-
Materia Socio-medica 2023Dental anomalies (DAs) represent a significant chapter in pediatric dentistry with a lot of practical relevance. Both primary and permanent dentitions may be affected.
BACKGROUND
Dental anomalies (DAs) represent a significant chapter in pediatric dentistry with a lot of practical relevance. Both primary and permanent dentitions may be affected.
OBJECTIVE
The main objective of our study was to evaluate, using digital panoramic radiographs, the prevalence, distribution, and patterns of DAs in a sample of Lebanese children aged between 8 and 15 years old.
METHODS
112 digital panoramic radiographs of patients aged between 8 and 15 years (60 males and 52 females) from the year 2017 till 2022 attending the department of Pediatric Dentistry and Dental Public Health at the Faculty of Dental Medicine at the Lebanese University were assessed for DAs of number (hypodontia, oligodontia, hyperdontia), of size (microdontia, macrodontia), of shape (fusion, gemination, dilaceration, taurodontism), of position (transposition, ectopia, impaction), and of structure (dentin dysplasia, amelogenesis imperfecta, dentinogenesis imperfecta). The data were analyzed statistically using Chi-square and Fisher's exact tests.
RESULTS
Out of 112 patient radiographs, 84 showed at least one DA, which suggests a very high prevalence (75%). Among them, 36.9% exhibited multiple types of anomalies. These 84 patients showed a total of 274 DAs, distributed equally among males and females.
CONCLUSION
Dentists should be alerted to the presence of DAs. Their high prevalence requires careful clinical and radiological examinations for early detection. Regular monitoring is mandatory and could guide preventive approaches to minimize associated dental complications.
PubMed: 38380282
DOI: 10.5455/msm.2023.35.319-324 -
Proceedings of the National Academy of... Dec 2022The outstanding mechanical and chemical properties of dental enamel emerge from its complex hierarchical architecture. An accurate, detailed multiscale model of the...
The outstanding mechanical and chemical properties of dental enamel emerge from its complex hierarchical architecture. An accurate, detailed multiscale model of the structure and composition of enamel is important for understanding lesion formation in tooth decay (dental caries), enamel development (amelogenesis) and associated pathologies (e.g., amelogenesis imperfecta or molar hypomineralization), and minimally invasive dentistry. Although features at length scales smaller than 100 nm (individual crystallites) and greater than 50 µm (multiple rods) are well understood, competing field of view and sampling considerations have hindered exploration of mesoscale features, i.e., at the level of single enamel rods and the interrod enamel (1 to 10 µm). Here, we combine synchrotron X-ray diffraction at submicrometer resolution, analysis of crystallite orientation distribution, and unsupervised machine learning to show that crystallographic parameters differ between rod head and rod tail/interrod enamel. This variation strongly suggests that crystallites in different microarchitectural domains also differ in their composition. Thus, we use a dilute linear model to predict the concentrations of minority ions in hydroxylapatite (Mg and CO/Na) that plausibly explain the observed lattice parameter variations. While differences within samples are highly significant and of similar magnitude, absolute values and the sign of the effect for some crystallographic parameters show interindividual variation that warrants further investigation. By revealing additional complexity at the rod/interrod level of human enamel and leaving open the possibility of modulation across larger length scales, these results inform future investigations into mechanisms governing amelogenesis and introduce another feature to consider when modeling the mechanical and chemical performance of enamel.
Topics: Humans; Dental Caries; Crystallography; Amelogenesis Imperfecta; Amelogenesis; Dental Enamel
PubMed: 36534796
DOI: 10.1073/pnas.2211285119 -
Swiss Dental Journal Dec 2022The diagnosis and treatment of amelogenesis imperfecta (AI) represents a considerable rehabilitative challenge. Three critical aspects must be emphasised in particular:...
The diagnosis and treatment of amelogenesis imperfecta (AI) represents a considerable rehabilitative challenge. Three critical aspects must be emphasised in particular: 1. as a congenital dental dysplasia, AI is a congenital defect, is covered by federal disability insurance and requires early definitive treatment before the age of twenty; 2. treatment is complex, interdisciplinary and usually invasive; and 3. restorations must be fixed on structurally compromised tooth structure.
