Is Genetics Needed in the Dental Curriculum?

Poornima Parameswarappa¹

Department of Pediatric and Preventive Dentistry, College of Dental Sciences, Davangere, Karnataka, India

Corresponding Author: Poornima Parameswarappa, Department of Pediatric and Preventive Dentistry, College of Dental Sciences, Davangere, Karnataka, India, Phone: +91 8105482841, e-mail: drpoornimas2@gmail.com

How to cite this article: Parameswarappa P. Is Genetics Needed in the Dental Curriculum? CODS J Dent 2023;15(1):1–2.

Source of support: Nil

Conflict of interest: None

According to the American Dental Education Association (2015), no dental schools currently require genetics prior to admission was the consensus. Though genetic disorders may or may not have an impact on their oral health, there may be some conditions that manifest with oral findings and are systemically asymptomatic, which needs further evaluation and timely referral to the concerned specialist.

The dentist needs to be able to take a family and medical history to distinguish the forms of gingival hyperplasia, drug-induced or hereditary, and decide on the treatment. Associations have been made between enamel defects and kidney disease (Jaureguiberry et al., 2013), between missing teeth and colon cancer (Lammi et al., 2004), and between microdontia and deafness (Riazuddin et al., 2011).

Awareness about dental phenotype may be an isolated presentation or associated with other systemic conditions with wider healthcare implications that can direct to appropriate referrals. Dentists regularly encounter patients with genetic disorders in their practice. These include Mendelian traits such as amelogenesis imperfecta and cystic fibrosis, cytogenetic disorders such as Smith–Magenis and Williams syndromes, as well as multifactorial traits such as cleft lip/cleft palate or diabetes. In the last few years, we have seen an explosion in the number of genes associated with craniofacial development and diseases. Currently, mutations in at least seven genes are associated with amelogenesis imperfecta, a disorder of qualitative or quantitative defects of enamel; dentinogenesis imperfecta (DI) may occur as an isolated finding or as part of a syndrome such as osteogenesis imperfecta (OI), which may manifest with bone fragility and hearing loss (Hart and Hart, 2007). Mild type 1 OI may be mistaken for isolated DI (Pallos et al., 2001). Correct diagnosis is critical for discussion of phenotypic presentations, management, and genetic counseling to avoid recurrence. Enamel renal syndrome is an autosomal recessive disorder due to mutations in the FAM20A gene; amelogenesis imperfecta and gingival hyperplasia are the key features of this condition.

The renal phenotype, nephrocalcinosis, is clinically asymptomatic in children, and dentists should be able to identify and refer these individuals to nephrologists for evaluation. Mutations in the AXIN2 gene have been associated with oligodontia and colorectal cancer. Although not all patients with oligodontia have an increased risk of colorectal cancer, a history of colorectal cancer in the blood relatives of an oligodontia patient should prompt consideration of referral to the clinical geneticist for further evaluation.¹

The X and Y chromosomes affect the tooth crown size as well as craniofacial growth and development. The X chromosome mainly regulates enamel thickness, whereas the Y chromosome affects both enamel and dentin.²

The viruses responsible for oral cancer are human papillomavirus (HPV), particularly the HPV-16 and the HPV-18 strains, and herpesviruses are also now considered contributors to some oral cancers. The genes encoded within these viruses are involved in the initiation of the multiple steps needed for a normal cell to become malignant.³

Nutrition has a role in the pathogenicity of dental caries. Genetically controlled taste preferences also affect what individuals consume in their diet. Vieira et al. reported positive correlations with 5q13.3, 14q11.2, and Xq27.1, regions with low caries susceptibility, and 13q31.1 and 14q24.3, regions with high caries susceptibility. The 5q13.3 gene plays a role in reward, nutrition, and stress. Genes of amelogenin (AMELX), kallikrein 4 (KLK4), ameloblastin (AMBN), enamelin (ENAM), tuftelin (TUFT1), and tuftelin-interacting protein (TFIP11), which are connected to enamel development and mineralization were reported as caries related genes. Among them, the combined effect of the TUFT1 gene with a high level of Streptococcus mutans was observed to increase susceptibility to dental caries.⁴

Heritability studies show there is a 38–82% population variance for the periodontal measures of disease, which may be attributed to a genetic factor, although there is a general consensus that bacteria are important in the pathogenesis of periodontal disease.⁵

Dentists and physicians should consider the genetic variability with the environmental interactions affecting the patient. Interaction between human genetics and microbial genomics, proteomics, metabolomics, and pharmacogenomics will bring a big leap in the management of dental and medical health problems. Understanding the genetic nature of caries etiology could ultimately lead to personalized interventions and preventive measures and bring a shift in the paradigm of dental care from restoration to caries prevention. Knowledge of the different sequencing techniques and the resulting genetic anomalies may help in diagnosing the conditions and their prognosis as a whole in the field of dentistry.

REFERENCES

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2. Townsend GC, Aldred MJ, Bartold PM. Genetic aspects of dental disorders. Aust Dent J 1998;43(4):269–286. DOI: 10.1111/j.1834-7819.1998.tb00176.x

3. Jyoti B, Gupta M, Srivastava R, et al. Human genetics in oral medicine: a review. J Indian Acad Oral Med Radiol 2014;26(1):62–68. DOI: 10.4103/0972-1363.141860

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