Aging effects on oropharyngeal swallow and the role of dental care in oropharyngeal dysphagia.

Difficulty with oropharyngeal swallow requires careful diagnosis and treatment from a team of professionals including the patients' physicians and the speech-language pathologist specializing in dysphagia. The dentist can be a critical team member in prevention, early identification, and management of oropharyngeal dysphagia. This manuscript reviews the physiology of normal oropharyngeal swallow and the effects of normal aging on this physiology. Typical etiologies for oropharyngeal dysphagia are defined as is the most commonly used physiologic diagnostic procedure, the modified barium swallow (MBS). The critical role of the dentist in identifying risk of oropharyngeal dysphagia, making appropriate referrals, and improving oral hygiene to prevent aspiration pneumonia in the elderly is discussed.

Dental risk factors for osteonecrosis of the jaws: a CONDOR case-control study.

BACKGROUND: Reports of osteonecrosis of the jaw (ONJ) have associated this lesion to treatment with bisphosphonates (BPs) and dental procedures. In this study, we investigated the association of specific dental diagnoses and procedures with ONJ among patients with past BP use. METHODS: Dentists from three practice-based research networks provided ONJ cases and controls (1:3). Data gathered from patients and dental offices with two respective standard questionnaires included demographic, medical, pharmaceutical, and dental information. Diagnoses and procedures up to 3 years prior to ONJ (prior to interview for controls) were analyzed within risk strata, defined by BP use and cancer status, using interaction terms within conditional logistic regression models. RESULTS: We enrolled 191 ONJ cases and 573 controls from 119 dental offices. Among participants who had used only oral BP, extraction was the only dental risk factor for ONJ (odds ratio (OR) = 12, p = 0.01). Suppuration was also more prevalent in cases (18 %) than in controls (9 %), but not statistically significant (OR = 9, p = 0.06). Among participants who had not used either oral or IV BP (a majority of whom received radiation therapy to the head and neck), suppuration was the only dental risk factor for ONJ (prevalence = 34 % for cases and 8 % for controls; OR = 7, p = 0.01). The prevalence of extractions in this group was also higher, but not statistically significant (44 vs 10 %; OR = 3). Limited power precludes definitive findings among participants exposed to IV BP. CONCLUSIONS: Among patients taking oral BP, extraction was the only dental procedure associated with subsequent ONJ development CLINICAL RELEVANCE: Results of this study suggest that routine dental procedures are not associated with development of ONJ in patients exposed to BPs.

Risk factors for osteonecrosis of the jaws: a case-control study from the CONDOR Dental PBRN.

Case reports and cohort studies have linked bisphosphonate therapy and osteonecrosis of the jaws (ONJ), but neither causality nor specific risks for lesion development have been clearly established. We conducted a 1:3 case-control study with 3 dental practice-based research networks, using dentist questionnaires and patient interviews for collection of data on bisphosphonate therapy, demographics, co-morbidities, and dental and medical treatments. Multivariable logistic regression analyses tested associations between bisphosphonate use and other risk factors with ONJ. We enrolled 191 ONJ cases and 573 controls in 119 dental practices. Bisphosphonate use was strongly associated with ONJ (odds ratios [OR] 299.5 {95% CI 70.0-1282.7} for intravenous [IV] use and OR = 12.2 {4.3-35.0} for oral use). Risk markers included local suppuration (OR = 7.8 {1.8-34.1}), dental extraction (OR = 7.6 {2.4-24.7}), and radiation therapy (OR = 24.1 {4.9-118.4}). When cancer patients (n = 143) were excluded, bisphosphonate use (OR = 7.2 {2.1-24.7}), suppuration (OR = 11.9 {2.0-69.5}), and extractions (OR = 6.6 {1.6-26.6}) remained associated with ONJ. Higher risk of ONJ began within 2 years of bisphosphonate initiation and increased 4-fold after 2 years. Both IV and oral bisphosphonate use were strongly associated with ONJ. Duration of treatment >2 years; suppuration and dental extractions were independent risk factors for ONJ.

The effect of thromboxane on contraction of canine mesenteric and lingual arteries.

