The Changing Scene of Practicing Dentistry: A Survey of the Past 200 Years.

If one could be a patient repeatedly, every twenty-five years, starting in 1825, the evolution and comparison of dental care and dental practice would be historically meaningful. Such a time travel, as a perpetual patient through 200 years, is the purpose of this paper. The changes that occurred over 200 years provide a sense of the progress in treating patients and the transformation of a painful and dreaded experience to a highly sophisticated painless profession.

John Greenwood's sidenotes on a 1778 John Hunter text at The New York Academy of Medicine.

John Greenwood (1760-1819) was George Washington's preferred dentist. He practiced in New York and made at least one of eight sets of dentures Washington wore (currently in the collection of the New York Academy of Medicine (NYAM). We know very little about John Greenwood's (JG) formal education, except that he came from a famous family of dentists. He inherited from his father, Isaac Greenwood, one important book of the time, John Hunter's 1778 treatise, A Natural History of the Human Teeth. That copy was donated to the New York Academy of Medicine by descendants of John Greenwood. Recently, we became aware of extensive marginalia that John Greenwood wrote in this book. The present article describes John Greenwood's opinion on a variety of dental subjects such as the causes and mechanisms of tooth destruction and gum disease and the presence of microscopic annamalcula that were thought to be connected to poor oral hygiene. Although John Greenwood was self-educated, his observations are surprisingly insightful and at least 37 years ahead of what was described in the contemporary literature.

Chemosensory loss in COVID-19.

The COVID-19 pandemic caused by SARS-CoV-2 virus quickly spread globally, infecting over half a billion individuals, and killing over 6 million*. One of the more unusual symptoms was patients' complaints of sudden loss of smell and/or taste, a symptom that has become more apparent as the virus mutated into different variants. Anosmia and ageusia, the loss of smell and taste, respectively, seem to be transient for some individuals, but for others persists even after recovery from the infection. Causes for COVID-19-associated chemosensory loss have undergone several hypotheses. These include non-functional or destroyed olfactory neurons and gustatory receptors or of their supporting cells, disruption of the signaling protein Neuropilin-1, and disruption in the interaction with semaphorins, key molecules in the gustatory and olfactory axon guidance. The current paper will review these hypotheses and chart out potential therapeutic avenues.

Magnetism.

Quackery in medicine is as old as medicine itself. In times of crisis desperate patients often believe extraordinary claims. In the annals of pain killer quack medicine, elixirs, nostrums and liniments hold a special position. The College of Dentistry at NYU received a collection of 234 bottles of nostrums and liniments dating from approximately 1850 through 1940. In this paper, the FOURTH in a series of articles featuring "Elixirs of the Past" we bring to light four more samples claiming to have magnetic properties: Dr. J.R. Miller's Magnetic Balm, Havens' Electromagnetic Liniment, Headman's Magnetic Liniments, and Magnetic Cream. It goes without saying that none of these had any magnetic properties. In 1906, Congress enacted The Pure Food and Drug Act to prohibit exaggerated or unsubstantiated claims in the marketing and labeling of household products and to control the use of potentially harmful ingredients. The modern-day use of internet advertisements to make unsupported claims is in some ways even more brazen than the advertisements from a century ago.

Electricity.

Quackery in medicine is as old as medicine. In times of crisis desperate patients believe in extraordinary claims. In the annals of pain killer quack medicine, elixirs, nostrums and liniments hold a special position. The College of Dentistry at NYU received a collection of 234 bottles of quack medicine dating from approximately 1850 through 1940.In this paper, the THIRD in a series of articles featuring "Elixirs of the Past", we focus on five particularly notable samples claiming to have "electric" properties: Electric Brand Oil Compound, Hunt's Lightening Oil, Electric Indian Liniment, Regent's Electric Liniment and Haven's Electro-magnetic Liniment. Needless to say, none of these contained electricity or even electrolytes for that matter. In 1906, Congress enacted The Pure Food and Drug Act to prohibit exaggerated or unsubstantiated claims in the marketing and labeling of household products and to control the use of potentially harmful ingredients. The modern-day use of internet advertisements to make unsupported claims is in some ways even more brazen than the advertisements from a century ago.

Snake Oil and Indian Liniment.

