Neuroendocrine responses to psychological stress in patients with myofascial pain

AIMS: To investigate the responses of the hypothalamus-pituitary-adrenocortical and sympathetic-adrenal-medullary systems to experimentally induced psychological stress in patients with myofascial pain. METHODS: To characterize the features of these systems, temporal variations in plasma cortisol, adrenaline, and noradrenaline concentrations in response to psychological stress were measured in 20 patients with myofascial pain and in 20 healthy controls. RESULTS: The concentrations of plasma cortisol, adrenaline, and noradrenaline in response to psychological stress were significantly higher in the pain patients than in the healthy controls. Furthermore, although the plasma cortisol, adrenaline, and noradrenaline concentrations were significantly increased from the basal levels in both groups, the rate of recovery from these levels was significantly slower in patients than in healthy controls. CONCLUSION: These results suggest that both the sympathetic-adrenal-medullary and hypothalamic-pituitary-adrenocortical systems are more highly activated in response to psychological stress in patients with myofascial pain than in healthy individuals.     

Proteomic profiles of the acquired enamel pellicle formed in vitro,in situ,or in vivo

This study compared the protein profile of the acquired enamel pellicle (AEP) formed under three conditions: in vitro, in situ, and in vivo. Nine volunteers participated in all procedures. In the in vitro condition, the volunteers donated saliva, in which specimens were incubated to form the AEP. In the in situ condition, the volunteers used an oral device containing specimens where the AEP was formed. In the in vivo condition, the AEP was collected from the volunteers own teeth. All AEPs were formed for 120 min, collected and processed by mass spectrometry. Overall, a total of 321 proteins were identified, among which 37 proteins are commonly considered typical in the AEP. For each of the in vitro, in situ, and in vivo conditions, respectively, 66, 174, and 170 proteins were identified. For the in vitro condition, 17 pellicle-typical proteins were not identified. Furthermore, several proteins with important functions within the AEP presented differences in expression in the three conditions. The qualitative profile of the proteins, especially the typical ones, is different in the in vitro condition. In addition, there are important quantitative differences that may interfere when attempting to extrapolate in vitro results to an in situ and in vivo condition.     

Prevalence of Dental Fluorosis in Fluoridated and Nonfluoridated Communities—a Preliminary Investigation

As a result of undocumented observations that the prevalence of dental fluorosis in both fluoridated and nonfluoridated communities may be higher than would be predicted on the basis of Dean's data from the 1940s, dental fluorosis assessments using a modification of Dean's Index were made in 1981 as part of routine examinations in a series of clinical trials. A total of 1,663 children in fluoridated or nonfluoridated communities, ranging in age from seven to 17 years, were examined during 1981-82. The prevalence of dental fluorosis in nonfluoridated communities ranged from 1.7 percent in 16-year-olds to 13.9 percent in 10-year-olds and, in fluoridated communities, ranged from 17.1 percent in 13-year-olds to 33.0 percent in 14-year-olds. At all age levels common to the two types of communities, the difference in prevalence of dental fluorosis was statistically significant. Compared with findings in Dean's studies in 1942, for children of comparable age in communities with essentially the same water-fluoride levels, the prevalence of dental fluorosis in the present study was 3 1/2 times higher in nonfluoridated communities and two times higher in fluoridated communities. Mean fluorosis scores, however, were similar. If additional studies substantiate that the prevalence and intensity of dental fluorosis are increasing, the accepted norms for fluoride dosage need to be reassessed--especially in supplements, dentifrices, and water.     

