Orthodontic treatment of patients with medical disorders.
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This article will highlight some of the problems encountered when orthodontic treatment is provided for patients who have serious medical conditions. The way in which various disease processes might influence treatment decisions will be described, as well as recommended methods of avoiding potential problems. (+info)
Morphological parameters as predictors of successful correction of Class III malocclusion.
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The aim of the study was to assess pre-treatment cephalometric parameters and measurements of the size of the apical bases as predictors of successful orthodontic correction of Class III malocclusions. Pre- and post-treatment lateral cephalograms and study models of 80 completed Class III subjects were examined to obtain 23 cephalometric parameters taken mainly from the analyses of McNamara and Schwarz, and to measure the size of the apical bases. Success of occlusal correction was evaluated as the percentage change of peer assessment rating score during treatment, which was used as the dependent variable in multivariate statistical analyses testing the predictive value of the parameters assessed. No improvement in the Class III skeletal pattern occurred during treatment and the treatment effects were confined to dentoalveolar changes. With the exception of the percentage midfacial length/mandibular length ratio, the net sum of maxillary and mandibular length differences, the mandibular ramus height/mandibular body length ratio and the gonion angle, most cephalometric parameters of pre-treatment craniofacial morphology assessed were poor predictors of successful correction of Class III malocclusions. Assessment of the size relationship of the maxillary and mandibular apical bases was the strongest predictor of occlusal correction achieved and may serve as a valuable diagnostic addition in the prediction of successful treatment outcome. (+info)
The role of removable appliances in contemporary orthodontics.
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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. (+info)
The relationship between Index of Complexity, Outcome and Need, and patients' perceptions of malocclusion: a study in general dental practice.
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AIM: To examine the relationship between the Index of Complexity, Outcome and Need (ICON) and the subjective opinions of patients attending for routine dental care. MATERIALS AND METHODS: This study was undertaken at two general dental practices in Cardiff and Bedford. 50 patients aged between 11-14 years and 50 patients aged 30-40 years presenting for routine dental treatment were selected in each. The subjects were assessed objectively using the ICON guidelines by two examiners trained and calibrated in the use of this index. The scores were recorded directly from the patient. Subjective assessments were obtained from the patients by means of a questionnaire consisting of four simple questions addressing aesthetics, function, speech and treatment need using a five point Likert scale. RESULTS: The mean ICON scores for the different genders and age groups participating in this study were; 11-14 year old males 58.4 (SE 3.17); 11-14 year old females 51.8 (SE 3.51); 30-40 year old males 51.2 (SE 2.70); 30-40 year old females 45.3 (SE 2.56). There were statistically significant differences in ICON scores between the younger and older groups (P = 0.024) and females and males (P = 0.04). Adult patients were more likely to reject treatment than younger patients. Analysis of the professional scores in relation to subjective assessments, using the Spearman rank correlation coefficient, for 11-14 and 30-40 year olds, and for the male and female genders, revealed that the ICON has a significant correlation with patients' perceptions of aesthetics, function, speech and treatment need (r2 = 0.01 to 0.28). The only exceptions were patients' perceptions of speech in the 30-40 year old group, and function in the female gender, which did not show a statistically significant correlation to the professional assessments. CONCLUSION: In this study, the ICON was found to correlate with patients' opinions of aesthetics, function, speech and treatment need. The strength of association, however, was low. It can be concluded that the ICON alone is not necessarily a suitable predictor for appearance, function, speech or treatment need for those individuals attending general dental practice for routine dental care. In combination with a simple question to assess the patients desire for treatment, the shared decision for any particular individual to enter the treatment process can be determined. (+info)
As treatment expectations of dental patients continue to escalate we, as restorative dentists, must provide an interdisciplinary treatment approach to ensure optimum results for our patients. In recent years the disciplines of periodontics, endodontics and oral surgery have continued to develop closer working relationships with the field of restorative dentistry. Unfortunately, this is not the common relationship that exists with the discipline of orthodontics. Most orthodontic therapy is directed at the treatment of malocclusion and is conducted with limited or no input from the restorative dentist. Orthodontics offers countless ways of assisting the restorative dentist in achieving treatment goals. Several of these orthodontic opportunities to enhance the restorative treatment plan are reviewed. (+info)
Three-dimensional finite element modelling of a dog skull for the simulation of initial orthopaedic displacements.
