Prevalence of orofacial injuries resulting from trauma in individuals with cerebral palsy: A systematic review and meta-analysis.

Individuals with cerebral palsy (CP) may have cognitive, sensitive, behavioral, communicative, and convulsive disorders. Because defensive reflexes are reduced by CP, the risk of orofacial trauma is greater in these individuals. This study aimed to evaluate the prevalence of orofacial injuries resulting from trauma in patients with CP. This review was reported according to preferred reporting items for systematic reviews and meta-analyses (PRISMA) and registered in the International Prospective Register of Systematic Reviews (PROSPERO-CRD42022293570). The search was performed for articles published until January 2023 in Embase, Latin American and Caribbean Literature on Health Sciences (LILACS), PubMed/Medline, Scopus, and Web of Science databases. Gray literature was also consulted through Google Scholar, OpenGrey, ProQuest Dissertations, and Theses. Studies in which orofacial injuries due to trauma were prevalent in individuals with CP were included. The risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Tool. Additionally, a random-effects meta-analysis was conducted. Twelve studies were included in the synthesis, of which nine presented a low risk of bias and three presented a moderate risk. When considering the general prevalence of orofacial injuries in patients with CP, a prevalence of 34% [95% CI = 18%-52%; I2 = 98%] was observed, with enamel and dentin fractures being the most common orofacial injuries. Approximately one in three patients with CP showed at least one type of orofacial injury involving dental trauma. There is a lack of literature assessing the prevalence of these traumas in soft tissues and the evidence for this outcome remains uncertain.

Impact of malocclusion treatments on Oral Health-Related Quality of Life: an overview of systematic reviews.

OBJECTIVE: To perform an overview of systematic reviews (SR) assessing the impact of malocclusion treatments (Orthodontic Treatment - OT and/or Orthodontic Surgical Treatment - OST) on Oral Health-Related Quality of Life (OHRQoL). MATERIALS AND METHODS: A search strategy was conducted in electronic databases until June 7th, 2021, followed by a manual search in grey literature and registration databases. Two independent authors applied the eligibility criteria, extracted the data, assessed the risk of bias (AMSTAR-2), and performed the certainty of evidence (GRADE) evaluation. Meta-analysis was planned to be carried out in RevMan 5.3 (with 95% confidence intervals (CI) considering p < 0.05), in case of homogeneous studies considering OHRQoL instrument and time of follow-up. RESULTS: A total of 126 articles were accessed on the database, 18 registers, 33 records on grey literature and 3 articles by means of citation searching. After duplicates removal and eligibility criteria analyses, 15 SR were included. From that, 13 showed improvement in OHRQoL after OT and/or OST. The methodological quality ranges from high (n = 2), to critically low (n = 9). Meta-analysis was conducted. Improvement on OHRQoL after a 6-month OST using the OQLQ-22 (p < 0.00001; 19.65; CI: 12.60-26.70) and OHIP-14 instruments (p < 0.00001; 10.70; CI: 9.89-11.51); and after a 6-month OT using the CPQ 11-14 instrument (p = 0.010; 3.57; CI: 0.86-6.28) with very low certainty of the evidence for all outcomes was observed. CONCLUSIONS: Although most SR selected in this overview are characterized by a critically low quality, as well as very low certainty of the evidence, OT and/or OST seem to have a positive impact in improving the OHRQoL. CLINICAL RELEVANCE: The overview of existing systematic reviews compiled that OT and/or OST seem to have a positive impact on improving the OHRQoL. This information will facilitate clinical decision-making considering the clinical and psychological parameters.

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.

Variation of Tooth Crown Size in Cleft Lip and Palate Patients.