Postural and maximum activity in elevators during mandible pre- and post-occlusal splint treatment of temporomandibular joint disturbance syndrome

Electromyograms (EMGs) of the temporal and masseter muscles in sixty patients with temporomandibular joint disturbance syndrome (TMJDS) and thirty controls were recorded and integrated on-line in the postural position and during maximum clenching, before and after occlusal splint therapy. Contrasting with the controls, the myoelectrical activity of the patients was higher in the postural position and lower during maximum clenching, whilst the former in percentage terms increased when compared to the latter. After treatment, the EMG indexes in some patients returned partially, and in others completely, to a normal level. Tenderness in the mandibular elevators, deviated opening and organic change in the TMJ increased the postural myoelectrical activity, in percentage terms, against that of maximum clenching. The myoelectrical activity of the mandibular elevators in the postural position and during maximum clenching was smaller in patients with the occlusal splint than in those without. The results show that the mandibular elevators in the patients with TMJDS were hyperactive and tense, and that the occlusal splint was useful for treating such dysfunction.     

Timing and effect of fissure sealants on permanent molars: a study in Finland and Sweden

Fissure sealants are frequently used in the Nordic countries for the prevention of caries in children. The aim here was to analyse their use and effect on dental health in children and adolescents in Finland and Sweden. A retrospective longitudinal population-based study was performed in northern Finland and Sweden, where different strategies have been adopted for sealing teeth. The timing of sealant and restoration placements up to 18 years was studied in representative samples of subjects born in the early 1980s in Kemi, Oulu, Raahe and Tornio in Finland (n = 908) and compared with a random sample of subjects from Norrbotten, Sweden (n = 634). A sensitive survival analysis method was applied to all the permanent molars separately (Virtanen et al. 1996). About 80-90% of molars had been sealed in the Finnish subjects, and approximately 30% in the Swedish cases, employing selective criteria. The filling increments were statistically significantly higher in Sweden than in Finland, although the differences were not of the same magnitude as the reduction in sealants. More than 30% of first molars and 50% of second molars had not been treated, i.e. were without sealants or fillings, by the end of the follow-up in Sweden, compared with 10% and 20%, respectively, in Finland. Fissure sealants were effective in preventing caries in molars in children and adolescents, and the use of selective criteria for targeting this treatment can yield savings in effort and costs in a low caries situation, although more research is needed to find the optimum cost-effective strategy.     

Genetic study on the congenital dislocation of the hip

A clinical and epidemiological study on congenital dislocation of the hip (CDH) was attempted with a genetic analysis of this condition, and the following results were obtained. The frequency of CDH in the general population is 0.08% in males and 0.59% in females, the latter being clearly higher. In examining the changes in the frequency of CDH over the years using the data reported in the literature, a statistically significant tendency for the frequency to decrease in more recent years was noted. It was confirmed by the recurrence rate of the subsequent sibling and twin data that CDH is a multifactorial disease, and, in estimating its heritability, in males h2 = 0.94-1.01 and in females h2 = 1.38, which are markedly high estimates exceeding the limit of 1. This is perhaps attributable to the small number of patients in this series and to the differences in the characteristics between the data on the frequency of CDH in the general population and those of the present pedigree study. When the corrected value of the frequency in the general population was used in estimating the heritability, in males h2 = 0.54 approximately 0.74 and in females h2 = 0.68, which are almost identical to the American data.     

The permeability of human dentine in vitro and in vivo

Experiments in cats have shown that Evans blue dye diffuses at a greater rate into dentine in recently extracted teeth than in vivo. These experiments have now been repeated in man and similar results were obtained except that, after applications in vivo, visible concentrations of the dye were present in the dentine, and in a few cases, even in the pulp. It is concluded that, as in the cat, the diffusion in vivo was impaired by outward flow of fluid in the dentinal tubules but the mean velocity of flow in the human dentine was less than that in the cat.     

Caries experience in nursery school children in Sendai,Japan: Time trends from 1972–2002

Since 1972, we have been conducting an annual clinical dental examination for young children at 13 nursery schools in the north district in Sendai, Japan. In the present study, we have included the results of examinations conducted in 1997 and 2002, and analyzed the time trends in caries experience of the primary dentition over a 30-year period from 1972 to 2002. The caries experience in the primary dentition markedly decreased in 1977 and remained stable for about 15 years, but in 1997, it markedly decreased again and continued to decrease in a linear fashion until 2002. The time trends in caries experience in the primary dentition in each age group were further analyzed by ascertaining caries experience in each tooth type. The results showed that, in 2 to 4-year-old, the decrease of caries experience for the primary maxillary incisors, canines and first molars seemed to stop decreasing in 2002, but for the 5-year-old, the caries experience for the maxillary incisors and canines and the maxillary and mandibular first and second molars markedly decreased from 1997 to 2002.     

