Cohort profile: the ESC EURObservational Research Programme Non-ST-segment elevation myocardial infraction (NSTEMI) Registry

AIMS

The European Society of Cardiology (ESC) EURObservational Research Programme (EORP) Non-ST-segment elevation myocardial infarction (NSTEMI) Registry aims to identify international patterns in NSTEMI management in clinical practice and outcomes against the 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without ST-segment-elevation.

METHODS AND RESULTS

Consecutively hospitalised adult NSTEMI patients (n = 3620) were enrolled between 11 March 2019 and 6 March 2021, and individual patient data prospectively collected at 287 centres in 59 participating countries during a two-week enrolment period per centre. The registry collected data relating to baseline characteristics, major outcomes (in-hospital death, acute heart failure, cardiogenic shock, bleeding, stroke/transient ischaemic attack, and 30-day mortality) and guideline-recommended NSTEMI care interventions: electrocardiogram pre- or in-hospital, pre-hospitalization receipt of aspirin, echocardiography, coronary angiography, referral to cardiac rehabilitation, smoking cessation advice, dietary advice, and prescription on discharge of aspirin, P2Y12 inhibition, angiotensin converting enzyme inhibitor (ACEi)/angiotensin receptor blocker (ARB), beta-blocker, and statin.

CONCLUSION

The EORP NSTEMI Registry is an international, prospective registry of care and outcomes of patients treated for NSTEMI, which will provide unique insights into the contemporary management of hospitalised NSTEMI patients, compliance with ESC 2015 NSTEMI Guidelines, and identify potential barriers to optimal management of this common clinical presentation associated with significant morbidity and mortality.

The Potassium Channel Kv1.5 Expression Alters During Experimental Autoimmune Encephalomyelitis

Multiple sclerosis (MS) is a chronic, inflammatory, neurodegenerative disease with an autoimmune component. It was suggested that potassium channels, which are involved in crucial biological functions may have a role in different diseases, including MS and its animal model, experimental autoimmune encephalomyelitis (EAE). It was shown that voltage-gated potassium channels Kv1.5 are responsible for fine-tuning in the immune physiology and influence proliferation and differentiation in microglia and astrocytes. Here, we explored the cellular distribution of the Kv1.5 channel, together with its transcript and protein expression in the male rat spinal cord during different stages of EAE. Our results reveal a decrease of Kv1.5 transcript and protein level at the peak of disease, where massive infiltration of myeloid cells occurs, together with reactive astrogliosis and demyelination. Also, we revealed that the presence of this channel is not found in infiltrating macrophages/microglia during EAE. It is interesting to note that Kv1.5 channel is expressed only in resting microglia in the naïve animals. Predominant expression of Kv1.5 channel was found in the astrocytes in all experimental groups, while some vimentin⁺ cells, resembling macrophages, are devoid of Kv1.5 expression. Our results point to the possible link between Kv1.5 channel and the pathophysiological processes in EAE.

P3125Five-year impact of immediate invasive strategy on clinical outcomes in patients with non-ST-segment elevation myocardial infarction: RIDDLE-NSTEMI study

Background

Most of the previous studies evaluated the impact of early versus delayed invasive intervention on clinical outcomes in patients with non-ST segment elevation acute coronary syndrome (NSTE-ACS) in one-year period.

Purpose

The aim of this study was to assess whether the immediate invasive intervention influences the occurrence of death and new myocardial infarction (MI), specifically in patients with non-ST segment MI (NSTEMI) in long-term follow-up.

Methods

In The Randomized Study of Immediate Versus Delayed Invasive Intervention in Patients With Non ST-segment Elevation Myocardial Infarction (RIDDLE-NSTEMI) 323 patients with NSTEMI were randomized to either immediate (median time to intervention was 1.4 hours) or delayed invasive strategy (61.0 hours). The incidence of primary outcome -death or new MI at 30 days was lower in patients assigned to the immediate (n=162) than in patients assigned to the delayed (n=161) invasive intervention group (4.3% vs. 13%, respectively; p=0.008). Long-term follow-up of 5 years was available for 96.90% of the patients.

Results

At 5 years, the immediate invasive intervention was associated with lower rate of death or new MI, compared with delayed invasive strategy (15.8% vs 32.9%, respectively; p=0.00). The observed benefit of the immediate intervention was mainly due to an increased early reinfarction risk with the delayed strategy (2.5% vs 9.9%, p=0.001) with similar new MI rates beyond 30 days (5.9% in the immediate and 10.7% in the delayed group, p=0.130). Five-year mortality was 12.0% in the immediate invasive intervention strategy group, and 18.1% in the delayed strategy group (p=0.135).

Conclusion

Immediate invasive intervention in the patients with NSTEMI significantly reduces the early risk of new MI. However, the timing of invasive intervention appears not to have significant impact on the clinical outcome beyond 30 days.

