while the traditional group received traditional classroom instruction for 6 one-hour sessions. Similar contents were taught to both groups by the same mentor. All students participated in a theoretical test with multiple-choice questions and an objective structured clinical examination (OSCE). Similar exams were also held 2 months later to assess knowledge retention. Data were analyzed using independent sample t-test and repeated measures ANOVA. RESULTS: The mean scores of theoretical test (P < 0.05) and OSCE (P > 0.05) in the virtual education group (16.60 ± 0.91 and 15.13 ± 0.78) were higher than those in the traditional education group (14.89 ± 0.99 and 14.71 ± 0.92). In both methods of instruction, the mean scores of theoretical test and OSCE at 2 months were lower than the scores acquired immediately after instruction but this difference was not statistically significant (P > 0.05). Type of education had a significant effect on the theoretical test score (P < 0.001) but had no significant effect on the clinical score (P = 0.072). CONCLUSIONS: Virtual learning was superior to traditional lecture-based method for enhancement of knowledge acquisition in radiographic interpretation of bony lesions of the jaw. However, to improve our students' reporting skills, we need to revise our virtual educational program so that the students have more opportunities to engage in reporting skills.

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.

Salivary and Serum Interferon-Gamma/Interleukin-4 Ratio in Oral Lichen Planus Patients: A Systematic Review and Meta-Analysis.

Background and Objectives: Interferon-gamma (IFN-γ)/interleukin-4 (IL-4) ratio may indicate a change in the immune response with a potential pathological effect presented in oral lichen planus (OLP) patients. Herein, this meta-analysis evaluated the role of serum and salivary interferon-gamma/interleukin-4 ratio in the severity and development of OLP. Materials and Methods: The Scopus, Cochrane Library, PubMed, and Web of Science databases were systematically searched to retrieve the relevant studies published up from the database inception to March 2019. The crude mean difference (MD) and 95% confidence interval (CI) were calculated by RevMan 5.3 software using a random-effects model. A sensitivity analysis was performed on the results using the CMA 2.0 software. A total of 98 studies were retrieved from the databases, of which at last seven studies were included in this meta-analysis. Results: The findings showed that the pooled MDs of serum and salivary IFN-γ/IL-4 ratio were -0.22 (95% CI: -1.16, 0.72; p = 0.64) and 0.17 (95% CI: -1.50, 1.84; p = 0.84) in OLP patients compared to controls, respectively. In addition, the pooled MDs of serum and salivary IFN-γ/IL-4 ratio were -0.15 (95% CI: -0.53, 0.23; p = 0.43) and -0.39 (95% CI: -0.63, -0.15; p = 0.001) in patients with erythematous/ulcerative subtype compared to patients with reticular subtype, respectively. Conclusions: In conclusion, the results of meta-analysis demonstrated that serum and salivary IFN-γ/IL-4 ratio cannot play a major role in OLP development and severity.

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.

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.

The effect of the buccal corridor and tooth display on smile attractiveness.

AIMS: The aim of the present study was to evaluate the lay perception of the effect of the buccal corridor and amount of tooth-gingival display on the attractiveness of a smile in different facial types. MATERIALS AND METHODS: Using Adobe Photoshop CS3 software, frontal facial images of two smiling Iranian female subjects (one short-faced and one long-faced) were altered to create different magnitudes of buccal corridor display (5, 10, 15, 20 and 25%) and tooth-gingival display (2 mm central incisor show, 6 mm central incisor show, total central incisor show, total tooth show with 2 mm gingival show and total tooth show with 4 mm gingival show). Sixty Iranians (30 males and 30 females) rated the attractiveness of the pictures on a 1-5 point scale. RESULTS: Narrower smiles were preferred in long-faced subjects compared with short-faced subjects. Minimal tooth show was more attractive than excessive gingival display in short-faced subjects. There were no gender specific, statistically significant differences found in the ratings given by the lay assessors. CONCLUSIONS: Harmonious geometry of the smile and face in both the vertical and transverse dimensions influences smile attractiveness and this should be considered in orthodontic treatment planning.

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.