Trends in socioeconomic disparities in oral health in Brazil and Sweden

Celeste RK, Nadanovsky P, Fritzell J. Trends in socioeconomic disparities in oral health in Brazil and Sweden. Community Dent Oral Epidemiol 2011; 39: 204–212. © 2010 John Wiley & Sons A/S Abstract – Objectives: To describe the dynamics of trends in socioeconomic disparities in oral health in Brazil and Sweden among adults, to assess whether trends follow expected patterns according to the inverse equity hypothesis. Methods: In Sweden, we obtained nationally representative data for the years 1968, 1974, 1981, 1991 and 2000, and in Brazil, for 16 state capitals in 1986 and in 2002. Trends in the prevalence of ‘edentulism’ and of ‘teeth in good conditions’ were described in two groups aged 35–44 with lower and higher economic standards, respectively. Results: There was an annual decline in disparities in ‘edentulism’ of 0.4 percentage points (pp) (95% CI = 0.2–0.7) in Brazil and 0.7pp (95% CI = 0.5–0.9) in Sweden, as a result of improvements in both income groups. Concerning ‘teeth in good conditions’, in Brazil, there was improvement only in the higher income group and absolute disparities have increased (0.5pp annually), while in Sweden, there was a nonsignificant decrease (0.3pp annually) with improvements in both groups. Since 1991 in Sweden and in 2002 in Brazil, our measures of socioeconomic disparities in ‘edentulism’ were not statistically significant. Trends did not differ by sex or dental visit. Conclusions: Despite improvements in both income groups and a decrease in disparities in ‘edentulism’, the poorer group in Brazil has seen no improvement in ‘teeth in good conditions’ and disparities have increased. It appears that Brazil and Sweden reflect different stages of trend for ‘teeth in good conditions’ and the same stages for ‘edentulism’, represented by the inverse equity hypothesis.     

Age-related changes in brain regional activity during chewing: a functional magnetic resonance imaging study

Age-related changes in mastication-induced brain neuronal activity have been suggested. However, in humans, little is known about the anatomical regions involved. Using fMRI during cycles of rhythmic gum-chewing and no chewing, we have examined the effect of aging on brain regional activity during chewing in young adult (19-26 yrs), middle-aged (42-55 yrs), and aged (65-73 yrs) healthy humans. In all subjects, chewing resulted in a bilateral increase in the BOLD signals in the sensorimotor cortex, cerebellum, thalamus, supplementary motor area, and insula, and a unilateral increase in the right prefrontal area. In the first three regions, the signal increases were attenuated in an age-dependent manner, whereas, in the right prefrontal area, the converse was seen. The remaining two regions showed no significant differences with ages. These results indicate that chewing causes regional increases in neuronal activity in the brain, some of which are age-dependent.     

Analysis of 154 cases of teeth with cracks

Abstract –  It is well known that cracked teeth occur most frequently in the mandibular molars with large or poor restorations, in those over 50 years of age. However, with increasing knowledge and experience with cracks of teeth, cracks appear to be found frequently in intact teeth without restorations. The aim of this study is to analyze the cases of tooth cracks in a dental hospital in a year, and to find out the characteristic features of cracks of teeth. For 1 year, each tooth that were identified as a cracked tooth was recorded and analyzed in terms of the classification of cavity and restorative material, the nature of opposing tooth, the location in the arch, the age and gender, and the clinical signs and symptoms, and treatment result. Cracked teeth were observed most frequently in the teeth with no restorations (60.4%) and with class I restorations (29.2%). The most prevalent age was in those over 40 years of age (31.2% in their 40s, 26.6% in their 50s) and the prevalence was similar in men (53.9%) and women (46.1%). Cracked teeth were found most frequently in the maxillary molars (33.8% in first molar, 23.4% in second molar) than in the mandibular molars (20.1% in first molar, 16.2% in second molar). 96.1% of the cracked teeth responded to the bite test, and 81.1% of the cracked teeth were observed in the mesiodistal direction. The prevalence of cracked tooth was highest in the intact teeth with no restoration, in maxillary molars, and in those over 40 years of age. When examining a intact maxillary posterior tooth that is sensitive to a bite and thermal change, crack in the mesiodistal direction need to be considered one of the causes.     

