Does occlusal morphology of artificial teeth improve chewing of removable dentures wearers? A systematic review and meta-analysis.

PURPOSE: This systematic review aimed to verify whether anatomic, semi-anatomic, or nonanatomic occlusal morphology of artificial teeth improves the masticatory function of complete or removable partial denture wearers. MATERIALS AND METHODS: According to the PICO strategy, six databases and the grey literature were searched to identify randomized (RCT) and non-randomized clinical trials (N-RCT) comparing masticatory function, in terms of masticatory performance and efficiency, and muscle activity as primary outcomes; and patient-reported results (O) in individuals using removable dentures (P) with different occlusal morphologies of artificial teeth (I/C). Masticatory ability, satisfaction with the prosthetic treatment, and oral health-related quality of life (OHRQoL) were evaluated as secondary outcomes. Risk of bias was assessed using the Cochrane risk-of-bias tool for randomized trials (RoB 2.0) for RCT and Risk of Bias for non-randomized studies with intervention (ROBINS-I) for N-RCT studies. Meta-analyses were performed to compare primary outcomes and masticatory ability between the occlusal morphologies of artificial teeth of complete or removable partial dentures (α = 0.05). Certainty of the evidence was verified using the GRADE approach. RESULTS: Eleven studies (seven RCTs and four N-RCTs) were included. The risk of bias was considered low for two studies, some concerns for five, and high for the last four studies. Meta-analyses showed that removable partial dentures with anatomic artificial teeth improved masticatory efficiency for carrot chewing (MD 6.31; 95% CI [3.39, 9.22], I2 = 0%). However, masseter and temporal muscle activities increased when removable partial dentures with nonanatomic teeth were used (MD -756.97; 95% CI [-892.25, -621.68], I2 = 100%). Masticatory ability was not influenced by occlusal morphology during chewing of all foods in complete denture users: Carrot (MD -0.88, 95% CI [-8.98, 7.23], I2 = 57%); sausage (MD -8.86, 95% CI [-23.05, 5.33], I2 = 71%); apple (MD -5.78, 95% CI [-28.82, 17.26], I2 = 87%); and cheese (MD -4.16, 95% CI [-15.14, 6.82], I2 = 62%). The certainty of evidence for all evaluated outcomes was very low, mainly due to very serious problems found in the parameters of inconsistency, indirectness, and imprecision. CONCLUSIONS: Despite the very low certainty of evidence, the occlusal morphology of artificial teeth influences masticatory function. Anatomic teeth improved the masticatory efficiency and muscle activity of removable partial denture wearers. Nonanatomic teeth increased temporal and masseter muscle activity, which negatively affected chewing in removable partial denture users. However, patients using complete dentures with anatomic and semi-anatomic teeth presented similar masticatory ability.

Global prevalence of human papillomavirus-related oral and oropharyngeal squamous cell carcinomas: a systematic review and meta-analysis.

OBJECTIVE: To conduct a systematic review to determine the global prevalence of HPV in oral squamous cell carcinoma (OSCC) and oropharyngeal squamous cell carcinoma (OPSCC). MATERIALS AND METHODS: Literature was searched through October 2022 in main databases to address the question "What is the global prevalence of Human Papillomavirus in oral and oropharyngeal cancer?" Studies had to identify HPV by PCR, ISH, or p16 immunohistochemistry to be eligible. Quality was assessed using the JBI checklist for prevalence studies. Meta-analyses were performed, and reporting followed PRISMA guidelines. RESULTS: Sixty-five studies were included, and most of them had methodological limitations related to sampling and the HPV detection tool. The pooled prevalence of HPV-positivity was 10% (event rate = 0.1; 95% CI: 0.07, 0.13; P < 0.01; I2 = 88%) in the oral cavity and 42% (event rate = 0.42; 95% CI: 0.36, 0.49; P = 0.02; I2 = 97%) in oropharynx. The highest HPV prevalence in OSCC was reached by Japan, meanwhile, in OPSCC, Finland and Sweden were the most prevalent. HPV16 is the genotype most frequent with 69% in OSCC and 89% in OPSCC, being the tonsils the intraoral location more affected by HPV (63%, p < 0.01, I2 76%). CONCLUSION: The evidence points to an apparent burden in HPV-related OPSCC, mostly in North America, Northern Europe, and Oceania, especially due to the HPV16 infection suggesting different trends across continents. CLINICAL RELEVANCE: This updated systematic review and meta-analysis provide sufficient evidence about the global HPV prevalence in OSCC and OPSCC and the most frequent HPV subtype worldwide.

Evaluation of tooth eruption rate of incisor teeth in rats with estrogen deficiency.