AIM: This study aims to compare the mesiodistal (MD) and buccolingual (BL) tooth crown size (TCS) of adult patients with cleft lip and palate (CL/P) and patients without CL/P. MATERIALS AND METHODS: The sample of this study consisted of 146 adult patients, of both genders, of which 73 were included in the case group (with CL/P) and 73 were included in the control group (without CL/P). Data regarding gender and age and cleft type were collected. In addition, dental models were evaluated to obtain the TCS in the maximum distance of the MD and BL dimensions of all erupted permanent teeth (except third molars). The results were submitted to statistical analysis with a significance level of 0.05. RESULTS: In the upper arch, the central incisors (CI) were smaller in the case group for the MD and BL dimensions (p < 0.05). The lateral incisors (LI) and canine (C) were smaller only in the BL width (p < 0.05) and the second molars (SM), were smaller only in the MD dimensions. In the lower arch, there were significant differences only in the BL width between groups, the CI and LI presented smaller measurements in CL/P patients, while the left first molar (FM) and right first premolar (FPM) were larger (p < 0.05) than in patients without CL/P. CONCLUSION: Patients with CL/P have different sizes in certain teeth compared to patients without CL/P. CLINICAL RELEVANCE: Cleft lip and palate patients usually present important dental anomalies; thereby, the knowledge about trends in tooth size variations in CL/P patients can aid in dental and orthodontic treatment planning to obtain a stable, functional, and esthetic occlusion.

Assessing the association between vitamin D receptor and dental age variability.

OBJECTIVES: To explore the association between genetic polymorphisms in vitamin D receptor (VDR), vitamin D serum levels, and variability in dental age. MATERIAL AND METHODS: This cross-sectional study was based on an oral examination, panoramic radiograph analysis, and genotype analysis from biological samples. Dental age was evaluated using two different methods: Demirjian et al. (Hum Biol 45:211-227, 1973) and Hofmann et al. (J Orofac Orthop.78:97-111, 2017). The genetic polymorphisms BglI (rs739837) and FokI (rs2228570) in VDR were genotyped through real-time PCR. The vitamin D level was also measured in the serum. Delta (dental age-chronological age) was compared among genotypes in VDR in the co-dominant model. Multiple linear regression analysis was also performed. An established alpha of 5% was used. RESULTS: Genotype distributions of BglI and FokI were not associated with dental maturity (p > 0.05). In the logistic regression analyses, genotypes in BglI and FokI and vitamin D levels were not associated with variability in dental age (p > 0.05). CONCLUSIONS: The genetic polymorphisms BglI and FokI in VDR and the vitamin D levels were not associated with variability in dental age. CLINICAL RELEVANCE: To unravel the factors involved in dental maturity can improve dental treatment planning in pediatric and orthodontic practice.

Oral Cleft Related-Genes may be Involved in Root Curvature of Maxillary Lateral Incisors.

The maxilla is formed by the medial nasal and maxillary processes fusion. The dental lamina develops from 2 origins connecting in the lateral incisor. The maxillary lateral incisor region is often affected by dental anomalies and clefting. It is possible that genes involved in oral cleft could also be associated with a variety of phenotypic variations in the maxillary lateral incisor. In this phenotype-genotype study, we explored the association between polymorphisms in the oral-cleft-related genes BMP2 and BMP4 and root curvature of maxillary lateral incisors.Cross-sectional study.Universities and private clinics.Panoramic radiographs and DNA from 231 patients were analyzed.Schneider method (1971) was applied to estimate the degree of root curvature of the maxillary lateral incisors and to classify the root as straight (5° or less) or curved (higher than 5°). Genetic polymorphisms in BMP2 (rs235768 and rs1005464) and BMP4 (rs17563) were genotyped. Statistical analysis was performed.A total of 401 teeth (199 left and 202 right) were evaluated. Genetic analysis demonstrated trends toward association for the rs1005464 in BMP2 (P = .025) in co-dominant model and in dominant model (P = .026) for left incisors. The rs235768 in BMP2 showed trends toward association with the degree of root curvature in left incisors in the recessive model (P = .031). rs17563 in BMP4 also showed trends toward association with the degree of the root curvature in left incisors (P = .019).BMP2 (rs235768 and rs1005464) and BMP4 (rs17563) might be involved in maxillary lateral incisor root curvature.

