Dental Hypotheses
Volume:2 Issue: 2, Apr-Jun 2011

Nanobacteria (NB) are mysterious particles that have spurred one of the biggest controversies in modern microbiology. NB has been reported to be present in animal and human blood, tissue culture cell lines, wastewater and etc. NB appear to cause or contribute to common diseases of the mankind e.g. periodontitis, formation of kidney stone, heart calcifications, coronary artery calcification, atherosclerotic plaque. Recent data on the farultraviolet extinction of starlight in our galaxy and in external galaxies is interpreted in terms of the widespread occurrence of organic particles of optical refractive index 1.4 and radii less than or equal to 20 nm. Such particles are candidates for NB such as recently been found in abundance on the Earth. Unbelievably nanobacteria-like rods observed at the surface of the Tataouine meteorite and Martian rock. The hypothesis: It seems logic to hypothesize that aliens from inner space, nanobacteria, can bring us new disease such as periodontal, cardiovascular and kidney diseases via space travels or meteorites or interstellar dusts.Evaluation of the hypothesis: The main criticism with this idea is how NB can keep alive during transfer among seriously life threatening condition in interstellar space. NB are generally thought to be very difficult to deactivation, exceptionally resistant to heat, are not deactivated by physical or chemical treatments including autoclaving, UV treatment, and various biocides. Health care providers, health policy makers and space agencies e.g. NASA and European Space Agency should make a concentrated effort to prevent transmission of NB especially following space travels.

Evidence-Based Dentistry (EBD) is a systematic approach for obtaining the best available clinically relevant scientific evidence with the ultimate goal and intent of increasing effectiveness and efficacy in clinical decision-making. EBD pursues optimizing both the patient’s benefit through the best utilization of dentist’s experience and clinical expertise, and on making full use of the most reliable and valid research outcomes. EBD is initiated by the patient-dentist interaction, which is translated into a patient-centered P.I.C.O. question. The resulting literature bibliome is assessed and quantified for the level and quality of the evidence by means of fully validated and reliable instruments based on common standard criteria of research methodology, design and statistical analysis. The outcomes are evaluated by acceptable sampling analysis, Such that studies, whose flaws have been identified to result potentially into misleading information to the patients and/or practitioner may be judiciously removed from further consideration". The research synthesis process tests for overarching statistical significance among nonheterogeneous outcomes, and yields a consensus of the best available evidence. The systematic nature of the research review and synthesis that characterizes EBD is reported in the literature as “systematic reviews”, “complex systematic reviews”, or “clinically relevant complex systematic reviews”. Thus the reported best available evidence ensures patient-centered clinical decision for interventions of the highest possible effectiveness and efficacy. EBD contrasts with traditional dentistry based on the evidence for its systematic stringency, coupled with its fundamental validity as a patient-centered optimization of clinical modes of interventions.

Although the development of normal dentition has been explored extensively, the mechanisms underlying congenitally missing teeth are far less understood. The hypothesis: Congenital absence of teeth occurs due to arrested development of a tooth primordium followed by involution, only at a stages preceding mineralized tissue formation. Evaluation of the hypothesis: We compared H & E stained serialsagittal sections of wild-type and EL mice that are congenitally missing 3rd molars (3M). 3M development was followed longitudinally in both types of mice. Occurrence of apoptosis was examined using a fluorescent TUNEL assay. To determine if a similar process might account for congenital absence of human teeth, we examined serial radiographs of developing dentitions. In EL mice, congenital absence of 3M is caused, not by a failure of initiation of tooth development rather; tooth development is initiated and subsequently arrested during early cap stage. This arrested tooth primordium is subsequently removed physiologically by apoptosis. Examination of serial radiographs where missing teeth were identified lent further evidence to support this hypothesis. Follicle spaces, with no calcified tissue within them, were noted at early stages which were seen to remodel and eventually blend with adjacent bone. Permanent teeth failed to develop in those locations. Based on the animal and human data, we propose a new model for congenital absence of teeth. Validation of this model could have profound clinical implications. If the genetic mechanisms involved in this proposed mechanism can be elucidated, it might lead to non-surgical management of supernumerary teeth.