OBJECTIVES: To assess the influence of estrogen deficiency on tooth eruption rate (TER) and gene expression of estrogen receptor alpha and beta (ERα and ERß) in the odontogenic region of teeth with continuous formation in a rat model. MATERIALS AND METHODS: Ovariectomies (OVX; n = 25) and sham surgeries (SHAM; n = 25) were performed in female Wistar rats when animals were 25 days old. The TER of the lower incisors, both in impeded (hyperfunction condition) and unimpeded (trimmed incisal edge-hypofunction condition) conditions, was evaluated using standardized digital photographs acquired every 48-72 h for 3 weeks (35th-53rd day of life), using a camera coupled to a stereomicroscope. Quantitative real-time PCR was performed to evaluate the relative gene expression of ERα and ERß in the odontogenic region. RESULTS: The OVX group showed a significant reduction in TER when compared to the SHAM group, only in the impeded condition (p = 0.03). There was no statistically significant difference between the groups in ERα gene expression (p = 0.33). ERß showed a significantly higher gene expression in the OVX group (p ≤ 0.05). CONCLUSIONS: Estrogen deficiency decreases TER in teeth under impeded condition. Estrogen deficiency also increases ERß gene expression in the odontogenic region of teeth with continuous formation. CLINICAL RELEVANCE: Hormonal disturbances affecting estrogen levels can cause alterations in dental formation and teeth eruption.

Clinical performance of and patient satisfaction with conventional complete dentures with different occlusal schemes: A systematic review of systematic reviews.

STATEMENT OF PROBLEM: The complete denture occlusal scheme may influence clinical performance and patient satisfaction. However, a consensus on which occlusal scheme should be used for complete denture users is lacking. As a result, many dentists choose the scheme based on their preferences and clinical experience. PURPOSE: The purpose of this review was to assess the methodological quality and summarize the scientific evidence from secondary studies about the influence of occlusal schemes on the clinical performance of and patient satisfaction with complete dentures. MATERIAL AND METHODS: Ten sources were surveyed according to the patient, intervention, comparison, outcome (PICO) strategy. Systematic reviews that evaluated the clinical performance and patient satisfaction (O) of rehabilitated edentulous patients with conventional complete dentures (P) under different occlusal schemes (I/C) were included. Methodological quality was assessed by using A MeaSurement Tool to Assess systematic Reviews (AMSTAR) 2 tool by 2 authors independently. The effect of each occlusal scheme in comparison with others was summarized and classified as positive, neutral, negative, or inconclusive based on the conclusions of the systematic review concerning clinical performance and patient satisfaction outcomes. RESULTS: The search led to the inclusion of 10 systematic reviews. Seven were classified as of critically low, 2 as low, and 1 as moderate methodological quality. The following occlusal designs were included and analyzed: bilateral balanced occlusion, lingualized occlusion, canine guidance, group function, and monoplane occlusion. Bilateral balanced occlusion and canine guidance obtained satisfactory results for both outcomes. Lingualized occlusion showed a trend toward better results than other occlusal schemes for normal and resorbed ridges. Group function presented mainly inconclusive results, and monoplane occlusion did not deliver satisfactory outcomes. CONCLUSIONS: The present overview concluded that occlusal schemes might interfere with the clinical performance of and patient satisfaction with complete dentures. Lingualized, bilateral balanced, and canine guidance are preferred compared with monoplane occlusion, but lingualized occlusion tends to show better results in some reviews. However, the results should be carefully considered because of the low quality of the systematic reviews included.

Influence of different presentations of denture adhesives on masticatory function of complete denture wearers: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: Denture adhesives improve the mastication of complete denture wearers. However, the impact of denture adhesives with different presentations on mastication remains unclear. PURPOSE: The purpose of this systematic review was to answer the focused question, "Do different presentations of denture adhesives affect the masticatory function of complete denture wearers?". MATERIAL AND METHODS: This review was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Six databases and the non-peer-reviewed literature were searched up to July 2021. Only clinical studies (randomized clinical trials and nonrandomized clinical trials) comparing the use of different denture adhesive presentations (cream, powder, or strips) were included, without language or follow-up restrictions. The risk of bias was assessed by using the Cochrane tools (RoB 2.0 and ROBINS-I). Masticatory performance, by using single and multiple sieves, masticatory performance with color-changing chewing gum (mixing ability), swallowing threshold (particle size and number of cycles), jaw kinematics, and occlusal force were considered. Meta-analyses were conducted to evaluate masticatory performance (single sieve) and occlusal force outcomes (α=.05), and the certainty of the evidence was determined with the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) evaluations. RESULTS: Nine studies (6 randomized and 3 nonrandomized clinical trials) were included. The risk of bias was considered moderate. Meta-analyses showed no differences between cream and powder denture adhesives for masticatory performance (standard mean difference=0.02; 95% CI=-0.46 to 0.50, P=.93) or between cream and strip denture adhesives for occlusal force (mean difference=14.35; 95% CI=-11.14 to 39.84, P=.27). Similarly, in qualitative analysis, cream and powder denture adhesives' performances were similar regarding masticatory performance with color-changing chewing gum (mixing ability), occlusal force, swallowing threshold (particle size and number of cycles), and jaw kinematics (P>.05). However, for resorbed ridges, cream denture adhesive resulted in a higher masticatory performance than strip (P<.05). When comparing powder to strip denture adhesives, the occlusal force was higher in the powder group (P<.05). The certainty of evidence was very low for all evaluated outcomes. CONCLUSIONS: Different presentations of denture adhesives seem to improve the masticatory function of complete denture wearers in a similar way. However, the qualitative analysis showed that, in patients with a resorbed ridge, a cream denture adhesive may be better than strips to improve mastication, although the certainty of evidence was very low.