Topics: Humans; Amelogenesis Imperfecta
PubMed: 36448981
DOI: 10.61872/sdj-2022-12-03 -
Children (Basel, Switzerland) Nov 2022Background: A prompt and accurate diagnosis of developmental defects of enamel (DDE) is mandatory for proper treatment management. This cross-sectional survey, designed...
Background: A prompt and accurate diagnosis of developmental defects of enamel (DDE) is mandatory for proper treatment management. This cross-sectional survey, designed and carried out using anonymous self-administered questionnaires, aimed to assess dental and dental hygiene students’ knowledge and their capability to identify different enamel development defects. Methods: The questionnaire consisted of twenty-eight closed-ended questions. Two different samples of undergraduate students were selected and enrolled: a group of dental hygiene (GDH) students and a group of dental (GD) students. A multivariate logistic regression was performed by adopting the correct answers as explanatory variables to assess the difference between the two groups. Results: Overall, 301 completed questionnaires were analyzed: 157 from the GDH and 144 from the GD. The dental student group showed better knowledge than the GDH of enamel hypomineralization and hypoplasia (p = 0.03 for both). A quarter (25.25%) of the total sample correctly identified the period of development of dental fluorosis with a statistically significant difference between the groups (p < 0.01). Amelogenesis imperfecta (AI) was identified as a genetic disease by 64.45% of the sample, with a better performance from the GD (p = 0.01), while no statistical differences were found between the groups regarding molar incisor hypomineralization. Multivariate analysis showed that AI (OR = 0.40, [0.23;0.69], p < 0.01) and caries lesion (OR = 0.58, [0.34;0.94], p = 0.03) were better recognized by the GD. Conclusions: Disparities exist in the knowledge and management of DDE among dental and dental hygiene students in Italy; however, significant knowledge gaps were found in both groups. Education on the diagnosis and treatment of DDE during the training for dental and dental hygiene students needs to be strongly implemented.
PubMed: 36421208
DOI: 10.3390/children9111759 -
Cureus Oct 2022Disturbances seen during tooth formation result in developmental dental anomalies presenting in the oral cavity. These anomalies manifest as discrepancies in the...
BACKGROUND
Disturbances seen during tooth formation result in developmental dental anomalies presenting in the oral cavity. These anomalies manifest as discrepancies in the number, color, size, and shape of the teeth. These dental anomalies can either be acquired, congenital, or developmental. Their early detection and management are necessary as they affect aesthetics and occlusion. The study had the aim of gauging the prevalence of developmental anomalies in the permanent dentition of Indian subjects.
METHODS
A total of 1192 participants recruited from the institute for study purposes, comprising males and females, were examined clinically and radiographically, and their dental casts were also evaluated. These subjects were assessed for anomalies in position, structure, number, and/or shape. Anomalies in the position include transmigration, transportation, and/or ectopic position; anomalies in the structure, including dentinogenesis imperfecta or amelogenesis imperfecta; anomalies in number, including hyperdontia or hypodontia; and anomalies in shape, including peg laterals, taurodontism, fusion, dens evaginatus, talon cusp, and/or microdontia.
RESULTS
A statistically significant difference was seen in unilateral microdontia and dentinogenesis imperfecta between males and females, with attained p-values of 0.003 and 0.06, respectively. The results of the present study showed that 9.89% (n = 118) study subjects, whereas 1% (n = 12) study subjects had two dental anomalies in their permanent dentitions, with no subject presenting more than two dental anomalies, showing that various dental anomalies have a low prevalence in the Indian population.
CONCLUSION
The present study has led to the conclusion that the prevalence of dental anomalies is low in Indian subjects. However, these anomalies should be detected and treated early to prevent them from causing further complications.
