Assessing lower incisor inclination change: a comparison of four cephalometric methods.

OBJECTIVE: Cephalometric inclination change of the lower incisors during orthodontics is used to assess treatment outcome. The lower border of the mandible is commonly used for measuring inclination change, despite it being subject to remodelling in growing patients. Superimposition of radiographs using Björk's 'stable structures' is intended to exclude these growth changes. We tested whether there is a significant difference for three commonly used methods to assess inclination change induced by orthodontic treatment (Me-Go, Go-Gn, the tangent to the lower border of the mandible) when comparing it to Björk's 'stable structures'. METHODS: Björk's superimposition does not allow measuring incisor inclination changes directly; hence, one pre- and mid-treatment cephalogram of 39 growing orthodontic patients were superimposed in this retrospective study. The radiographs were taken at least 1 year apart (120 weeks; SD = 34.4). Patients undergoing growth modification treatment were excluded. Standardized cephalograms were hand traced and changes in lower incisor inclination, using the three mandibular planes, were compared to the changes obtained by anatomical superimposition of Björk's 'stable structures'. RESULTS: Linear regression showed good intra-class correlation (ICC) between all methods. ICC was 0.96 for Me-Go, 0.94 for Go-Gn, and 0.92 for the lower border tangent. ICC for operator reliability was 0.99. LIMITATIONS: Measurement errors affect all investigations of both analogue and digital radiographs, but movement artefacts particularly apply to the latter. Cephalometry uses two-dimensional measurements of a three-dimensional subject, which can lead to further inaccuracies. These limitations have to be taken into account when interpreting the results of our investigation. CONCLUSION: Data obtained from Björk's superimposition did not vary significantly from the other more commonly used techniques (Me-Go, Go-Gn, and the tangent to the lower border of the mandible). Remodelling of the lower border of the mandible was insignificant for the time period investigated.

Effect of Model Variables on in vitro Erosion.

The aim of this study was to investigate the effects of tooth type (molar/premolar), tooth surface (buccal/lingual), smear layer or no smear layer, storage of specimens in deionised water, mode and speed of agitation, and rinsing method between cycles on mean step height loss and Knoop microhardness (KHN) change. Polished human enamel specimens embedded in acrylic resin were prepared from sound permanent molar and premolar tooth surfaces. A 0.3% (pH 3.2) solution of citric acid was used to erode the specimens, in a cycling procedure, consisting of 10 min immersion followed by rinsing in deionised water for 30 s with a spray bottle, for 5 cycles. The specimens were analysed with a non-contact white light profilometer and KHN. Molar teeth (148.99±24.49 KHN) and buccal surfaces (155.62±30.35 KHN) produced significantly less microhardness change compared to premolar (186.40±20.74 KHN) and lingual surfaces (179.76±23.21 KHN; p<0001). The effect of storage and rinsing showed little difference in mean step height loss (<1 µm) and microhardness change. With no smear layer a significantly lower mean step height loss and microhardness change (p<0.001) was observed. Agitation was performed with Orbital, Gyro and See-Saw rockers at 30, 40, 60, and 70 rpm. The mean step height loss was largest for See-Saw at 70 rpm (11.73±0.91 µm) and lowest for Orbital at 30 rpm (2.76±1.12 µm). A statistical difference was found between all types of agitation and speeds (p<0.001). In conclusion, this study has shown that the variables investigated here have a significant impact on the measurable outcome, highlighting the importance of accurate and detailed method sections.

Sniff nasal inspiratory pressure in patients with moderate-to-severe chronic obstructive pulmonary disease: learning effect and short-term between-session repeatability.

