Showing papers in "Journal of Orthodontics in 1998"

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

Abstract: 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.

Clinical performance of orthodontic brackets and adhesive systems: a randomized clinical trial.

Abstract: The aim of the study was to evaluate and compare the clinical performance of adhesive precoated brackets (APC) with that of two types of uncoated bracket bases, Straight-Wire and Dyna-Lock, bonded using two types of orthodontic adhesives, Transbond XT, and Right-On. Forty consecutive orthodontic patients entered the trial and 607 brackets were bonded. The incidence and site of first time bond failures were recorded over a period of 1 year. The time required for bonding was also recorded. The overall bond failure rate was 6.6 per cent. There were no significant differences between the failure rates of the five groups, or between the upper and lower arch. However, significantly more brackets failed on the left side than on the right. Premolar brackets were lost most often, whilst incisor brackets failed least. No association was found between bond failure and time elapsed since bonding. Bonding time was least with Right-On adhesive. There were no significant differences between bonding times using APC or Transbond. Results of the present study conflict with those of a previous ex vivo study by the authors, using the same materials and bonding technique. Suggested reasons for this are discussed.

The effect of extraction of third molars on late lower incisor crowding: a randomized controlled trial.

Abstract: The problem of late mandibular incisor crowding is a well established phenomenon, the cause of which has been the substance of considerable debate over the years. A central issue is the possible ro...

Autotransplantation of teeth: is there a role?

Abstract: Autotransplantation of teeth, if carried out successfully, ensures that alveolar bone volume is maintained due to physiological stimulation of the periodontal ligament. Autotransplantation has been carried out for many years, but with varying success rates. As a result, it is seldom regarded as an appropriate treatment option for patients with missing teeth especially with the continued development of osseo-integrated implants. Since placement of osseo-integrated implants in growing alveolar bone is contra-indicated, transplantation of available teeth remains a suitable choice for replacing missing units in the young patient. The role of autotransplantation of teeth in several clinical situations, the clinical techniques involved and factors influencing success of the transplant are discussed. The aim of this paper is to underline the evidence based principles for successful autotransplantation and present the technique as a viable treatment option in present day orthodontic practice.

The ectopic maxillary canine: a review.

Abstract: This article reviews the aetiology and management of the ectopic maxillary canine. Much controversy surrounds the causes of canine palatal ectopia. The recent evidence surrounding the genetic and guidance theories are examined. The management options are detailed and the indications for each treatment modality based on the available scientific evidence are presented. Finally, the untoward sequelae of canine ectopia are discussed.

An Evaluation of the Biomechanical Response of the Tooth and Periodontium to Orthodontic Forces in Adolescent and Adult Subjects

Abstract: This study was designed to quantify the magnitude of tooth mobility in adolescents and adults, and to investigate the differences in the biomechanical response of tooth and periodontium to orthodontic forces. The initial displacement of the maxillary central incisor was measured in 50 adolescent and fifty adult patients and the biomechanical properties of the periodontium were examined using the finite element method (FEM) and supporting experimental data. The magnitude of tooth mobility was significantly greater in the adolescent group than in the adult group. By integrating the differences in tooth mobility in both subject groups with analytical tooth displacements, the Young's modulus of the periodontal ligament (PDL) was demonstrated to be greater in the adults than in the adolescent subjects. The differing biomechanical properties of the PDL in adults were demonstrated to result in almost equivalent or somewhat increased stress levels in the PDL in adult subjects. It is suggested that this might produce a reduction in the biological response of the PDL and thus lead to a delay in tooth movement in adults.

A study of transposed canines in a sample of orthodontic patients.

Abstract: Tooth transposition is a positional interchange of two adjacent teeth. The most commonly transposed tooth is the permanent canine with either the first premolar or lateral incisor. The records of 54 subjects with transposed canines, both maxillary and mandibular, were collected. Pretreatment study models of these subjects were matched with a similar number of models from unaffected individuals. Bucco-lingual and mesio-distal tooth widths, arch depth and arch width were measured on each model. Thirty-four subjects (63 per cent) were female. Thirty-seven (68.5 per cent) of the cases involved the maxillary arch and thirty-three (89.2 per cent) of these upper arch transpositions were of the canine and first premolar. In cases involving the lower arch the canine was invariably transposed with the lateral incisor. Peg-shaped lateral incisors, supernumerary and/or congenitally absent teeth occurred in 19 subjects. There were some small, but significant differences in the dimensions of some teeth, however...