Intratubular Sealer Penetration: Scanning Electron Microscopy Associated with Cathodoluminescence Analysis.

AIM: The aim of the study was to compare the ability of three endodontic sealers, Endofill (END), AH Plus (AHP), and Sealer Plus BC (SPB), to penetrate dentinal tubules. MATERIALS AND METHODS: Forty-five human teeth, single-rooted and previously instrumented mandibular premolars, were randomly divided into three experimental groups (n = 15): END (n = 15), AHP (n = 15), and SPB (n = 15). After obturation, dental sections were performed horizontally, at 2 and 5 mm from the root apex. The samples were analyzed by scanning electron microscopy associated with cathodoluminescence. Percentage penetration (PP%) and maximum penetration depth (MPD) of the sealers were evaluated by the Kruskal-Wallis and Mann-Whitney tests, for general and paired data, respectively. The Wilcoxon test was applied to analyze the differences between the 5 and 2 mm distances. A 5% significance level was adopted. RESULTS: As for PP%, AHP and SPB were similar (p = 0.127) and presented higher values than END (AHP, p = 0.024 and SPB, p <0.001); with regard to MPD, AHP and SPB did not differ either (p = 0.450), but were higher than END (p <0.001); in both analyses, penetration was greater at 5 mm than at 2 mm (p <0.001). CONCLUSION: SPB showed satisfactory performance in penetrating dentinal tubules, being similar to AHP, and superior to END. CLINICAL SIGNIFICANCE: Greater penetration of sealer into the dentinal tubules may increase the chance of successful endodontic treatment.

Influence of Filling Material Remnants on the Diffusion of Hydroxyl Ions in Endodontically Retreated Teeth: An Ex Vivo Study.

AIM: To assess the influence of remnants of filling material on hydroxyl ion diffusion from calcium hydroxide (CH) paste, measured by the pH value, in retreated teeth. MATERIALS AND METHODS: A total of 120 single-rooted extracted teeth were prepared up to a size 35 hand file and filled. For retreatment, the specimens were divided into four groups (n = 20): ProTaper Universal Retreatment (PUR), PUR with additional instrumentation (PURA), Mtwo Retreatment (MTWR), and MTWR with additional instrumentation (MTWRA). Negative (NEG) and positive (POS) control groups were composed by 20 specimens each one. The specimens, except NEG, were filled with CH paste. The retreated groups were scanned using cone-beam computed tomography (CBCT) for analysis of filling remnants. The pH assessment was performed at the baseline, after seven, 21, 45, and 60 days of immersion in saline. Data were analyzed using Shapiro-Wilk and Levene's test, followed by a two-way analysis of variance (ANOVA) and Tukey's test. RESULTS: Additional instrumentation (PURA and MTWRA) were superior regarding removal of the filling material (p <0.05); however, without significant difference (p >0.05). The mean pH value in all groups increased (p <0.05). After 60 days, no statistical difference was observed among POS and PURA; and MTWR and MTWRA. There was less diffusion of hydroxyl ions when the amount of remnants was greater than 59%. CONCLUSION: Additional instrumentation improved the ability to remove filling material in both systems. All groups presented increasing pH; however, the higher the amount of remnants, the lower the diffusion of hydroxyl ions. CLINICAL SIGNIFICANCE: The amount of remnants allows less diffusion of calcium hydroxyl ions. Thus, additional instrumentation improves the ability to remove these materials.

The role of postnatal estrogen deficiency on cranium dimensions.