Clinical guidance and an evidence-based approach for restoration of worn dentition by direct composite resin

This paper aims to provide the dentist with practical guidance on the technique for direct composite restoration of worn teeth. It is based on current evidence and includes practical advice regarding type of composite, enamel and dentine preparation, dentine bonding and stent design. The application of direct composite has the advantage of being additive, conserving as much of the remaining worn tooth as possible, ease of placement and adjustment, low maintenance and reversibility. A pragmatic approach to management is advocated, particularly as many of the cases are older patients with advanced wear. Several cases restored by direct composite build-ups illustrate what can be achieved. The restoration of the worn dentition may be challenging for many dentists. Careful planning and simple treatment strategies, however, can prove to be highly effective and rewarding. By keeping any intervention as simple as possible, problems with high maintenance are avoided and management of future failure is made easier. An additive rather than a subtractive treatment approach is more intuitive for worn down teeth. Traditional approaches of full-mouth rehabilitation with indirect cast or milled restorations may still have their place but complex treatment modalities will inevitably be more time consuming, more costly, possibly require specialist care and still have an unpredictable outcome. Composite resin restorations are a universal restorative material familiar to dentists from early-on in the undergraduate curriculum. This review paper discusses the application of composite to restore the worn dentition.

A novel approach to study in situ enamel erosion and abrasion lesions

OBJECTIVES

This study investigated previous hypotheses that the tongue can abrade acid softened/eroded enamel surfaces.

METHODS

Twelve upper removable appliances each retaining 2 anterior and 2 posterior human enamel specimens were constructed. Each specimen was exposed to acid on both surfaces, but only one surface was allowed contact with the tongue. Therefore, 96 surfaces were assessed. Appliances were worn from 9.30 to 17.00 Monday to Friday for 22days. Acid eroded lesions were created by immersing the specimens for 5min in 50ml orange juice three times daily. Enamel loss was measured using Quantitative light- induced fluorescence (QLF) and Non- contact profilometry (NCLP) and the differences (D) between tongue (D_t) and palate facing (D_P) surfaces determined.

RESULTS

%ΔF_D(t-p) from the two anterior specimens were greater than from those placed posteriorly with mean values of 15.9% (±9.1) and 14.4% (±8.4), 5.6% (±8.7) and 4.5% (±6.6) respectively. Similarly, NCLP data showed anterior specimens had greater differences for mean step height (MSH) between tongue- facing and the palate- facing (control) surfaces than posterior specimens. MSH_D(t-p) values were 59.4μm (±30.3) for anterior tongue facing surfaces and 55.5μm (±29.4) for posterior palate facing surfaces. For the posterior specimens MSH was 48.1μm (±26.1) and 51.7μm (±30.4) respectively (p<0.05).

CONCLUSION

The greater enamel surface loss of the anterior specimens demonstrates that abrasion by the tongue on acid softened/eroded enamel in situ is likely.

The clinical features and their impact on the prosthodontic management in a case of Gardner's syndrome

Gardner's syndrome is a variant of Familial Adenomatous Polyposis (FAP), a condition that manifests as hundreds of colorectal polyps likely to undergo malignant change by the fourth decade. Early diagnosis of this condition has the potential to be life saving for individuals and due to its inherited nature other family members can often also be affected. Additional features of Gardner's Syndrome include multiple jaw osteomas with missing teeth that can make prosthodontic treatment a challenge. This case report highlights the presenting features and the prosthodontic problems faced when treating a patient with Gardner's syndrome.

Reproductive differentiation into sexual and apomictic polyploid cytotypes in Potentilla puberula (Potentilleae, Rosaceae)

BACKGROUND AND AIMS

Intraspecific reproductive differentiation into sexual and apomictic cytotypes of differing ploidy is a common phenomenon. However, mechanisms enabling the maintenance of both reproductive modes and integrity of cytotypes in sympatry are as yet poorly understood. This study examined the association of sexual and apomictic seed formation with ploidy as well as gene flow towards sexuals within populations of purely polyploid Potentilla puberula.

METHODS

The study is based on 22 populations representing various combinations of five polyploid cytotypes (tetraploid-octoploid) from East Tyrol, Austria. Embryo ploidy and the endosperm/embryo ploidy ratio obtained by a flow cytometric seed screen were used to infer reproductive modes of seed formation and to calculate the male and female genomic contributions to the embryo and endosperm. Self-incompatibility (SI) patterns were assessed and a new indirect approach was used to test for the occurrence of intercytotype matings based on the variation in the male genomic contribution to sexually derived embryos on the level of developed seed.

KEY RESULTS

Tetraploids formed seeds almost exclusively via sexual reproduction, whereas penta- to octoploids were preferentially apomictic. Non-random distribution of reproductive modes within maternal plants further revealed a tendency to separate the sexual from the apomictic mode among individuals. Self-incompatibility of sexuals indicated functionality of the gametophytic SI system despite tetraploidy of the nuclear genome. We found no indication for significant cross-fertilization of tetraploids by the high polyploids.

CONCLUSIONS

The study revealed a rare example of intraspecific differentiation into sexual and apomictic cytotypes at the polyploid level. The integrity of the sexual tetraploids was maintained due to reproductive isolation from the apomictic higher polyploids. Functionality of the gametophytic SI system suggested that the tetraploids are functional diploids.

UK National Clinical Guidelines in Paediatric Dentistry: diagnosis, prevention and management of dental erosion

This revised Clinical Guideline in Paediatric Dentistry replaces the previously published ninth guideline (Shaw L, O'Sullivan E. Int J Paediatr Dent 2000; 10: 356-365). The process of guideline production began in 1994, resulting in first publication in 1997. Each guideline has been circulated widely for consultation to all UK consultants in paediatric dentistry, council members of the British Society of Paediatric Dentistry (BSPD), and to people of related specialities recognized to have expertise in the subject. The final version of this guideline is produced from a combination of this input and thorough review of the published literature. In the case of the present guideline, an internationally recognized expert in the field was invited to be a co-author (AM). The intention is to encourage improvement in clinical practice and to stimulate research and clinical audit in areas where scientific evidence is inadequate. Evidence underlying recommendations is scored according to the SIGN classification and guidelines should be read in this context. Further details regarding the process of paediatric dentistry guideline production in the UK is described in the Int J Paediatr Dent 1997; 7: 267-268.