Is there a correlation between dental and cervical vertebrae maturation stages in growing subjects? A systematic review with meta-analysis.

OBJECTIVE: To assess the evidence on the relationship between dental and cervical vertebrae maturation. MATERIALS AND METHODS: Searches were performed (up to December 2021) in seven databases, as well as in gray literature. Studies that included growing subjects, which evaluated the correlation between the stages of tooth formation and the maturation of cervical vertebrae, were eligible. The methodological quality of the selected reports was assessed using the JBI checklist for cross-sectional studies. Random-effects meta-analyses were implemented to calculate the pooled correlation coefficients between the maturation stages of cervical vertebrae and each tooth type. The GRADE approach was followed to assess the certainty of evidence. RESULTS: Seventy-seven studies were selected. Most of them had limitations related to sampling and reliability of the methods to evaluate maturation. The syntheses evidenced positive correlations between the maturation of cervical vertebrae and the formation/calcification stages of the following lower teeth: canine (n = 7318; r = 0.692; 95% CI: 0.656-0.724), first premolar (n = 6194; r = 0.689; 95% CI: 0.649-0.725), second premolar (n = 6194; r = 0.695; 95% CI: 0.659-0.729), and second molar (n = 7905; r = 0.698; 95% CI: 0.652-0.739). All estimates were affected by the risk of bias and the presence of unexplained statistical heterogeneity. CONCLUSIONS: The evidence points to an apparent positive correlation between dental and cervical vertebrae maturation. These results need to be carefully evaluated as the body of evidence is of very low quality. CLINICAL RELEVANCE: Dental maturation might be a potential indicator of skeletal craniofacial growth status. A routine dental x-ray could be sufficient, reducing radiation exposure by requesting additional radiographs.

Effect of micro-osteoperforations on the gene expression profile of the periodontal ligament of orthodontically moved human teeth.

OBJECTIVES: This study aimed to evaluate the effect of micro-osteoperforations (MOPs) on the gene expression profile of the periodontal ligament (PDL) of orthodontically moved teeth. MATERIALS AND METHODS: Fifteen participants were randomly assigned into two groups: tooth movement only (Tr1, n = 7) and tooth movement supplemented with MOPs (Tr2, n = 8). In each subject, orthodontic tooth movement (OTM) was performed on premolar in one side, while no force was applied on contralateral premolar (Unt, n = 15). Seven days after loading, premolars were extracted for orthodontic reasons. RNA extraction from PDL and subsequent RNA-sequencing were performed. False discovery rates (Padj < 0.05) and log2 fold change (+ / - 1.5) thresholds were used to identify sets of differentially expressed genes (DEGs) among the groups. DEGs were analyzed with gene ontology enrichment, KEGG, and network analysis. RESULTS: Three hundred thirty-one DEGs were found between Tr1 and Unt, and 356 between Tr2 and Unt. Although, there were no significantly DEGs between Tr2 and Tr1, DEGs identified exclusively in Tr1 vs. Unt were different from those identified exclusively in Tr2 vs. Unt. In Tr1, genes were related to bone metabolism processes, such as osteoclast and osteoblast differentiation. In Tr2, genes were associated to inflammation processes, like inflammatory and immune responses, and cellular response to tumor necrosis factor. CONCLUSIONS: MOPs do not significantly alter the PDL gene expression profile of orthodontically moved human teeth. This study provides for the first time evidence on the whole PDL gene expression profiles associated to OTM in humans. Novel biomarkers for OTM are suggested for additional research. Clinical relevance The identified biomarkers provide new insights into the molecular mechanisms that would occur when OTM is supplemented with MOPs. These markers are expected to be useful in the near future for the application of personalized strategies related to the OTM.