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From 55 frontal tomograms (CT-scans) using the 'Patran' finite element processor, a three-dimensional finite element model (FEM) of a dog skull was constructed. The model was used to calculate bone displacements under orthopaedic loads. This required good representation of the complex anatomy of the skull. Five different entities were distinguished: cortical and cancellous bone, teeth, acrylic and sutures. The first model consisted of 3007 elements and 5323 nodes, including three sutures, and the second model 3579 elements and 6859 nodes, including 18 sutures. Prior to construction of the FEM, an in vivo study was undertaken using the same dog. The initial orthopaedic displacements of the maxilla were measured using laser speckle interferometry. Under the same loading conditions, using the second FEM, bone displacements of the maxilla were calculated and the results were compared with the in vivo measurements. Compared with the initial displacement measured in vivo, the value of the constructed FEM to simulate the orthopaedic effect of extra-oral force application was high for cervical traction and acceptable for anterior traction. (+info)
Skeletal and dento-alveolar stability after surgical-orthodontic treatment of anterior open bite: a retrospective study.
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The aim of this investigation was to assess skeletal and dento-alveolar stability after surgical-orthodontic correction of skeletal anterior open bite treated by maxillary intrusion (group A) versus extrusion (group B). The cephalometric records of 49 adult anterior open bite patients (group A: n = 38, group B: n = 11), treated by the same maxillofacial surgeon, were examined at different timepoints, i.e. at the start of the orthodontic treatment (T1), before surgery (T2), immediately after surgery (T3), early post-operatively (+/- 20 weeks, T4) and one year post-operatively (T5). A bimaxillary operation was performed in 31 of the patients in group A and in six in group B. Rigid internal fixation was standard. If maxillary expansion was necessary, surgically assisted rapid palatal expansion (SRPE) was performed at least 9 months before the Le Fort I osteotomy. Forty-five patients received combined surgical and orthodontic treatment. The surgical open bite reduction (A, mean 3.9 mm; B, mean 7.7 mm) and the increase of overbite (A, mean 2.4 mm; B, mean 2.7 mm), remained stable one year post-operatively. SNA (T2-T3), showed a high tendency for relapse. The clockwise rotation of the palatal plane (1.7 degrees; T2-T3), relapsed completely within the first post-operative year. Anterior facial height reduction (A, mean -5.5 mm; B, mean -0.8 mm) occurred at the time of surgery. It can be concluded that open bite patients, treated by posterior Le Fort I impaction as well as with anterior extrusion, with or without an additional bilateral sagittal split osteotomy (BSSO), one year post-surgery, exhibit relatively good clinical dental and skeletal stability. (+info)
The clinical significance of error measurement in the interpretation of treatment results.
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The aims of this investigation were to determine the errors involved in cephalometric landmark identification and to link these to the interpretation of treatment results. Fifty cephalograms were randomly selected from patient files and the following were determined. (i) Accuracy of the digitizer--single tracing digitized on five occasions on each of 10 different positions on the digitizer by one observer. (ii) Intra- and inter-observer digitizing error--35 landmarks on the same tracing (on a fixed position) digitized on five occasions by each of four judges. (iii) Intra- and inter-observer tracing error--five separate tracings of 10 different cephalograms by four judges. There were no significant differences in the variances of the co-ordinates for each landmark between the different positions on the digitizer (mean variance x-axis 0.07 mm and y-axis 0.08 mm). (ii) One-way ANOVA showed no significant intra- or inter-observer differences in digitation. (iii) Levene's test for homogeneity of variance showed significant differences in the co-ordinates of different landmarks and between the same landmarks on different cephalograms. Two-way ANOVA showed significant differences between observers for the same landmark that were greater than the intra-observer differences. The results indicate that tracing accuracy is a limiting factor in cephalometry. The variance of each landmark is dependent on the quality of the cephalogram. Inter-observer differences were greater than intra-observer effects and these were random, rather than systematic errors. Minimal error estimation calculations enable discrimination between treatment results and measurement errors. (+info)