Thromboxane A2 (TXA2), a potent vasoconstrictor agent, is released from platelets and smooth muscle during inflammation and trauma. TXA2 may cause lingual artery (LA) contraction, leading to lingual paresthesia. The effects of U-46619, a TxA2 mimetic, on isolated rings of canine LA and mesenteric artery (MA) were examined. U-46619 (1 nmol/L to 1 mumol/L) caused a triphasic contraction of LA and MA; a rapid, phasic contraction; a slow, sustained contraction; and, upon washout of U-46619, a maintained contraction. The MA relaxed slowly, but the LA remained contracted for at least three h after washout. Decreasing extracellular calcium ion (Ca2+o) to less than 0.1 mumol/L with 2 mmol/L EGTA relaxed MA, but not LA. EGTA (4 mmol/L) partially relaxed the maintained contraction of LA. Inhibition of protein kinase C with amphotericin B or staurosporine inhibited the phasic and sustained contractions of LA, but did not affect the maintained contraction in the presence or absence of EGTA. Thus, CA2+o was required for the initial contraction of the LA by U-46619, but did not appear to be required for the maintained contraction following washout of U-46619. The data support the conclusion that following a brief exposure to U-46619, maintained contraction of LA persists by a unique mechanism that may be independent of Ca2+ and protein kinase C. Sustained LA contraction after exposure to endogenous TXA2 during inflammation and trauma may contribute to impaired lingual blood flow and orofacial tissue injury.

Toxicological assessment of lidocaine in the pregnant rat.

Teratogenic and toxicological effects of lidocaine administered during pregnancy were evaluated in the Sprague Dawley rat. High doses of lidocaine administered during specific periods of gestation were shown to produce no apparent adverse toxicological or teratogenic effects. Histological, enzymological, and physical features of the fetuses, utilizing conventional toxicological parameters, were all found to be normal following maternal administration of lidocaine. Analysis of these data suggests that the administration of lidocaine during pregnancy had no detectable adverse effects on the fetus.

In vitro effects of lithium chloride on TNF alpha and IL-6 production by monocytes from breast cancer patients.

It is well known that lithium chloride (LiCl) is able to trigger human monocytes to release tumor necrosis factor alpha (TNF alpha). In this study we have evaluated the in vitro effect of LiCl on TNF alpha and interleukin-6 (IL-6) release by monocytes from patients affected by non-metastatic (BCa/M0) and metastatic breast cancer (BCa/M1), preincubated with autologous serum (sPt). Our data demonstrate that monocytes from cancer patients (BCa) treated with LiCl released lower amounts of TNF alpha compared to those from healthy donors (HD). Preincubation in autologous serum (sPt) impaired TNF alpha production by monocytes from BCa with LiCl. On the contrary, our data indicate that IL-6 production by monocytes treated was not impaired. Moreover, the results obtained from the same cells, preincubated in sPt and treated with LiCl, indicate that serum factors may synergize with LiCl treatment in releasing IL-6.

Differential inhibition of 5-hydroxytryptamine (5-HT) mediated contraction of rat thoracic aortae by phentolamine and tolazoline: correlation with inhibition of 5-HT binding and calcium ion.

The contribution of alpha receptor stimulation to the contractile responses of vascular smooth muscle to 5-HT was evaluated, in vitro utilizing helical strips of rat thoracic aortae (RTA). The contractile responses of RTA to 5-HT and norepinephrine (NE) were inhibited by the alpha receptor blocking agent phentolamine. The inhibition persisted in RTA obtained from rats treated with reserpine (1.5 mg/kg/day for 6 days). Analysis of the interaction of phentolamine with 5-HT and NE demonstrated that: 1) phentolamine is a competitive inhibitor of the responses to 5-HT; and 2) the pA2 values for the interaction of phentolamine with 5-HT and NE differed. When the concentration of calcium ion in the physiologic saline solution (PSS) was increased from 1.6 mM to 2.5 mM, phentolamine was approximately 100 times more potent an inhibitor of the response to NE than 5-HT. Phentolamine decreased the binding of 14C-5-HT to rat thoracic aortae in control PSS, but not when the calcium concentration was increased to 2.5 mM. Tolazoline inhibited the contractile responses of RTA to NE but not 5-HT. The data support the conclusion that the contractile responses of RTA to 5-HT are mediated by receptors similar to the alpha receptor. The ability of phentolamine to inhibit 5-HT induced contraction may be dependent on the ability of phentolamine to bind to anionic sites of the 5-HT receptor. The inhibitory effect of calcium ion may result from its ability to combine with, and neutralize, these negatively charged moieties on the smooth muscle membrane. The lack of effect of tolazoline may result from the absence of the third ring structure present in the phentolamine molecule, and therefore an inability to bind to these postulated anionic sites. Alternatively, the absence of an imino-nitrogen in the chain separating the phenyl and imidazole groups of tolazoline may prevent tolazoline from interacting with the 5-HT receptor. The different pA2 values for phentolamine mediated inhibition of the responses to 5-HT and NE, and the ability of NE to poorly displace 5-HT from the RTA, despite blockade of alpha receptors with tolazoline, support the possibility that the 5-HT receptor of RTA differs from the alpha receptor and that phentolamine has affinity for both 5-HT and adrenergic receptors.

