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PubMed2000

Orthodontic dental visits during 1987 and 1996.

Americans underwent approximately 355 million dental procedures during 1987, approximately 8% for orthodontic treatment. Individual rates of utilization vary and are not uniform across the population. This article provides estimates of orthodontic utilization for each of several socioeconomic and demographic categories, using household data from the 1987 National Medical Expenditure Survey (NMES) and the 1996 Medical Expenditure Panel Survey (MEPS). These data show that slightly more than 3% of the population, or approximately 39 million Americans, visited a dentist to receive orthodontic care nationwide during 1987 and 1996. For those with an orthodontic visit, the mean number of visits per patient decreased in number from 1987 to 1996.

Adolescent↗
PubMed2002

Effect of misoprostol, a prostaglandin E1 analog, on orthodontic tooth movement in rats.

The purpose of this study was to investigate the effects of oral administration of misoprostol, a prostaglandin E1 analog, on orthodontic tooth movement and root resorption in rats. Sixty-four male Sprague-Dawley rats that initially weighed 250 +/- 20 g were used in this study. The animals were randomly assigned to 1 of 6 experimental and 2 control (nonappliance and appliance) groups. The experimental groups received 2.5, 5.0, 10.0, 25.0, 50.0, and 100.0 microg/kg misoprostol by gastric lavage every 24 hours for 2 weeks. A fixed orthodontic appliance consisting of a nickel-titanium closed-coil spring, 5.0 mm long was ligated between the maxillary right incisor and the maxillary right first molar. The initial activating force was 60 g. For analysis of root resorption, 99 maxillary right and left first molars from 61 animals were chosen. Serial histologic sections of the mesial root of the maxillary first molars were made, and histologic analysis of root resorption on the mesial and distal surfaces was performed. The results showed that oral misoprostol did increase the amount of orthodontic tooth movement in all the experimental groups compared with the appliance control group. This increase was statistically significant in doses of 10.0, 25.0, 50.0, and 100.0 microg/kg (P <.001). However, there were no statistically significant differences among these 4 different doses. There were no statistically significant differences in the amount of root resorption among the groups. However, a trend toward more root resorption was registered. On the basis of these findings, oral misoprostol can be used to enhance orthodontic tooth movement with minimal root resorption.

Analysis of Variance↗
PubMed2003

Magnetic resonance imaging diagnosis of the temporomandibular joint in patients with orthodontic appliances.

OBJECTIVE: The purpose of this study was to investigate the accuracy of magnetic resonance imaging diagnosis of the temporomandibular joint in those with orthodontic appliances by comparing magnetic resonance images of the temporomandibular joints with and without orthodontic appliances. STUDY DESIGN: Magnetic resonance imaging was performed in a total of 20 temporomandibular joints before and after the insertion of 6 kinds of orthodontic appliances (types 1-6), and the magnetic resonance images were compared. RESULTS: With respect to disk position, the diagnostic accuracy was 80%, 75%, 70%, 70%, 65%, and 60% in order from type 1 through type 6. The distribution of stages for the assessment of condylar configurations was 80%, 55%, 40%, 40%, 20%, and 10% in order from type 1 through type 6. No significant changes were found in the condylar head marrow signals. CONCLUSION: Magnetic resonance imaging is performed in orthodontic patients preferably by using ceramic brackets in the front teeth and direct bonding tubes in the molar teeth while removing arch wires.

Adult↗
PubMed1994

The monitoring of orthodontic tooth movement over a 2-year period by analysis of gingival crevicular fluid.

Gingival crevicular fluid (GCF) was collected from around canine teeth before orthodontic treatment, during retraction, and in retention. The aim was to investigate the changes in the flow of GCF and its glycosaminoglycan (GAG) components at these three stages of orthodontic treatment, and relate them to tooth movement, gingival inflammation, and other clinical parameters recorded at the time of GCF sampling. GAG in GCF samples, collected for a 15-minute period into microcapillary tubes, were separated and identified electrophoretically, stained with Alcian blue and quantitated using a laser densitometer. The increase in GCF volume during orthodontic tooth movement and the decrease during retention are only partly due to changes in the severity of gingival inflammation. Levels of the GAG component chondroitin sulphate found in GCF samples taken during retention appear to be related to the duration of retention, particularly the length of time that the fixed appliance is passive before debonding. GCF analysis may assist the clinician to conduct this phase of orthodontic retention more reliably.