Bleeding after dental extractions in patients taking warfarin

OBJECTIVE

To assess the incidence of bleeding after dental extractions in subjects taking warfarin continuously before and after extractions whose International Normalised Ratio (INR) was below 4.0 at the time of extraction.

METHODS

This was a case series study of 150 patients without controls who required extraction of at least one tooth under local anaesthetic. All sockets were subsequently packed with absorbable oxycellulose and sutured.

RESULTS

A total of 58 women and 92 men were included (mean age 66 years); their ages were similar. The mean INR (S.D.) was 2.5 (0.56), although most patients had an INR less than 2.5 (n=101). Ten patients (7%) bled after extraction, enough to require a return to hospital. Five patients of 101 with an INR</=2.5, and 5 with an INR>2.5 out of 49 bled after extraction (p=0.29). Bleeding after extraction was not associated with operative antibiotics. All patients who bled were managed conservatively and none was admitted to hospital.

CONCLUSION

Patients taking warfarin whose INR is up to 4.0 and who have dental extractions in hospital do not have clinically significant bleeds post-operatively.

Epidemiological studies of tooth wear and dental erosion in 14-year old children in North West England. Part 2: The association of diet and habits

OBJECTIVE

To determine the strength of association (expressed as Odds Ratios) of potential risk factors with erosion and tooth wear in 14-year-old schoolchildren.

DESIGN

A random sample of 2,385 children were selected by a stratified two-stage technique based on schools and children.

SETTING

Schools in NW England.

METHODS

Tooth wear was assessed by one examiner on three surfaces of all 12 anterior teeth (labial, incisal and palatal) and the occlusal surface of all four first molars using a four-point scale. Enamel wear was scored 0, dentine exposure <1/3 scored 1, >1/3 scored 2 and secondary dentine or pulpal exposure, scored 3. A questionnaire enquired about general health, dental health, habits and the frequency of intake of a wide range of foods and drinks.

RESULTS

The Odds Ratios for tooth wear on any surface for habits, reflux and certain foods were: bruxism, 1.10; stomach upset, 1.45; pickles 1.86; vinegar 1.36; salt and vinegar crisps 1.33; brown/other sauces 1.57. Similarly, the odds ratios for potentially erosive drinks were: fizzy drinks 1.32; sport drinks 1.58; herbal/lemon tea 3.97. The frequency of intake was bi-modal with 397 children drinking a can per day and 207 drinking two cans per day. A significant number drank acidic beverages at bedtime but this was not associated with dental erosion.

CONCLUSION

Although odds ratios greater than unity indicate an association, this was not high for carbonated beverages and many other acidic foods or drinks. Examining at fourteen years may not be ideal, as the determinants of erosion/tooth wear have not acted for long, the indices do not discriminate sufficiently and proportionately few subjects have dentine exposed on smooth surfaces.

Epidemiological studies of tooth wear and dental erosion in 14-year-old children in North West England. Part 1: The relationship with water fluoridation and social deprivation

OBJECTIVE

The effect of water fluoridation upon dental erosion/tooth wear in the UK has not been investigated. This study aimed to compare the prevalence of tooth wear in 14-year-old schoolchildren in non-fluoridated and fluoridated districts of North West (NW) England. The influence of deprivation and tooth brushing was also investigated.

DESIGN

A random sample of 10% of the 14-year-old population in NW England was selected and stratified according to fluoridation status as determined from water authority postcode listings.

METHODS

Tooth wear was scored on the labial, incisal and palatal/lingual surfaces of the 12 anterior teeth and the occlusal surfaces of the first molars. Enamel wear was scored 0, dentine was scored 1 or 2, dependent on whether less than or more than a third of the surface had exposed dentine. Secondary dentine or pulpal exposure scored 3. Townsend deprivation scores were gained from residential post codes.

RESULTS

A total of 2,351 children were examined, of which 637 (27%) lived in the one fluoridated district of South Cheshire and 1,714 (73%) lived in 11 non-fluoridated districts. Fifty-three per cent of the children had exposed dentine with significantly more males affected than females (p<0.001). In the fluoridated district, significantly fewer children had exposed dentine on labial and palatal smooth surfaces (p<0.001) but no differences were found for incisal and occlusal surfaces. The interaction of fluoridation and tooth brushing twice per day resulted in a significant (30%) reduction in erosion. Smooth surface wear was more prevalent in children resident in affluent areas.

CONCLUSION

Children in non-fluoridated districts are 1.5 times more likely to have smooth surface wear compared with children in fluoridated districts. Fluoridation and use of fluoridated toothpaste twice a day provide added protection from dental erosion. The risk of tooth wear is greater with increasing affluence.