Differences in adrenergic receptor populations in canine dorsal metatarsal veins and intralobar pulmonary arteries.

The contractile responses of the canine intralobar pulmonary arteries (IPA) and dorsal metatarsal veins (DMV) to alpha adrenergic receptor agonists were evaluated in the absence and presence of alpha receptor antagonists to determine the type of post-synaptic alpha receptor predominant in the cutaneous and pulmonary canine vasculature. Rings of IPA, in vitro, contracted in response to the alpha 1 receptor agonist phenylephrine (PE), and the mixed alpha agonist norepinephrine (NE) but did not contract in response to clonidine (C), an alpha 2 receptor agonist. DMV contracted in response to each of the agonists. The contractile responses of the IPA to NE and PE were antagonized by tolazoline, phentolamine, clonidine and prazosin. The contractile responses of the DMV to clonidine were only antagonized by clonidine and phentolamine but not by tolazoline or prazosin. These data suggest that: 1) IPA are selectively endowed with post-synaptic alpha 1 adrenergic receptors; 2) DMV are endowed with both post-synaptic alpha 1 and alpha 2 adrenergic receptors; and 3) clonidine interacts with alpha 1 adrenergic receptors to elicit alpha blockade and with alpha 2 adrenergic receptors to initiate contraction of the DMV. In an attempt to verify this hypothesis, experiments were performed in solutions in which the pH was altered above or below pH 7.4. Under these conditions, the agonist properties of clonidine were selectively inhibited whereas its blocking potency was retained. These data support the conclusion that clonidine is antagonistic at alpha 1 adrenergic receptors and agonistic at alpha 2 adrenergic receptors.

A framework for risk assessment and decision-making strategies in dangerous good transportation.

The risk from dangerous goods transport by road and strategies for selecting road load/routes are faced in this paper, by developing an original site-oriented framework of general applicability at local level. A realistic evaluation of the frequency must take into account on one side inherent factors (e.g. tunnels, rail bridges, bend radii, slope, characteristics of neighborhood, etc.) on the other side factors correlated to the traffic conditions (e.g. dangerous goods trucks, etc.). Field data were collected on the selected highway, by systematic investigation, providing input data for a database reporting tendencies and intrinsic parameter/site-oriented statistics. The developed technique was applied to a pilot area, considering both the individual risk and societal risk and making reference to flammable and explosive scenarios. In this way, a risk assessment, sensitive to route features and population exposed, is proposed, so that the overall uncertainties in risk analysis can be lowered.

Tooth hypersensitivity in the spectrum of pain.

Dentinal hypersensitivity satisfies all the criteria to be classified as a true pain syndrome that can be acute, but for our purposes is a chronic condition with acute episodes without the disabling characteristics and severe dysfunction of a chronic pain syndrome. It is estimated that the frequency of dentinal hypersensitivity affects one of six people, and one or more teeth can be affected. The incidence of dentinal hypersensitivity appears to peak around the third decade of life and may appear as root sensitivity in the fifth decade of life as root sensitivity particularly in patients undergoing periodontal surgery. The relationship of dentinal hypersensitivity to acute and chronic pain is shown in Table 1. Dentists' ability to soothe or stop pain has always been their greatest asset in establishing patient rapport. The experience of pain is so subjective that none of us can ever be sure another person is having it. Physicians, dentists, and especially those affiliated with pain centers and clinics have resolved this dilemma in a commonsensical way. They simply treat the pain as if it were real, and their track record in confronting this inscrutable condition has contributed to their high regard as professionals.

Desensitizing effect of a potassium chloride dentifrice.