Quackery in medicine is as old as medicine itself. In times of crisis, desperate patients often believe extraordinary claims. In the annals of pain-killer quack medicine, snake oil, elixirs, nostrums and Indian liniments hold a special position. NYU College of Dentistry (NYUCD) has a collection of 234 bottles of such medicines dating from the mid-1800s through 1940. This paper is the fifth in a series of articles featuring "Elixirs of the Past" in which we bring to light six more samples with claims to traditional Chinese or American Indian medicine using snake oil: Virex Compound, Rattlesnake Bill's Oil, Electric Indian Liniment, The King of All Indian Oils, Millerhaus Antiseptic Oil and Celebrated Indian Lotion. The six examples are just a few quack medications linked to fraud, overdose, addiction or death. In 1906, Congress enacted The Pure Food and Drug Act and reinforced it with the Federal Food, Drug and Cosmetic Act of 1938, to stop unsubstantiated medicinal claims and control the use of addictive and dangerous substances. The modern-day use of social media to advertise quack medicine is in some ways even more brazen than selling patent medicine a century ago.

Opium.

Quackery in medicine is as old as medicine itself. In times of crisis, desperate patients often believe extraordinary claims. In the annals of pain-killer quack medicine, elixirs, nostrums and liniments hold a prominent position. NYU College of Dentistry (NYUCD) has a collection of 234 bottles of such medicines dating from the mid-1800s through 1940. This paper is the second in a series of articles featuring "Elixirs of the Past" in which we bring to light five more samples containing opium: Dr. B.J. Kendall's Instant Relief for Pain, Dr. Munn's Elixir of Opium, Dill's Balm of Life, Foley's Pain Relief, and Brown's Instant Relief for Pain. These are just five examples out of countless syrups, nostrums, balm or liniments that contained narcotics and were linked to overdose, addiction and sometimes death. In 1906, Congress enacted The Pure Food and Drug Act to stop unsubstantiated medicinal claims and control the use of addictive substances. The modern-day use of internet advertisements to make unsupported claims is in some ways even more brazen than the advertisements from a century ago. Indeed, the recent widespread use of prescription painkillers, along with the resulting epidemic in opiate addiction that has caused upwards of 50,000 deaths is a case in point.

Zika virus infection in chemosensory cells.

Zika virus (ZIKV) is an emerging virus belonging to the genus Flavivirus. ZIKV infection is a significant health concern, with increasing numbers of reports of microcephaly cases in fetuses and Guillain-Barré syndrome (GBS) in adults. Interestingly, chemosensory disturbances are also reported as one of the manifestations of GBS. ZIKV infects several human tissues and cell types in vitro and in vivo. However, there is no study demonstrating ZIKV infection and replication in chemosensory cells, including olfactory and taste cells. Taste papilla and olfactory cells are chemosensory receptor cells with unique histological, molecular, and physiological characteristics. Here we examined ZIKV infection (PRVABC59) in cultured human olfactory epithelial cells (hOECs) and fungiform taste papilla (HBO) cells in vitro, as well as in vivo mouse taste and olfactory epithelial and olfactory bulb tissues. Interestingly, while HBO cells showed resistance to ZIKV replication, hOECs were highly susceptible for ZIKV infection and replication. Further, we demonstrated the presence of ZIKV particles and expression of viral proteins in olfactory epithelium, as well as in olfactory bulb, but not in taste papillae, of immunocompromised mice (ifnar/-) infected with the PRVABC59 strain of ZIKV. These observations suggest that chemosensory cells in the olfactory neuroepithelium and olfactory bulb may be important tissues for ZIKV replication and dissemination.

The College of Dentistry at New York University Brings this Section to Life with "Elixers of the Past".

Quackery in medicine is as old as medicine. In times of crisis desperate patients believe in extraordinary claims. In the annals of pain killer quack medicine, elixirs, nostrums and liniments hold a preeminent position. The College of Dentistry at NYU received a collection of 237 bottles of nostrums and liniments dating from approximately 1850 through 1940. In this paper we inaugurate a series of articles featuring "Elixirs of the Past". We start this series with four samples, Mrs. Winslow's Soothing Syrup, Dr. Grove's Anodyne for Infants, Jadway's Elixir for Infants and Kopp's, four of many teething syrups that contained narcotics and were linked to infant death at the end of the 19th century. In 1906 Congress introduced The Pure Food and Drug Act to stop unsubstantiated claims. Companies were fined in court cases and finally compelled to remove narcotics and stop making unsubstantiated claims. Unmasking past claims hopefully stops quacks of today. Nevertheless, far more unfounded and extraordinary claims are being made today, using social media, perhaps more brazenly than one hundred years ago.

