BOS response to article on 'Hold that smile' campaign.

The British Orthodontic Society launched a campaign called 'Hold that smile' to highlight to patients the importance of wearing retainers as a means of reducing relapse following orthodontic treatment. This opinion piece, on behalf of the British Orthodontic Society, is written in response to an article entitled 'British Orthodontic Society's initiative on orthodontic retention, A GDP's perspective' ( 2018; 224: 481-486). In this short opinion article, we take the opportunity to clarify the aims of the campaign, which set out to educate patients about orthodontic relapse and to highlight the importance of wearing, and taking responsibility for, retainers long-term.

Retention and relapse in clinical practice.

Maintaining teeth in their corrected positions following orthodontic treatment can be extremely challenging. Teeth have a tendency to move back towards the original malocclusion as a result of periodontal, gingival, occlusal and growth related factors. However, tooth movement can also occur as a result of normal age changes. Because orthodontics is unable to predict which patients are at risk of relapse, those which will remain stable and the extent of relapse that will occur in the long-term, clinicians need to treat all patients as if they have a high potential to relapse. To reduce this risk, long term retention is advocated. This can be a significant commitment for patients, and so retention and the potential for relapse must form a key part of the informed consent process prior to orthodontic treatment. It is vital that patients are made fully aware of their responsibilities in committing to wear retainers as prescribed in order to reduce the chance of relapse. If patients are unable or unwilling to comply as prescribed, they must be prepared to accept that there will be tooth positional changes following treatment. There is currently insufficient high quality evidence regarding the best type of retention or retention regimen, and so each clinician's approach will be affected by their personal, clinical experience and expertise, and guided by their patients' expectations and circumstances.

Retention in orthodontics.

Retention is necessary following orthodontic treatment to prevent relapse of the final occlusal outcome. Relapse can occur as a result of forces from the periodontal fibres around the teeth which tend to pull the teeth back towards their pre-treatment positions, and also from deflecting occlusal contacts if the final occlusion is less than ideal. Age changes, in the form of ongoing dentofacial growth, as well as changes in the surrounding soft tissues, can also affect the stability of the orthodontic outcome. It is therefore essential that orthodontists, patients and their general dental practitioners understand the importance of wearing retainers after orthodontic treatment. This article will update the reader on the different types of removable and fixed retainers, including their indications, duration of wear, and how they should be managed in order to minimise any unwanted effects on oral health and orthodontic outcomes. The key roles that the general dental practitioner can play in supporting their patients wearing orthodontic retainers are also emphasised.

Interdisciplinary management of severe intrusion injuries in permanent incisors: a case series.

Intrusion injuries to the permanent dentition are amoung the most severe types of dental injuries, occurring in 0.3-1.9% of all dental trauma cases. The current clinical guidelines in the management of intrusion injuries are based on level B evidence due to the infrequent nature of this type of injury, coupled with a lack of high quality evidence-based studies. This paper presents four cases of severe intrusion injuries that were successfully managed using an interdisciplinary approach. The cases described here highlight the benefits of orthodontic repositioning of severely intruded teeth in the short and medium terms. Although orthodontic repositioning was unsuccessful in the final case, this did not preclude subsequent surgical repositioning. Interdisciplinary collaboration allowed two of the cases described to be effectively managed with premolar autotransplantation alongside orthodontic treatment. The cases demonstrated here indicate the difficulties in providing the current recommended treatment modalities at non-specialist clinics. They accentuate the importance of an immediate referral of such complex cases to a specialist centre where interdisciplinary management is readily available.

Are general dental practitioners effective in the management of non-apnoeic snoring using mandibular advancement appliances?

OBJECTIVE: This study assessed the effectiveness of general dental practitioners (GDPs) in the management of subjects with non-apnoeic snoring using a mandibular advancement appliance (MAA), following a one day training course. SUBJECTS AND METHODS: Sixty subjects suffering from simple, non-apnoeic snoring were treated by 15 GDPs, in three hospital centres, using a monobloc mandibular advancement appliance design. All GDPs attended a one day training course prior to the study which covered theoretical and practical training in the use of mandibular advancement appliances. Snoring and level of disturbance were assessed using a questionnaire completed by their sleeping partner before and after a three month treatment period. Daytime sleepiness was assessed by the patients using the Epworth sleepiness scale questionnaire (ESS) before and after a three month treatment period. In addition, patients completed an outcome questionnaire, to assess side-effects experienced from the MAA. RESULTS: A success rate of 48% (95% CI 0.35, 0.61) was achieved in partner-assessed snoring and disturbance levels, following a three month period of MAA treatment. The median ESS score reduced from 9 to 7.5 (95% CI 0, 3). General dental practitioners experienced problems during protrusive bite registrations, with 10% being judged inadequate. CONCLUSION: GDPs were not effective in the management of non-apnoeic snoring using a monobloc appliance after a one day training course. Further training and/or selection of a different design of appliance should be considered for GDPs to become highly competent in this area.

Twin-block re-activation.

This paper briefly reviews reasons for re-activating Twin-blocks, discussing different approaches and describing a new, simple, cost effective approach, which can be undertaken at the chairside.