Sensodyne F is a potassium chloride (KCl) and sodium monofluorphosphate (MFP) containing dentifrice currently marketed in the United Kingdom and Germany was compared to a KCl only dentifrice and to a placebo dentifrice for effectiveness in alleviating dentin hypersensitivity. This 3-cell, randomized, double-blind, parallel clinical study utilized 62 subjects for an 8-week duration of product use. The degree of hypersensitivity of the affected teeth was assessed by tactile stimulation, cold air stimulation and overall subjective patient response. The results from these three methods of assessment indicated that a KCl containing dentifrice either alone or in combination with sodium MFP were significantly more effective than the placebo dentifrice in reducing dentin hypersensitivity. The therapeutic response to the KCl dentifrices as measured by air sensitivity and tactile sensitivity was statistically significant when compared to the placebo dentifrice within 4 weeks of use. Significant improvement was seen for all parameters at the conclusion of the 8-week clinical study period. Plaque reduction was significantly reduced at 8 weeks. The results indicate that KCl is an efficacious molecule in reducing dentin hypersensitivity when used either alone or in combination with sodium MFP as measured by improved overall patient comfort.

Clinical effectiveness of a dentifrice containing potassium chloride as a desensitizing agent.

Sensodyne F, a dentifrice currently marketed in the United Kingdom, containing potassium chloride (KCl) and sodium monofluorophosphate (MFP) was compared to a placebo dentifrice for effectiveness in alleviating dentinal hypersensitivity. This randomized, double-blind, parallel clinical study covered 12 weeks of product use by 41 subjects. Hypersensitivity levels of the affected teeth were assessed by tactile stimulation, cold air stimulation and overall subjective patient response. The results from these three methods of assessment demonstrated that the KCl/MFP dentifrice was significantly more effective than the placebo dentifrice in reducing dentinal hypersensitivity. The therapeutic response to the KCl/MFP dentifrice as measured by air sensitivity and overall subjective evaluation was statistically significant when compared to the placebo dentifrice within 4 weeks of use. Significant improvement was observed for all parameters at the conclusion of the 12-week clinical study period. Plaque reduction was significantly reduced at week 8 and continued to improve by week 12. The results indicate that KCl with sodium MFP significantly reduced dentinal hypersensitivity and improved overall patient comfort.

Toothbrush bristle density: relationship to plaque removal.

A double-blind, parallel, controlled study was conducted to determine the effect of toothbrush bristle density (total number of bristles divided by the brush head area) in removing plaque from tooth surfaces. Ninety subjects (29 males, 61 females), aged 18-65, were randomly assigned to one of three groups using the Sensodyne Search 4-Rowa toothbrush modified to have the following bristle densities: A (4.5 bristles per mm2); B (8.3 bristles per mm2); or C (11.8 bristles per mm2). The average trim height of the bristles was 10.77 mm. Subjects brushed without any dentifrice once a day for 7 days in order for adherent deposits (salivary pellicle and plaque remnants) to accumulate on their teeth. On the eight day, examinations for stained deposits were performed according to the Global Scoring Index before and after one minute of brushing with a commercially available toothpaste. Percent reductions in deposits were highly significant for the eighty-seven subjects who completed the study. A paired t-test between the pre- and post-treatment scores (p = 0.005) demonstrated the following: Toothbrushes A, B and C had reductions in plaque of 45.5%, 51.9% and 56.8%, respectively. On an overall basis, the intergroup percent reductions were significantly different using ANOVA (p = 0.001), and demonstrated a relationship in terms of data clustering for percent plaque removal of toothbrushes with varied bristle densities.

Amlexanox oral paste: a novel treatment that accelerates the healing of aphthous ulcers.

Five percent Amlexanox oral paste is a novel treatment for aphthous ulcers. In 3 controlled clinical studies that evaluated 1,124 immunocompetent patients with mild to moderate aphthous ulcers, 5% Amlexanox oral paste (Aphthasol) was shown to accelerate healing of these ulcers. Treatment with Aphthasol reduced the median time to ulcer healing and to complete pain resolution in a statistically significant manner. This was true both when treatment with 5% Amlexanox oral paste was compared to treatment with a vehicle and when treatment with the Amlexanox paste was compared to no treatment. Study results after 3 days comparing treatment with the paste and no treatment indicated complete healing of ulcers for 21% and 8% of patients, respectively. Complete resolution of pain after 3 days was reported for 44% and 20% of patients, respectively.

