Amelogenin gene influence on enamel defects of cleft lip and palate patients

Characterization of enamel developmental defects in patients with orofacial clefts and their relationship to surgical procedures

AIMS

This study aimed to characterize the prevalence of development defects of enamel (DDE) in patients with cleft based on the cleft phenotype and explore the relationship between surgical procedures and different types of DDE.

MATERIAL AND METHODS

In this cross-sectional study, 290 standardized orthodontic documentation and medical records from a reference hospital were evaluated, which treated patients with: cleft lip (CL), cleft lip with alveolar bone involvement (CLa), cleft lip and palate (CLP), cleft palate (CP), cleft median (CM), and considering laterality as unilateral or bilateral. DDE was assessed using the Ghanim Index (2015). Information on surgical intervention periods was obtained from medical records. Statistical analyses were performed using prevalence ratio (PR) for DDE comparisons between cleft phenotypes and surgical procedures.

RESULTS

The prevalence of DDE was 77.2%. Demarcated hypomineralization was associated with CP and CLP, while hypoplasia was associated with CLa, especially when bilateral. Hypoplasia was also associated with the labial adhesion surgery.

CONCLUSION

Demarcated hypomineralization was the most common DDE in this population, and the cleft phenotype influenced the type of DDE manifested. The lip adhesion surgery increased the chances of hypoplasia manifestation.

CLINICAL RELEVANCE

The type of DDE in patients with cleft depends on the cleft phenotype. Understanding this susceptibility enables the multidisciplinary team to monitor dental development, thus allowing early diagnosis and timely referral to the pediatric dentist and better prognoses.

Tooth abnormalities associated with non-syndromic cleft lip and palate: systematic review and meta-analysis

OBJECTIVE

To evaluate the association between orofacial clefts (OFC) and tooth abnormalities (TA).

METHODS

We searched PubMed, Scopus, Web of Science, Cochrane Library, LILACS, and BBO, and in the gray literature and selected observational studies that evaluated the association between TA and OFC. The risk of bias was analyzed using the Newcastle-Ottawa Scale. A random-effects meta-analysis was performed comparing the presence and absence of OFC, cleft type-cleft palate (CP) and cleft lip with or without palate (CL/P)-and cleft laterality-unilateral and bilateral. The certainty of evidence was evaluated using the GRADE approach.

RESULTS

A total of 99 studies were included in the qualitative analysis, and 37 were included in the meta-analysis. Only four studies were classified as low risk of bias. Significant associations were observed between the presence of OFC and tooth agenesis (OR = 19.46; 95%CI = 4.99-75.96), supernumerary teeth (OR = 4.04; 95%CI = 1.26-12.99), developmental defects of enamel (OR = 3.15; 95%CI = 1.28-7.80), microdontia (OR = 15.57; 95%CI = 1.06-228.51), and taurodontism (OR = 1.74; 95%CI = 1.74-2.86). Individuals with CP had a lower frequency of supernumerary teeth (OR = 0.22; 95%CI = 0.08-0.64), peg-shaped tooth (OR = 0.31; 95%CI = 0.12-0.80), and morphological TA (OR = 0.13; 95%CI = 0.04-0.45) than individuals with CL/P. No TA was significantly associated with cleft laterality (p > 0.05). The quality of the evidence was very low in all analyses.

CONCLUSION

Individuals with OFC had a higher frequency of TA than those without OFC. Individuals with CP had a lower frequency of TA than individuals with CL/P. No TA was associated to cleft laterality.

CLINICAL RELEVANCE

Help to identify the treatment needs of individuals affected by OFC, improving the services provided to this population.

Evaluating the Expression of Candidate Homeobox Genes and Their Role in Local-Site Inflammation in Mucosal Tissue Obtained from Children with Non-Syndromic Cleft Lip and Palate

Craniofacial development including palatogenesis is a complex process which requires an orchestrated and spatiotemporal expression of various genes and factors for proper embryogenesis and organogenesis. One such group of genes essential for craniofacial development is the homeobox genes, transcriptional factors that are commonly associated with congenital abnormalities. Amongst these genes, DLX4, HOXB3, and MSX2 have been recently shown to be involved in the etiology of non-syndromic cleft lip and palate. Hence, we investigated the gene and protein expression of these genes in normal and cleft affected mucosal tissue obtained from 22 children, along with analyzing their role in promoting local-site inflammation using NF-κB. Additionally, we investigated the role of PTX3, which plays a critical role in tissue remodeling and wound repair. We found a residual gene and protein expression of DLX4 in cleft mucosa, although no differences in gene expression levels of HOXB3 and MSX2 were noted. However, a significant increase in protein expression for these genes was noted in the cleft mucosa (p < 0.05), indicating increased cellular proliferation. This was coupled with a significant increase in NF-κB protein expression in cleft mucosa (p < 0.05), highlighting the role of these genes in promotion of pro-inflammatory environment. Finally, no differences in gene expression of PTX3 were noted.

Effect of Alternative Preservatives on the Quality of Rice Cakes as Halal Food

The halal food market is steadily increasing. The use of alcohol for any reason is strictly prohibited in halal foods; however, ethanol is widely used as a preservative for commercial rice cakes (tteok). The purpose of this study was to investigate the use of natural substances as alternative preservatives for rice cakes. Four different solutions were tested: distilled water (control), ethanol, grapefruit seed extract (GSE), and a mixture of citric extracts and organic acids (MCO). We investigated the total plate count (TPC), yeast and mold counts, color, texture profile assays (TPA), and sensory evaluation. Significant reductions of 3.65 log CFU were observed in TPC in rice cake treated with MCO solution after 28 days of storage. However, mold and yeast counts were only reduced by ethanol treatment. Among the physical texture properties analysis, hardness was maintained for the 28 days in all samples. The total color difference values (ΔE) revealed no significant color changes in any rice cake compared to the controls. The ethanol-treated rice cake scored the lowest for overall preference and desired hardness.