The importance of antioxidant enzyme and total antioxidant status of patients with acute myocardial infarction on thrombolytic therapy

It is believed that intensive production of free radicals occurs immediately after reperfusion, and that it explains a series of adverse effects of reperfusion. The aim of the study was to establish the importance of the antioxidative enzymes superoxide dismutase (SOD), glutathione peroxidase (GPX) and the total antioxidant status (TAS) in patients with acute myocardial infarction according to success or failure of reperfusion. Enzyme activities in erythrocyte hemolysate and concentration of TAS in plasma were determined by Randox kits in 50 patients with acute myocardial infarction. No significant differences in TAS between the mean values against either clinical status or the 10 time intervals were recorded. The SOD and GPX values were significantly influenced by the presence or absence of reperfusion (p<0.05). Monitoring of SOD and GPX at ten time points: before administration of streptokinase, 1, 3, 6, 12, 18, 24 hours, 2, 3 and 5 days after administration of streptokinase revealed the lowest SOD levels up to one hour before administration of streptokinase, supporting the fact that the maximum production of free radicals is achieved at that time. GPX values differed for 24 hours according to whether reperfusion was achieved or not. The obtained results suggest that free radical production is increased after reperfusion, and monitoring of antioxidant enzymes may help to evaluate the success of thrombolytic therapy.

Comparison of three facebow/semi-adjustable articulator systems for planning orthognathic surgery

Our aim was to measure the steepness of the occlusal plane produced by three different semi-adjustable articulators: the Dentatus Type ARL, Denar MkII, and the Whipmix Quickmount 8800, and to assess the influence of possible systematic errors in positioning of study casts on articulators that are used to plan orthognathic surgery. Twenty patients (10 skeletal class II, and 10 skeletal class III) who were having pre-surgical orthodontics at Liverpool University Dental Hospital were studied. The measurement of the steepness of the occlusal plane was taken as the angle between the facebow bite-fork and the horizontal arm of the articulator. This was compared with the angle of the maxillary occlusal plane to the Frankfort plane as measured on lateral cephalometry (the gold standard). The Whipmix was closest to the gold standard as it flattened the occlusal plane by only 2 degrees (P<0.05). The results of the Denar and Dentatus differed significantly from those of the cephalogram as they flattened the occlusal plane by 5 degrees and 6. 5 degrees (P<0.01), respectively. Clinicians are encouraged to verify the steepness of the occlusal plane on mounted study casts before the technician makes the model.

Use of articulators in the United Kingdom by consultant orthodontists in planning orthognathic surgery

This questionnaire survey aimed to investigate articulator use in orthognathic surgical planning by consultant specialists in the United Kingdom (UK). A total of 205 questionnaires was sent to all consultant orthodontists in the UK. One hundred thirty questionnaires were completed, representing a 63.4% response rate. Consultants had been in their post for a median of 10.5 years (range 0 to 30 years) with a mean of 11.3 (SD 8.4) surgical cases per year. When asked which cases had been planned on a semiadjustable articulator, two thirds of consultants (67.7%) planned maxillary single-jaw procedures, 45.4% planned mandibular single-jaw procedures, and 77.7% planned bimaxillary procedures. While 98.5% of consultants reported access to at least one type of articulator, 14.6% of maxillary single-jaw and 5.4% of bimaxillary surgery was not planned on any articulator. Twice as many consultants who had been in their post fewer than 11 years had been trained on a semiadjustable articulator, compared to those who had more than 11 years of experience. Semiadjustable articulators were the most popular for planning orthognathic surgery. Consultants with less than 11 years of experience completed more surgical cases each year and were more likely to have been trained on a semiadjustable articulator than consultants with more than 11 years of experience. However, no link exists between the age of the consultant and the type of articulator selected for planning; this suggests that more mature consultants have received further training on contemporary articulator systems since receiving their accreditation.

The post-orthodontic prevalence of temporomandibular disorder and functional occlusion contacts in surgical and non-surgical cases

This study aimed to assess mandibular mobility and the prevalence of functional occlusal contacts in subjects treated to a Class 1 incisor relationship by fixed orthodontic appliance therapy. Two hundred and thirty subjects participated (mean age=18 years) of whom 42 underwent orthognathic surgery. All subjects were in retention with a mean time of 7 months between debond and examination. Maximal mandibular opening, lateral and protrusive excursions were all significantly reduced in the surgical cases compared to the non-surgical group. Centric and eccentric non-ideal occlusal contacts were not different between surgical and non-surgical groups. Non-working side contacts occurred in 30% of subjects, posterior contacts on protrusion in 20% and RCP-ICP prematurities in 18% of subjects. Non-working side contacts were significantly more frequent in post-graduate cases compared to staff cases (P<0.05). An overbite less than the mean of 2.4 mm resulted in a reduced likelihood of canine guidance on the working side (P<0.001) and an increased frequency of non-working side contacts and posterior contacts on protrusion (P<0.001).

Thickness of acquired salivary pellicle as a determinant of the sites of dental erosion

Dental erosion shows a typical distribution pattern within the dental arches. Tooth protection from erosion by salivary pellicle has been shown in vitro, but the hypothesis that pellicle may differ quantitatively at sites of erosion has not been investigated. This study aimed to determine the thickness of acquired salivary pellicle within the dental arches, investigate the possible relationship of this thickness to the distribution and severity of erosion within the arches, and confirm the protective effect of pellicle against dental erosion. Eight enamel blocks were produced from each of 5 bovine incisors assigned to five volunteers. Each block was further cut into 2 slabs, producing control and experimental slabs. Pellicle developed on experimental slabs located on 8 intra-oral sites after 1 hr of exposure was stained by "sheep anti-human IgGAM-FITC". Slabs were then visualized, and pellicle thickness measured, by confocal laser scanning microscopy. Eroded enamel lesions were produced in experimental and control slabs by means of pure orange juice. The degree of erosion was quantified by transverse microradiography. Pellicle thickness varied significantly within the dental arches and among individuals. An inverse relationship (r = -0.96, p<0.001) was observed between the degree of erosion and pellicle thickness. Significant differences in erosion were observed between slabs with and those without pellicle. This study has shown that the thickness of acquired salivary pellicle varies within the dental arches, which may be responsible for the site-specificity of dental erosion, and that pellicle does protect the teeth from erosion.