BACKGROUND: Sniff nasal inspiratory pressure (SNIP) is a non-invasive measure of inspiratory muscle function often used as an outcome measure in clinical studies. An initial period of familiarisation with the test is recommended to minimise the learning effect. The repeatability of SNIP in patients with chronic obstructive pulmonary disease (COPD) is currently unknown. OBJECTIVES: The aim of this study was to assess the between-session repeatability of SNIP over a 3-week period in moderate-to-severe COPD patients and compare it with that of maximal inspiratory (PI max) and expiratory pressure (PE max). METHODS: Twenty-one patients (13 males) with a mean forced expiratory volume in 1 s (FEV1) of 38% of predicted (SD: 15) and FEV1/forced vital capacity of 34.3% (SD: 10.4) performed SNIP and PI max and PE max manoeuvres on 3 different sessions (S1, S2 and S3) 3-7 days apart. SNIP was performed at functional residual capacity (FRC), and PI max was performed at FRC and at residual volume (RV) to explore volume-dependent differences in the learning effect between sessions and PE max from total lung capacity. RESULTS: The intra-class correlation coefficient (ICC) for SNIP was the highest of the three measures: S1-S3 ICC (95% CI) SNIP: 0.96 (0.88-0.94); PI max at FRC 0.82 (0.63-0.92); PI max at RV: 0.89 (0.78-0.95), and PE max: 0.96 (0.92-0.98), and had the lowest mean change between sessions [mean S2 - S1: 2.1(p = 0.4) and S3 - S2: -0.3 (p = 0.9)]. CONCLUSIONS: SNIP is repeatable over a period of 3 weeks in medically stable, moderate-to-severe COPD patients. In our study, 2 sessions were adequate to learn how to perform the test.

Use of the out-of-hours emergency dental service at two south-east London hospitals.

BACKGROUND: Prior to the introduction of the 2006 NHS dental contract in England and Wales, general dental practitioners (GDPs) were responsible for the provision of out-of-hours (OOH) emergency dental services (EDS); however there was great national variation in service provision. Under the contractual arrangements introduced 1st April 2006, local commissioning agencies became formally responsible for the provision of out-of-hours emergency dental services. This study aimed to examine patients' use of an out-of-hours emergency dental service and to determine whether the introduction of the 2006 national NHS dental contract had resulted in a change in service use, with a view to informing future planning and commissioning of care. METHODS: A questionnaire was administered to people attending the out-of-hours emergency dental service at two inner city London hospitals over two time periods; four weeks before and six months after the introduction of the dental contract in April 2006. The questionnaire explored: reasons for attending; dental registration status and attendance; method of access; knowledge and use of NHS Direct; satisfaction with the service; future preferences for access and use of out-of-hours dental services. Data were compared to determine any impact of the new contract on how and why people accessed the emergency dental service. RESULTS: The response rate was 73% of attendees with 981 respondents for the first time period and 546 for the second. There were no significant differences between the two time periods in the gender, age, ethnic distribution or main language of service users accessing the service. Overall, the main dental problem was toothache (72%) and the main reason for choosing this service was due to the inability to access another emergency dental service (42%). Significantly fewer service users attended the out-of-hours emergency dental service during the second period because they could not get an appointment with their own dentist (p = 0.002 from 28% to 20%) and significantly more service users in the second period felt the emergency dental service was easier to get to than their own dentist (P = 0.003 from 8% to 14%). Service users found out about the service from multiple sources, of which family and friends were the most common source (30%). In the second period fewer service users were obtaining information about the service from dental receptionists (P = 0.002 from 14% to 9%) and increased use of NHS Direct for a dental problem was reported (P = 0.002 from 16% to 22%) along with more service users being referred to the service by NHS Direct (P = 0.02 from 19% to 24%). The most common preference for future emergency dental care was face-to-face with a dentist (79%). CONCLUSION: This study has provided an insight into how and why people use an out-of-hours emergency dental service and has helped to guide future commissioning of these services. Overall, the service was being used in much the same way both before and after the 2006 dental contract. Significantly more use was being made of NHS Direct after April 2006; however, informal information networks such as friends and family remain an important source of information about accessing emergency dental services.

Fecal M2-pyruvate kinase (M2-PK): a novel marker of intestinal inflammation.

