Use and knowledge of IOTN among GDPs in Scotland.

OBJECTIVES: To evaluate the use and knowledge of the index of orthodontic treatment need (IOTN) by general dental practitioners (GDPs) working within Scotland. SETTING: Scottish general dental services (SGDS). METHODS: Questionnaires were posted to randomly selected dentists (n=356) working within the SGDS for self-completion and return. MAIN OUTCOME MEASURES: Use of IOTN.Knowledge of IOTN Participants were asked to match 12 malocclusions to the correct IOTN category. Kappa statistics evaluated agreement to a gold standard. RESULTS: The overall response rate was 64%. Sixty-one percent of respondents did not use IOTN. The most common reason for using the index was to assess treatment eligibility (40.2%). The main reason for non-use was that it was only considered suitable for secondary dental care (27%). Over half (56%) of respondents had received IOTN training at undergraduate level. Knowledge of the index was found to be low--the mean level of agreement was k=0.42 (fair). 10.5% of respondents scored k≥0.61(substantial). The factors most likely to contribute to both use and knowledge of IOTN were having a postgraduate qualification and carrying out orthodontic treatment in practice. CONCLUSION: Overall use and knowledge of IOTN among GDPs in Scotland appears to still be low. More resources need to be directed towards improving both undergraduate and postgraduate orthodontic training with the focus on IOTN in particular.

Randomized, open-label, 5-way crossover study to evaluate the pharmacokinetic/pharmacodynamic interaction between furosemide and the non-steroidal anti-inflammatory drugs diclofenac and ibuprofen in healthy volunteers.

OBJECTIVE: Nonsteroidal anti-inflammatory drugs (NSAIDs) can induce renal complications in patients taking loop diuretics. This study investigated the pharmacokinetic/pharmacodynamic effects and safety profile of orally administered diclofenac sodium, ibuprofen and diclofenac epolamine topical patch (DETP) on furosemide in healthy adult subjects. METHODS: This open-label, randomized, 5-way crossover study was conducted in 40 subjects (aged 19 - 45 y). Diclofenac (75 mg taken orally twice daily), DETP (1.3% applied topically twice daily), or ibuprofen (800 mg taken orally thrice daily) was administered for 3 consecutive days, followed by co-administration with furosemide (given intravenously as 20 mg/2 min). Plasma furosemide and NSAID concentrations, urine furosemide, sodium and potassium concentrations and urine output were determined throughout the 24 h period following furosemide administration. RESULTS: Orally administered ibuprofen significantly increased furosemide AUC(0-t) (37%) and AUC(0-inf) (36%) and decreased total body CL (27%), R(max) (19%) and CLR (23%) geometric mean ratios compared with furosemide control. Oral and topical diclofenac had no pharmacokinetic effects on furosemide. Ibuprofen increased sodium excretion (Ae(0-24), 16%) and decreased sodium R(max) (15%), and oral diclofenac decreased urine output (Vu(0-24), 15%). DETP had no effect on furosemide pharmacodynamics; total systemic exposure to diclofenac during DETP treatment was < 1% that of oral diclofenac. Treatments were generally safe, with 25 subjects reporting a total of 112 adverse events. CONCLUSIONS: Pharmacodynamic effects were seen with oral diclofenac (urine output) and ibuprofen (urine sodium excretion). Furosemide also affected plasma and urine pharmacokinetic profiles. Pharmacologic effects of DETP on furosemide were not observed under these conditions. Additional research is warranted to delineate the potential interactions of other NSAIDs with furosemide and other loop diuretics.

Ameloblastic fibroma of the anterior maxilla presenting as a complication of tooth eruption: a case report.

Ameloblastic fibroma is a rare mixed odontogenic tumour, which is extremely uncommon in the anterior maxillary region. A case report is presented where failure of eruption of an upper central incisor was the presenting feature.

Predictors of outcome among patients with class II division 1 malocclusion treated with fixed appliances in the permanent dentition.

This retrospective study investigated the outcomes achieved in 212 consecutively completed patients with Class II Division 1 malocclusion (overjet > 6 mm). All patients were treated in the permanent dentition with upper and lower fixed appliances. A composite outcome measure was used to identify those cases with an excellent outcome (posttreatment PAR

Treatment outcome for a sample of patients with Class II division 1 malocclusion treated at a regional hospital orthodontic department.

This retrospective study assessed the outcome of orthodontic treatment of 264 patients with Class II division 1 malocclusion (overjet greater than 6 mm). The sample comprised patients who had completed their fixed appliance orthodontic treatment at a regional hospital orthodontic unit in the Republic of Ireland. The PAR Index (Peer Assessment Rating) was used to evaluate treatment outcome using before and after treatment study casts. The results revealed that treatment for this particular type of malocclusion was highly effective with a very few patients failing to benefit from their orthodontic treatment.

