To compare Hawley with vacuum-formed retainers.Eighty-two patients who had received treatment with upper and lower fixed appliances were randomly assigned either a Hawley or a vacuum-formed retainer. Study models were fabricated for each patient on day of debond and 2 months, 6 months, and 12 months after debond. Using a specially constructed pantograph, four variables were measured for each set of models at each of these time periods. These were upper and lower intermolar widths, intercanine widths, arch length, and a modified Little's index of irregularity. Method error was determined by repeating the measurements on 10 sets of models.For each of the variables under test and at each of the four time periods, there were no statistically significant differences (α = .05) between each of the two retainers, vacuum-formed and Hawley.The degree of relapse that is likely to occur following a course of fixed appliance therapy is unlikely to be affected by the choice of retainer, vacuum-formed or Hawley. Therefore, when deciding on the type of retainer to be fitted following fixed appliance therapy, other factors such as cost may play a more significant role.
Abstract Function and health are controversial reasons for carrying out orthodontic treatment. These are covered extensively in other texts and in the Index of orthodontic treatment need (dental health component) for deciding whether a patient would benefit from orthodontic treatment (see Suggested reading). Aesthetics is certainly the main reason for orthodontic treatment, but what are the boundaries of the aesthetic ideals to which orthodontic treatment can be planned? In other words what can be considered to be normal, and when normal is not present can orthodontics bring the dentofacial complex back towards what can be considered to be an acceptable norm? In order to explore these questions it is worth considering the current description and classification of normal and abnormal occlusion or malocclusion. Similarly, the description and classification of the extraoral structures of the jaws and soft tissues will be discussed in this chapter.
We are living through a period of immense change following the outbreak of the COVID-19 pandemic in mainland China in December 2019. Even before the pandemic, the cost of managing healthcare-associated infections in the UK was considerable. The risk of acquiring any infection from the dental environment must be reduced to a minimum. As we have observed in recent years, new infectious agents emerge frequently, and the dental profession must be ready to respond appropriately and quickly. Orthodontic practice presents unique challenges in relation to infection control procedures. The impact of healthcare waste on the environment must also be considered. CPD/Clinical Relevance: This paper describes the range of infectious agents posing a risk to dental team members and patients. The aim is to place the recent coronavirus pandemic in the context of other recent emerging infections. Some of the latest research regarding infection control procedures is reviewed. Current best practice is described.
The success of orthodontic treatment can be judged in a number of ways, two of which are treatment efficiency and occlusal outcome. Treatment efficiency can be measured in terms of length of treatment and number of visits, whilst occlusal outcomes can be both dynamic and static. The factors that affect success can be considered under three headings, namely patient factors, operator factors and appliance factors. This article will consider outcome and the patient factors which might affect treatment success in our adolescent patients, whilst Part 2 will consider operator and appliance factors. Clinical Relevance: The conversational model of consent requires that clinicians disclose all of the appropriate information to patients prior to them making the decision whether to accept or decline treatment. 1 Understanding factors that could affect the outcome with respect to both treatment efficiency and occlusal result will therefore help inform this consent process.
Background: Decalcification and gingivitis caused by plaque accumulation around brackets are common iatrogenic effects of fixed appliances. The influence of conventional versus self-ligating bracket design on microbial colonisation is unknown. Objective: To assess the levels of microbial colonisation associated with conventional and self-ligating brackets. Search sources: Three databases were searched for publications from 2009 to 2021. Data selection: Randomised controlled trials comparing levels of microbial colonisation before and during treatment with conventional and self-ligating brackets were assessed independently and in duplicate. Data extraction: Data were extracted independently by two authors from the studies that fulfilled the inclusion criteria. Risk of bias assessments were made using the revised Cochrane risk of bias tool for randomized trials. The quality of the included studies was assessed using the Critical Appraisal Skills Programme Checklist. Results: A total of 11 randomised controlled trials were included in this systematic review. Six of the studies were found to be at low risk of bias and five presented with some concerns. The studies were considered moderate to high quality. Five trials reported no statistically significant difference in microbial colonisation between bracket types. The remaining studies showed mixed results, with some reporting increased colonisation of conventional brackets and others increased colonisation of self-ligating brackets. The heterogeneity of study methods and outcomes precluded meta-analysis. Conclusion: Of the 11 studies included in this systematic review, five found no differences in colonisation between conventional and self-ligating brackets. The remaining studies showed mixed results. The evidence is inconclusive regarding the association between bracket design and levels of microbial colonisation.