BACKGROUND: Surrogate markers of bowel inflammation are increasingly being recognized as important, not only as markers of disease activity in inflammatory bowel disease (IBD) but also to differentiate irritable bowel syndrome (IBS) from IBD. The dimeric M2-isoform of pyruvate kinase (M2-PK) has been reported to be elevated in fecal specimens from colorectal cancer (CA) patients, but its role in IBD is unknown. This study investigated the usefulness of fecal M2-PK in cohorts of patients with IBD, IBS, and CA. METHODS: Stool samples were obtained for calprotectin and M2-PK measurements in patients with previously diagnosed IBD or new patients being investigated for lower gastrointestinal (GI) symptoms in a UK university hospital. Other investigations were performed as directed by the investigating physician and patients with known IBD were assessed for disease activity by a physician global assessment, Harvey-Bradshaw index (HBI), or endoscopic grading. RESULTS: Fecal M2-PK and calprotectin measurements were obtained for 148 patients: 50 with ulcerative colitis (UC); 31 with Crohn's disease (CD), 43 with irritable bowel syndrome/functional bowel disorders (IBS); 7 with colorectal CA, and 17 with miscellaneous conditions (excluded from the analysis). Median M2-PK values (U/mL) were significantly elevated in UC: 20.0 (95% confidence interval [CI] 5.4-69.0, P < 0.0001), CD: 24.3 (95% CI 6.4-44.0, P < 0.0001), and CA: 7.0 (95% CI 4.3-88.0, P < 0.0006) compared to IBS: 0.1 (95% CI 0.0-3.2). There was a strong linear correlation of M2-PK with calprotectin levels. A predetermined cutoff level of 3.7 U/mL for a normal M2-PK test produced a sensitivity, specificity, and positive predictive value (PPV) of 73%, 74%, and 89%, respectively, for organic disease. Furthermore, M2-PK levels were significantly elevated in active, compared to inactive, disease for CD (30 versus 0.55 U/mL, P < 0.005) and UC (40 versus 1.2 U/mL, P = 0.006), respectively. CONCLUSIONS: Fecal M2-PK is elevated in IBD as well as in CA patients and is a sensitive and relatively specific marker for organic GI pathology, with a PPV of 89%. Furthermore, it appears to be a potentially valuable, noninvasive marker of disease activity in IBD.

Sleeping position, oxygen saturation and lung volume in convalescent, prematurely born infants.

OBJECTIVE: To determine whether the effects of sleeping position on lung volume and oxygenation are influenced by postmenstrual age (PMA) and oxygen dependency in convalescent prematurely born infants. DESIGN: Prospective study. SETTING: Tertiary neonatal unit. PATIENTS: 41 infants (21 oxygen dependent), median gestational age 28 weeks (range 24-31 weeks) and birth weight 1120 g (range 556-1780 g). INTERVENTION: Infants were studied both supine and prone at two-weekly intervals from 32 weeks' PMA until discharge. Each posture was maintained for 1 h. MAIN OUTCOME MEASURES: Pulse oximeter oxygen saturation (Spo(2)) was monitored continuously, and at the end of each hourly period functional residual capacity (FRC) was measured. RESULTS: Overall, lung volumes were higher in the prone position throughout the study period; there was no significant effect of PMA on lung volumes. Overall, Spo(2) was higher in the prone position (p = 0.02), and the effect was significant in the oxygen-dependent infants (p = 0.03) (mean difference in Spo(2) between prone and supine was 1.02%, 95% CI 0.11% to 1.92%), but not in the non-oxygen-dependent infants. There was no significant influence of PMA on Spo(2). CONCLUSION: In the present study, prone sleeping did not improve oxygenation in prematurely born infants, 32 weeks' PMA or older and with no ongoing respiratory problems. However, the infants were monitored in each position for an hour, thus it is recommended that oxygen saturation should continue to be monitored after 32 weeks' PMA to be certain that longer periods of supine sleeping are not associated with loss of lung volume and hypoxaemia.

The emerging dental workforce: why dentistry? A quantitative study of final year dental students' views on their professional career.