Do smokers have a different gingival crevicular fluid cytokine/chemokine profile than nonsmokers in clinically healthy periodontal sites? A systematic review and meta-analysis.

OBJECTIVES: Assessing the evidence and comparing the levels of cytokines in gingival crevicular fluid (GCF) of periodontal healthy sites of smokers and nonsmokers. MATERIALS AND METHODS: Seven databases were surveyed for observational studies up to April 8, 2021. Studies comparing cytokine levels on GCF in periodontally healthy sites of smokers vs. nonsmokers were included in the study. The risk of bias was evaluated using NIH (2014) tool. For meta-analyses, levels in GCF were analyzed, followed by evidence certainty assessment using the GRADE approach. RESULTS: Eighteen studies were included for qualitative evaluation, and eight were included in meta-analysis. Qualitatively, despite high heterogeneity and risk of bias observed among the studies, most of them presented no significant difference in the gingival crevicular cytokine fluid levels between groups. Regarding meta-analyses, interleukin-8 (IL-8) and superoxide dismutase (SOD) levels in GCF were analyzed. The significant difference was observed only in SOD levels, where heavy smokers had lower levels compared to nonsmokers (MD - 30.06 [- 40.17, - 19.96], p = 0.07, 95%CI), as well as light smokers had lower levels compared to nonsmokers (MD - 15.22 [- 16.05, - 14.39], p < 0.00001, 95%CI). CONCLUSION: No distinct GCF cytokine profiles were detected for smokers and non-smokers. However, despite the limitations observed in the included studies, lower levels of SOD were identified in smokers. CLINICAL RELEVANCE: Indicating a distinct GCF profile of cytokines in periodontal healthy smokers may help to understand the mechanism whereby smoking may affect the host response.

Palatal coverage and oral stereognosis: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: Complete denture wearers present with less sensory function than dentate individuals because of the loss of periodontal receptors. However, the role of the palatal receptors on such function is still unclear. PURPOSE: The purpose of this systematic review and meta-analysis was to evaluate the influence of palatal coverage associated with complete dentures or palatal devices on oral stereognosis in edentulous or dentate adults. MATERIAL AND METHODS: Eight major literature databases and the nonpeer-reviewed literature were searched up to December of 2021. Randomized clinical trials and nonrandomized clinical trials comparing oral stereognosis in edentulous or dentate participants using conventional complete dentures or implant-supported prostheses or those using palatal devices were included. Bias was assessed with Cochrane tools (ROBINS-I and RoB 2.0). Meta-analyses were conducted to compare oral stereognosis before and after palatal coverage (α=.05). Certainty of the evidence was verified using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. RESULTS: Of 14 included studies, the risk of bias was considered low for 9 studies and moderate for 5 studies. Despite the very low certainty of evidence, meta-analyses showed no differences in oral stereognosis immediately after complete denture insertion (standardized mean difference [SMD]=0.302; 95% confidence interval [CI]: -0.124, 0.728; P=.165; I2=92.4%). Oral stereognosis scores improved after ≥1 month of complete denture use compared with initial evaluations without them. Qualitative analysis indicated that oral stereognosis was not influenced by palatal coverage shortly after complete denture installation and that oral stereognosis scores improved over time after prosthesis use. CONCLUSIONS: Oral stereognosis improved with the use of palate-covering prostheses over time. However, because of the very low certainty of evidence, the statement must be interpreted with caution.

Effect of treatment of transverse maxillary deficiency using rapid palatal expansion on oral health-related quality of life in children: A randomized controlled trial.

INTRODUCTION: This trial aimed to longitudinally evaluate the effect of the treatment of transverse maxillary deficiency using rapid palatal expansion (RPE) on self-perceived oral health-related quality of life (OHRQOL) in children. METHODS: Eighty participants aged 8-10 years with transverse maxillary deficiency and bilateral posterior crossbite were randomly assigned to 2 groups (n = 40 each): a group treated with RPE using hyrax-type appliances and a nontreated control group. OHRQOL was assessed by using the Child Perceptions Questionnaire for 8-10-year-olds at 4 times: before RPE, during RPE (T1), at the end of RPE (T2), and 1 month after the appliance removal (T3). Generalized mixed models were used for data analysis (α = 0.05). RESULTS: Both groups exhibited similar demographic characteristics and OHRQOL scores at baseline. All participants completed the study. RPE had a time-dependent effect on OHRQOL. At T1 and T2, this therapy is expected to increase the overall OHRQOL scores by 1.17 times (ie, ∼17% increase; T1 95% confidence interval [CI], 1.08-1.26; T2 95% CI, 1.09-1.27; P = 0.001). In contrast, the overall OHRQOL scores at T3 are expected to be 0.28 times the baseline scores (ie, ∼72% reduction; T3 95% CI, 0.26-0.31; P = 0.001). All individual domains of the OHRQOL evidenced a positive impact of treatment at T3 (P = 0.001). Only the oral symptoms and social well-being domains showed a significantly negative impact of the treatment at T1 and T2. CONCLUSIONS: Correction of the transverse maxillary deficiency by RPE in children aged 8-10 years improves OHRQOL. There is a temporary worsening of OHRQOL during the treatment of this condition using RPE. REGISTRATION: This trial was not registered. PROTOCOL: The protocol was not published before trial commencement. FUNDING: This study was financed by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brazil, Financing Code 001.

