PubMed Health⌕ Search

Biomedical subjects

T J Freer

Publications and source records attributed to T J Freer.

At least 37 records · Page 2Linked to original sources
PubMed1997

Perceptions of orthodontic appliances among grade seven students and their parents.

A survey of 468 Grade Seven students and 437 parents in the North Brisbane region was undertaken to determine perceptions of orthodontic appliances. Based on responses to statements on the survey, a Perception Score was created for both students and parents in relation to both fixed and removable appliances. Both students and parents had more negative perceptions of fixed appliances than of removable appliances. Fixed appliances were perceived to attract more teasing, to cause more problems in the maintenance of oral hygiene and to be more painful than a removable plate. Respondents also felt that children would have to be more careful about what they eat when wearing fixed appliances. Approximately forty per cent of students and parents did not know whether teeth could be damaged by orthodontic appliances nor whether the appliances would cause discomfort. Parents had significantly more negative perceptions of both types of orthodontic appliances than did the students. The Perceptions scores were not significantly influenced by whether the students attended a private or public sector dentist, the frequency of dental visits, any history of orthodontic treatment, nor by the parents' level of education and their occupations. A forewarning about experiences of orthodontic appliances would better prepare patients and assist operators in providing the community with a more comprehensive orthodontic service.

Adolescent↗
PubMed1997

Application of a case-based expert system to orthodontic diagnosis and treatment planning.

Expert systems are being utilised increasingly in medical fields for the purposes of assisting diagnosis and treatment planning. A case-based system is a particular type of expert system that uses a store of previously treated cases to provide the knowledge for solving new problems. The aim of this study was to investigate the application of this methodology in the field of orthodontic diagnosis and treatment planning. Using a limited group of features, a case-base of 300 cases was entered into a case-based expert system shell. A test set of 30 consecutive cases was then used to test the diagnostic capacity of the system. The computer-generated treatment plan matched the actual treatment plan in 24 of the 30 cases. The system was also tested for its capacity to handle unusual cases. The system has useful potential.

Case-Control Studies↗
PubMed1996

Application of a case-based expert system to orthodontic diagnosis and treatment planning: a review of the literature.

Computer expert systems are being utilised increasingly in medical fields to assist diagnosis and treatment planning. Traditional rule-based expert systems have some limitations when applied to orthodontic diagnosis and treatment planning. These limitations may be avoided by using a case-based system which is a particular type of expert system that uses a stored data bank of previously-treated cases to provide the knowledge for solving new treatment problems. This article reviews the use of expert systems for orthodontic diagnosis and treatment planning, outlines the rationale, processes and advantages of case-based systems, and gives examples of the application of this technology in medical fields.

Case-Control Studies↗
PubMed1996

A genetic aetiology for some common dental anomalies: a pilot twin study.

This pilot study investigated the aetiology of various dental anomalies. Twin-pair correlations were obtained for the total number of missing, ectopic, malformed and rotated permanent teeth which were scored from panoramic radiographs of 59 monozygotic (identical) and 42 dizygotic (non-identical) twin-pairs. All monozygotic (MZ) twin correlations were greater than the dizygotic (DZ) twin correlations, suggesting a significant hereditary aetiology. A familial history of such common dental anomalies could become a valuable asset in treatment planning.

Adolescent↗
PubMed1994

The graphical analysis of tooth width discrepancy.

The standard tooth width ratio tables currently do not provide an overall indication of the final interdigitation of teeth. To provide a comprehensive analysis of inter-arch tooth width discrepancy, this study has developed a combination of cumulative percentage tooth width ratios and a method to visually determine the harmony between maxillary and mandibular tooth widths. Mesiodistal tooth widths from the first permanent molar to the corresponding first permanent molar were measured from 60 sets of pretreatment study models which were selected consecutively. Cumulative percentage ratios relating mandibular teeth to maxillary teeth were calculated utilising the mesiodistal tooth width measurements. The 13 mean cumulative percentage ratios developed in this study were plotted on graph paper showing plus and minus two standard deviations from the mean. These ratios provide a standard from which cumulative percentage ratios obtained from any new case may be compared graphically. Deviations from the mean cumulative percentage ratios are immediately recognised. No simple graphical method of assessment on the final interdigitation of anterior and posterior teeth has previously been devised. The graphical analysis of tooth width discrepancy is invaluable as an aid in localising any tooth width discrepancy and ensuring that incompatible maxillary-to-mandibular tooth widths are recognised prior to orthodontic treatment.

Humans↗
PubMed1994

Clinical application of the graphical analysis of tooth width discrepancy.