The influence of operator changes on orthodontic treatment times and results in a postgraduate teaching environment.

There is some concern that patients treated by postgraduate students during their specialty training may be disadvantaged in the quality of treatment result and subject to longer treatment times if they are treated by more than one operator. This study analysed the pre- and post-treatment study models of orthodontic patients from a district general hospital department, debonded by one junior member of junior staff in the calendar years 1991 and 1992. All patients were treated using the same pre-adjusted edgewise appliance in both arches. Two groups of patients were identified: patients whose treatment was started and finished by the same operator (registrar A), and those whose treatment was begun by another operator (registrar B), but finished by registrar A. A random sample of 30 patients from each group was selected and the study models at the start and end of treatment were scored using the PAR (Peer Assessment Rating) Index. No significant differences were found between the average PAR scores for each group at the beginning of treatment, or between groups A and B at the end of treatment; the average treatment time for the patients treated by one operator was 17.67 months (SD 4.15 months), while the average treatment time for the patients treated by more than one operator was 26.1 months (SD 6.78 months). Statistically, this difference was highly significant (P < 0.001). A highly linear relationship (R2 = 0.92) was found between the percentage PAR score reduction and the initial PAR score. The findings and their implications are discussed.

The management of first trimester miscarriage by general practitioners in Ireland.

A single shot questionnaire was sent to 500 general practitioners, with 39 per cent valid response, to audit first trimester miscarriage management. With threatened miscarriage 60 per cent were cared for at home (10 per cent of these had ultrasound) and 40 per cent were transferred to hospital. The miscarriage rate was 14 per cent-61.7 per cent had no symptoms (of these 42.2 per cent had a positive pregnancy test), 24.4 per cent had threatened miscarriage with 11.6 per cent incomplete and 2.3 per cent complete. The general practitioner is ideally placed to develop initial clinical management strategies and direct access to ultrasound would be helpful.

An investigation into the ability of soft drinks to adhere to enamel.

Loss of enamel due to dietary causes, either by acid erosion or the fermentation of dietary sugars, is well known. These processes will be affected by a number of factors, one of which is the ability of the food to adhere to the enamel. The aim of this study was to determine the thermodynamic work of adhesion of a number of soft drinks to enamel. The results indicated significant differences in the ability of various drinks to adhere to enamel in vivo. In addition to obtaining a ranking of the drinks under test, the likelihood of them being displaced by saliva was considered.

The finite element analysis of stress in the periodontal ligament when subject to vertical orthodontic forces.

In the past, vertical intrusive movement of teeth has been considered difficult and most routine clinical vertical movement of teeth has been confined to extrusion. It has been suggested that attempts at intrusion may result in an increased incidence of root resorption and also in occasional devitalization. The displacement and resulting stress fields associated with such treatment can be successfully studied using the finite element method. In the case being considered initial movements are known to be small; therefore, the assumption in the study that the material behaves linear-elastically is considered to be reasonable. This study of vertical tooth movement demonstrated that the maximum cervical margin stress in the periodontal ligament was 0.0046 N/mm2, whilst the highest apical stress was 0.00205 N/mm2 when intrusive and extrusive forces of 1 Newton were applied to the buccal surface of the crown of a tooth model. These stresses were evaluated in the light of previous studies and found to be within the suggested clinical optimum level. However, the periodontal stress distribution following orthodontic loading within this three-dimensional finite element model was found to be highly complex.

An introduction to indices of malocclusion.

Orthodontic indices have been used for many years to assess the severity of a patient's malocclusion and hence determine the need for treatment. Two indices--the Index of Orthodontics Treatment Need (IOTN) and the Peer Assessment Rating (PAR) Index--have recently been developed. The use of indices is likely to become more widespread in the future so that more uniformity is achieved in assessing need for treatment and its success. This article describes how the two indices are applied.

Holograms and study models assessed by the PAR (Peer Assessment Rating) Index of malocclusion--a pilot study.

A selection of 30 sets of study models, representing a wide range of malocclusions, was drawn from the records of a clinical orthodontic department. Four holograms were made of each set of models; the study models and their corresponding holograms were then scored using the Peer Assessment Rating (PAR) Index of malocclusion. Significantly lower scores (P < 0.01) were obtained from the holograms, which were ascribed to three out of the seven components which make up the index.

Storage of orthodontic study models in hospital units in the U.K.

Orthodontic study models form an essential part of the dental records of patients undergoing diagnosis and treatment. In order to ascertain the problems encountered by hospital orthodontic units in the utilization and storage of study models, a questionnaire was circulated in February 1991 to members of the Consultant Orthodontists Group. All respondents took pretreatment study models, while 9 per cent took their final study models at some time other than the end of active treatment; 85.5 per cent of respondents stored their study models in their units, but most were beginning to experience difficulties in this regard. There was a wide range for storage times, and only 10 per cent of employing authorities had a stated policy on the storage of study models. There was a highly significant difference (P much less than 0.001) between the time that models are stored at present, and the desired storage times. Most respondents appeared to be rather uncertain about the precise medico-legal requirements concerning model storage. The implications for audit and medico-legal matters are discussed in the light of these findings.