OBJECTIVES: The aim of this study was investigate the cranium dimensions of adult female rats, who suffered estrogen deficiency during the prepubertal stage, to assess the impact of estrogen deficiency on craniofacial morphology. MATERIAL AND METHODS: Twenty-two female Wistar rats were divided into ovariectomy (OVX) (n = 11) and sham-operated control (n = 11) groups. Bilateral ovariectomy were performed in both groups at 21 days old (prepubertal stage), and rats were euthanized at an age of 63 days (post-pubertal stage). Micro-CT scans were performed with rat skulls, and the cranium morphometric landmark measurements were taken in the dorsal, lateral, and ventral view positions. Differences in measurements between the OVX and sham control groups were assessed using t test with an established alpha error of 5%. RESULTS: The measures of the rats' skull showed that the inter-zygomatic arch width and anterior cranial base length were significantly larger in OVX group (p = 0.020 and p = 0.050, respectively), whereas the length of parietal bone was significantly higher in the sham group (p = 0.026). For the remaining measurements no significant differences between groups were detected (p > 0.05). CONCLUSION: This study provides evidence that ovariectomized rats had alterations in cranial bone dimensions, demonstrating that estrogens during puberty are important for skull morphology. CLINICAL RELEVANCE: To understand the role of estrogen on the postnatal cranium development will impact the clinical diagnose and therapy during childhood and adolescence.

Single nucleotide polymorphism rs4284505 in microRNA17 and risk of dental fluorosis.

OBJECTIVES: The aim of this study is to evaluate the association between the single nucleotide polymorphism (SNP) rs4284505 within the gene that codifies microRNA17 (miRNA17) and dental fluorosis (DF) in a group of children. METHODS: Children living in a city with fluoridation of public water supplies were included. DF was assessed in erupted permanent teeth by Dean's modified index. The miR-SNP rs4284505 was selected in miRNA17 and genotyping was carried out by real-time PCR. Genotype and allelic distributions between DF and control, and between DF phenotypes (mild, moderate and severe) and control were analysed. RESULTS: Among a total of 527 children enrolled for the study, 383 were DF free and 144 presented DF. In the dominant model analysis (AA + AG vs. GG) the miR-SNP rs4284505 was associated with moderate DF, with carriers of the GG genotype having an increased risk of more than two times for DF (p = 0.031; Odds Ratio = 2.26, Confidence Interval 95%= 1.04-4.73). Allelic distribution showed borderline statistical significance for moderate DF with the carriers of G allele having an increased risk for DF (p = .050; Odds Ratio = 1.75, Confidence Interval 95%= 1.00-3.12). CONCLUSION: The miR-SNP rs4284505 in miRNA17 was associated with an increased risk of DF.

Effect of surface treatment and cement type on dentin bonding of processed resin composite.

PURPOSE: To examine the effect of surface treatment and cement type on dentin bonding of processed resin composite restorations. METHODS: Bovine incisors were sectioned to expose mid-dentin, and randomly assigned to four different groups: Group ULT, Lava Ultimate composite blocks were bonded to dentin with RelyX Ultimate; Group ULT-CJ was treated as in Group ULT but CoJet was used to treat the intaglio surface prior to bonding; Group UNC was bonded with RelyX Unicem 2; and Group UNC-CJ was treated as in Group UNC but CoJet was used to treat the intaglio surface. RelyX Unicem 2 was used as a self-adhesive resin cement, while RelyX Ultimate was used as an adhesive resin cement with Scotchbond Universal. All adhesives and resin composites were polymerized with a high-irradiance LED polymerizing light (Elipar DeepCure-S). After bonding, all specimens were kept in 100% humidity and 37°C for 7 days and then processed for microtensile bond strength (µTBS) testing (n=15). The failure mode was analyzed under SEM as cohesive, adhesive, or mixed. Data were analyzed for statistical significance using two-way ANOVA and Tukey's HSD post-hoc test (α=0.05). RESULTS: Mean µTBS values ranged from 8.83 MPa (±3.13 MPa) for UNC to 25.63 MPa (±5.94 MPa) for ULT-CJ. Means were statistically significantly higher for the adhesive cement when compared with the self-adhesive cement (P< 0.05), and, for the adhesive cement, CoJet resulted in statistically significantly higher means (P< 0.05). The number of pre-test failures was uniform across groups (n=2-4). Failures were predominantly adhesive and mixed. The adhesive resin cement RelyX Ultimate performed significantly better than the self-adhesive resin cement RelyX Unicem 2, and surface treatment with CoJet improved bond strengths of Lava Ultimate to dentin. CLINICAL SIGNIFICANCE: CoJet treatment and adhesive resin cements should be used when bonding laboratory/CAD-CAM processed resin composite restorations to dentin.