BACKGROUND: Dental graduates are joining a profession experiencing changes in systems of care, funding and skill mix. Research into the motivation and expectations of the emerging workforce is vital to inform professional and policy decisions. The objective of this research was to investigate final year dental students' perceived motivation for their choice of career in relation to sex, ethnicity and mode of entry. METHODS: Self-administered questionnaire survey of all final year dental students at King's College London. Data were entered into SPSS; statistical analysis included Chi Squared tests for linear association, multiple regression, factor analysis and logistic regression. RESULTS: A response of 90% (n = 126) was achieved. The majority were aged 23 years (59%), female (58%) and Asian (70%). One in 10 were mature students. Eighty per cent identified 11 or more 'important' or 'very important' influences, the most common of which were related to features of the job: 'regular working hours' (91%), 'degree leading to recognised job' (90%) and 'job security' (90%). There were significant differences in important influences by sex (males > females: 'able to run own business'; females > males: 'a desire to work with people'), ethnic group (Asians > white: 'wish to provide public service', 'influence of friends', 'desire to work in healthcare', having 'tried an alternative career/course' and 'work experience') and mode of entry (mature > early entry: 'a desire to work with people'). Multivariate analysis suggested 61% of the variation in influences is explained by five factors: the 'professional job' (31%), 'healthcare-people' (11%), 'academic-scientific' (8%), 'careers-advising' (6%), and 'family/friends' (6%). The single major influence on choice of career was a 'desire to work with people'; Indian students were twice as likely to report this as white or other ethnic groups. CONCLUSION: Final year dental students report a wide range of important influences on their choice of dentistry, with variation by sex, ethnicity and mode of entry in relation to individual influences. Features of the 'professional job', followed by 'healthcare and people' were the most important underlying factors influencing choice of career.

The effects of blood pressure reduction on cognitive function: a review of effects based on pooled data from clinical trials.

OBJECTIVE: To review systematically and synthesize quantitatively the evidence from completed randomized, controlled trials of blood pressure reduction on cognitive performance. METHODS: MEDLINE, EMBASE and Cochrane databases were searched to identify randomized, controlled trials that measured the effect of blood pressure reduction on cognitive performance. Additional studies were identified by searching bibliographies of retrieved articles and contacting experts in the field. Data were extracted on study quality, blood pressure, performance on cognitive function tests, antihypertensive treatment regimens and the duration of treatment. Studies were reviewed and abstracted independently by two trained researchers. RESULTS: Sixteen studies with 19 501 subjects were identified. Modest reductions in blood pressure (< 5/3 mmHg) in 13 860 subjects were associated with improvements in Mini Mental State Examination score [weighted mean difference (WMD) = 0.19; 95% confidence interval (CI) = 0.19-0.19] and performance on immediate (WMD = 0.62; 95% CI = 0.21-1.02) and delayed (WMD = 0.67; 95% CI = 0.23-1.11) logical memory tasks. However, studies in 2380 subjects that included tests of perceptual processing and learning capacity (trail making test-A, paired associated learning test) showed impaired performance (WMD = -1.12 s; 95% CI = -1.22 to -1.02 and WMD = -0.04; 95% CI = -0.04 to -0.04) on these tests. CONCLUSION: Blood pressure lowering may have a heterogeneous effect on different aspects of cognitive function. Future studies with specific cognitive end-points are needed for greater clarity to guide practice.

Acquisition of competence in paediatric ileocolonoscopy with virtual endoscopy training.

This study prospectively compared the rates of skill acquisition in ileocolonoscopy in 2 consecutive groups of trainees in paediatric gastroenterology, with 1 cohort exposed to virtual endoscopy. All paediatric gastroenterology trainees rotating through our department during a 7-year period between 1997 and 2004 were formally assessed while performing ileocolonoscopies using a trainer case-by-case method. Fourteen consecutive trainees with no previous experience of ileocolonoscopy were assessed. Comparison of rates of skill acquisition and lesion recognition using multiple linear regressions revealed a significant acceleration of achievement of endoscopic goals (P < 0.0001) in the group with prior exposure to virtual endoscopy.