Maxillary incisor enamel defects in individuals born with cleft lip/palate

Roles of the histone methyltransferase SET domain bifurcated 1 in epithelial cells during tooth development

OBJECTIVE

This study aimed to reveal the effects of SET domain bifurcated 1 (SETDB1) on epithelial cells during tooth development.

DESIGN

We generated conditional knockout mice (Setdb1fl/fl,Keratin14-Cre+ mice), in which Setdb1 was deleted only in epithelial cells. At embryonic day 14.5 (E14.5), immunofluorescence staining was performed to confirm the absence of SETDB1 within the epithelium of tooth embryos from Setdb1fl/fl,Keratin14-Cre+ mice. Mouse embryos were harvested after reaching embryonic day 13.5 (E13.5), and sections were prepared for histological analysis. To observe tooth morphology in detail, electron microscopy and micro-CT analysis were performed at postnatal months 1 (P1M) and 6 (P6M). Tooth embryos were harvested from postnatal day 7 (P7) mice, and the epithelial components of the tooth embryos were isolated and examined using quantitative RT-PCR for the expression of genes involved in tooth development.

RESULTS

Setdb1fl/fl,Keratin14-Cre+ mice exhibited enamel hypoplasia, brittle and fragile dentition, and significant abrasion. Coronal sections displayed abnormal ameloblast development, including immature polarization, and a thin enamel layer that detached from the dentinoenamel junction at P7. Electron microscopic analysis revealed characteristic findings such as an uneven surface and the absence of an enamel prism. The expression of Msx2, Amelogenin (Amelx), Ameloblastin (Ambn), and Enamelin (Enam) was significantly downregulated in the epithelial components of tooth germs in Setdb1fl/fl,Keratin14-Cre+ mice.

CONCLUSIONS

These results indicate that SETDB1 in epithelial cells is important for tooth development and clarify the relationship between the epigenetic regulation of SETDB1 and amelogenesis imperfecta for the first time.

Molar-incisor hypomineralization in a cohort of individuals born with cleft lip and palate

OBJECTIVE

This study aimed to investigate the frequency of molar-incisor hypomineralization (MIH) in individuals born with cleft lip and or cleft palate.

SETTINGS AND SAMPLE

Three hundred eighty-six individuals born with cleft lip and/or palate before orthodontic treatment.

METHODS

All the individuals were submitted to a clinical examination and intraoral standardized photos. The registration of MIH was taken by two orthodontists and analysed in association with the cleft type and laterality. The Kruskal-Wallis test and the regression test were used to compare the frequency of molars and incisors affected according to cleft type and laterality, sex and age.

RESULTS

We found a frequency of 67.87% of MIH in the studied sample. The frequency varied from 25% (in individuals born with cleft palate) to 77% in individuals born with bilateral cleft lip and palate). The number of affected molars was statistically different depending on cleft type and laterality (P < .001- Kruskal-Wallis test). Differences were found between individuals born with unilateral cleft lip and palate and unilateral cleft lip and alveolus (P = .03), and with isolated cleft palate (P = .03), and between individuals born with bilateral cleft lip and palate and born with unilateral cleft lip and alveolus (P = .01), and cleft palate (P = .01). Sex (P = .21) and age (P = .36) had no influence on the frequency of MIH. A positive correlation was found between the number of molars affected and incisors affected (P < .001).

CONCLUSION

Individuals born with cleft lip and palate have a higher frequency of MIH, and the complexity of cleft type was associated with the number of affected molars.

Erosive Tooth Wear, Wine Intake, and Genetic Variation in COMT and MMP2

INTRODUCTION

Erosive tooth wear (ETW) is a multifactorial condition of increasing prevalence in the younger population. This study aimed to explore the association between different ETW phenotypes with MMP2 and COMT single-nucleotide variants and selected environmental factors.

METHODS

Saliva samples, erosive wear, and dental caries experience data and dietary/behavioral information from 16- to 18-year-old patients (n = 747) were used. Genotypes were obtained, and phenotypes were further analyzed considering diet and behavioral data, using logistic regression as implemented in PLINK, with an alpha of 0.05.

RESULTS

When comparing individuals' ETW-free with those with mild ETW, an association was found with COMT rs6269 (p = 0.02). The comparison between ETW-free individuals with individuals with severe ETW also showed an association with COMT rs6269 under the recessive model (p = 0.03). Logistic regression showed that in the presence of less common alleles of MMP2 rs9923304 and COMT rs6269, ETW was more likely to occur when individuals drank wine. The GG genotype of COMT rs6269 was associated with the presence of lower (p = 0.02) and higher (p = 0.02) caries experience when individuals with ETW only in enamel were compared with individuals with ETW involving dentin.

CONCLUSION

The results support a role of genes in ETW, with wine consumption being identified as a significant modulator, suggesting that gene-environment interactions may contribute to the development of ETW.

