The confidence of undergraduate dental students when carrying out prosthodontic treatment and their perception of the quality of prosthodontic education

INTRODUCTION

Despite the falling number of edentulous patients within the UK, there is still a large demand for the provision of removable prostheses. On qualification, dentists should have the knowledge and skills to provide these prostheses, but previous studies have shown that final-year dental undergraduate confidence in treating denture patients is lacking.

AIM

To explore undergraduate dental student confidence whilst carrying out prosthodontic treatment, and to explore their perceptions of the quality of their prosthodontic education.

METHOD

An anonymous questionnaire was distributed to all (n=203) dental undergraduates in Years 3 to 5 at the University of Bristol. The questionnaire utilised a range of data collection methods including confidence interval ranked responses and qualitative measures. The data were analysed using SPSS.

RESULTS

The response rate was 51%. Undergraduate perception of confidence increased throughout the years of study (P<.001). There was also an increase in the number of partial and complete denture cases treated as students progressed through the course (P<.001). Overall, students were satisfied with their prosthodontic teaching, although students thought that too much time was allocated to laboratory teaching, and that increasing their clinical experience would be most beneficial in increasing their confidence levels.

CONCLUSION

Student confidence in carrying out prosthetic treatment increased as students progressed through the course, and confidence levels would be increased further with increased clinical experience.

Improved single- and multi-contact life-time testing of dental restorative materials using key characteristics of the human masticatory system and a force/position-controlled robotic dental wear simulator

This paper presents a new in vitro wear simulator based on spatial parallel kinematics and a biologically inspired implicit force/position hybrid controller to replicate chewing movements and dental wear formations on dental components, such as crowns, bridges or a full set of teeth. The human mandible, guided by passive structures such as posterior teeth and the two temporomandibular joints, moves with up to 6 degrees of freedom (DOF) in Cartesian space. The currently available wear simulators lack the ability to perform these chewing movements. In many cases, their lack of sufficient DOF enables them only to replicate the sliding motion of a single occlusal contact point by neglecting rotational movements and the motion along one Cartesian axis. The motion and forces of more than one occlusal contact points cannot accurately be replicated by these instruments. Furthermore, the majority of wear simulators are unable to control simultaneously the main wear-affecting parameters, considering abrasive mechanical wear, which are the occlusal sliding motion and bite forces in the constraint contact phase of the human chewing cycle. It has been shown that such discrepancies between the true in vivo and the simulated in vitro condition influence the outcome and the quality of wear studies. This can be improved by implementing biological features of the human masticatory system such as tooth compliance realized through the passive action of the periodontal ligament and active bite force control realized though the central nervous system using feedback from periodontal preceptors. The simulator described in this paper can be used for single- and multi-occlusal contact testing due to its kinematics and ability to exactly replicate human translational and rotational mandibular movements with up to 6 DOF without neglecting movements along or around the three Cartesian axes. Recorded human mandibular motion and occlusal force data are the reference inputs of the simulator. Experimental studies of wear using this simulator demonstrate that integrating the biological feature of combined force/position hybrid control in dental material testing improves the linearity and reduces the variability of results. In addition, it has been shown that present biaxially operated dental wear simulators are likely to provide misleading results in comparative in vitro/in vivo one-contact studies due to neglecting the occlusal sliding motion in one plane which could introduce an error of up to 49% since occlusal sliding motion D and volumetric wear loss V(loss) are proportional.

Why are multi-centre clinical observational studies still so difficult to run?

Despite the introduction of IRAS, obtaining R&D approvals for multicentre studies is a major rate limiting step. Our experience with cleft research demonstrates that this approvals process must be drastically and rapidly improved if we wish to continue attract clinical research to the UK.

Orthodontic management of a Le Fort II and midline palatal fracture

An unusual presentation of palatal fracture is described. Reduction and fixation with an orthodontic appliance proved to be an efficient and novel method in the treatment of this fracture.

The Use of Osseointegrated Implants in Orthodontic Patients: 1. Implants and Their Use in Children

Implants have been used successfully for the rehabilitation of edentulous adults. However, their use in children is limited because of the special problems of implants relating to continuing growth and development. This, the first of two articles, provides a review of the use of osseointegrated implants in the context of facial growth, and the role of the orthodontist in the management of implant-supported prosthodontic structures. A second article will discuss the role of implants in orthodontics in providing what has been termed 'absolute anchorage'.