Early development and composition of the human primordial plexiform layer: An immunohistochemical study

The early expression of reelin, calcium-binding proteins (calretinin, calbindin, and parvalbumin), and neurofilament proteins have been explored in the developing central nervous system of human embryos and fetuses during the first trimester of gestation. Our objective has been to determine further the nature, developmental roles, and contributions of the early neurons and fibers of the original subpial neuropil, i.e., the primordial plexiform layer (PPL). In young embryos (4-5 weeks old), neurofilament protein-labeled fibers run through the subpial neuropil of the caudal portion of the neural tube, reaching the mesencephalon rostrally. At this age, calretinin-immunoreactive and calbindin-immunoreactive neurons are also found among cells already detached from the ventricular zone. The expression of neurofilament protein, calretinin, and calbindin follows an ascending caudorostral gradient, reaching the cerebral vesicles by the 6th-7th week of gestation. In the cerebral cortex, this timing coincides with the initial expression of reelin in the PPL. The reelin immunoreactivity throughout the most superficial cellular population of the cortical PPL supports the early genesis of Cajal-Retzius cells, around the 6th week of gestation. After the splitting of the PPL by the formation of the cortical plate (7-8 weeks of gestation), reelin-immunoreactive cells remain only in the newly established layer I. This study proposes that an initial PPL may be a universal feature of the developing central nervous system.

The occurrence of toothwear in users of Ecstasy (3,4-methylenedioxymethamphetamine)

Ecstasy users have reported that dry mouth, jaw tension and tooth grinding were common side effects of its use although the influence of these effects upon toothwear have not been previously investigated.

OBJECTIVE

This study aimed to compare incisal and occlusal toothwear in Ecstasy users and a group of non-users of Ecstasy but users of other drugs.

METHODS

Groups were established by a snowball peer information network from visitors to the "drop-in" Maryland Centre in Liverpool. Volunteers completed a questionnaire about social life, drug use and diet. Clinical examination for wear on the incisal edges and on canine tips was conducted with a mirror and probe, whereas occlusal wear was recorded in impressions and subsequently scored from stone replica casts. The degree of toothwear was scored according to the criteria of the Tooth Wear Index (Smith & Knight, Br Dent J 1984;157:16).

RESULTS

Ecstasy users (n = 30) were compared with non-users (n = 28). Toothwear through the enamel into the underlying dentine occurred in 18 (60%) Ecstasy users but in only three (11%) non-users. The overall mean toothwear score in Ecstasy users was 0.63 compared with 0.16 in non-users (t = 4.34, P < 0.001). Dry mouth was reported by 93% of Ecstasy users whilst 89% stated that they clenched or ground their teeth after taking the drug. Tooth grinding commonly continued into the following morning. Carbonated (acidic) beverages were consumed by 93% of the users with a mean of three cans per "trip".

CONCLUSION

The severity of toothwear and the number of teeth affected were greater in Ecstasy users than in a group of non-users. The occlusal surfaces were more commonly affected than the incisal, which may indicate jaw clenching rather than grinding as a feature of Ecstasy-induced muscle hyperactivity.

Calcium signaling molecules in human cerebellum at midgestation and in ataxia

A fundamental question in brain development is how neurons make the precise topographic connections necessary for function. The hypothesis that transient expression of calcium (Ca2+) signaling molecules may have a role in this process was tested by studying human cerebella at midgestation. In addition, four adult brains, two controls and two from patients with ataxia, were studied as well. The temporal and spatial distribution of intracellular Ca2+ channel/receptors, inositol trisphosphate receptor type 1 (IP3R1) and ryanodine receptor (RyR) and three Ca2+ binding proteins were examined with immunocytochemical methods. A positive immune reaction with all markers of Ca2+ signaling was found in the Purkinje cell layer starting from 17 g.w. (gestational weeks), the youngest age studied. The immune reactions were not homogeneous throughout the extent of the Purkinje cell layer, but instead displayed a 'patchy' appearance in all intrauterine stages. In the adult cerebellum the expression of Ca2+ signaling molecules was homogenous. In the two cerebella obtained from patients suffering from ataxia, a several-fold reduction of immunostaining with IP3R1 was found. Our findings suggest that transient and differential mobilization of intracellular Ca2+ in seemingly homogenous neuronal types may play a role in development of highly organized projection maps of the cerebellar cortex. Moreover, lack of IP3R1 in the diseased brains suggests that internal stores of Ca2+ play an important role in normal function of the cerebellum.

Eating disorders and the dentist

Dentists are likely to encounter patients who have eating disorders. The paper explains the various types and considers both the risk factors, and the psychological and medical complications. The effect on oral health and the principles of dental management are outlined. Dentists have an important part to play in the overall care of these patients.