This paper explores past natural disasters such as Hurricane Katrina (USA), the Great East Japan and Christchurch (New Zealand) Earthquakes as well as the HIV and SARS pandemics and the impact they had on providing orthodontic services at the time of the crisis. It also addresses the lessons learnt during the process of recovery and the long-term changes made as a result to the provision of care. CPD/Clinical Relevance: To provide a review of how orthodontics as a specialty survived past crises and to use the lessons learnt to navigate the current COVID-19 pandemic.
The aim of this research was to determine the choices made by clinicians with respect to archwires and arch form during the initial and latter stages of orthodontic treatment with fixed appliances. A questionnaire-based study was carried out at Bristol Dental Hospital between November 2005 and March 2006. Questionnaires were distributed within the dental hospital and at local meetings in order to obtain a mixed sample of hospital and practice-based orthodontists. The clinicians asked to complete the questionnaire were consultant orthodontists (n = 37), specialist practitioners (n = 36), senior specialist registrars in orthodontics (n = 10), and dentists with a special interest in orthodontics (n = 17). The questionnaire consisted of two parts: the first was concerned with the initial alignment phase of treatment and the second with the space-closing phase of treatment in premolar extraction cases. The choice of archwires, significance of arch form, and intra-arch dimensions considered important at both stages were assessed. The clinicians were also asked about their usual practice with regard to adaptation of working archwires and the use of study models and symmetry charts. One hundred questionnaires were returned, giving a response rate of 92.6 per cent. The majority of clinicians felt that preservation of the pre-treatment arch form was essential in the latter but not in the early stages of treatment. In particular, conservation of the original intercanine width was considered important. However, there was no uniformity in how arch form should be preserved. Some respondents used study models and symmetry charts as an aid, but even then they were used in different ways. There was no uniformity in the landmarks used when adapting stainless steel archwires to arch form. Therefore, even when clinicians do adapt their archwires carefully with the intention of preserving arch form, are they choosing the correct arch form?
This in vitro study was designed to determine the effect of time on the measured mean force to debond when brackets were bonded using resin‐modified glass poly(alkenoate) cements and to compare them with a light‐cured diacrylate. Changes in surface topography and composition of the cements were also investigated. Stainless steel orthodontic brackets were bonded to 160 upper premolar teeth in four test groups: Transbond, Fuji Ortho LC, and 3M Multi‐Cure with and without enamel etching. Shear bond testing to failure was performed after 1 hour, 1 week, 1 month, and 1 year. The first three groups were then rebonded and stored for the same time periods before being shear tested again. Debond force was recorded in Newtons and the locus of bond failure was scored using the Adhesive Remnant Index (ARI). Surface topography and composition of the test materials were also studied at time periods of 1 day, and 1, 6, and 18 months, using scanning electron microscopy (SEM) and energy dispersive X‐ray analysis (EDAX). The mean force to debond (N) was observed to increase with time in all four test groups, with there being little significant difference between the groups. When the same brackets were rebonded, the mean force to debond reduced. Surface topography and compositional changes over time were only observed with the resin‐modified glass poly(alkenoate) cements. Resin‐modified glass poly(alkenoate) cements have a mean force to debond comparable with diacrylate bonding agents. However, unlike diacrylates they undergo surface changes with time, the significance of which is unknown.
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