AMELX Gene Association with Dental Caries in Iranian Adults

Dental decay is a disease that is greatly affected by environmental components, but recently there have been an increasing number of documents supporting a genetic factor in the development of caries. The purpose of this study was to examine the association between dental caries and single-nucleotide polymorphisms in the AMELX gene. This research was carried out on 360 individuals of both sexes, who were referred to the dental school at the Shiraz University of Medical Sciences. In this research, individuals aged 20–65 years were divided into two groups: controls (decayed, missed, or filled teeth (DMFT) ≤ 5; n = 180) and cases (DMFT ≥ 14; n = 180). The tetra-primer ARMS-PCR technique was performed for genotyping the DNA extracted from blood cells. Analysis of the AMELX rs946252 polymorphism showed that the T allele of rs946252 was a significant protective factor against dental caries in Iranian adults (T vs. C: OR = 0.70, 95% CI: 0.49–0.98, P = 0.04). We demonstrated the significant differences in the genotype frequencies under two genetic models: overdominant (TC vs. TT + CC: OR 0.35, 95% CI 0.19–0.64, P = 0.0006) and recessive (CC vs. TC + TT: OR 2.57, 95% CI 1.39–4.76, P = 0.002). Our results show that the SNPs of the AMELX gene may be related with susceptibility to dental caries in Iranian adults.

A Novel AMELX Mutation, Its Phenotypic Features, and Skewed X Inactivation

Amelogenesis imperfecta (AI) is a group of genetic disorders of defective dental enamel. Mutation of AMELX encoding amelogenin on the X chromosome is a major cause of AI. Here we report a Chinese family with hypoplastic and hypomineralized AI. Whole exome analysis revealed a novel mutation c.185delC in exon 5 of AMELX causing the frame shift p.Pro62ArgfsTer47 (or p.Pro62Argfs*47). By sequencing of polymerase chain reaction products and T-vector clones, the mutation was confirmed as homozygous in the proband, hemizygous in her father, and heterozygous in her mother. The proband and her father had small and yellowish teeth with thin and rough enamel that was radiographically indistinguishable from the underlying dentin. Scanning electronic microscopy of 1 maternal tooth showed cracks and exposed loosely packed enamel prisms in affected areas. Consistent with a 25:75 skewing of X inactivation in the peripheral blood DNA as measured by androgen receptor allele methylation, the surface of the mother’s tooth had alternating vertical ridges of transparent normal and white chalky enamel in a 34:66 ratio. In summary, this study provides one of the few phenotypic comparisons of hemizygous and homozygous AMELX mutations and suggests that the skewing of X inactivation in AI contributes to the phenotypic variations in heterozygous carriers of X-linked AI.

Enamel defects in permanent teeth of patients with cleft lip and palate: a cross-sectional study

OBJECTIVE

This study investigated the prevalence, type, and location of enamel defects in the permanent teeth of patients with complete unilateral or bilateral cleft lip and palate (CLP), and compared the prevalence and characteristics of defects between CLP patients and non-CLP individuals.

METHODS

We examined completely erupted permanent dentition, except for third molars, of CLP patients and non-CLP individuals of both sexes, 9-36 years of age, and analyzed corresponding panoramic radiographs. Two independent examiners performed clinical examinations in accordance with the Modified Developmental Defects of Enamel index.

RESULTS

A total of 210 (87.9%) CLP patients and 194 (41.4%) non-CLP individuals had at least one enamel defect; these were more prevalent in the CLP group than in the non-CLP group. Upper teeth were primarily affected by enamel defects associated with the cleft; defects were most prevalent on the cleft side in CLP patients, followed by the non-cleft side in CLP patients, and then by non-CLP individuals.

CONCLUSION

Enamel defects were more common in CLP patients than in non-CLP individuals. Among CLP patients, enamel defects were more prevalent in the cleft side of the maxilla; the central incisor was the most commonly affected tooth in this quadrant.

Factores genéticos y fisuras orofaciales no sindrómicas

<p>Las fisuras orofaciales son un grupo de anomalías cuya etiología es resultante de la interacción entre factores genéticos y ambientales. Entre todos los genes candidatos para la ocurrencia de fisuras orofaciales no sindrómicas, el más citado y conocido es el IRF6; otros genes importantes son el FOXE1, PVRL1 y el MSX1. A partir de nuevos datos consolidados referentes a esta etiología, se puede establecer un sistema más efectivo de orientación genética para prevenir la ocurrencia de estos tipos de anomalías.  Abstract Orofacial clefts are a group of anomalies whose etiology derives from the interaction between genetic and environmental factors. Among all candidate genes for the occurrence of nonsyndromic orofacial clefts, IRF6 is the most quoted and known. Other important genes are FOXE1, PVRL1 and MSX1. Thus, from new consolidated data for this etiology a more effective system of genetic counseling can be established to prevent the occurrence of these types of anomalies.</p>

A Cytogenomic Approach in a Case of Syndromic XY Gonadal Dysgenesis

This is the first molecular characterization of a female XY patient with an Xp duplication due to an X;22 translocation. Array CGH detected a copy number gain of ∼36 Mb in the Xp22.33p21.1 region involving 150 genes. Clinical and molecular studies described in the literature have suggested DAX1 duplication as the major cause responsible for a sex reversal phenotype. Additionally, the interaction between genes and their possible role in clinical features are presented to support the discussion on genotype-phenotype correlation in cases of syndromic XY gonadal dysgenesis.