Functional occlusion after fixed appliance orthodontic treatment: a UK three-centre study

This study aimed to assess the prevalence of functional occlusal contacts in cases treated to a Class I incisor relationship by upper and lower fixed appliance therapy. Helkimo's dysfunction indices were used by one examiner to assess mandibular mobility, clinical dysfunction and occlusal status. One-hundred-and-eighty-eight subjects participated in three UK orthodontic centres; Cardiff, Newport and Liverpool. The results show that RCP (CR)-ICP (CO) discrepancies occurred in 33 (18 per cent) cases, non-working side contacts were present in 31 per cent and posterior contacts on protrusion occurred in 44 (23 per cent) subjects. These interferences were significantly more frequent in cases treated by postgraduate students compared with those treated by staff clinicians (P < 0.05). An overbite greater than 2.4 mm resulted in a highly significant reduction in the occurrence of non-working side contacts and posterior protrusive contacts (P < 0.001). The prevalence of functional occlusal discrepancies in this UK sample of orthodontic cases is similar to that reported in the American literature.

Developmental changes in human cerebellum: expression of intracellular calcium receptors, calcium-binding proteins, and phosphorylated and nonphosphorylated neurofilament protein

Few recent data are available on the development of the precise projection maps of the cerebellar cortex in humans. To address this topic, we studied temporal and spatial distribution of several antigens involved in calcium (Ca)-dependent processes: the intracellular Ca receptors, inositol 1,4,5-trisphosphate receptor type 1 (IP3R1) and ryanodine receptor (RyR); the Ca-binding proteins, calbindin D-28k (CB), parvalbumin (PV), and synaptophysin; and phosphorylated (SMI 31) and nonphosphorylated (SMI 32) forms of neurofilament protein. All antigens were studied in the human cerebellum during intrauterine development. The results of this study show that immunocytochemical markers appeared in the following sequence: CB and both forms ofneurofilament protein were observed at 4-5 gestational weeks (g.w.), PV appeared in the external granular layer and in a few Purkinje cells at 11 g.w., a diffuse immunostaining for IP3R1 and synaptophysin were observed at 13 g.w., whereas RyR was observed at 17-18 g.w. From 24 g.w. on, Purkinje cells expressed all four examined markers of intracellular Ca signaling as well as two forms of neurofilament protein. At the same time, compartmentation of the Purkinje cell layer was detected with three intracellular Ca-signaling molecules (IP3R1, CB, and PV) and with SMI 32. These results indicate that the developmentally regulated expression of antigens studied here may play a role in establishing a highly regular organization of terminal fields in the human cerebellar cortex. Moreover, the initial expression of these antigens is correlated temporally with other developmental processes in the cerebellum, such as cellular maturation, revealed by the immunoreaction to cytoskeletal protein, and synaptogenesis, revealed by immunoreaction to synaptophysin.

Mandibular mobility and occlusal relationships after orthognathic surgery

Mandibular mobility and the occurrence of occlusal interferences were assessed in a group of 42 subjects, all of whom underwent orthognathic surgery without maxillomandibular fixation. A minimum period of 3 months (mean of 12.9 months) had elapsed since surgery. Mandibular advancement (n = 8) and bimaxillary advancement procedures (n = 8) resulted in significantly greater end-of-treatment overjet than did Le Fort I (n = 12), mandibular setback (n = 3), or maxillary advancement with mandibular setback (n = 11). Mean maximum protrusion (5.9 mm) and mean maximum excursions to right and left (6.8 and 6.1 mm, respectively) were significantly higher after Le Fort I osteotomy. The frequency of right lateral, but not left lateral, non-working-side contacts was significantly greater in the mandibular setback group and the maxillary advancement with mandibular setback group. The mandibular setback group exhibited the only severe interference between retruded contact position and intercuspal position.

Toothwear: management

The management of toothwear encompasses a broader approach than the active treatment of the problem, taking in as it does both passive and active interventions. This paper gives guidelines on how to assess and broadly manage toothwear rather than specific examples of treatment.

Toothwear: aetiology and presentation

A worn dentition is a frequent clinical finding and presents two major challenges to the dental team. The first challenge is to ascertain the cause of the toothwear, the second is its management. This paper aims to present an overview of aetiologies associated with toothwear.

Risk factors associated with tooth wear in teenagers: a case control study

OBJECTIVE

To measure the association of various aetiological risk factors with tooth wear in 15-year-old school children.

BASIC RESEARCH DESIGN

A case control study conducted one year after a prevalence study (Milosevic et al., 1994). The 80 children, identified from the prevalence study with palatally and/or occlusally exposed dentine, acted as cases. The control group were systematically selected from every tenth name on year registers. The only matching criteria were age, gender and school. All children answered a questionnaire detailing the risk factors and the tooth wear was further scored by one examiner (AM).

SETTING

Ten randomly selected schools in Liverpool.

PARTICIPANTS

102 children participated out of a possible 160, an overall response rate of 64 per cent. Of the 54 controls, six had developed tooth wear into dentine during the 12-month interval following the prevalence study and were therefore excluded from the analysis.

RESULTS

The odds ratio on 37 matched pairs was 1.7 (95% CI 0.72, 3.87) for grinding and clenching teeth and 2.6 (95% CI 0.91, 7.45) for carbonated drink consumption. Eating pickled food other than pickled onions was significantly more frequent in cases than in controls. Other potential aetiological factors which were not significantly associated with tooth wear in this group of children included stomach upsets, frequency of tooth brushing, weight/body shape and drinking fruit juice or using ketchup/sauces. Conditional logistic regression analysis of the paired data showed that carbonated beverage consumption was on the borderline of significance (P = 0.055) as a predictor for tooth wear in teenagers either on its own or allowing for the effect of tooth grinding.