Dental health in schoolchildren 5 years after water fluoridation ceased in south-west Scotland

A follow-up study of the dental health of children resident in two towns in south-west Scotland, one of which had fluoridated water until 1983, was carried out at the end of 1988. Comparison with an identical 1980 study allowed trends in the prevalence of caries to be examined. In 1988, the mean, decayed, missing and filled deciduous teeth (dmft) score for 5-year-old children in Stranraer, the formerly fluoridated town, was 3.08, 24 per cent worse than the score of 2.48 reported in 1980. In Annan, mean dmft for 5-year-old children was 3.18 in 1988, 27 per cent lower than the 1980 dmft score of 4.38. The difference in caries prevalence between the two towns in 1988 was a non-significant 3.1 per cent compared with the 44 per cent difference found in 1980. Similar trends in caries prevalence were also found in 10-year-old children with mean DMFT scores of 2.28 in Stranraer and 2.56 in Annan in 1988, a 10.9 per cent difference compared with the 50 per cent difference reported in 1980. The Stranraer DMFT score was 37.4 per cent higher than the DMFT of 1.66 recorded in 1980, while in Annan, the mean DMFT of 2.56 was 23.6 per cent lower than the 1980 score of 3.35. The comparison confirms a trend to lower caries levels in Annan children in line with the general trend in caries prevalence in much of western Europe. However, despite the almost universal use of fluoride toothpaste, caries prevalence in Stranraer children has increased since fluoridation ceased to almost parity with children in the non-fluoridated area. This study shows that there is still a benefit to be gained in terms of lower caries rates by implementing water fluoridation despite the general decline in dental caries.     

Perspectives in carbohydrate toxicology with special reference to carcinogenicity

All chemicals, even water and salt, can cause toxic effects if they are given to humans or laboratory animals in high enough doses. Similarly, the incidences of various kinds of neoplasm may be increased non-specifically in animals by the administration of innocent chemicals by an inappropriate route or in doses that are excessive enough to disturb normal nutritional, or hormonal status or interfere with mineral balance. High dietary concentrations of sorbitol or xylitol, if fed to laboratory rats cause enlargement of the caecum, increased absorption of calcium from the gut, increased urinary excretion of calcium, pelvic and corticomedullary nephrocalcinosis, acute tubular nephropathy, urinary calculus formation and both hyperplasia and neoplasia of the adrenal medulla. High dietary concentrations of lactose give rise to a similar spectrum of effects when given in excessive dosage to laboratory rats. Recent evidence suggesting that in the rat, but not in the mouse or in man, excessive calcium absorption stimulates the adrenal medulla is reviewed. In the mouse, but not in the rat or in man, a biologically significant amount of glycolic acid, which is a minor metabolite of xylitol in all three species, is converted to oxalate which then appears in the urine. Although the increase in urinary oxalate in the mouse is only about 20% of normal, this is enough in animals fed on diets containing 10% or 20% xylitol to predispose to bladder stone formation, and the prolonged presence of stones in the bladders, particularly of mice, in turn, predisposes to bladder tumour development. Neither bladder stones nor bladder tumours are seen in rats because biologically significant conversion of glycolate to oxalate does not occur. Studies in humans exposed up to 1 g/xylitol/kg body weight/day have revealed no evidence of increased urinary oxalate excretion. It is concluded that both the bladder tumours seen in mice, in response to 10% or 20% xylitol in the diet, and the adrenal tumours seen in rats, in response to 20% sorbitol or 20% xylitol in the diet, are laboratory artefacts. In other words, humans exposed to "normal" levels of these agents would be at no risk of developing either of these kinds of neoplasm.     