Retention procedures for stabilising tooth position after treatment with orthodontic braces.

BACKGROUND: Retention is the phase of orthodontic treatment that attempts to keep teeth in the corrected positions after treatment with orthodontic (dental) braces. Without a phase of retention there is a tendency for the teeth to return to their initial position (relapse). To prevent relapse almost every patient who has orthodontic treatment will require some type of retention. OBJECTIVES: To evaluate the effectiveness of different retention strategies used to stabilise tooth position after orthodontic braces. SEARCH STRATEGY: The Cochrane Oral Health Group's (OHG) Trials Register, CENTRAL, MEDLINE and EMBASE were searched. Handsearching of orthodontic journals was undertaken in keeping with the Cochrane OHG search programme. No language restrictions were applied. Authors of randomised controlled trials (RCTs) were identified and contacted to identify unpublished trials. Most recent search: May 2005. SELECTION CRITERIA: RCTs on children and adults, who have had retainers fitted or adjunctive procedures undertaken, following orthodontic treatment with braces to prevent relapse. The outcomes were: how well the teeth were stabilised, survival of retainers, adverse effects on oral health and quality of life. DATA COLLECTION AND ANALYSIS: Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. As no two studies compared the same retention strategies (interventions) it was not possible to combine the results of any studies. MAIN RESULTS: Five trials satisfied the inclusion criteria. These trials all compared different interventions: circumferential supracrestal fiberotomy (CSF) combined with full-time removable retainer versus a full-time removable retainer alone; CSF combined with a nights-only removable retainer versus a nights-only removable retainer alone; removable Hawley retainer versus a clear overlay retainer; multistrand wire retainer versus a ribbon-reinforced resin bonded retainer; and three types of fixed retainers versus a removable retainer. There was weak unreliable evidence, based on data from one trial, that there was a statistically significant increase in stability in both the mandibular (lower) (P < 0.001) and maxillary (upper) anterior segments (P < 0.001) when the CSF was used, compared with when it was not used. There was also weak, unreliable evidence that teeth settle quicker with a Hawley retainer than with a clear overlay retainer after 3 months. The quality of the trial reports was generally poor. AUTHORS' CONCLUSIONS: There are insufficient research data on which to base our clinical practice on retention at present. There is an urgent need for high quality randomised controlled trials in this crucial area of orthodontic practice.

Retention procedures for stabilising tooth position after treatment with orthodontic braces.

BACKGROUND: Retention is the phase of orthodontic treatment that attempts to keep teeth in the corrected positions after orthodontic (dental) braces. Without a phase of retention there is a tendency for the teeth to return to their initial position (relapse). To prevent relapse almost every patient who has orthodontic treatment will require some type of retention. OBJECTIVES: To evaluate the effectiveness of different retention strategies used to stabilise tooth position after orthodontic braces. SEARCH STRATEGY: The Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and EMBASE were searched. Several journals were handsearched. No language restrictions were applied. Authors of randomised controlled trials (RCTs) were identified and contacted to identify unpublished trials. Most recent search: December 2002. SELECTION CRITERIA: RCTs on children and adults, who have had retainers fitted or adjunctive procedures undertaken, following orthodontic treatment with braces to prevent relapse. The outcomes are: how well the teeth are stabilised, survival of retainers, adverse effects on oral health and quality of life. DATA COLLECTION AND ANALYSIS: Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two reviewers. As no two studies compared the same retention strategies (interventions) it was not possible to combine the results of any studies. MAIN RESULTS: Four trials satisfied the inclusion criteria. These trials all compared different interventions: circumferential supracrestal fiberotomy (CSF) combined with full-time removable retainer versus a full-time removable retainer alone; circumferential supracrestal fiberotomy (CSF) combined with a nights-only removable retainer versus a nights-only removable retainer alone; removable Hawley retainer versus a clear overlay retainer; and three types of fixed retainers versus a removable retainer. There was weak unreliable evidence, based on data from one trial, that there was a statistically significant increase in stability in both the mandibular (p < 0.001) and maxillary anterior segments (p < 0.001) when the CSF was used, compared with when it was not used. There was also weak, unreliable evidence that teeth settle quicker with a Hawley retainer than with a clear overlay retainer after 3 months. The quality of the trial reports was generally poor. REVIEWER'S CONCLUSIONS: There are insufficient research data on which to base our clinical practice on retention at present. There is an urgent need for high quality randomised controlled trials in this crucial area of orthodontic practice.

A randomized controlled trial to investigate brackets bonded with a hydrophilic primer.

OBJECTIVE: To compare the clinical failure rates of brackets bonded using a prototype hydrophilic primer, designed to be insensitive to moisture, with brackets bonded with a conventional primer. DESIGN: Single centre randomised controlled clinical study. Thirty-three patients were bonded using a split mouth technique: randomly allocating the hydrophilic primer to one side of the mouth and a conventional primer to the other. SETTING: Hospital orthodontic department, Bradford, UK. SUBJECTS: Orthodontic patients requiring fixed appliances. MAIN OUTCOME MEASURES: The site and time to bond failure was recorded for each bracket that failed over 6 months. RESULTS: Using survival analysis, there was an increased risk of bracket failure when bonded with the hydrophilic primer compared with the conventional primer (hazard ratio = 2.2, 95% confidence interval: 1.1 to 4.5, P = 0.01). CONCLUSIONS: This hydrophilic primer cannot be recommended for routine clinical use.