Adolescent↗
PubMed1996

Biodegradable implants for orthodontic anchorage. A preliminary biomechanical study.

The use of endosseous implants as temporary orthodontic anchoring elements has good results in many clinical applications. The development of a new orthodontic implant anchorage system comprising an implant produced of biodegradable polylactide with a metal superstructure is described. The presented bioresorbable implant anchor for orthodontics system (BIOS) implant is designed to provide orthodontic anchoring functions in adolescents and adult patients, and to then be resorbed without a foreign body reaction or signs of clinical inflammation. Shear strength and maximum vertical strength have been measured in biomechanical in vitro tests. BIOS fixtures can be loaded with horizontal shearing forces of 50 N with a mean deflection of 0.26 +/- 0.13 mm and mean vertical removal forces of 155 +/- 80 N. Clinical studies are currently being undertaken to evaluate clinical practicability and biocompatibility of the BIOS implants.

Adolescent↗
PubMed2005

Factors influencing the wearing of protective gloves in orthodontic practice.

The purpose of this study was to explore how wearing, or not wearing, protective gloves affects the efficiency of orthodontists in performing certain orthodontic procedures. Thirty-six volunteers were randomly selected from members of the Taiwan Association of Orthodontists. A visual analogue scale (VAS) was used to determine the degree of convenience subjects felt in performing 11 specified orthodontic procedures, with and without gloves. In addition, the time required to bend round and rectangular archwires and to tie and untie ligature wires was recorded.The results showed that for 10 of the 11 orthodontic tasks there was perceived to be no difference when wearing, or not wearing, gloves. Only when bending a round archwire was there perceived to be a difference. When the four orthodontic procedures were undertaken on a typodont and timed, no significant difference was found between the use of gloves/no gloves.

Adult↗
PubMed1997

Treatment strategies for lower third molars following orthodontic care.

To examine the extent to which orthodontists consider it appropriate to refer post-orthodontic patients for lower third molar treatment. The subjects were 10 orthodontists from hospital, specialist practice and community setting. Participants were presented with 15 case histories of orthodontic patients (including full records) and asked to state whether they would have referred the case to an oral surgeon for management of their third molars. Data were analysed using multi-kappa measure. Two-hundred-and-sixty-two decisions of 300 (88%) were not to refer cases for third molar management. Little consensus was seen between orthodontists on which post-orthodontic cases referral (kappa = 0.14). Some clinicians referred cases much more frequently than others (Kruskall-Wallis = 46.84, P < 0.001) and some clinicians referred much more frequently (Kruskall-Wallis = 85.57, P < 0.001). This group of orthodontists did not refer post-orthodontic cases for third molar management and little consensus was observed regarding which cases did warrant removal.

Adolescent↗
PubMed2000

An evaluation of the stresses generated in a bonded orthodontic attachment by three different load cases using the Finite Element Method of stress analysis.

The objective of the investigation was to develop a clinically valid three-dimensional computer model of the orthodontic bracket-cement-tooth continuum, and determine the magnitude and distribution of stresses generated by three different load cases. A three-dimensional finite element model of the bracket-cement-tooth system was constructed consisting of 15,324 nodes and 2,971 finite elements. The stresses induced in the bracket-tooth interface by a masticatory load, a peel force and a twisting couple were recorded. The maximum principal stresses resulting from occlusal and 'twisting' forces are distributed toward the lute periphery. Peel forces, applied to the bracket tie wing, are concentrated beneath the bracket stem. Twisting forces result in the highest enamel stresses. The quality of orthodontic attachment can be explained by the magnitude and distribution of major principal stresses within the cement and impregnated bracket base. Shear and shear/peel forces are most likely to induce crack propagation within the adhesive layer. However, when a twisting action is used to remove orthodontic brackets, enamel failure is most likely. A clearer insight into the complexity of the bracket-cement-tooth system has been provided by numerical and finite element investigations. Further investigations, evaluating the influence of bracket base designs and orthodontic cement physical and geometric properties are indicated. Refereed Scientific Paper

Compressive Strength↗
PubMed2002

A randomized clinical trial to compare three methods of orthodontic space closure.