Orthodontics. Part 11: orthodontic tooth movement

Orthodontic tooth movement is dependent on efficient remodelling of bone. The cell-cell interactions are now more fully understood and the links between osteoblasts and osteoclasts appear to be governed by the production and responses of osteoprotegerin ligand. The theories of orthodontic tooth movement remain speculative but the histological documentation is unequivocal. A periodontal ligament placed under pressure will result in bone resorption whereas a periodontal ligament under tension results in bone formation. This phenomenon may be applicable to the generation of new bone in relation to limb lengthening and cranial-suture distraction. It must be remembered that orthodontic tooth movement will result in root resorption at the microscopic level in every case. Usually this repairs but some root characteristics apparent on radiographs before treatment begins may be indicative of likely root resorption. Some orthodontic procedures (such as fixed appliances) are also known to cause root resorption.

Orthodontics. Part 10: Impacted teeth

This section deals with the important issue of impacted teeth. Impacted canines in Class I uncrowded cases can be improved by removal of the deciduous canines. There is some evidence that this is true for both buccal and palatal impactions. Treatment of impacted canines is lengthy and potentially hazardous. Interceptive measures are effective and preferred to active treatment. Supernumerary teeth may also cause impaction of permanent incisors, their early diagnosis and appropriate treatment is essential to optimise final outcomes. If there are any doubts about impacted teeth it is better to refer too early than too late, this latter option may unnecessarily extend the length of treatment as well as the treatment required.

Orthodontics. Part 12: Combined orthodontic treatment

Dentistry is becoming more sophisticated and capable of providing much higher treatment standards than ever before. Treatments previously considered impossible can now be achieved as a direct consequence of these advances. However, this increased complexity of treatment also means that the different branches of dentistry have, as a necessity, become more and more specialised. It is important that the specialities collaborate in a systematic focused way to ensure the optimal treatment outcome with the minimum burden of care for the patient.

Orthodontics. Part 9: Anchorage control and distal movement

Anchorage is an important consideration when planning orthodontic tooth movement. Unwanted tooth movement known as loss of anchorage can have a detrimental effect on the treatment outcome. Anchorage can be sourced from the teeth, the oral mucosa and underlying bone, implants and extra orally. If extra-oral anchorage is used, particularly with a facebow then the use of at least two safety devices is mandatory.

Orthodontics. Part 8: Extractions in orthodontics

Extractions in orthodontics remains a relatively controversial area. It is not possible to treat all malocclusions without taking out any teeth. The factors which affect the decision to extract include the patient's medical history, the attitude to treatment, oral hygiene, caries rates and the quality of teeth. Extractions of specific teeth are required in the various presentations of malocclusion. In some situations careful timing of extractions may result in spontaneous correction of the malocclusion.

Orthodontics. Part 7: Fact and fantasy in orthodontics

Clinical research has previously lacked good methodology and much opinion was based on anecdote which is widely regarded as the weakest form of clinical evidence. There are few randomised control trials in orthodontics which support or refute areas of dogma. The number of randomised control trials is increasing significantly. There is currently however no good evidence that orthodontics causes or cures temporomandibular joint dysfunction, that appropriate extractions in orthodontics ruin patients' profiles, or that the orthodontist is able to significantly influence facial growth with appliances.

Orthodontics. Part 4: Treatment planning

The treatment plan is an integral part of orthodontic management. It should be divided into both treatment aims (what do you want to do?) and plan (how are you going to do it?). The treatment aims will include, for example overjet reduction. The plan will consider how to create space in order to accomplish this as well as the appliance system that will be used.

Orthodontics. Part 6: Risks in orthodontic treatment

Orthodontics has the potential to cause significant damage to hard and soft tissues. The most important aspect of orthodontic care is to have an extremely high standard of oral hygiene before and during orthodontic treatment. It is also essential that any carious lesions are dealt with before any active treatment starts. Root resorption is a common complication during orthodontic treatment but there is some evidence that once appliances are removed this resorption stops. Some of the risk pointers for root resorption are summarised. Soft tissue damage includes that caused by archwires but also the more harrowing potential for headgears to cause damage to eyes. It is essential that adequate safety measures are included with this type of treatment.

Orthodontics. Part 5: Appliance choices

There are bewildering array of different orthodontic appliances. However, they fall into four main categories of removable, fixed, functional and extra-oral devices. The appliance has to be selected with care and used correctly as inappropriate use can make the malocclusion worse. Removable appliances are only capable of very simple movements whereas fixed appliances are sophisticated devices, which can precisely position the teeth. Functional appliances are useful in difficult cases and are primarily used for Class II Division I malocciusions. Extra-oral devices are used to re-enforce anchorage and can be an aid in both opening and closing spaces.