Mammalian Taste Cells Express Functional Olfactory Receptors.

The peripheral taste and olfactory systems in mammals are separate and independent sensory systems. In the current model of chemosensation, gustatory, and olfactory receptors are genetically divergent families expressed in anatomically distinct locations that project to disparate downstream targets. Although information from the 2 sensory systems merges to form the perception of flavor, the first cross talk is thought to occur centrally, in the insular cortex. Recent studies have shown that gustatory and olfactory receptors are expressed throughout the body and serve as chemical sensors in multiple tissues. Olfactory receptor cDNA has been detected in the tongue, yet the presence of physiologically functional olfactory receptors in taste cells has not yet been demonstrated. Here we report that olfactory receptors are functionally expressed in taste papillae. We found expression of olfactory receptors in the taste papillae of green fluorescent protein-expressing transgenic mice and, using immunocytochemistry and real-time quantitative polymerase chain reaction experiments, the presence of olfactory signal transduction molecules and olfactory receptors in cultured human fungiform taste papilla (HBO) cells. Both HBO cells and mouse taste papilla cells responded to odorants. Knockdown of adenylyl cyclase mRNA by specific small inhibitory RNA and pharmacological block of adenylyl cyclase eliminated these responses, leading us to hypothesize that the gustatory system may receive olfactory information in the periphery. These results provide the first direct evidence of the presence of functional olfactory receptors in mammalian taste cells. Our results also demonstrate that the initial integration of gustatory and olfactory information may occur as early as the taste receptor cells.

Tissue-Dependent Expression of Bitter Receptor TAS2R38 mRNA.

TAS2R38 is a human bitter receptor gene with a common but inactive allele; people homozygous for the inactive form cannot perceive low concentrations of certain bitter compounds. The frequency of the inactive and active forms of this receptor is nearly equal in many human populations, and heterozygotes with 1 copy of the active form and 1 copy of the inactive form have the most common diplotype. However, even though they have the same genotype, heterozygotes differ markedly in their perception of bitterness, perhaps in part because of differences in TAS2R38 mRNA expression. Other tissues express this receptor too, including the nasal sinuses, where it contributes to pathogen defense. We, therefore, wondered whether heterozygous people had a similar wide range of TAS2R38 mRNA in sinonasal tissue and whether those with higher TAS2R38 mRNA expression in taste tissue were similarly high expressers in nasal tissue. To that end, we measured gene expression by quantitative PCR in taste and sinonasal tissue and found that expression abundance in one tissue was not related to the other. We confirmed the independence of expression in other tissue pairs expressing TAS2R38 mRNA, such as pancreas and small intestine, using autopsy data from the Genotype-Tissue Expression project (although people with high expression of TAS2R38 mRNA in colon also tended to have higher expression in the small intestine). Thus, taste tissue TAS2R38 mRNA expression among heterozygotes is unlikely to predict expression in other tissues, perhaps reflecting tissue-dependent function, and hence regulation, of this protein.

Digital Access to the Weinberger Rare Book Collection at NYU College of Dentistry.

Dr. Bernhard Weinberger (1885-1960), an alumnus of the University of Pennsylvania School of Dental Medicine, class of 1910 and a specialist in orthodontics, was a faculty at NYU Dentistry from 1923-1931 as lecturer and later professor in History of Dentistry. Part of his famous collection of rare books ended up at New York University College of Dentistry shortly before his death. For decades, the collection was forgotten. Now, with the help of technology we started a project of digitization. The current paper is an effort to take a full inventory of the collection, catalogue the titles, condition, discrepancies and missing books and take a digital photo of the cover page, and to create a digital platform to showcase highlights of this collection worldwide with features that include photos, blogs, digital content and links to outside resources. The ultimate goal is to digitize at least 20% (about 200) of the books in the collection. Access the collection at https://dental.nyu.edu/aboutus/rare-book-collection.html.

Caffeine Bitterness is Related to Daily Caffeine Intake and Bitter Receptor mRNA Abundance in Human Taste Tissue.