Is there variation in the depth of the curve of Spee in individuals with different dentoskeletal patterns? A systematic review with meta-analysis.

OBJECTIVE: To systematically evaluate all the evidence assessing variations in the depth of the curve of Spee (COS) according to the presence/absence of different dentoskeletal characteristics. SEARCH METHODS AND ELIGIBILITY CRITERIA: The eligibility criteria were outlined following the PECO framework, as follows: studies evaluating individuals with complete permanent dentition including second molars (P), which compared a group with a certain dentoskeletal variation (E) versus another group without the variation (C), regarding the depth of the COS (O). MEDLINE (via PubMed), Scopus, Web of Science, The Cochrane Library, LILACS and BBO (via Virtual Health Library), OpenGrey, and Google Scholar were searched up to September 2021 to identify eligible reports. DATA COLLECTION AND ANALYSIS: Duplicates were removed from all the records retrieved. The selection process and data collection were performed independently by two review members. The risk of bias was also assessed independently and in duplicate, using the guideline described by Fowkes and Fulton. Several meta-analyses (α = 0.05) were conducted to estimate the mean differences (MD) or standardized mean differences (SMD) in the depth of COS between individuals presenting or not certain dentoskeletal characteristics. The certainty of evidence was assessed using the GRADE tool. RESULTS: Thirty-five studies were selected for qualitative synthesis, and 29 of them for quantitative synthesis. All studies had methodological limitations that affected the risk of bias and increased the likelihood that results were due to chance. Syntheses showed that Class II malocclusion (SMD = 0.87; 95% CI: 0.61, 1.13; P < 0.00001; six datasets including 260 subjects analysed), Class II division 1 (SMD = 1.09; 95% CI: 0.62, 1.56; P < 0.00001; 14 datasets including 823 subjects analysed) and Class II division 2 (SMD = 2.65; 95% CI: 1.51, 3.79; P < 0.00001; eight datasets including 476 subjects analysed) had deeper COS than Class I malocclusion. The skeletal Class II also presented higher COS values than skeletal Class I (SMD = 0.57; 95% CI: 0.02, 1.12; P = 0.04; four datasets including 299 subjects analysed). Individuals with Class III malocclusion had flatter COS than the subjects having Class I malocclusion (SMD = -0.57; 95% CI: -1.07, -0.08; P = 0.02; nine datasets including 505 individuals analysed). No difference was shown in the COS depth between skeletal Class III and Class I (P > 0.05). Deep bite individuals had higher COS depth than those with normal overbite (MD = 0.61; 95% CI: 0.41, 0.82; P < 0.00001; two datasets including 250 subjects analysed). In addition, hypodivergent individuals presented deeper COS than normodivergents (SMD = 0.62; 95% CI: 0.37, 0.86; P < 0.00001; six datasets including 305 subjects analysed), and there was no significant difference in the COS depth between hyperdivergent and normodivergent individuals (P = 0.66). The certainty of evidence was rated as very low for all the syntheses. LIMITATIONS: All the quantitative syntheses included results from studies with methodological flaws. Therefore, they are potentially biased. Moreover, the evidence was also mainly affected in terms of the inconsistency of the results and the imprecision of the estimates. CONCLUSIONS: Although an apparent influence of dentoskeletal Class II, Class III malocclusion, deep bite, and the hypodivergent skeletal pattern on the depth of the COS is suggested, it is not possible to make definitive conclusions on the matter due to the very low certainty of the evidence. Further high-quality research is necessary.

Genetic variants in tooth agenesis-related genes might be also involved in tooth size variations.