The PBRN initiative: transforming new technologies to improve patient care.

The NIDCR-supported Practice-based Research Network initiative presents dentistry with an unprecedented opportunity by providing a pathway for modifying and advancing the profession. It encourages practitioner participation in the transfer of science into practice for the improvement of patient care. PBRNs vary in infrastructure and design, and sustaining themselves in the long term may involve clinical trial validation by regulatory agencies. This paper discusses the PBRN concept in general and uses the New York University College of Dentistry's Practitioners Engaged in Applied Research and Learning (PEARL) Network as a model to improve patient outcomes. The PEARL Network is structured to ensure generalizability of results, data integrity, and to provide an infrastructure in which scientists can address clinical practitioner research interests. PEARL evaluates new technologies, conducts comparative effectiveness research, participates in multidisciplinary clinical studies, helps evaluate alternative models of healthcare, educates and trains future clinical faculty for academic positions, expands continuing education to include "benchmarking" as a form of continuous feedback to practitioners, adds value to dental schools' educational programs, and collaborates with the oral health care and pharmaceutical industries and medical PBRNs to advance the dental profession and further the integration of dental research and practice into contemporary healthcare (NCT00867997, NCT01268605).

An assessment of the perceived benefits and challenges of participating in a practice-based research network.

BACKGROUND: A survey was conducted to describe the benefits of and challenges to practitioner participation in the Practitioners Engaged in Applied Research and Learning (PEARL) Network, a dental practice-based research network (PBRN). The results were compared with results from medical PBRNs across different tiers of participation (based on practitioner-investigators previous involvement with PEARL research protocols). METHODS: A 39-item web-based survey addressed the benefits of PBRN participation on three levels: individual/practitioner, practice (office), and community/professional. Participants were also asked to rate challenges to participation. RESULTS: A total of 153 of 216 PEARL practitioner-investigators participated, a response rate of 71%. The majority (70%) was male, with a median of 23 years in private practice. 'Means to stay informed of new developments in my profession' was considered a 'very important' benefit for nearly three-quarters of the sample (71%). 'Opportunity to improve clinical procedures' was considered as 'very important' by 73% of respondents. In terms of benefits related to the community and profession, 65% of respondents reported 'means to directly contribute to the evidence base of dental practice' as being 'very important'. 'Disruption in practice routine/clinical practice' was considered the most important challenge to participation. CONCLUSIONS: The benefits of and challenges to participation identified did not differ across tiers of participation and were similar to benefits identified by participants in medical PBRNs. The results of this study will help facilitate the design of future PBRN protocols to encourage greater participation by the profession. Results suggest that practitioners with similar interests could be recruited to collaborative studies between medicine and dentistry.

Risk factors for osteonecrosis of the jaws: a case-control study from the CONDOR dental PBRN.

Case reports and cohort studies have linked bisphosphonate therapy and osteonecrosis of the jaws (ONJ), but neither causality nor specific risks for lesion development have been clearly established. We conducted a 1:3 case-control study with three dental Practice-based Research Networks, using dentist questionnaires and patient interviews for collection of data on bisphosphonate therapy, demographics, co-morbidities, and dental and medical treatments. Multivariable logistic regression analyses tested associations between bisphosphonate use and other risk factors with ONJ. We enrolled 191 ONJ cases and 573 controls in 119 dental practices. Bisphosphonate use was strongly associated with ONJ (odds ratios [OR] 299.5 {95%CI 70.0-1282.7} for intravenous [IV] use and OR = 12.2 {4.3-35.0} for oral use). Risk markers included local suppuration (OR = 7.8 {1.8-34.1}), dental extraction (OR = 7.6 {2.4-24.7}), and radiation therapy (OR = 24.1 {4.9-118.4}). When cancer patients (n = 143) were excluded, bisphosphonate use (OR = 7.2 {2.1-24.7}), suppuration (OR = 11.9 {2.0-69.5}), and extractions (OR = 6.6 {1.6-26.6}) remained associated with ONJ. Higher risk of ONJ began within 2 years of bisphosphonate initiation and increased four-fold after 2 years. Both IV and oral bisphosphonate use were strongly associated with ONJ. Duration of treatment > 2 years; suppuration and dental extractions were independent risk factors for ONJ.