CONCLUSIONS

The frequent consumption of carbonated beverages is probably related to tooth wear. Future case control studies should seek to incorporate around 100 to 160 cases.

Sports supplement drinks and dental health in competitive swimmers and cyclists

AIM

To assess dental status and sports supplement uptake in swimmers and cyclists. To determine chemico-physical properties of the most popular sports drinks.

DESIGN

Descriptive, prevalence study of tooth wear and caries experience. Questionnaire analysis of sports drinks usage.

SETTING

Two public swimming pools in Liverpool and three cycle clubs in North West England.

SUBJECTS AND METHOD

A convenience sample of swimmers and cyclists was examined for caries and tooth wear. A questionnaire ascertained which sports drinks were consumed and their pattern of consumption. pH and titratable acidity, concentrations of calcium, phosphate and fluoride, and viscosity were analysed. Salivary flow rate in response to these drinks and water was also determined.

RESULTS

25 swimmers and 20 cyclists participated. Caries experience and tooth wear into dentine (excluding incisally exposed dentine) was significantly more frequent among cyclists (P < 0.05). Cyclists had significantly more upper palatal wear (P < 0.001). Pattern of sport drink consumption between the two groups was significantly different (P < 0.001). pH range of the most popular sport drinks was 2.4-4.5. Salivary flow rate after a 1-minute rinse was significantly lower (P < 0.05) with one drink (0.47 ml/min) and water (0.41 ml/min) compared with the other drinks.

CONCLUSIONS

An association between caries or erosive tooth wear and sport drink consumption was not found. However, the erosive potential of sport drinks is real and must be borne in mind as an aetiological factor for erosion in young people.

Initial development of gamma-aminobutyric acid immunoreactivity in the human cerebral cortex

The development of cortical cells immunoreactive for gamma-aminobutyric acid (GABA) was studied in human cerebral cortex in the first trimester of gestation (from 4 to 13 gestational weeks; g.w.). The first GABA-immunoreactive (IR) cells were observed at 6.5 g.w., i.e., before the appearance of the cortical plate, which gives rise to a majority of the adult cortical layers. GABA-IR cells were found initially in the telencephalic wall, where a lateromedial gradient in the density of GABA-positive cells was observed at this early developmental time point, but not at later stages. At 7 g.w., as the cortical plate emerged in the ventrolateral region of the cerebral vesicle, GABA-immunoreactive cells were found dorsal and ventral to the developing cortical plate. At this stage, immunoreactivity was also observed in the other transient developmental zones of the cortical anlage: in the subplate layer and in the intermediate, subventricular and ventricular zones. From 8 to 9 g.w. and continuing throughout the end of the studied period (13 g.w.), GABA-IR cells were distributed throughout the full width of the telencephalic wall, and, at 13 g.w., the newly formed subpial granular layer contained GABA-immunoreactive cells, as well. However, the predominant sites for GABA immunoreactivity remained the prospective layer I and the subplate. The population of GABA-positive cells described here was not immunoreactive for glial fibrillary acidic protein (GFAP) at any gestational age examined and, therefore, probably represents GABA-containing neurons. The observation that GABA-IR neurons appear in human developing cortex slightly before the cortical plate formation and beginning of synaptogenesis (6.5 g.w.) suggests that GABA plays an important role in the initial organization of the developing human cerebral cortex.

Sports drinks hazard to teeth

OBJECTIVE

To determine the dental hazards associated with sports supplement drinks by investigating the chemicophysical properties of eight brands of sports drinks.

METHODS

The pH and titratable acidity against 0.1 M NaOH was measured. Calcium, phosphate, and fluoride concentrations and viscosities of Carbolode, Gatorade, High Five, Isostar, Lucozade Sport Lemon, Lucozade Sport Orange, Maxim, and PSP22 were determined.

RESULTS

The pH values of the drinks ranged from 4.46 (Maxim) to 2.38 (Isostar) and therefore were below the critical pH value (5.5) for enamel demineralisation. Both Lucozade varieties had high titratable acidities (16.30 ml 0.1M NaOH to neutrality) with Gatorade, High Five, and Isostar displaying intermediate titratable acidity, although Isostar had 74.5 ppm calcium and 63.6 ppm phosphate. The fluoride concentration of all drinks was low, and none of the drinks was particularly viscous (range 3.1-1.4 mPa.s).

CONCLUSIONS

The chemicophysical analyses indicate that all the sports drinks in this study have erosive potential. However, drinks with higher pH, lower titratable acidity, and higher concentrations of calcium, phosphate, and fluoride will reduce this erosive potential.

Dental erosion, oral hygiene, and nutrition in eating disorders

OBJECTIVE

To determine the influence of oral hygiene practices and additional fluoride on erosive tooth wear in eating disorders. The proportional dietary intake of carbohydrates, fats, and proteins was also investigated.

METHOD

Tooth wear was measured with the use of the tooth wear index (TWI). All subjects completed a questionnaire on past dental history as well as a 1-week diet sheet. A total of 33 subjects participated in the study, 20 of whom were follow-ups, allowing the progress of dental erosion to be made. All subjects were referred from the Department of Clinical Psychology.