OBJECTIVE: The present study aimed to evaluate if genetic variants in PAX9, MSX1, TGFα, FGF3, FGF10, FGF13, GLI2 and GLI3 are involved in TS of permanent teeth. MATERIALS AND METHODS: Pretreatment dental records from orthodontic patients were assessed prior to recruitment. Patients with tooth agenesis and congenital anomalies (including oral cleft) and/or syndromes were excluded. Dental casts were used to measure the maximum crown dimensions of all fully erupted permanent teeth except second and third molars in mesiodistal direction. Teeth with caries, occlusal wear, mesiodistal restorations, and obvious deformities were not evaluated. Genomic DNA samples were used for genotyping. The allelic discrimination of 13 genetic variants was performed. The associations between TS and genotype were analyzed by linear regression, adjusted by gender at a significance level of p ≤ 0.05. RESULTS: Genetic polymorphisms in the tooth agenesis-related genes studied here were associated with increased and decreased TS, in both maxilla and mandible (p < 0.05). CONCLUSION: This study reported associations of novel tooth agenesis-related gene variants with permanent tooth size variations. CLINICAL RELEVANCE: The presence of some genetic variants could allow the prediction of permanent tooth size.

Is the buccal alveolar bone less affected by mini-implant assisted rapid palatal expansion than by conventional rapid palatal expansion?-A systematic review and meta-analysis.

OBJECTIVE: To systematically review the existing literature comparing mini-implant assisted rapid palatal expansion (MARPE) and conventional rapid palatal expansion (RPE) regarding the effect on the buccal alveolar bone thickness (BT) and marginal bone level (BL). METHODS: PubMed/MEDLINE, Scopus, Web of Science, The Cochrane Library, Virtual Health Library, Embase, Ovid, LIVIVO, CINAHL, the Portal de Periódicos da CAPES, Google Scholar and SIGLE were searched up to January 2020. Risk of bias (RoB) assessments were performed using the Cochrane Collaboration and ROBINS-I tools. Fixed-effects meta-analysis of standardized mean differences (SMD) was implemented to assess the pooled estimates for the BT outcome. The analyses were performed adopting a significance level of 5%. A narrative synthesis was performed to summarize the results on the BL. The GRADE tool was used to assess the quality of the evidence. RESULTS: Three randomized clinical trials and one retrospective study were included. Only one study was rated as with low RoB, while the others were scored as with moderate to serious RoB. Limited evidence indicated that patients using conventional RPE had a greater loss of the BT compared to patients using MARPE (SMD = 0.55; 95% CI: 0.29-0.80; P < .0001). Subgroup analyses showed that differences were significant in both premolars' regions, right (SMD = 0.75; 95% CI: 0.24-1.25; P = .004) and left (SMD = 1.05; 95% CI: 0.52-1.57; P < .0001), and these were not significant for the molars' regions (P > .05) (Low quality of evidence). LIMITATIONS: Limited amount of selected papers, methodological issues that could lead to bias and high clinical heterogeneity among the studies. Due to the statistical model applied for the quantitative synthesis of the results, no generalization to any other population is recommended. CONCLUSIONS: Limited evidence suggests that MARPE could decrease the loss of the buccal alveolar bone when compared to conventional RPE.

Effect of ovariectomy on maxilla and mandible dimensions of female rats.

OBJECTIVE: The role of oestrogen in craniofacial growth still remains unclear. Therefore, the present study aimed to assess the effect of oestrogen deficiency on maxilla and mandible dimensions. SETTING AND SAMPLE POPULATION: The study was conducted at the Department of Pediatric Dentistry at the School of Dentistry of Ribeirão Preto, University of São Paulo, and used forty female Wistar rats. MATERIAL AND METHODS: Ovariectomy (OVX) and placebo surgery (Sham) were performed when animals were twenty-one days old (prepubertal stage). Dimensions of the maxilla and mandible were assessed by craniometric analysis using radiographs, during and after puberty of the animals (45 and 63 days old, respectively). Quantitative real-time PCR and immunohistochemical analyses were performed to determine the expression and localization, respectively, of oestrogen receptor alpha (ERα) and oestrogen receptor beta (ERß) in different growth sites of the evaluated structures at puberty. The differences between the groups for each outcome were evaluated using the t test with an established alpha error of 5%. RESULTS: There were significant differences between the OVX and Sham groups for horizontal and vertical linear measurements in the maxilla and the mandible at both pubertal and post-pubertal stages (P < .05). The ovariectomized rats showed significantly greater measures for all dimensions assessed. No differences in gene expression of ERα and ERß were identified at the different growth sites between the OVX and Sham groups (P > .05). Immunohistochemical analyses revealed the presence of both oestrogen receptors in osteoblasts and chondrocytes in the midpalatal suture and mandibular condyle, respectively, in the OVX and Sham groups. CONCLUSION: Our results suggest that oestrogen deficiency from the prepubertal stage might increase the growth of the maxilla and mandible in female rats.