Prevention in orthodontics--a review.

Increasing numbers of patients are being orthodontically treated by specialist and general dental practitioners, after postgraduate courses and clinical assistantships. The potential for iatrogenic damage to the teeth and supporting structures has, therefore, also increased. This paper examines these problems and outlines measures for their prevention.

Stresses induced by edgewise appliances in the periodontal ligament--a finite element study.

The quantification of stress in the periodontal ligament is an important concept, as stress in this tissue is transmitted to the alveolus, with subsequent bone remodelling and tooth movement. A number of clinical studies have suggested figures for such an optimal stress range. This study makes use of a finite element technique to determine the stress induced in the periodontal ligament in three dimensions when a maxillary canine tooth is subjected to an orthodontic force similar to that produced by an edgewise appliance. The maximum stress induced at the cervical margin of the periodontal ligament was 0.072 N/mm2, while the maximum stress induced at the level of the apical foramen was 0.0038 N/mm2. These results are discussed in the light of known clinical experience and compared with the stresses produced in the periodontal ligament by other orthodontic forces. The findings would suggest that even with 'perfect' edgewise mechanics it would be difficult to obtain canine movement by pure translation or 'bodily movement.'

The effects of trans-ACPD on long-term potentiation in the rat hippocampal slice.

Trans-ACPD, a metabotropic glutamate receptor agonist, enhanced both the short-term potentiation (STP) at 1 and 5 min, and long-term potentiation (LTP) at 20 min, following tetanic stimulation, of the population, excitatory postsynaptic potential (epsp) recorded from CA1 of the rat hippocampal slice. The enhancement of both STP and LTP also occurred in the presence of the protein kinase inhibitor sphingosine, indicating that the enhancement is most likely to occur through the inositol phosphate rather than the protein kinase limb following receptor activation and phosphoinositide hydrolysis. LTP of the low frequency population epsp was not induced by t-ACPD, even at 100 microM. The metabotropic glutamate receptor may have an important role in LTP induction or modulation.

Inhibition of an N-methyl-D-aspartate induced short-term potentiation in the rat hippocampal slice.

The effects of the phorbol ester 4 beta-phorbol-12,13 dibutyrate (PDBu) and the protein kinase (PK) inhibitors H-7 and sphingosine were investigated on the short-term potentiation (STP) of the population excitatory postsynaptic potential (EPSP) induced by perfusion of N-methyl-D-aspartate (NMDA) in the stratum radiatum of CA1 of the rat hippocampal slice. Bath perfusion of 130 microM NMDA for 10 s caused an initial depression of the population EPSP followed by a STP, which averaged 46% and lasted 16 min. PDBu (100 nM) perfused for 2 h completely inhibited the NMDA induced STP, suggesting that the stimulation of PKC inhibited an NMDA receptor activated process which induced the STP. The protein kinase inhibitors H-7 and sphingosine did not alter the NMDA induced STP.

The effects of external calcium on the N-methyl-D-aspartate induced short-term potentiation in the rat hippocampal slice.

The effect of altered extracellular Ca concentration was studied on the N-methyl-D-aspartate (NMDA) induced short-term potentiation (STP) of the population excitatory post-synaptic potential recorded from the stratum radiatum of CA1 of the rat hippocampal slice. Perfusion of 130 microM of NMDA for 10 s in control media containing 2.0 mM extracellular Ca evoked an STP with a maximum amplitude of 46% and a duration of 16 min. Perfusion of media containing a reduced Ca concentration of 0.8 mM or 1.0 mM did not alter the amplitude or time course of the STP. However, raising the Ca concentration to 3.0 mM or 4.0 mM caused a significant reduction in the amplitude of the STP to 23% and 2% respectively. The abolition of the NMDA induced STP in 4 mM Ca could not have been produced by response saturation since an identical long-term potentiation (LTP) was produced in this high Ca media as in the control media. These studies show that the NMDA induced STP has a very different Ca dependency to LTP.

A finite element study of canine retraction with a palatal spring.

The use of a removable appliance to retract a maxillary canine tooth into a first premolar extraction space is one of the most commonly performed orthodontic procedures. However, unwanted movements may occur, including excessive tipping, rotation, and flaring of the tooth. The present investigation by the use of a finite element model quantifies some of the initial stresses produced within the periodontal ligament when two obliquely directed forces are applied to a maxillary canine tooth. In simulating the action of a removable appliance it attempts to relate the stress patterns to the nature of the subsequent tooth movement.