RESULTS

Oral hygiene practices between subjects with and without severe erosion were not significantly different. Only 8 bulimics spent more time brushing after vomiting than at other times. The pH of vomitus from 6 subjects ranged between 2.9 and 5.0, with a mean of 3.8, well below the critical pH for enamel demineralization to occur. Of the 20 follow-up subjects, 12 (60%) exhibited worsening tooth wear. The mean values for daily carbohydrate, protein, and fat intake were not significantly different at baseline and at recall, and the proportional dietary intake was similar to recommended energy provision at 47%, 40%, and 13%, respectively.

DISCUSSION

The contribution by toothbrush abrasion to the overall wear in the eroded dentition of bulimics is not significant. Therefore, immediate post-vomiting oral hygiene practices can be recommended. The proportional nutritional intake values of carbohydrates, fats, and proteins in this group of bulimics are acceptable.

Tooth wear in three ethnic groups in Sabah (northern Borneo)

The prevalence and associated aetiologies of tooth wear were investigated in three ethnic groups in Sabah (Northern Borneo) using the Tooth Wear Index (TWI). The number of surfaces with enamel wear only, dentine exposed for less than a third or dentine exposed for more than a third were categorised into the TW minimal, moderate or severe respectively. A structured questionnaire was used to elicit medical/dental history, oral hygiene practices, satisfaction with body image, diet and other personal habits/details. The sample comprised of a self selected sample of 148 dental hospital attenders; 47 (32 per cent) each of ethnic Chinese and Malay and 54 (36 per cent) of ethnic Kadazan, matched for age and with a similar number of scoreable teeth per subject. Dentine exposure within the total sample was a common finding (95 per cent TW with moderate, 41 per cent TW severe). The Kadazan group had significantly (P < 0.05) more surfaces with severe tooth wear than the Chinese or Malay. Tobacco chewing was positively associated (rho = +0.4, P < 0.05) with both moderate and severe tooth wear, as was the habit of crushing/eating bones. Neither carbonated beverages or fresh fruit intake were associated with tooth wear, but their frequency of consumption was low. The buccal and occlusal surfaces of the posterior teeth were the most severely worn. Generally, wear was greater in the upper anterior sextant compared to the lower anterior sextant, with the exception of the lower incisal edges in the Kadazan group. Tooth wear into dentine was a common occurrence, especially among the Kadazan subjects and least among the Chinese subjects. The aetiological factors associated with this tooth wear are different to those encountered in Western cultures.

GAP-43 mRNA expression in early development of human nervous system

The temporal and spatial distribution of GAP-43 mRNA in early human development, from 6 to 23 gestational weeks (g.w.), was examined by in situ hybridization histochemistry. GAP-43 mRNA was expressed as early as 6 g.w. in all regions of developing nervous system, the spinal cord, brainstem, cerebellum, diencephalic and telencephalic regions. Although the pronounced level of expression persisted during the entire examined period, the intensity of expression varied along the spatial axis over time. Analysis at the cellular level revealed that early on in development (6 g.w.) GAP-43 mRNA was expressed in the entire neuroblast population. With the onset of differentiation, at 13-23 g.w., GAP-43 mRNA expression had switched to the neurons that are in the process outgrowth. The highest level of GAP-43 mRNA expression was localized in the regions consisting of differentiating neurons, such as the cortical plate and intermediate zone of the telencephalic wall, and several delineated subcortical and thalamic nuclei. The spatial and temporal pattern of GAP-43 mRNA expression obtained suggests a possible dual role of GAP-43 in the development of the human nervous system: in the embryonic brain it could be involved in fundamental processes underlying cell proliferation; in the fetal brain its expression is specifically correlated with differentiation and the outgrowth of axons.

Use of resin-bonded ceramic crowns in a bulimic patient with severe tooth erosion

Bulimia nervosa, an increasingly common eating disorder, involves binge eating and subsequent purging behavior. Repeated self-induced vomiting may lead to dental erosion. This article describes the use of resin-bonded ceramic crowns to manage a severely eroded maxillary dentition in such a patient.

Salivary factors in vomiting bulimics with and without pathological tooth wear

The increased occurrence of dental erosion from self-induced vomiting in bulimia nervosa is not linearly associated with the frequency or the duration of vomiting. Possible changes in the buffering and lubricating role of saliva in bulimia nervosa and their relationship to erosion have not been previously investigated. Chewing-gum-stimulated salivary flow rate, pH, bicarbonate concentration and viscosity were compared between two groups of vomiting bulimics and with 10 healthy controls. One bulimic group (n = 9) had pathological tooth wear present according to the criteria of the Tooth Wear Index and the other bulimic group (n = 10) did not. The influence of salivary pellicle on enamel acid dissolution by perchloric acid was also assessed by an enamel biopsy method. Bicarbonate was measured in a Natelson microgasometer. Both the bulimic groups had mean initial 3-min flow rates and overall 9-min flow rates significantly lower (p < 0.01) than the healthy subjects. The mean pH values were not significantly different between the two bulimic groups or the control group. However, the mean bicarbonate concentration in both bulimic groups was significantly less (p < 0.01) than in the control group. The mean salivary viscosity of 7.4 centipoise (cP), measured by a DV1 Brookfield viscometer, was significantly greater (p < 0.05) in the pathological tooth-wear-present group than in the tooth-wear-absent group (4.5 cP) and the control group (4.1 cP). Slightly more calcium was released from the pellicle-free surface in both groups but this was not statistically significant, whilst the dissolved calcium in enamel biopsies was significantly lower (p < 0.05) in the tooth-wear-present group.