Orthodontics. Part 3: patient assessment and examination II

The intra-oral assessment examines the oral health, individual tooth positions and inter-occlusal relationships. When this has been completed in conjunction with the extra-oral examination, a treatment plan can then be formulated.

Orthodontics. Part 2: Patient assessment and examination I

The patient assessment forms the essential basis of orthodontic treatment. This is divided into an extra-oral and intra-oral examination. The extra-oral examination is carried out first as this can fundamentally influence the treatment options. The skeletal pattern, soft tissue form and the presence or absence of habits must all be taken into account.

Arylamine N-acetyltransferases: a pharmacogenomic approach to drug metabolism and endogenous function

The arylamine N-acetyltransferases (NATs) are a unique family of enzymes that catalyse the transfer of an acetyl group from acetyl-CoA to the terminal nitrogen of hydrazine and arylamine drugs and carcinogens. The NATs have been shown to be important in drug detoxification and carcinogen activation, with humans possessing two isoenzymes encoded by polymorphic genes. This polymorphism has pharmacogenetic implications, leading to different rates of inactivation of drugs, including the anti-tubercular agent isoniazid and the anti-hypertensive drug hydralazine. Mice provide a good model for human NAT, allowing genetic manipulation of expression to explore possible endogenous roles of these enzymes. The first three-dimensional NAT structure was resolved for NAT from Salmonella typhimurium, and subsequently the structure of NAT from Mycobacterium smegmatis has been elucidated. These identified a 'Cys-His-Asp' catalytic triad (conserved in all NATs), which is believed to be responsible for the activation of the active site cysteine residue. As more genomic data become available, NAT homologues continue to be found in prokaryotic species, many of which are pathogenic, including Mycobacterium tuberculosis. The discovery of NAT in M. tuberculosis is particularly significant, since this enzyme participates in inactivation of isoniazid in the bacterium, with implications for isoniazid resistance. Structural studies on NAT proteins and phenotypic analyses of organisms (both mice and prokaryotes) following genetic modifications of the nat genes are leading to an understanding of the potentially diverse roles of NAT in endogenous and xenobiotic metabolism. These studies have indicated that NAT, particularly in Mycobacteria, has the potential to be a drug target. Combinatorial chemical approaches, together with in silico structural studies, will allow for advances in the identification of NAT substrates and inhibitors, both as experimental tools and as potential drugs.

Arylamine N-acetyltransferase of Mycobacterium tuberculosis is a polymorphic enzyme and a site of isoniazid metabolism

Arylamine N-acetyltransferases (NATs; E.C 2.3.1.5) N-acetylate arylhydralazine and arylamine substrates using acetyl coenzyme A. Human NAT2 acetylates and inactivates the antituberculosis drug, isoniazid (INH), and is polymorphic. We previously demonstrated that there is a homologue of human NAT2 in Mycobacterium tuberculosis, whose product N-acetylates INH in vitro. We now demonstrate that the nat gene is expressed in M. tuberculosis and M. bovis Bacille Calmette-Guerin (BCG), using reverse transcription-polymerase chain reaction and Western blotting. The NAT protein is active in M. bovis BCG in vivo, as detected by the presence of N-acetyl INH in M. bovis BCG lysates grown in INH. Sequence analysis of the M. tuberculosis nat coding region reveals a single nucleotide polymorphism in 18% of a random cohort of M. tuberculosis clinical isolates, conferring a G to R change. The recombinant mutant protein appears less stable than the wild type, and has an apparent affinity for INH of 10-fold less than the wild type. Modelling the change in M. tuberculosis NAT shows that the G to R change is close to the active site, and supports the experimental findings. Minimum inhibitory concentration data suggest that this polymorphism in nat is linked to low-level changes in the INH susceptibility of M. tuberculosis clinical isolates.

Arylamine N-acetyltransferases - of mice, men and microorganisms

Arylamine N-acetyltransferases (NATs) catalyse the transfer of an acetyl group from acetyl CoA to the terminal nitrogen of hydrazine and arylamine drugs and carcinogens. These enzymes are polymorphic and have an important place in the history of pharmacogenetics, being first identified as responsible for the polymorphic inactivation of the anti-tubercular drug isoniazid. NAT has recently been identified within Mycobacterium tuberculosis itself and is an important candidate for modulating the response of mycobacteria to isoniazid. The first three-dimensional structure of the unique NAT family shows the active-site cysteine to be aligned with conserved histidine and aspartate residues to form a catalytic triad, thus providing an activation mechanism for transfer of the acetyl group from acetyl CoA to cysteine. The unique fold could allow different members of the NAT family to play a variety of roles in endogenous and xenobiotic metabolism.