We investigated whether the abundance of bitter receptor mRNA expression from human taste papillae is related to an individual's perceptual ratings of bitter intensity and habitual intake of bitter drinks. Ratings of the bitterness of caffeine and quinine and three other bitter stimuli (urea, propylthiouracil, and denatonium benzoate) were compared with relative taste papilla mRNA abundance of bitter receptors that respond to the corresponding bitter stimuli in cell-based assays ( TAS2R4, TAS2R10, TAS2R38, TAS2R43, and TAS2R46). We calculated caffeine and quinine intake from a food frequency questionnaire. The bitterness of caffeine was related to the abundance of the combined mRNA expression of these known receptors, r = 0.47, p = .05, and self-reported daily caffeine intake, t(18) = 2.78, p = .012. The results of linear modeling indicated that 47% of the variance among subjects in the rating of caffeine bitterness was accounted for by these two factors (habitual caffeine intake and taste receptor mRNA abundance). We observed no such relationships for quinine but consumption of its primary dietary form (tonic water) was uncommon. Overall, diet and TAS2R gene expression in taste papillae are related to individual differences in caffeine perception.

Membrane-permeable tastants amplify ß2-adrenergic receptor signaling and delay receptor desensitization via intracellular inhibition of GRK2's kinase activity.

BACKGROUND: Amphipathic sweet and bitter tastants inhibit purified forms of the protein kinases GRK2, GRK5 and PKA activities. Here we tested whether membrane-permeable tastants may intracellularly interfere with GPCR desensitization at the whole cell context. METHODS: ß2AR-transfected cells and cells containing endogenous ß2AR were preincubated with membrane-permeable or impermeable tastants and then stimulated with isoproterenol (ISO). cAMP formation, ß2AR phosphorylation and ß2AR internalization were monitored in response to ISO stimulation. IBMX and H89 inhibitors and GRK2 silencing were used to explore possible roles of PDE, PKA, and GRK2 in the tastants-mediated amplification of cAMP formation and the tastant delay of ß2AR phosphorylation and internalization. RESULTS: Membrane-permeable but not impermeable tastants amplified the ISO-stimulated cAMP formation in a concentration- and time-dependent manner. Without ISO stimulation, amphipathic tastants, except caffeine, had no effect on cAMP formation. The amplification of ISO-stimulated cAMP formation by the amphipathic tastants was not affected by PDE and PKA activities, but was completely abolished by GRK2 silencing. Amphipathic tastants delayed the ISO-induced GRK-mediated phosphorylation of ß2ARs and GRK2 silencing abolished it. Further, tastants also delayed the ISO-stimulated ß2AR internalization. CONCLUSION: Amphipathic tastants significantly amplify ß2AR signaling and delay its desensitization via their intracellular inhibition of GRK2. GENERAL SIGNIFICANCE: Commonly used amphipathic tastants may potentially affect similar GPCR pathways whose desensitization depends on GRK2's kinase activity. Because GRK2 also modulates phosphorylation of non-receptor components in multiple cellular pathways, these gut-absorbable tastants may permeate into various cells, and potentially affect GRK2-dependent phosphorylation processes in these cells as well.

Interprofessional education between dentistry and nursing: the NYU experience.

In 2005, New York University Colleges of Dentistry and Nursing formed an organizational partnership to create a unique model of interprofessional education, research, service and practice. This paper describes the first eight years of experience, from the early reaction of the public to the partnership, to examples of success and past and current challenges.

Dental education and practice: past, present, and future trends.

This position paper explores the historical transitions and current trends in dental education and practice and attempts to predict the future. Dental education and practice landscape, especially after the COVID-19 epidemic, are at a crossroads. Four fundamental forces are shaping the future: the escalating cost of education, the laicization of dental care, the corporatization of dental care, and technological advances. Dental education will likely include individualized, competency-based, asynchronous, hybrid, face-to-face, and virtual education with different start and end points for students. Dental practice, similarly, will be hybrid, with both face-to-face and virtual opportunities for patient care. Artificial intelligence will drive efficiencies in diagnosis, treatment, and office management.

Inducible desensitization to capsaicin with repeated low-dose exposure in human volunteers.