Effect of Endodontic Irrigation Protocols on Crown Fracture Resistance.

AIM: This study aimed to evaluate the fracture resistance of tooth crowns endodontically irrigated using different protocols. MATERIALS AND METHODS: A total of 76 bovine incisors were divided into four groups (n = 19): irrigation with distilled water (control; CON); conventional irrigation with positive apical pressure (PAP); passive ultrasonic irrigation using continuous flushing (PUI); and irrigation with PAP and heated sodium hypo-chlorite solution (PHS). The force required to fracture the crown was measured on a universal testing machine at an angle of 45°. RESULTS: The CON group had higher fracture resistance (351.71 ± 58.66 N) than the PAP and PUI groups (140.96 ± 37.26 N; 167.49 ± 40.08 N respectively). The PHS group had the lowest fracture resistance value (115.15 ± 41.07 N). Irrigation protocols had a significant effect on crown resistance (p < 0.01). CONCLUSION: Teeth subjected to irrigation with heated sodium hypochlorite showed decreased resistance to crown fracture. CLINICAL SIGNIFICANCE: The contact of the irrigating solution with the root canal walls potentially can cause their weakness, determining crown fracture.

A micro-computed tomography assessment of the efficacy of rotary and reciprocating techniques for filling material removal in root canal retreatment.

OBJECTIVES: The aim of this study was to compare the efficacy of rotary and reciprocating techniques for removing filling material from root canals, using micro-computed tomography (micro-CT) imaging. MATERIALS AND METHODS: The distal root canals of 42 human mandibular molars were instrumented with hand files up to size 40 according to a step-down technique and obturated with gutta-percha and an epoxy resin-based sealer using Tagger's hybrid technique. Teeth were divided into six groups (n = 7) according to the instruments used for removal of filling material: group PTUR (Protaper Universal Retreatment), group W40 (WaveOne 40.08), group R40 (Reciproc 40.06), group R50 (Reciproc 50.05), group W25/W40 (WaveOne 25.08/40.08), and group R25/R40/R50 (Reciproc 25.08/40.06/50.05). Teeth were scanned with a micro-CT device before and after use of the instruments to calculate the percentage of remaining filling material. Data were compared using one-way ANOVA and Fisher's LSD test at 5 % significance level. RESULTS: The mean percentage of remaining filling material was significantly lower when canals were retreated with the set of instruments R25/R40/R50 and single instruments W40 and R50 compared with the set of instruments W25/W40 (P < 0.05), which promoted material compaction in the apical region. CONCLUSION: None of the retreatment techniques removed the root fillings completely. PTUR instruments performed equally effective regarding filling removal compared with W40, R40, R50, W25/W40, and R25/R40/R50. For WaveOne, the use of a single instrument (size 40, taper 0.08) was more effective in removing filling material, while for Reciproc showed similar cleaning ability using single instrument or combination of instruments. CLINICAL RELEVANCE: The results of this in vitro study provide consistent information on filling material removal capacity of mechanized systems during retreatment at the different root canal thirds.

Influence of cervical preflaring on apical transportation in curved root canals instrumented by reciprocating file systems.

BACKGROUND: The aim of this study was to evaluate the influence of cervical preflaring on apical transportation in curved root canals prepared using the Reciproc and WaveOne reciprocating file systems. METHODS: Sixty curved canals were instrumented using Reciproc R25 and WaveOne Primary files, with and without preflaring (n = 15). A double-digital technique was used to digitally superimpose the file before instrumentation (#15 K-file) on the final apical reciprocating file (#25/08). The angle between the tip of the initial and final file was measured and recorded. Groups were compared using the Kruskal-Wallis test, and significance was set at p < 0.05. RESULTS: The mean and standard deviation for apical transportation was 0.93 ± 2.48 for the Reciproc Group, 0.84 ± 1.94 for the Preflaring + Reciproc Group, 0.40 ± 1.14 for the WaveOne Group, and 0.83 ± 2.20 for the Preflaring + WaveOne Group. No statistically significant differences were found among the groups (p = 0.9509). CONCLUSIONS: Under the conditions of this study, cervical preflaring did not influence apical transportation in curved root canals instrumented using Reciproc R25 and the WaveOne Primary files. Based on the in vitro measurements of apical transportation, the reciprocating files may be used without preflaring in curved root canals.