PubMed: 36397922
DOI: 10.7759/cureus.30156 -
Open Medicine (Warsaw, Poland) 2022Congenital adrenal hyperplasia (CAH) is a genetic disorder characterized by an impairment of steroid synthesis due to an altered production of 21-hydroxylase enzyme.... (Review)
Review
Congenital adrenal hyperplasia (CAH) is a genetic disorder characterized by an impairment of steroid synthesis due to an altered production of 21-hydroxylase enzyme. Corticoid hormones are involved in the development and functioning of many organs. The aim of the present study was to review the international literature to collect data regarding oral manifestations of CAH. A review of the literature describing oral features of patients affected by CAH was performed using electronic databases (PubMed and Scopus). The data about number of patients, form of CAH, and oral findings were extracted and analyzed. Seven studies were included in the final analysis. The principal findings reported regarded an advanced dental development observed in patients with CAH. One paper reported amelogenesis imperfecta and periodontal issues. The dentist could be the first specialist involved in the CAH syndrome diagnosis, identifying the characteristic features described above, especially for the classical simple virilizing and non-classical form.
PubMed: 36382053
DOI: 10.1515/med-2022-0524 -
Oral Diseases Nov 2023Amelogenesis imperfecta (AI) is defined as inherited enamel malformations. LAMA3 (laminin alpha-3) encodes a critical protein component of the basement membrane...
OBJECTIVE
Amelogenesis imperfecta (AI) is defined as inherited enamel malformations. LAMA3 (laminin alpha-3) encodes a critical protein component of the basement membrane (laminin-332). Individuals carrying heterozygous LAMA3 mutations have previously been shown to have localized enamel defects. This study aimed to define clinical phenotypes and to discern the genetic etiology for four AI kindreds.
MATERIALS AND METHODS
Whole-exome analyses were conducted to search for sequence variants associated with the disorder, and micro-computed tomography (μCT) to characterize the enamel defects.
RESULTS
The predominant enamel phenotype was generalized thin enamel with defective pits and grooves. Horizonal bands of hypoplastic enamel with chalky-white discoloration and enamel hypomineralization were also observed and demonstrated by μCT analyses of affected teeth. Four disease-causing LAMA3 mutations (NM_198129.4:c.3712dup; c.5891dup; c.7367del; c.9400G > C) were identified. Compound heterozygous MMP20 mutations (NM_004771.4:c.539A > G; c.692C > T) were also found in one proband with more severe enamel defects, suggesting a mutational synergism on disease phenotypes. Further analyses of the AI-causing mutations suggested that both α3A (short) and α3B (long) isoforms of LAMA3 are essential for enamel formation.
CONCLUSIONS
Heterozygous LAMA3 mutations can cause generalized enamel defects (AI1A) with variable expressivity. Laminin-332 is critical not only for appositional growth but also enamel maturation.
Topics: Humans; Amelogenesis Imperfecta; Laminin; X-Ray Microtomography; Dental Enamel; Extracellular Matrix Proteins; Mutation; Phenotype; Biological Variation, Population; Pedigree
PubMed: 36326426
DOI: 10.1111/odi.14425 -
Journal of Cellular and Molecular... Nov 2022Family with sequence similarity 83 members H (Fam83h) is essential for dental enamel formation. Fam83h mutations cause human amelogenesis imperfecta (AI), an inherited...
Family with sequence similarity 83 members H (Fam83h) is essential for dental enamel formation. Fam83h mutations cause human amelogenesis imperfecta (AI), an inherited disorder characterized by severe hardness defects in dental enamel. Nevertheless, previous studies showed no enamel defects in Fam83h-knockout/lacZ-knockin mice. In this study, a large deletion of the Fam83h gene (900 bp) was generated via a dual sgRNA-directed CRISPR/Cas9 system in rabbits. Abnormal tooth mineralization and loose dentine were found in homozygous Fam83h knockout (Fam83h ) rabbits compared with WT rabbits. In addition, reduced hair follicle counts in dorsal skin, hair cycling dysfunction and hair shaft differentiation deficiency were observed in Fam83h rabbits. Moreover, X-rays and staining of bone sections showed abnormal bending of the ulna and radius and an ulnar articular surface with insufficient trabecular bone in Fam83h rabbits. Taken together, these data are the first report of defective hair cycling, hair shaft differentiation and abnormal bending of the ulna and radius in Fam83h rabbits. This novel Fam83h rabbit model may facilitate understanding the function of Fam83h and the pathogenic mechanism of the Fam83h mutation.
