08/06/2010 Inherited Risks for Susceptibility to Dental Caries

Resident: Hencler
Date: 08/06/2010

Article title: Inherited Risks for Susceptibility to Dental Caries
Author: Charles F. Shuler, DMD, PhD
Journal: Journal of Dental Education Vol. 65, No. 10 October 2001

Major topic: Genetic inheritance and caries susceptibility
Type of Article: Review

Main Purpose:
Investigate if the risk for dental decay is related to patterns of genetic inheritance.

Overview of method of research:
The literature was searched for evidence of a genetic contribution to caries based on four factors: 1) the role of dental hard tissues, the target for acid dissolution by cariogenic bacteria, and the genetics of altered enamel biomineralization. 2) Alterations in the immune response reducing the clearance of the bacteria. 3) The impact of inherited deficiencies in sugar metabolism that could alter the substrate availability. 4) Inheritance of parameters related to either salivary flow or saliva constituents.

Twin Studies:
The study of caries susceptibilities in twins represented one of the most direct measures of analyzing the contribution of inheritance to disease incidence. Investigating twins raised apart provides the strongest evidence of a genetic contribution to the incidence of caries but studies were unable to provide any evidence of linkage to specific genes.

Key points in the article discussion:
1) Numerous studies report dental caries as a component of a well-defines inherited genetic syndrome with craniofacial phenotypes. These studies document alterations in tooth morphology and enamel formation and the overall caries experience of the patient; but fail to link the genetic syndrome, often resulting from a single gene mutation, to the incidence of dental caries. Such an example is epidermolysis bullosa (EB). EB has 4 variants that are associated with increased caries incidence due to enamel defects. 2) Studies show that individuals with an inherited or acquired immune deficiency are subject to increased risk for and incidence of dental caries. Studies have provided evidence that the genes in the human leukocyte antigen (HLA) complex are associated with altered enamel development and increased susceptibility to dental caries. The role of HLA genes in the immune response to cariogenic bacteria represent a mechanism that is based on inherited genetic complement that may be a potential marker for increased dental caries risk. 3) Since ingestion of the cariogenic substrate contributes to the multifactorial process of dental caries, inherited defects in sugar metabolism would most likely alter substrate availability in a manner identical to any other dietary restriction and not by a genetically unique mechanism. 4) Xerostomia is associated with dramatically increased rates of dental caries.

Summary of conclusions:
The multifactorial nature of dental caries has limited the opportunity to link patterns of inheritance with susceptibility to dental caries.

Assessment of article:
Article was okay. Some pertinent information, but nothing new or ground breaking. Dental caries incidence is multifactorial and because of this, determining a specific genetic basis for dental caries very will be very difficult.