Caries prevalence and distribution in individuals aged 20-80 years in J?nk?ping, Sweden, 1973 and 1983

In 1973 an epidemiological study was performed in the community of J?nk?ping, Sweden. The study covered 1000 individuals, evenly distributed in the age groups 3, 5, 10, 15, 20, 30, 40, 50, 60 and 70 years. In 1983 a new cross-sectional study was carried out on the age-groups 3-80 years. The aim of the present study was to compare and analyse in detail caries prevalence and distribution in the age-groups 20-80 years at the examinations in 1973 and 1983. The subjects were examined clinically and radiographically regarding number of teeth, caries, restorations, etc. The mean number of teeth increased between 1973 and 1983, especially in the older age-groups. During the same period, the percentage of DFS decreased in the age-groups 20, 30 and 70 years, and was unchanged in the age-groups 40 to 60 years. There were only minor differences in DS in the respective age-group during the 10-year period. The distribution of subjects according to DFS showed that a large proportion of individuals in the age-groups 20 and 30 years had low DFS in 1983 as compared to 1973. For the age-group 40-years, the distribution was unchanged. For the 50, 60 and 70-year-olds, there was a change in distribution towards a larger proportion of individuals with high DFS values in 1983 as compared to 1973. The frequency distribution of individuals with primary and secondary carious lesions respectively was skewed, a small number of individuals having a high number of lesions in each age-group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prevalence of mandibular dysfunction in an urban population in Hungary

600 randomly selected subjects from an urban community in Hungary were examined anamnestically and clinically concerning signs and symptoms of mandibular dysfunction. The anamnestic (Ai) and clinical dysfunction (Di) indices according to Helkimo were used. The percentage distribution of the sample was the following: AiO = 79.3%, AiI = 15.3%, AiII = 5.3%; DiO = 20.1%, DiI = 72.3%, DiII = 7%, DiIII = 0.5%. Headache was reported in 23%, bruxism in 10%, joint sounds in 9%, pain in the face, neck, or around the ears in 6%. Clinical signs found at the examination were joint sounds in 46% (crepitation 29%, clicking 22%), muscle tenderness on palpation in 17%, joint tenderness in 3%, pain on movement in 2.5%, restricted mouth opening in 4%, deviation of the mandible in 20%.     

Cervical necrotizing fasciitis of odontogenic origin: A report of 11 cases

PURPOSE: Although most cases of cervical necrotizing fasciitis (CNF) are odontogenic in origin, reports of this disease in the dental literature are sparse. The purpose of this study was to review the cases treated on our service, and to analyze the features of this disease and the responses to management, to supplement the understanding of this relatively rare and life-threatening disease. PATIENTS AND METHODS: All cases of infection admitted to the OMS service in a period of 10.5 years were studied retrospectively. The diagnosis of CNF was established by the findings on surgical exploration and histologic examination. The patients' age, sex, medical status, causes of the infection, bacteriology, computed tomography scan findings, surgical interventions, complications, survival, and other clinical parameters were reviewed. RESULTS: A total of 422 cases of infection were admitted, and 11 cases of cervical necrotizing fasciitis were found. The incidence of CNF was 2.6% among the infections hospitalized on the OMS service. There were 7 male and 4 female patients. Eight patients were older than 60 years of age. Seven patients had immunocompromising conditions, including diabetes mellitus in 4, concurrent administration of steroid in 2, uremia in 1, and a thymus carcinoma in 1. All patients showed parapharyngeal space involvement; four also showed retropharyngeal space involvement. Gas was found in the computed tomography scan in 6 patients, extending to cranial base in 3 of them. Anaerobes were isolated in 73% of the infections, whereas Streptococcus species were uniformly present. All patients received 1 or more debridements. Major complications occurred in 4 patients, including mediastinitis in 4, septic shock in 2, lung empyema in 1, pleural effusion in 2, and pericardial effusion in 1. All major complications developed in the immunocompromised patients, leading to 2 deaths. CONCLUSION: The mortality rate in this study was 18%. Early surgical debridement, intensive medical care, and a multidisciplinary approach are advocated in the management of CNF.     