Psychological Assessment of Patients Requesting Orthognathic Surgery and the Relevance of Body Dysmorphic Disorder

Abstract: The psychological assessment of patients requesting orthognathic treatment is a vital and integral part of the overall assessment procedure. It allows identification of potential problems at an early stage before irreversible decisions have been made. This paper aims to highlight some of the aspects of psychological assessment which are particularly important. It also discusses current concepts in the diagnosis and treatment of those patients suffering from body dysmorphic disorder (BDD). This is the term applied to those individuals with a normal appearance who present requesting treatment because they believe that they have a 'defect'.

An investigation into the behavioural characteristics of orthodontic elastomeric modules

Abstract: The object of the study was to investigate the behavioural characteristics of orthodontic elastomeric modules with regard to their effect on frictional resistance and their failure load forces, and involved the use of an experimental laboratory-based study. Six cohorts were assembled employing five types of module and two bracket types. Straight lengths of 0.018 x 0.025-inch stainless steel were pulled through the ligated brackets and frictional resistance was measured using an Instron universal testing machine. Recordings were repeated over a 4-week period, during which time the cohorts were placed in a simulated oral environment. Failure load forces of new and used modules were also recorded, and frictional resistance and failure load forces. Analysis of variance revealed that the Minitwin cohort exhibited significantly higher frictional resistance and that the clear modules demonstrated the lowest levels of friction. Time soaked in a simulated oral environment had a variable effect on frictional resistance. A wide range of failure load forces was seen for the five types of module and all types showed a reduction in failure load force following their soaking in the simulated oral environment. There was variation in performance of the different modules both in friction testing and failure load testing.

Video versus lecture: effective alternatives for orthodontic auxiliary training.

Abstract: Many studies have compared the relative effectiveness of visually-aided lectures and videotapes, but methodological flaws have prevented definitive comparison of the techniques. This study assessed the relative effectiveness of the two approaches for orthodontic auxiliary training. This study was a prospective, randomised trial, conducted at the Eastman Dental Hospital and Institute. Two groups of 16 dental auxiliaries, selected at random, studied identification and positioning of orthodontic brackets: one group attended a lecture accompanied by slides and the other viewed a video. Subjects bonded brackets onto acrylic teeth and the results were assessed by computerised image analysis. The subjects completed a questionnaire on their attitudes to the respective teaching methods. Results were assessed for accuracy of bracket placement and variations in type of auxiliary. There was no significant difference between the teaching methods except for bracket positioning where video was slightly better (P < 0.05). There was no significant difference between the types of auxiliary. Generally, video teaching and lecturing were equally effective, with video achieving slightly better results. Both methods were effective at teaching bracket placement, and dental nurses and student hygienists proved equally adept at bracket positioning.

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

Abstract: 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.

An ex vivo investigation into the effects of chemical solvents on the debond behaviour of ceramic orthodontic brackets.

Abstract: The problems of ceramic bracket debond have been well documented. A peppermint oil material has been marketed previously as a debonding agent. This study assessed ex vivo the effects of peppermint ...

Parental perceptions and attitudes on orthodontic care.

Abstract: The objective of this paper is to determine whether an association existed between parents' attitudes to orthodontic issues affecting themselves and their attitudes to possible orthodontic treatment for their child. It consisted of an analytical survey using a self-administered questionnaire, taken in South East England of six-hundred parents of children aged 9 years. The questionnaires were delivered to the parent with the help of their child's school. Four-hundred-and-thirty-seven questionnaires were returned (73 per cent). Significant associations were found between desire by the parents for orthodontic treatment for themselves and perception of need in their child, parental satisfaction with own dental appearance and perception of need in their child, a parental history of orthodontic treatment and a determination to insist on their child's co-operation with orthodontic treatment. Logistic regression models show the odds of parents who desire orthodontic treatment themselves, perceiving need in their ...

Assessing malocclusion--the time factor.