Responses to capsaicin are reduced following repeated exposure, a phenomenon known as capsaicin desensitization. Heavy consumers of chilies consistently report reduced oral burn relative to infrequent consumers, presumably due to chronic desensitization. However, the mechanism(s) underlying capsaicin desensitization remain poorly understood. We hypothesized that reduced response to capsaicin due to repeated oral exposure may result from a change in the expression of the capsaicin receptor (TRPV1) gene. To test this, we conducted two longitudinal desensitization studies in healthy human volunteers. In Study 1, 51 adults completed a 17-day capsaicin desensitization protocol. The study consisted of three in-person visits where they were asked to sample stimuli, including 3, 6, and 9 ppm capsaicin, and rate intensity on a general labeled magnitude scale (gLMS). Between days 3 & 17, participants rinsed at home with 6 ppm capsaicin (n = 31) or a control (n = 20) solution (20 uM sucrose octaccetate; SOA) twice a day. Before and after the oral exposure protocol, a clinician collected fungiform papillae. Participants randomized to the capsaicin rinse showed a statistically significant reduction in oral burn ratings that was not observed in controls, indicating repeated low-dose exposure can systematically induce desensitization. TRPV1 expression was not associated with reported capsaicin burn, and there was no evidence of a decrease in TRPV1 expression following capsaicin exposure. In Study 2, participants (n = 45) rinsed with 6 ppm capsaicin in a similar protocol, rating capsaicin, vanillyl butyl ether (VBE), cinnamaldehyde, ethanol, menthol, and sucrose on days 1, 3, & 17. Burn from capsaicin, VBE, cinnamaldehyde, and ethanol all showed a statistically significant change - capsaicin, VBE and cinnamaldehyde burn all dropped ∼20 %, and a larger reduction was seen for ethanol - while menthol cooling and sucrose sweetness did not change. Collectively, this suggests reductions in oral burn following chronic capsaicin exposure generalizes to other stimuli (i.e., cross desensitization) and this cannot be explained by a change in TRPV1 mRNA expression. More work is needed to elucidate the underlying mechanism for capsaicin desensitization in the oral cavity.

Oral pathologies of the Neolithic Iceman, c.3,300 BC.

The famous Iceman 'Ötzi' (South Tyrol Museum of Archaeology, Bolzano, Italy), a Neolithic human ice mummy, offers a unique opportunity to study evolutionary aspects of oral disease. The aim of this study was to assess, for the very first time, his oral cavity, which surprisingly had never been examined systematically. Based on several computed tomography (CT) scans from 1991 onwards and on macroscopic investigation, only a few findings, such as a central maxillary diastema, heavy abrasions, and missing wisdom teeth, were known. We re-evaluated the latest CT scans from 2005 and found various oral pathologies. In line with the increase of tooth decay in the Neolithic - because of diet change in this historic transition phase - several carious lesions were found, one of which penetrated into the dental pulp. In accordance with the Iceman's troubled life, as several injuries on his body and his violent death attest, mechanical trauma of one of his upper front teeth is evident. Finally, the poor periodontal condition of the Iceman's dentition (e.g. loss of alveolar bone), indicative of periodontitis, was assessed. These oral pathological findings in the Iceman's dentition provide a unique glimpse into the evolutionary history of oral conditions.

Reprogramming cultured human fungiform (HBO) taste cells into neuron-like cells through in vitro induction.

Human taste cells are a heterogeneous population of specialized epithelial cells that are constantly generated from progenitor taste cells. Type I and type III taste cells express some neural markers, and studies have reported that direct innervation by neurons is not required for taste cell development. To our knowledge, no previous study has demonstrated that taste cells can differentiate into neuron-like cells or any other non-taste cell type. Here, for the first time, we describe a simple in vitro method that uses a serum-free neural induction medium to differentiate cultured physiologically functional primary human taste (HBO) cells into neuron-like cells in 2-3 wk with high efficiency. We verified neural attributes of these HBO-derived neuron-like with immunocytochemistry, single-cell calcium imaging, and DiI staining and examined cell morphology using transmission electron microscopy. Induced neuron-like cells demonstrated neuron-specific proteins, dendritic and axonal morphology, and networking behaviors. This technique will open new avenues for translational medicine, autologous cell therapy, regenerative medicine, therapy for neurodegenerative disorders, and drug screening.