Dental fluorosis in the primary and the permanent dentition in fluoridated areas with consumption of either powdered milk or natural cow's milk

The aim of the present study was to describe the patterns of dental fluorosis in the primary and the permanent dentition of children born and reared in two different fluoridated areas, one in which powdered milk suspended in tap water was commonly used (Narssaq, Greenland: 1.1 ppm fluoride in the water) and one in which cow's milk was provided (Vordingborg, Denmark: 1.4-1.6 ppm fluoride in the water). Dental fluorosis was recorded by Thylstrup and Fejerskov's classification. In both locations, the prevalence of dental fluorosis increased the later in life the tooth type was formed. The prevalence of dental fluorosis in the earliest formed teeth was higher in the area where powdered milk was suspended in fluoride-containing tap water than where pasteurized cow's milk was used. In the first permanent molars, the maxillary incisors, and the canines, the prevalence was rather similar in the two areas. In the latest formed teeth, the premolars, the level of fluorosis was higher in Vordingborg. The pattern of dental fluorosis suggests that when powdered milk was used frequently, the children were exposed to a higher fluoride intake earlier in life than were those consuming cow's milk during infancy and childhood.     

Corrosion of dental amalgam and mercury vapor emission in vitro

Abstract – Amalgam specimens were immersed for 30 days in 1) water, 2) 0.9% NaCl in water, 3) 0.9% NaCl and 10 mM phosphate buffer in water, and 4) 0.9% NaCl, 7.7 mM phosphate, and 6.1 mM citric acid in water. The solutions were stored in stoppered glass tubes. Hg-drops were immersed in solutions 1, 2, and 3. The concentration of mercury vapor in the air above the solutions was measured once a day. After 30 days the amounts of Cu, Zn, Hg, and Ag in the solutions were analyzed by atomic absorption spectrophotometry. The results showed that 0.9% NaCl alone or in combination with the additives increased the amounts of elements released into the solutions. The concentration of Hg° in the glass tubes increased with the amount of Hg in the solutions, with the exception of solution No. 3, from which significantly less Hg° evaporated. The results indicate that the composition of the saliva, oral hygiene and dietary factors may be determinants of Hg° emission from amalgams in the oral cavity.     

Acidic soft drinks effects on the shear bond strength of orthodontic brackets and a scanning electron microscopy evaluation of the enamel

This study investigated the effects of acidic soft drinks on the resistance of metal brackets to shear forces in vitro and in vivo. Thirty noncarious maxillary premolar teeth, scheduled for extraction for orthodontic purposes, were used in the in vivo group. Thirty other noncarious maxillary premolar teeth, already extracted for orthodontic purposes, were used in the in vitro group. The teeth in both groups were divided equally in three subgroups, ie, the Coca-Cola, Sprite, and control subgroups. Brackets were bonded using conventional methods. Teeth in the in vivo group were rinsed with the acidic drink three times for five minutes daily and extracted after three months. Teeth in the in vitro group were kept in the acidic drink for five minutes on three equal time intervals within 24 hours. The brackets from both groups were subjected to shearing forces using a Universal test machine. After the shearing tests, a scanning electron microscope was used to determine the amount and the localization of erosion. The results indicated that both acidic soft drink subgroups had a reduced debonding resistance in vivo and in vitro compared with their control subgroups. No statistical difference in debonding resistance was found between the in vivo and in vitro groups. Areas of defect due to erosion were observed on the enamel surface around the brackets in both the in vitro and in vivo groups. Acidic soft drinks such as Coca-Cola and Sprite have a negative effect on bracket retention against shearing forces and enamel erosion.