Abstract: Assessment of occlusal status for orthodontic purposes may be undertaken by subjective assessment or by means of an index of occlusion. The assessment method should be reproducible and should achieve the intended outcomes. This study investigated another possible modifying factor--performance over time. Photographs and dental casts of 45 subjects at 12 years of age were compared with follow-up records at 16 years of age. No orthodontic intervention had occurred during the 4 years. Subjective severity assessments and Aesthetic Component (AC) scores of the Index of Treatment Need (IOTN) for first and second series records were made by four orthodontists. Scores of the Dental Aesthetic Index (DAI) and Dental Health Component (DHC) of the IOTN were made by one of the authors. Implications for hypothetical decisions to treat were considered. There was a significant reduction in the subjective severity and DAI scores across the whole sample and in the mixed dentition subgroup. There was a non-significant reduction in the AC (IOTN) scores across the whole samples, but there was a significant reduction in the AC (IOTN) scores in the mixed dentition subgroup. The DHC (IOTN) categorisations proved to be more stable over the period of study.

Orthodontic reconstruction in a victim of murder.

Abstract: Accurate comparison of ante-mortem photographs and the skull of a deceased person is dependent upon suitable superimposition techniques and a post-mortem dentition which is comparable to the situation obtaining in the individual at the time of death. The skull featuring in this case presented with a missing upper lateral incisor, lost after death, and the occlusion was studied enabling a replacement tooth to be provided and positioned as in life. Although no dental records were available, good quality photographs of a putative identity were compared by electronic superimposition and the restored occlusal characteristics of the skull were shown to accurately match the photographs of one possible victim. This evidence resulted in positive identification by a Coroner. This case illustrates the importance of seeking specialist clinical advice in forensic dental cases.

How UK orthodontists advise patients on oral hygiene.

Abstract: In 1993, 1038 UK orthodontists (all the members of the British Association of Orthodontists and the British Society for the Study of Orthodontics) were asked by questionnaire about the oral hygiene advice they gave to patients undergoing routine orthodontic treatment. All the orthodontists gave advice on tooth brushing. Most (89.5 per cent) gave dietary advice and (84 per cent) used disclosing tablets. A fluoride rinse was recommended by 73 per cent and a chlorhexidine mouthwash by 41.9 per cent. Many orthodontists advocate appropriate oral hygiene measures, but the efficacy of such methods is determined by the patient's motivation. The orthodontist therefore requires skills in behavioural management. Oral hygiene measures may be more cost-effective when undertaken by trained auxiliaries.

Hypodontia: genotype or environment? A case report of monozygotic twins.

Abstract: A case report is presented of monozygotic twins with variable expression of hypodontia. DNA fingerprinting was used to confirm monozygosity, and this evidence supports the theory that genetic coding is not the sole controlling factor in tooth agenesis. It is suggested that DNA fingerprinting should be considered the gold standard for determination of monozygosity.

The ectopic maxillary canine: a case report.

Abstract: A case is described of a severely ectopic maxillary canine, which underwent initial spontaneous improvement, and following extraction of the deciduous canine erupted satisfactorily. It provides a cautionary tale when considering surgical removal of ectopic maxillary canines.

Toothbrushing forces in children with fixed orthodontic appliances.

Abstract: The aim of this investigation was to determine whether toothbrushing forces are influenced by wearing fixed orthodontic appliances. Thirty children, (10 males, 20 females) with planned fixed appliance therapy and aged 10-15 years, were recruited to the study. No subject had previously worn an orthodontic appliance. At baseline, each subject brushed their teeth in their usual way, unsupervised. The toothbrush used was a purpose-designed electronic instrument that measured the force applied to the brush and transmitted force data by radio to a remote PC. After toothbrushing, subjects had orthodontic brackets fitted. Toothbrushing was repeated at 2 and 14 weeks after baseline, and brushing forces recorded. There were no significant differences between the measurements made at baseline and those made at 2 and 14 weeks. There were no differences between males and females in the forces used at any time point. It was concluded that toothbrushing forces are unaffected by placing fixed orthodontic applianc...

A Critical Assessment of High-earning Orthodontists in the General Dental Services of England and Wales (1990-1991)

Abstract: Cases from the Dental Practice Board's 2 per cent random sample of completed cases which had been treated by orthodontic practitioners with high gross earnings, were compared to all the cases within the sample from other practitioners. They were assessed using the PAR index and IOTN. High earning orthodontists treated slightly more cases with lower objective need for treatment, but treated no more cases 'Unnecessarily' than other practitioners. They used more fixed appliances, and had marginally better levels of residual need for treatment at finish, although this was at least partially explained by lower levels at start. Generally, their standards were not substantially different to other practitioners. Appliance type had a marked effect on outcome, as did levels of malocclusion and need for treatment at start. Both groups of practitioners performed similarly (better) with dual arch fixed appliances: however, overall standards could only be described as mediocre. There is no justification to sing...