Variant creutzfeldt jakob disease (vCJD) is the human neurological disease known to be caused by the same proteinaceous infectious agent (“prion”) that causes Bovine Spongiform Encephalopathy or "Mad Cow Disease". Two unusual and unexplained characteristics of the vCJD epidemic are its geographical distribution within the UK (about twice as frequent in Scotland and Northern England) and its median age of onset of 26 years that has remained unchanged over the fifteen years of the epidemic. The hypothesis: Infection via the dental route as a consequence of poor dental health, most probably the presence of untreated decay may account for the geographical distribution of vCJD in the UK and offer an explanation for the constant median age of onset of the disease by representing a fixed stage in development.Evaluation of the hypothesis: Analysis of existing data indicates that vCJD incidence by region and an index of dental health by region are positively correlated (r=0.737, p= 0.015). The hypothesis that infection via the dental route may explain the constant median age of onset and geographical distribution of vCJD could be investigated further with a case control study based on individual dental records and by further animal experiments to confirm the biological plausibility of this route.

Dental disease can have devastating effects on children who lack access to dental care. The US was shocked to learn of the recent death of a child from a caries related infection. The biological basis of dental caries risk is usually considered interims of individual behavior. The role of the family and other more complex units of social organization in determining caries risk are not often appreciated. The transmission of caries causing bacteria from mothers (or other care givers having extensive contact with the child) has been well documented. In addition the age at which children are vulnerable to colonization with caries causing organisms is known. Despite the fact that the dental and scientific communities possess knowledge concerning the routs of caries transmission, efforts to implement preventive programs specifically targeting the reduction of caries transmission have been inconsistent. Working with and motivating families to prevent caries transmission should be the shared objective of researchers and clinicians. Armed with the available knowledge, caries should not the thought of as an inevitable part of life. The goal of this essay is to challenge readers to empower people at risk to make decisions that enable them to break the chain of caries infection.

Trigeminocardiac reflex (TCR) is currently defined as a sudden bradycardia and decrease in mean arterial blood pressure by 20% during the manipulation of the branches of trigeminal nerve. TCR, especially during the last decade has been mostly studied in the course of neurosurgical procedures which are supposed to elicit the central subtype of TCR. Previously the well-known oculocardiac reflex was also considered as a subtype of TCR. Recently, surgeons dealing with the other branches of the fifth cranial nerve have become more interested in this reflex. Some noteworthy points have been published discussing new aspects of the trigeminocardiac reflex (TCR) in simple oral surgical procedures. Arakeri et al. have reviewed the similarities and differences between TCR, vasovagal response (VVR), and syncope. They have also explained a new possible pathway for the reflex during the simple extraction of upper first molars. The present paper aims to briefly discuss these recently presented points. Although the discussed concepts are noteworthy and consistent our preliminary results of our yet to be published studies, it seemed timely for us to discuss some possible shortcomings that may affect the results of such assessments.

Melatonin is released from the pineal gland and its release is regulated by the light. It is a well-known hormone for circadian rhythm that affects various activities of our body. In particular, melatonin has been reported to enhance the differentiation of osteoblasts in vitro and promotes bone formation in vivo. Melatonin acts on its specific receptors on the cell surface and the receptors were found to be widely distributed in many organs including the teeth, which were reported recently. Interestingly, the teeth have also been known for a long time that may grow in a rhythmic fashion. The hypothesis: Based on the aforementioned understanding on melatonin and the distribution of its receptors, we hypothesized that melatonin may be the driving force for circadian rhythmic tooth growth.Evaluation of the hypothesis: Since melatonin regulates various intracellular activities via its receptor, it is possible that melatonin also affects early development of teeth and their postnatal growth. In addition, the melatonin receptors may also involve in the pathology of various dental diseases including malocclusions.