Influence of Prior Cervical Enlargement on Apical Cleaning Using Single File.

The goal of this study was to compare the apical cleaning capabilities of single files from 3 different rotary systems in the presence or absence of prior cervical preparation based on a histological analysis. A total of 84 human single-rooted mandibular permanent incisors were divided into 6 groups (14 canals each). Cleaning and shaping was performed under the following protocols: Group I, F2 ProTaper at working length; Group II, SX ProTaper and F2 ProTaper; Group III, size 25, .06 taper Mtwo at working length; Group IV, SX ProTaper and size 25, .06 taper Mtwo; Group V, size 25, .06 taper BR3 BioRace at working length; and Group VI, SX ProTaper and size 25, .06 taper BR3 BioRace. After cleaning and shaping, the root canals were evaluated by histological analysis. The percentage of remaining debris was evaluated using a cross-hatched grid superimposed over each image. Data were assessed using the Shapiro-Wilk and ANOVA tests. Statistically significant differences were observed between groups (p =0.0001) with respect to amount of remaining debris; use of SX in conjunction with F2 ProTaper yielded a significantly lower mean percentage of debris. It was concluded that cleaning ability improves when root canal preparation with F2 ProTaper is complemented by prior cervical enlargement.

Cuspal movement related to different polymerization protocols.

OBJECTIVE: The aim of this study to investigate the effects of different polymerization protocols on the cuspal movement in class II composite restorations. MATERIALS AND METHODS: Human premolar teeth were prepared with class II cavities and then restored with composite and three-step and two-step etch-and-rinse adhesive systems under different curing techniques (n = 10). It was used a light- emitting-diode curing unit and the mode of polymerization were: standard (exposure for 40 seconds at 700 mW/cm(2)), pulse-delay (initial exposure for 6 seconds at 350 mW/cm(2) followed by a resting period of 3 minutes and a final exposure of 37 seconds at 700 mW/cm(2)) and soft-start curing (exposure 10 seconds at 350 mW/cm(2) and 35 seconds at 700 mW/cm(2)). The cuspal distance (µm) was measured before and after the restorative procedure and the difference was recorded as cuspal movement. The data were submitted to two-way ANOVA and Bonferroni test (p < 0.05). RESULTS: The type of adhesive system did not influenced the cuspal movement for all the curing methods. Standard protocol showed the highest values of cuspal movement and was statistically different from the pulse-delay and soft-start curing modes. CONCLUSION: Although the cuspal displacement was not completely avoided, alternative methods of photocuring should be considered to minimize the clinical consequences of composites contraction stress.

Exploring the association between PITX2, third molars agenesis and sella turcica morphology : PITX2, third molars agenesis and sella turcica morphology.

OBJECTIVES: PITX2 is required for mammalian development and single nucleotide polymorphisms (SNPs) in this gene could be involved in dental agenesis and sella turcica patterns. Thus, the present study evaluated the association between SNPs in PITX2, third molars agenesis and sella turcica phenotypes. MATERIALS AND METHODS: The sample consisted of healthy orthodontic German patients with lateral cephalometric radiographs with clearly visualization of the sella turcica, and dental orthopantomograms. The morphological variations of the sella turcica were evaluated using the lateral cephalograms, while third molar agenesis was evaluated using orthopantomograms. DNA isolated from buccal cells was used for genotyping three SNPs in PITX2 (rs3796902, rs1947187, and rs2595110). The analyzes were performed using a significance of 5%. There was no association between third molar agenesis and sella turcica phenotypes (p > 0.05). SNPs in PITX2 were also not associated with third molars agenesis (p > 0.05). RESULTS: SNPs in PITX2 were associated with sella turcica phenotypes. The rs3796902 was associated with hypertrophic posterior clinoid process (p = 0.013). The rs1947187 and rs2595110 were associated with sella turcica bridge type A (p = 0.013 and p = 0.011, respectively for genotype distribution). Patients that carry the genotypes GG-CC-AG (rs3796902- rs1947187- rs2595110) had 7.2 higher chance to present sella turcica bridge type A (p = 0.002; Odds ratio = 7.2, Confidence interval 95% 2.04-27.04). CONCLUSIONS: Third molar agenesis was not associated with SNPs in PITX2 and sella turcica phenotypes. SNPs in PITX2 may have an important role in sella turcica pattern.