Patient attitudes to glove use by orthodontists.

Abstract: The aim of this study was to evaluate the awareness of orthodontic patients of the importance of glove wearing by orthodontists, and consisted of a patient completed questionnaire carried out at an orthodontic clinic in Ireland. The subjects were 194 consecutive patients [122 (63 per cent) female, 72 (37 per cent) male; mean +/- SD age: 15.5 +/- 2.2 years] attending an orthodontic clinic. They completed a questionnaire designed to determine their attitudes to the wearing of gloves by orthodontists. Most patients (97 per cent; n = 188) considered that orthodontists should routinely wear gloves. However, approximately 15 per cent of patients (n = 30) would attend an orthodontist who did not wear gloves. Ninety-four per cent (n = 182) of patients considered that gloves were worn to protect both the orthodontist and the patient. A total of 86.5 per cent (n = 168) of patients thought that the orthodontist should change gloves between patients. The overwhelming majority of patients surveyed demonstrated...

Notching of orthodontic bonding resin to facilitate ceramic bracket debond--an ex vivo investigation.

Abstract: This ex vivo study assessed the potential of introducing a notch in the bond layer, as a means of facilitating the removal of ceramic brackets. Sixty extracted premolar teeth were divided into three groups of 20 teeth and bonded with Intrigue brackets using Concise chemically-cured adhesive. The bonding technique was modified with groups 1 and 2 by introducing a notch in the bond layer. Group 1 was notched from the gingival aspect, group 2 from the occlusal, and group 3 served as a control. The brackets were removed by applying a shear load from the gingival aspect using an Instron universal testing machine. The mean force to debond was calculated for each group. The results showed that introducing a notch significantly reduced the mean and maximal debond forces. This was confirmed with Weibull analysis with the notched specimens having a higher probability of failure at any force. In addition, ceramic bracket fracture was eliminated. Notching the bonding resin may be helpful in facilitating the removal of ceramic brackets.

Applications of Scanora multimodal maxillofacial imaging in orthodontics.

Abstract: The principles of the Scanora multimodal radiography system are described. This self-contained unit of X-ray generator, patient chair, and imaging elements incorporates the two basic principles of narrow beam radiography and spiral tomography. Conventional panoramic images or magnified images of the dentition can be produced. In orthodontics, the application of spiral tomography in order to obtain cross sectional images has proved helpful in the assessment of a number of patients. Four cases are reported in which the images obtained using this system has substantially contributed to their management.

The benefits of marketing in orthodontics.

Abstract: This article gives an outline of marketing basics and how they could be used to best effect in the Orthodontic profession.

Electrothermal bonding: shear bond strength of orthodontic brackets after two weeks.

Abstract: Electrothermal bonding is based on acceleration of the setting reaction of a bonding: resin by the selective application of heat to the orthodontic bracket through the passage of a low voltage electric current. The purpose of this study was to compare the shear bond strength of nine resins comprising chemically-cured, light-cured, and glass ionomer types, 14 days after electrothermal and conventional bonding. Mean shear and bond strengths ranged from a low of 7.4 MPa for Sequence (electrothermally bonded) to a high of 15.4 MPa Concise (control). There was no statistically significant difference between the electrothermal and conventional bonding methods. All the resins produced bond strengths adequate for clinical orthodontics at 14 days.

The periodontal-orthodontic interface: a simple solution to a difficult problem.

Abstract: A technique which combines the use of a sectional fixed and removable appliance in periodontally compromised dentitions is described. The rationale behind treatment in these patients is discussed and the relative advantages over other techniques highlighted.

Task Group for Orthodontics Report.

Abstract: The UK Specialist Review Group of the General Dental Council's Education Committee has been charged with taking forward the recommendations in the Chief Dental Officer's report 'UK Specialist Dental Training'. The Specialist Review Group has, in turn, established a number of specialty task groups. This report is from the Task Group for Orthodontics. It was submitted in May 1996.