Structure of arylamine N-acetyltransferase reveals a catalytic triad

Enzymes of the arylamine N-acetyltransferase (NAT) family are found in species ranging from Escherichia coli to humans. In humans they are known to be responsible for the acetylation of a number of arylamine and hydrazine drugs, and they are strongly linked to the carcinogenic potentiation of certain foreign substances. In prokaryotes their substrate specificities may vary and members of the gene family have been linked to pathways including amide synthesis during rifamycin production. Here we report the crystal structure at 2.8 A resolution of a representative member of this family from Salmonella typhimurium in the presence and absence of a covalently bound product analog. The structure reveals surprising mechanistic information including the presence of a Cys-His-Asp catalytic triad. The fold can be described in terms of three domains of roughly equal length with the second and third domains linked by an interdomain helix. The first two domains, a helical bundle and a beta-barrel, make up the catalytic triad using a structural motif identical to that of the cysteine protease superfamily.

Initial cleft size does not correlate with outcome in unilateral cleft lip and palate

Clinical outcomes in children born with a cleft lip and palate (CLP) have been an area of interest for orthodontists for a number of years. Whilst tools for measurement of these outcomes are available, there is no widely accepted measure of initial cleft severity and no known quantitative indices. Therefore, the potential influence of initial severity remains unmeasured and largely ignored. The aim of this investigation was to determine the importance of initial cleft severity in determining patient outcome. The longitudinal records of 49 children born with a unilateral cleft lip and palate (UCLP), and treated in a single centre were examined. An index of initial cleft severity was developed that categorizes the cleft area as a percentage of the total palate area. The dental arch relationships of the same patients at 6 years of age were also determined. The nature of the association between these was investigated for agreement and correlation by calculation of weighted Kappa and Spearman's correlation coefficient, respectively. No evidence was found in this sample that the initial cleft area had any bearing on the quality of outcome at 6 years of age.

Measuring binge eating in adolescents: adolescent and parent versions of the questionnaire of eating and weight patterns

OBJECTIVE

This study investigated the psychometric properties of an adolescent version of the Questionnaire of Eating and Weight Patterns (QEWP-A).

METHOD

Male and female adolescents between 10-18 years completed the QEWP-A and measures of depression and eating attitudes. Height and weight were also measured. Parents completed a parental version (QEWP-P) that was referenced to their children. Adolescent and parent responses to the QEWP were independently categorized into no diagnosis (ND), nonclinical binge eating (NCB), and binge eating disorder (BED) groups.

RESULTS

Adolescent and parental agreement over the diagnostic categories was as follows: 81.6% for ND, 15.5% for NCB, and 25% for BED with an overall kappa of. 19. Adolescents with BED had significantly higher levels of depression than the other two groups with NCB being higher than ND. For eating attitudes, BED adolescents were more deviant than the other two groups who did not differ from one another.

DISCUSSION

The QEWP-A displayed adequate concurrent validity. The low overall agreement between adolescents and their parents was influenced by high and low base rates in the NCB and BED categories, respectively. This lack of agreement is consistent with other behavioral problems such as depression. The data suggest that parental perceptions of eating problems approximate those of their children when no problem is present. However, parents are not as likely to be aware of eating difficulties when they actually exist.

Holes in the head: parietal foramina, a developmental anomaly seen during a routine orthodontic assessment

Parietal foramina (Catlin marks) are developmental anomalies which affect approximately 1 in 25,000 people. They are thought to be inherited as an autosomal trait and may be associated with other skeletal anomalies such as cleft lip or palate. The majority of enlarged parietal foramina are usually completely asymptomatic.

Early detection of differences in surgical outcome for cleft lip and palate

This study examined the dento-alveolar relationships of 5-year-old children born with a unilateral cleft lip and palate with primary surgical repair performed in one of two centres (Bristol or Oslo). The Bristol sample comprised 46 sets of study models and the Oslo CLP Growth Archive provided 54 cases with a very similar sex distribution. We used a recently developed 5-year-old index to measure differences in outcome between the two centres. The Oslo sample were assessed as having up to 57 per cent in the ideal groupings (1 and 2), in the Bristol group this was only 35 per cent. Bristol had up to 46 per cent of cases assessed in the worst groups (4 and 5). The comparative figure from the Oslo group was 15 per cent. These results suggest that it is possible to detect differences in surgical outcome at 5 years of age.