The role of removable appliances in contemporary orthodontics.

The contemporary uses of removable appliances are considerably more limited than in the past. This article discusses possible reasons for their declining use, including recognition of their limitations. It is possible to achieve adequate occlusal improvement with these appliances providing that suitable cases are chosen. Specific indications for their appropriate use on their own in the mixed dentition are presented. Removables can also be used as an adjunct to more complex treatments, to enhance the effect of fixed appliances, headgear or in preparation for functional appliances. Further research is required to confirm whether their use in conjunction with more complex treatments enhances the quality and efficiency of treatment or not.

Investigation of a hydrophilic primer for orthodontic bonding: an in vitro study.

A common reason for bond failure is moisture contamination. This study investigates the in vitro bond strength of brackets bonded using a new hydrophilic primer, designed to be insensitive to moisture, and compares it with a conventional primer. Using a standardized technique, the in vitro bond strength of brackets bonded with the hydrophilic primer was compared to identical brackets bonded with a conventional primer. Although designed to be moisture insensitive, the directions for use stipulate drying the teeth before bonding. Therefore, for the purposes of comparison with a conventional primer the experiment was conducted under dry conditions. The results were analysed using the Weibull distribution modelling. The median bond strength with the hydrophilic primer (6.43 MPa, 95 per cent C.I. 7.69-9.50) was significantly lower (P = 0.0001) than the conventional primer (8.71 MPa, 95 per cent C.I. 5.89-7.59). The Weibull distribution modelling showed that brackets bonded with the hydrophilic primer were 3.96 times more at risk of failure (95 per cent C.I.: 2.39-6.56; P <0.0001). The bond strength at which 5 per cent of the brackets failed was also lower for the hydrophilic primer. The bond strengths obtained with the hydrophilic primer were significantly lower than with the conventional primer. Although the median bond strength values were promising, the laboratory results for this particular hydrophilic primer were disappointing when using the Weibull analysis, where the whole distribution of bond strength is taken into account.

A videofluoroscopic comparison of straw and cup drinking: the potential influence on dental erosion.

OBJECTIVE: Videofluoroscopy was used to compare drinking from a cup with drinking through straws of two varying bore diameters in different positions in the mouth. DESIGN: Clinical study at a single centre. SETTING: UK dental school. SUBJECTS AND METHODS: Twenty patients showing clinical signs of erosion which had necessitated advice and/or treatment. INTERVENTIONS: Subjects drank from a cup and through a narrow straw, which was then repositioned more posteriorly. A wide bore straw was used in two equivalent positions. Swallowing was viewed laterally and anteroposteriorly to assess involvement of incisors and molars respectively. MAIN OUTCOME MEASURES: Video recordings examined for presence or absence of fluid contact with teeth following each swallow. If contact occurred, the time was measured. RESULTS: Fourteen patients avoided fluid contact with both incisors and molars when using a straw. Compared with the cup, significant differences were found with the narrow straw (P = 0.03, 95% confidence interval of 22.6% to 31.6%), the narrow straw repositioned (P = 0.008, 95% confidence interval of 12.3% to 47.1%) and the wide straw repositioned (P = 0.03, 95% confidence interval of 3.1% to 37.5%). Contact time of fluid with anterior teeth was also significantly reduced. CONCLUSIONS: Drinking through a straw positioned toward the back of the mouth may reduce the erosive potential of soft drinks.

Use of jigs to standardise orthodontic bond testing.

OBJECTIVES: The aim of this study was to test whether the use of jigs for in vitro orthodontic bond strength testing helped to standardise the technique. METHODS: Two jigs were developed, one for mounting teeth with bonded brackets all in the same plane, and the second for debonding the brackets at 90 degrees to this plane. These jigs ensured the debonding force was applied in a controlled direction. Teeth mounted and debonded in this manner were compared with teeth tested with an existing protocol where the direction of the debonding force is not standardised. RESULTS: Although the same material was tested in both groups the use of jigs produced much higher mean bond strengths, and a reduced spread in the distribution of the results. CONCLUSIONS: To allow more legitimate comparisons between products and approaches, orthodontic bond strength testing must be universally standardised. The use of jigs to accurately direct the plane of the debonding force reduces the wide variations in results often seen in laboratory bond testing, improving standardisation.

The dental problems and management of a patient suffering from congenital insensitivity to pain.

Congenital insensitivity to pain is a rare condition usually manifested in childhood by a history of unrecognized trauma, indifference to painful stimuli or self-mutilation. This paper describes the management of a 13-month-old male who had severely lacerated his tongue by habitually chewing it, using soft polyvinyl mouthguards retained with a minimal amount of denture fixative.