Frequency and variability of nonmetric dental crown traits of primary and permanent molars in a group of orthodontic patients.

BACKGROUND: The present study aimed to assess the frequency and variation of 13 nonmetric dental crown traits (NDCT) in permanent and primary molars in German orthodontic patients. METHODS: Dental records from orthodontic patients were screened and evaluated. First and second permanent and primary upper and lower molars (from left and right sides) were assessed. Teeth with cavitated dental caries, occlusal wear, restorations and obvious dental deformities were not evaluated. The NDCT for permanent molars were identified and scored according to the odontoscopic system developed by Arizona State University Dental Anthropology System (ASUDAS). The NDCT for primary molars were identified and scored according to ASUDAS, Hanihara's method and Sciulli's method. The χ2 test was used to investigate side preference and sexual dimorphism at a significance level of p ≤ 0.050. RESULTS: A total of 163 orthodontic patients (82 males and 81 females) aged 8-14 years were included. A sexual dimorphism was observed for the hypocone in first upper permanent molar (p = 0.041). The protostylid was observed in lower permanent molars (range 2.1-10%). Males presented more hypoconulid than females (p = 0.019). Only females presented the distal trigonid crest in lower first permanent molars (p = 0.002). The most common groove pattern in primary molars was Y; male presented more Y grade than females in the lower second primary molar (p = 0.039). Asymmetry was observed in some traits, ranging from 0 to 100%. CONCLUSION: The present study showed the frequency of NDCT of molars in German orthodontic patients and demonstrated that some traits present sexual dimorphism.

Correction: The investigation of WNT6 and WNT10A single nucleotide polymorphisms as potential biomarkers for dental pulp calcification in orthodontic patients.

[This corrects the article DOI: 10.1371/journal.pone.0288782.].

Exploring the sex-associated differences in molars fused roots.

BACKGROUND: Human sexual dimorphism is associated with many biological characteristics, including dental variables. OBJECTIVES: To investigate if molars fused roots present sex-associated differences. METHODS: Panoramic radiographs were used to investigate the frequency and distribution of permanent molars fused roots. Only patients with all first and second permanent molars were included. Third molars were not investigated. Any molar with roots fused apical to the usual furcal position were considered molar fused roots. Comparisons between males and females were performed using chi-square or Fisher's and Mann-Whitney tests and the established alpha was 5% (p<0.05). Sex-differential liability models were also proposed. RESULTS: A total of 84 males and 86 females were included and 1360 molars were analyzed. Among them, 46 (26.06%) present at least one molar with fused root. Second maxillary molars were the most affected teeth. There was an association between sex and molars with fused roots. Females had a 3.4 higher chance to present fused roots than males (OR=3.4, CI 95% 1.6-6.8; p=0.0008). The female: male ratio of molars with fused roots was 2.5:1. The number of molars with fused roots ranged from 1 to 6 per patient, and the mean number of Females presented more molars with fused roots (mean = 1.01; standard deviation = 1.52) than males (mean = 0.31; standard deviation = 0.85) (p<0.05). CONCLUSIONS: Molar fused root of permanent teeth presents sex-associated differences, in which females are more affected than males. Our results support sex-differential liability models for molars fused roots.