|Year : 2012 | Volume
| Issue : 2 | Page : 53-54
Ectopic odontogenesis: A hypothesis for malocclusion to guide future research and treatment
Edward F Rossomando
University of Connecticut School of Dental Medicine and DH Editor in Chief, Farmington CT 06030, USA
|Date of Web Publication||3-Sep-2012|
Edward F Rossomando
263 Farmington Ave, Farmington CT 06030
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Rossomando EF. Ectopic odontogenesis: A hypothesis for malocclusion to guide future research and treatment. Dent Hypotheses 2012;3:53-4
| W.D. Miller and the Microbial Hypothesis for Caries and Periodontitis|| |
For most of the 20 th century W.D. Miller's hypothesis, that microbes caused caries and periodontitis, guided dental research.  Research focused on the identification of the microbes involved; the role of dietary sugar; and established that reduction of the microbial population reduces the incidence of both diseases. Because this research proved his hypothesis correct, it did much more : i0 t provided the scientific rationale for equipment and products for the dentists to diagnosis treat and attempt to prevent these diseases.
For example, the research results justified reductions in dietary sugar; education in oral hygiene promoting development of the tooth brush and tooth paste; G.V. Black's principle of extension for prevention in cavity preparation; and the fluoridation of drinking water. Given these successes it is no surprise that for most of the 20 th century, Miller's germ theory guided our profession.
| Edward Angle : O0 rthodontics Emerges to Treat Malocclusion|| |
Malocclusion is an example of a clinical dental condition. But because this condition is not caused by microbes Miller's hypothesis did not apply. In the 1890's, about the same time Miller was conducting his laboratory experiments, Edward Angle was making clinical observations from which he developed a classification of malocclusion based on the position of the maxillary first molar relative to the mandibular first molar.  He noted that malocclusion results when the teeth are in the wrong position relative to side by side neighbors or neighbors in the opposing arch. Angle did not hypothesize why the teeth were mal-positioned teeth, but did hypothesize that by applying forces to each tooth he could move the teeth into proper occlusion.
To test his hypothesis, Angle invented new methods and equipment to apply forces to a tooth and demonstrated that teeth could be moved and he could correct the malocclusion. Because of the success of his clinical research, his force application hypothesis guided research into bone remodeling for most of the 20 th century. As with Miller's hypothesis, the success of Angle's hypothesis encouraged the manufacture of equipment to apply forces to move teeth and products such as adhesives to attach brackets; radiographic techniques to measure biological age; and oral hygiene methods for patients.
| An Embryological Hypothesis for Malocclusion|| |
Two hypothesis guided dental research for most of the 20 th century : W0 .D. Miller's hypothesis for microbial based diseases and Angle's hypothesis for malocclusion. Miller's hypothesis has remained viable for microbial diseases for more than a century. In contrast, the results of extensive laboratory research during the last 30 years suggest 2012 might be an appropriate time to look at malocclusion in a new light and perhaps formulate a new way of thinking of malocclusion, a molecular hypothesis of malocclusion, based on integrating embryology of the head with genomic expression during odontogenesis.
It has been known for some years that during odontogenesis in humans a lingual extension of the primary tooth germ, the successional lamina, is the precursor for the permanent tooth. , A hypothesis for the origin of malocclusion could be developed based on the fate if this is lingual lamina. The hypothesis would postulate that ectopic positioning of the lingual lamina would result in ectopic odontogenesis which would result in malocclusion of the permanent teeth.
The hypothesis makes several predictions : i0 f ectopic odontogenesis is causal for malocclusion then controlling the positioning of the lingual lamina during embryogenesis could correct the malocclusion before birth. Unfortunately, in 2012, the dental profession has neither the scientific knowledge nor the technology to intervene during embryogenesis and alter lingual laminas position. But testing this hypothesis would shift research on malocclusion from bone remodeling to ectopic localization of tooth germs during gestation. In addition, to perform these experiments in utero would require the development of equipment and protocols that could become precursors to treatment by 21 st century orthodontists.
In addition if future research proved correct, that manipulation of the lingual lamina could alter the number and positioning of the permanent teeth, the ectopic odontogenesis hypothesis might promote the emergence of a new evidence-based dental specialty-one that could be called neonatal orthodontics.
| References|| |
|1.||Miller WD. The human mouth as a focus of infection. Dent Cosmos 1890;33:689-706. |
|2.||Angle E. Available from: http://en.wikipedia.org/wiki/Edward_Angle. [Last accessed on 2012 May 10]. |
|3.||Nanci A. Development of the Tooth and Supporting Tissues. Ch. 5 in Ten Cate's Oral Histology : D0 evelopment, Structure and Function. 8 th ed. S0 t. Louis, MO: Elsevier, Mosby : 0 2013. p. 86. |
|4.||Richman JM, Handrigan GR. Reptilian tooth development. Genesis 2011;49:247-60. |