Topics: Humans; Mice; Animals; Rabbits; CRISPR-Cas Systems; Proteins; Amelogenesis Imperfecta; Tooth Calcification; Hair
PubMed: 36300761
DOI: 10.1111/jcmm.17597 -
Frontiers in Physiology 2022Junctional epidermolysis bullosa (JEB) is a group of autosomal recessive disorders characterized by amelogenesis imperfecta (AI) and fragility of the skin and mucous...
Junctional epidermolysis bullosa (JEB) is a group of autosomal recessive disorders characterized by amelogenesis imperfecta (AI) and fragility of the skin and mucous membranes. The purpose of this study was to identify pathogenic gene variants and investigate the phenotypic characteristics of abnormal enamel structure and mucocutaneous lesions in a patient with JEB. Clinical examination of the patient revealed hypoplastic AI, skin lesions, and oral ulcers, whereas her parents were normal. Whole-exome sequencing (WES) and cDNA cloning identified compound heterozygous variants of in the proband: c.125G>C in exon 3, c.1288 + 1G>A in intron 11, and c.1348C>T in exon 12. Among these, c.125G>C was inherited from her father, and the other two variants were inherited from her mother. Functional prediction indicated that the variants might change protein structure and cause disease. Scanning electron microscopy (SEM) examination of the primary and permanent teeth revealed abnormal enamel morphology and microstructures. Hematoxylin-eosin (HE) and immunofluorescence (IF) staining showed significantly abnormal and disorganized epithelial cells in the gingival mucosa. Our results showed that this was a case of intermediate JEB1A (OMIM #226650) with autosomal recessive inheritance. The proband carried rare compound heterozygous variants of . Our results broaden the variant spectrum of the gene and JEB cases. Moreover, this is the first study to identify histological malformations of the primary teeth and oral mucosa in -related patients.
PubMed: 36299258
DOI: 10.3389/fphys.2022.1006980 -
Scientific Reports Oct 2022Human ACP4 (OMIM*606362) encodes a transmembrane protein that belongs to histidine acid phosphatase (ACP) family. Recessive mutations in ACP4 cause non-syndromic...
Human ACP4 (OMIM*606362) encodes a transmembrane protein that belongs to histidine acid phosphatase (ACP) family. Recessive mutations in ACP4 cause non-syndromic hypoplastic amelogenesis imperfecta (AI1J, OMIM#617297). While ACP activity has long been detected in developing teeth, its functions during tooth development and the pathogenesis of ACP4-associated AI remain largely unknown. Here, we characterized 2 AI1J families and identified a novel ACP4 disease-causing mutation: c.774_775del, p.Gly260Aspfs*29. To investigate the role of ACP4 during amelogenesis, we generated and characterized Acp4 mice that carry the p.(Arg110Cys) loss-of-function mutation. Mouse Acp4 expression was the strongest at secretory stage ameloblasts, and the protein localized primarily at Tomes' processes. While Acp4 heterozygous (Acp4) mice showed no phenotypes, incisors and molars of homozygous (Acp4) mice exhibited a thin layer of aplastic enamel with numerous ectopic mineralized nodules. Acp4 ameloblasts appeared normal initially but underwent pathology at mid-way of secretory stage. Ultrastructurally, sporadic enamel ribbons grew on mineralized dentin but failed to elongate, and aberrant needle-like crystals formed instead. Globs of organic matrix accumulated by the distal membranes of defective Tomes' processes. These results demonstrated a critical role for ACP4 in appositional growth of dental enamel probably by processing and regulating enamel matrix proteins around mineralization front apparatus.
Topics: Acid Phosphatase; Ameloblasts; Amelogenesis; Amelogenesis Imperfecta; Animals; Dental Enamel Proteins; Histidine; Humans; Mice; Mutation
PubMed: 36183038
DOI: 10.1038/s41598-022-20684-9