Transgenerational Inheritance and Primary Molar Ankylosis

A Review

Transgenerational Inheritance: Models and mechanisms of non-DNA sequence-based inheritance. E.A. Miska, A.C. Ferguson-Smith, Science 354, 59-63 (2016)

This review suggests the possibility of a non-DNA based sequence-based inheritance model that could be applied to Primary Molar Ankylosis (PMA). Older concepts that placed this oral pathology into a less defined etiology suggests that a conceptualization of an epigenetic etiology could materially influence the creation of a treatment plan that more correctly identifies the role played by a putative epigenetic etiology, thus maximizing the management of this oral disease.

The dental practitioner must carefully consider the ramifications of a treatment regimen that redefines the etiology of PMA into a newer genetic/epigentic category that will improve our construction of a treatment plan. Our treatment protocols would then allow a more complete visualization of the pathology and generate a treatment plan that fits the projected model of progression based upon new information contained within the research community. The adoption of the revised treatment protocol based on a newer thesis of etiology will likely allow current Pediatric Dental practitioners to more accurately define etiology and to define future outcomes more accurately.

A Dental Model for non-DNA sequence-based Inheritance

The contributor to this blog has often sought to blend the pure DNA model of inheritance with emerging tenets that extend the understanding of pure DNA inheritance with blending of an additional component…epigenetics. Extant inheritance models have some difficulty explaining how a pediatric dental patient can exhibit PMA that is too often simply explained as a post traumatic incident. Pediatric Dentistry has often not been able to succinctly describe the etiology of this anomaly that occurs quite often in the primary dentition. While the dental literature often suggests that there is hereditable component to this pathology, the exact nature of the etiology has yet to be described. The dental literature is often lacking an up-to-date survey of the literature is related to PMA. However, few research articles are able to expand on a growing awareness of the complicated etiology that surrounds the lack of the periodontal ligament in the primary dentition. A basic understanding of the role-played by genetics/ epigenetics is often missing which results in the distribution of misinformation to the profession and the general public. Our profession must address this issue by continuing to support research and provide aid to families that are afflicted with this oral pathology that severely modifies the eruption pattern of the succedaneous dentition An emerging model of epigenetic regulation has appeared in the literature that could clarify this pathology and provide a newer overview of treatment possibilities and the creation of awareness among Pediatric Dental practitioners. This pathology cannot be trivialized and practitioners and patients alike must be aware of the early stages of the disease that often initially presents as a minor occlusal problem. The initial diagnosis of PMA can be the simple observation that the offending primary molar does not occlude with the opposing arch. In addition, the dental x-ray will be unable to define an intact periodontal ligament. The root surface of the offending primary molar will appear to be confluent with the surrounding alveolar bone. The use of percussion will also indicate that the attachment of the primary molar has a distinct “feel” and a “modified” sound response as compared to a adjoining non-affected molar. A gentle tap with the handle of the mouth mirror will often be a capable diagnostic tool.