GHR and IGF2R genes may contribute to normal variations in craniofacial dimensions: Insights from an admixed population.

INTRODUCTION: This study aimed to determine whether single nucleotide polymorphisms in the growth hormone receptor (GHR) and insulin-like growth factor 2 receptor (IGF2R) genes are associated with different craniofacial phenotypes. METHODS: A total of 596 orthodontic and 98 orthognathic patients from 4 cities in Brazil were included for analyses. Angular and linear cephalometric measurements were obtained, and phenotype characterizations were performed. Genomic DNA was collected from buccal cells and single nucleotide polymorphisms in GHR (rs2910875, rs2973015, rs1509460) and IGF2R (rs2277071, rs6909681, rs6920141) were genotyped by polymerase chain reactions using TaqMan assay. Genotype-phenotype associations were assessed in the total sample (statistical significance was set at P <8.333 × 10-3) and by a meta-analytic approach implemented to calculate the single effect size measurement for the different cohorts. RESULTS: Rare homozygotes for the GHR rs2973015 showed increased measurements for the lower anterior facial height (ANS-Me) and mandibular sagittal lengths (Co-Gn and Go-Pg). In contrast, common homozygotes for the IGF2R rs6920141 presented reduced measurements for these dimensions (ANS-Me and Go-Pg). Furthermore, the less common homozygotes for IGF2R rs2277071 had reduced maxillary sagittal length (Ptm'-A'). The meta-analytical approach replicated the associations of rs2973015 with ANS-Me, rs2277071 with Ptm'-A', and rs6920141 with Go-Pg. CONCLUSIONS: Our results provide further evidence that GHR contributes to the determination of mandibular morphology. In addition, we report that IGF2R is a possible gene associated with variations in craniofacial dimensions. Applying meta-analytical approaches to genetic variation data originating from likely underpowered samples may provide additional insight regarding genotype and/or phenotype associations.

Possible association between craniofacial dimensions and genetic markers in ESR1 and ESR2.

OBJECTIVE: To investigate the association of genetic markers in ESR1 and ESR2 with craniofacial measurements. DESIGN: Cross-sectional study. SETTING: School of Dentistry of Ribeirão Preto, University of São Paulo. PARTICIPANTS: A total of 146 biologically unrelated, self-reported Caucasian Brazilians with no syndromic conditions were included. METHODS: Sagittal and vertical measurements (ANB, S-N, Ptm'-A', Co-Gn, Go-Pg, N-Me, ANS-Me, S-Go and Co-Go) from lateral cephalograms were examined for craniofacial evaluation. DNA was extracted from saliva and genetic markers in ESR1 (rs2234693 and rs9340799) and in ESR2 (rs1256049 and rs4986938) were analysed by real-time polymerase chain reaction. Hardy-Weinberg equilibrium was evaluated using the Chi-square test within each marker. The associations between craniofacial dimensions and genotypes were analysed by linear regression and adjusted by sex and age. The established alpha was 5%. RESULTS: Individuals carrying CC in ESR1 rs2234693 had a decrease of -3.146 mm in ANS-Me (P = 0.044). In addition, rs4986938 in ESR2 was associated with S-N measurement (P = 0.009/ ß = -3.465). This marker was also associated with Go-Pg measurement, in which the CC genotype had a decrease of -3.925 mm in the length of the mandibular body (P = 0.043). CONCLUSION: The present study suggests that in ESR1 and ESR2 are markers for variations in the craniofacial dimensions. However, further research should confirm the results.

Polymorphisms in FGF3, FGF10, and FGF13 May Contribute to the Presence of Temporomandibular Disorders in Patients Who Required Orthognathic Surgery.

BACKGROUND: To evaluate whether genetic polymorphisms in FGF3, FGF10, and FGF13 are associated with temporomandibular disorders (TMD) in patients that presented dentofacial deformities requiring orthognathic surgery. MATERIAL AND METHODS: The sample comprised a total of 113 patients of both sexes. The diagnosis of TMD was performed before orthognathic surgery between Research Diagnostic Criteria for Temporomandibular Disorders (RDC-TMD). According to the TMD assessment, the patients were divided into 3 major groups: myofascial pain, articular disc displacements and other TMD conditions (arthralgia, arthritis, and arthrosis). Genomic DNA was collected from saliva samples and genetic polymorphisms in FGF3 (rs1893047 and rs7932320), FGF10 (rs900379) and FGF13 (rs5931572 and rs5974804) were analyzed by real-time polymerase chain reactions. The association between the TMD conditions and the genetic polymorphisms assessed were analyzed by Poisson Regression. The model was calculated on bivariate and adjusted by sex. The established alpha was 5%. Data were analyzed by using SPSS software (IBM, Armonk, NY). RESULTS: The genetic polymorphisms rs7932320 in FGF3 (P < 0.001) and rs900379 in FGF10 (P < 0.05) were associated with the presence of muscle disorder. The genetic polymorphisms rs1893047 in FGF3, rs900379 in FGF10, and rs5974804 and rs5931572 in FGF13, were associated with the presence of disk displacement (P < 0.05). The genetic polymorphisms rs1893047 and rs7932320 in FGF3, rs900379 in FGF10, and rs900379 in FGF10 were associated with other TMD conditions (P < 0.05). CONCLUSION: Genetic polymorphisms in FGF3, FGF10, and FGF13 genes were associated with temporomandibular disorders in a population with dentofacial deformities.