Evaluation of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in human cases with orofacial clefts: A systematic review

INTRODUCTION

The interaction between several cell populations or many genes and the coordination of multiple signal transmission pathways can lead to defects such as orofacial clefts (OFCs). Herein, a systematic review was designed to evaluate a group of important biomarkers (matrix metalloproteinases [MMPs] and tissue inhibitors of metalloproteinases [TIMPs]) in human cases with OFCs.

MATERIAL AND METHODS

Four databases including PubMed, Scopus, Web of Science, and Cochrane Library databases were searched until March 10, 2023, without any restriction. STRING, the protein-protein interaction (PPI) network software, was applied to investigate the functional interactions among the examined genes. The effect sizes including odds ratio (OR) dealing with a 95% confidence interval (CI), were extracted by the Comprehensive Meta-Analysis version 2.0 (CMA 2.0) software.

RESULTS

Thirty-one articles were entered into the systematic review that four articles were analyzed in the meta-analysis. Single studies reported that several polymorphisms of MMPs (rs243865, rs9923304, rs17576, rs6094237, rs7119194, and rs7188573); and TIMPs (rs8179096, rs7502916, rs4789936, rs6501266, rs7211674, rs7212662, and rs242082) had an association with OFC risk. There was no significant difference for MMP-3 rs3025058 polymorphism in allelic (OR: 0.832; P=0.490), dominant (OR: 1.177; P=0.873), and recessive (OR: 0.363; P=0.433) models and MMP-9 rs17576 polymorphism in an allelic model (OR: 0.885; P=0.107) between the OFC cases and the controls. Based on immunohistochemistry reports, three MMPs (MMP-2, MMP-8, and MMP-9) and TIMP-2 had significant correlations with several other biomarkers in OFC cases.

CONCLUSIONS

MMPs and TIMPs can impact the tissue and cells affected by OFCs and the process of apoptosis. The interaction between some biomarkers with MMPs and TIMPs (e.g., TGFb1) in OFCs can be interesting for future research.

Salivary Diagnostics in Pediatrics and the Status of Saliva-Based Biosensors

Salivary biomarkers are increasingly being used as an alternative to diagnose and monitor the progression of various diseases due to their ease of use, on site application, non-invasiveness, and most likely improved patient compliance. Here, we highlight the role of salivary biosensors in the general population, followed by the application of saliva as a diagnostic tool in the pediatric population. We searched the literature for pediatric applications of salivary biomarkers, more specifically, in children from 0 to 18 years old. The use of those biomarkers spans autoimmune, developmental disorders, oncology, neuropsychiatry, respiratory illnesses, gastrointestinal disorders, and oral diseases. Four major applications of salivary proteins as biomarkers are: (1) dental health (caries, stress from orthodontic appliances, and gingivitis); (2) gastrointestinal conditions (eosinophilic esophagitis, acid reflux, appendicitis); (3) metabolic conditions (obesity, diabetes); and (4) respiratory conditions (asthma, allergic rhinitis, small airway inflammation, pneumonia). Genomics, metabolomics, microbiomics, proteomics, and transcriptomics, are various other classifications for biosensing based on the type of biomarkers used and reviewed here. Lastly, we describe the recent advances in pediatric biosensing applications using saliva. This work guides scientists in fabricating saliva-based biosensors by comprehensively overviewing the potential markers and techniques that can be employed.

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.

Pulp enlargement in individuals born with cleft lip and palate pulp, a radiographic study from the cleft lip and palate service of paraiba, Brazil'

PURPOSE

Pulp chamber enlargement impacts endodontic treatment planning. The aim of this study was to evaluate alterations in pulp chamber size of posterior teeth in individuals born with cleft lip with or without cleft palate.

METHODS

Ninety individuals were treated at the Cleft Lip and Palate Service of the University Hospital Lauro Wanderley, Federal University of Paraíba, between the ages of 4 and 15 years born with cleft lip with or without cleft palate were selected. Ninety-nine patients from the archives of the residency program in Orthodontics of the Brazilian Dental Association (ABO) were paired by sex and age as a comparison group. Radiographs were evaluated by a single examiner, observing the presence/absence of an enlarged pulp chamber in the first and second permanent molars of all quadrants. Chi square or Fisher's exact tests were used (α = 0.05) in all comparisons.

RESULTS

Pulp enlargement was more frequently found among individuals born with cleft lip with or without cleft palate (p = 0.0005). However, pulp enlargement frequency was different among subjects born with clefts (p = 0.0006). Pulp enlargement was more common in the maxilla, in both groups. Individuals born with cleft lip with or without cleft palate more often had six or more teeth affected (p = 0.02). Furthermore, individuals with a bilateral cleft more often had six or more teeth affected in comparison to unilateral cases (p = 0.002).

CONCLUSION

Pulp enlargement is a frequent finding, particularly among individuals born with cleft lip with or without cleft palate, with a higher prevalence in the maxilla.