Mesiodistal tooth width discrepancies between the maxillary and mandibular teeth may be present in any dentition. A mismatch in width between the maxillary and mandibular teeth can have a pronounced effect on the occlusion by preventing the correct interdigitation of buccal teeth and the correct overbite/overjet relation of anterior teeth. No simple graphical method of analysis of tooth width discrepancy has previously been devised. The present graphical analysis of tooth width discrepancy has been developed to comprehensively assess new cases for tooth width discrepancy. The findings from the graphical analysis of tooth width discrepancy were invaluable as an aid in diagnosis and treatment planning. Diagnostic set-ups performed on each malocclusion supported the findings from the graphical analysis. The analysis provided the ability to visually recognise and localise the tooth or teeth causing the tooth width discrepancy. Computerisation of the graphical analysis of tooth width discrepancy will simplify and encourage its use in the overall diagnosis and treatment planning of all malocclusions.

Algorithms↗
PubMed1993

Orthodontic treatment need and the dental aesthetic index.

The Dental Aesthetic (DAI) was devised as a measure of dental appearance and based on lay opinions as opposed to professional assessments of need. The DAI is calculated from the weighted scores of ten occlusal variables. These same variables have been used in other malocclusion indices intended to measure morphological deviations from normality. It is, therefore, important to ask if the DAI might be used to screen both deviations of dental appearance and deviations of occlusion from accepted norms. The original DAI design was based on analysis data from permanent dentitions. However, a large percentage of orthodontic assessments are carried out in the mixed dentition. Therefore, the present study includes a sample of mixed dentitions to test the effectiveness of the DAI in this group. The DAI was tested against the subjective assessments of severity made by orthodontists. Sensitivity and negative predictive power were high. Performance in the mixed dentition group was slightly lower than the permanent dentition group. It is concluded that while the DAI is not sufficiently reliable for assessment of treatment need in the individual, its sensitivity and negative predictive power might provide a useful screening mechanism which reflects both the concerns of patients regarding appearance and the general treatment recommendations of orthodontists. Testing on much larger samples is now required.

Adolescent↗
PubMed1993

Expert systems in orthodontic clinical diagnosis.

Computer-aided diagnosis of orthodontic anomalies is of particular interest in the screening of potential patients. General practitioners and public dental health workers would find considerable benefit in a reliable automated system capable of reflecting the clinical assessments of orthodontists. This study investigates the application of an expert system (Xpert Rule) to the assessment of treatment need using thirteen traits of malocclusion to construct a knowledge base. Decision trees were generated using a pruning option available with the expert system. The results of the study are encouraging and suggest that an expert system is able to generate a useful clinical screening device. Further modification of the knowledge base is required to provide a broader range of case types, particularly those of less common occurrence. It is also suggested that the random aggregation of cases is not the most effective means of developing a knowledge base.

Algorithms↗
PubMed1991

Occlusal contacts: comparison of orthodontic patients, posttreatment patients, and untreated controls.

Orthodontic treatment may severely alter tooth contacts during early treatment, but after its completion the number of contracts increases with settling of the occlusion. Long-term changes are sparsely documented and this investigation examined changes by comparing adequate control groups before treatment, during treatment, and several years after treatment. Although the number of contacts is gradually elevated after orthodontic treatment, the present data suggested that orthodontic patients may not realize the same number of contacts as untreated controls despite prolonged periods out of retention. The functional significance of this finding remains unknown and suggests the need for further research.

Adolescent↗
PubMed1990

Towards a revised undergraduate orthodontic curriculum.

The undergraduate curriculum in Dentistry at the University of Queensland, as elsewhere, is under scrutiny. Developments in the tertiary education system, and changes in the profession of dentistry have to be taken into account. Orthodontics is a specialty area which is particularly affected by these pressures. This paper describes the conduct, results and implications of a survey undertaken to ascertain the attitudes of practising dentists towards their own orthodontic education and their perceived needs in continuing education. Data was obtained from a substantial sample of those present practitioners who are registered and are practising in Queensland, the majority having graduated from the University of Queensland.

Attitude of Health Personnel↗
PubMed1989

The reproducibility of gnathosonic recordings over time.

Gnathosonic recordings are obtained on rapid closure of the teeth to occlusion. A general relationship between gnathosonic tracings and occlusal contact patterns has been demonstrated. Variation of gnathosonic recordings over time for the same individual has not been satisfactorily investigated. The present study suggests that recordings taken at the same sitting are relatively reproducible but reproducibility over time is not high. The series of recordings obtained in this study suggests caution when interpreting a single series of gnathosonic tracings.

Adult↗
PubMed1989

Post-orthodontic occlusal function.

The significance of orthodontic treatment in the aetiology of temporomandibular dysfunction continues to be a matter of controversy. However, the evidence of any association has been generally negative. This investigation involved the examination of a study group of 87 post-orthodontic patients, the average time out of all retention being 52 months. They were compared with an untreated control group. Signs and symptoms of temporomandibular disfunction were assessed for both groups. In only one instance, soft joint click, was there found to be a significant association between the treatment category and the occurrence of the symptom, there being a higher rate of soft clicks in the post-treatment group. While this may be ascribed to orthodontic treatment, there was also a different restorative pattern in the two groups. No other significant associations were found.

Adult↗