Aesthetic and functional outcomes using a multiloop edgewise archwire for camouflage orthodontic treatment of a severe Class III open bite malocclusion.

Occasionally, orthodontists will be challenged to treat malocclusions and skeletal disharmonies, which by their complexity one might think that the only treatment alternative is the surgical-orthodontic approach. A male patient, aged 17 years old, was diagnosed with a skeletal Class III malocclusion, anterior open bite and negative overjet. An unpleasant profile was the patient's 'chief complaint' showing interest in facial aesthetics improvement. Nevertheless, the patient and his parents strongly preferred a non-surgical treatment approach. He was treated with a multiloop edgewise archwire to facilitate uprighting and distal en-masse movement of lower teeth, correct the Class III open bite malocclusion, change the inclination of the occlusal plane and obtain the consequent morphological-functional adaptation of the mandible. The Class III malocclusion was corrected and satisfactory changes in the patient's profile were obtained. Active treatment was completed in 2 years, and facial result remained stable at 2 years 6 months after debonding.

Occlusion development after premature loss of deciduous anterior teeth: preliminary results of a 24-month prospective cohort study.

OBJECTIVE: This study aimed to evaluate occlusion development after premature loss or extraction of deciduous anterior teeth, by means of a prospective cohort study. METHODS: Fifteen infants and children aged 1 to 5 years old were longitudinally assessed (with loss or extraction of deciduous anterior teeth [n = 9], and without tooth losses [n = 6]). Photographs and dental casts at the baseline and after 24 months of follow-up were performed. Dental casts were scanned, and linear measurements were made on the digitalized models (missing tooth space, arch perimeter, arch length, arch width, intercanine length and intercanine width). The t-test was used for groups comparisons (α = 0.05). RESULTS: Individuals' mean age at baseline was 2.93 (± 1.18) years. No statistically significant differences were observed in the missing tooth space in the group with tooth loss during the 24 months of follow-up (p > 0.05). Arch perimeter, arch length, arch width, intercanine length and intercanine width did not show differences between the groups (p > 0.05). Qualitative photographic evaluation revealed other changes in the dental arches and occlusion, such as exfoliation and eruption of deciduous teeth, eruption of permanent teeth, self-correction or establishment of malocclusion, among others. CONCLUSION: The results suggest that the premature loss of deciduous anterior teeth does not affect the perimeter, length and width of the dental arches; however, other alterations that lead to malocclusion could be established.

Management and recurrence of the odontogenic keratocyst: an overview of systematic reviews.

MATERIALS AND METHODS: An extensive literature search among six eletronic databases and Grey Literature was used to identify systematic reviews (S) that could respond if: in individuals diagnosed with OKC (P), is there any influence of the treatment method (I/C) on the recurrence rate of the lesion (O)? After evaluating all titles and abstracts and then applying the eligibility criteria, the included studies were read in full, and data were extracted based on a standardized sheet ordered in the PICO sequence. The assessment of the quality of the systematic reviews included, was determined by AMSTAR2, and final synthesis were descriptively made based on the results and quality of the systematic reviews. RESULTS: From a total of 19 included systematic reviews, it was observed that the most used treatment for OKC was enucleation, followed by enucleation with adjuvant techniques and marsupialization. The mean percentage of recurrence was 16,2%, and the highest OKC recurrence rate was 43.2% after simple enucleation. The use of adjuvant techniques promoted reductions in OKC recurrence rates. The overall methodological quality of systematic reviews was critically low, and this parameter demonstrate the need for more studies to facilitate the choose of the treatment. CONCLUSION: Despite being the most used treatment, simple enucleation is related to the highest rate of recurrence, except when performed after marsupialization/decompression. In addition, the use of adjuvant techniques has a strong impact on reducing the likelihood of recurrence. However, these findings are not conclusive because of the critically low quality of the systematic reviews.