Signal pathways that transduce growth factor-stimulated mitogenesis in bone cells

This investigation examined which signal pathways are of relevance in growth factor-stimulated bone cell mitogenesis. Platelet-derived growth factor (PDGF) and insulin-like growth factor-II (IGF-II) were potent mitogens for both the MG-63 osteoblast cell line and for primary cultures of human osteoblasts (HObs). The mitogenic action of both IGF-II and PDGF was attenuated by pertussis toxin (Ptx), by indomethacin, and by the lipoxygenase inhibitors BW755C74 and BW4AC. A combination of Ptx and indomethacin caused much greater inhibition but failed to abolish mitogenesis completely. PDGF significantly elevated inositol phosphates levels in both cell types; IGF-II had no effect on this pathway. In MG-63 cells, we demonstrated tyrosine phosphorylation of high-molecular-weight substrates elicited by both PDGF and IGF-II. Genistein inhibited the phosphorylation and mitogenic response to PDGF, but had no effect on IGF-II-induced tyrosine phosphorylation or mitogenesis. Another inhibitor of tyrosine kinases, methyl 2,5-dihydroxycinnamate, (MDHC), inhibited PDGF-stimulated mitogenesis effectively in both cell types but only blocked IGF-II-induced mitogenesis in MG-63 cells. The specificity of these inhibitors suggests that particular tyrosine kinases may regulate growth factor-induced stimulation of bone cells.

The Clinical Standards Advisory Group (CSAG) Cleft Lip and Palate Study

A national study of care and outcomes in children born with a unilateral cleft lip and palate (UCLP) was performed over a 15-month period. Two cohorts of children ('5-year-olds' and '12-year-olds') were examined. There were 57 active cleft teams in the U.K. with 105 consultant orthodontists involved in the care of these children. Only 36 teams could provide basic data such as patients names. Of the patients, 47-51 per cent had neonatal appliances. The dental arch relationships were measured with the Goslon Index and a Five-Year-Old Index, 37-39 per cent of both age groups were either 'poor' or 'very poor'. Seventy per cent of the 12-year-old patients had a Skeletal III relation and 42 per cent of bone grafts were seriously deficient or failed. Dental treatment for active caries was needed by 40 per cent of 5-year-olds and 20 per cent of 12-year-olds. In addition, the training of recently appointed consultant orthodontists involved in the care of these children was scrutinized. As a whole, the results were disappointing with standards of care not significantly raised in the last decade. Recommendations have been made to the Department of Health and the implications for the orthodontic profession are explored. Overall, it seems that fewer orthodontists will need to be involved in a centralized care model for these children.

Heterogeneity in the families of sons of alcoholics: the impact of familial vulnerability type on offspring characteristics

In 2 samples of sons of alcoholics (family history positive for alcoholism; FHP: N = 74 & N = 72), cluster analyses identified 3 subtypes of familial vulnerability: 1 with low levels of familial psychopathology (FHP-LP) and moderate levels of familial alcoholism; a 2nd with high levels of familial antisocial personality (FHP-ASP), violence, and alcoholism; and a 3rd with high levels of familial depression (FHP-DEP), mania, anxiety disorder, and alcoholism. Compared with family history negative (FHN) participants (N = 106), FHP offspring had higher levels of alcohol problems. FHP-ASP offspring had elevated levels of antisocial traits and negative affect. Compared with FHN participants, FHP-DEP offspring elevated levels of antisocial traits, hypomania, and experience seeking. FHP-LP offspring had moderate levels of antisocial traits.

Study models of 5 year old children as predictors of surgical outcome in unilateral cleft lip and palate

This study examined features of dental occlusion in patients born with a unilateral cleft lip and palate (UCLP). The intention was to develop a 'Goslon type' index for 5 year old children. The Goslon ranking system was used on longitudinal study models taken at 5 and 10 years of age of the same patients. All patients had UCLP and this had been repaired using a Millard type lip repair and a Veau Wardill or Von Langenbeck palatal closure. There was good intra-examiner agreement for ascribing 5 and 10 year old models to one of five categories (excellent-very poor). Inter-examiner agreement on both sets of models was at worst moderate. Two of the examiners identified up to 93 per cent of 5 year old models which either remained in the same category or deteriorated by 10 years of age. At worse the results demonstrated 70 per cent of cases of 5 years of age remained in the same category or deteriorated by 10 years of age. Consensus agreement has produced five categories of outcome for these 5 year old models. This new index is to be subjected to further validation. This study has therefore provided, for the first time, a mechanism for assessing the results of CLP surgery earlier than indices already available.