AIM: To compare the rates of orthodontic space closure for: Active ligatures, polyurethane powerchain (Rocky Mountain Orthodontics, RMO Europe, Parc d'Innovation, Rue Geiler de Kaysersberg, 67400 Illkirch-Graffenstaden, Strasbourg, France) and nickel titanium springs. SAMPLE: Patients entering the space closure phase of fixed orthodontic treatment attending six orthodontic providers. Twelve patients received active ligatures (48 quadrants), 10 patients received powerchain (40 quadrants) and 11 patients, nickel-titanium springs (44 quadrants). METHOD: Patients were randomly allocated for treatment with active ligatures, powerchain or nickel titanium springs. Upper and lower study models were collected at the start of space closure (T(o)) and 4 months later (T(1)). We recorded whether the patient wore Class II or Class III elastics. Space present in all four quadrants was measured, by a calibrated examiner, using Vernier callipers at T(o) and T(1.) The rate of space closure, in millimetres per month (4 weeks) and a 4-monthly rate, was then calculated. Examiner reliability was assessed at least 2 weeks later. RESULTS: Mean rates of space closure were 0.35 mm/month for active ligatures, 0.58 mm/month for powerchain, and 0.81 mm/month for NiTi springs. No statistically significant differences were found between any methods with the exception of NiTi springs showing more rapid space closure than active ligatures (P < 0.05). There was no effect of inter-arch elastics on rate of space closure. CONCLUSIONS: NiTi springs gave the most rapid rate of space closure and may be considered the treatment of choice. However, powerchain provides a cheaper treatment option that is as effective. The use of inter-arch elastics does not appear to influence rate of space closure.

Adolescent↗
PubMed1993

The effects of orthodontic tooth movement on the glycosaminoglycan components of gingival crevicular fluid.

In this study, gingival crevicular fluid (GCF) was collected from around a canine tooth, in children, before and during orthodontic tooth movement. The aim was to identify and quantify the glycosaminoglycan (GAG) components of GCF and relate them to tooth movement, gingival inflammation, plaque accumulation, pocket probing depth and GCF volume recorded at the site of sampling. GAG in GCF samples, collected for a 15-min period into microcapillary tubes, were separated electrophoretically, stained with Alcian blue and quantified using a laser densitometer. 2 GAG components of hyaluronic acid (HA) and chondroitin sulphate (CS) were identified. The increase in GCF volume during orthodontic tooth movement was only partly due to increased gingival inflammation. GAG levels varied with different types of orthodontic tooth movement. In GCF, levels of CS, in particular, may reflect the changes in the deeper periodontal tissues which could be monitored during orthodontic tooth movements.

Adolescent↗
PubMed1997

A validation study of three indexes of orthodontic treatment need in the United States.

The purpose of this study was to compare the reliability and validity of three occlusal indexes of orthodontic treatment need in predicting the opinion of treatment need of a panel of 18 orthodontists. A set of 160 study casts representing all types of malocclusion was used. The casts were scored with the following occlusal indexes: the Index of Orthodontic Treatment Need (IOTN), the Handicapping Labio-Lingual Deviations index (HLD), and the Handicapping Malocclusion Assessment Record (HMAR modified). The diagnostic accuracy or validity of each index was calculated using the mean opinion of the orthodontic raters as a "gold standard". Receiver Operating Characteristic curves were plotted for each index. The overall diagnostic accuracy, as determined by percent area under the curve, was similar for each index: IOTN 98.6%; HLD 96.1%; HMAR 96.6%. The score optimizing the sensitivity and specificity relationship for each index was as follows: IOTN (dental health component) 4; HLD 13; HMAR 12. These results indicate that the three occlusal indexes provided valuable information for determining orthodontic treatment need.

Esthetics, Dental↗
PubMed2005

Learner-control vs. program-control instructional multimedia: a comparison of two interactions when teaching principles of orthodontic appliances.

BACKGROUND: Many studies have compared computer assisted learning (CAL) to more traditional learning formats and have shown CAL to be as effective as or superior to the alternative resources. However, there are only scarce attempts to show which style of CAL leads to the best learning outcomes in orthodontics. AIM: To compare the effectiveness of a learner-control (group A) vs. program-control (group B) multimedia learning environment courseware packages regarding knowledge, understanding and transfer of content when applied to teaching principles of orthodontic appliances to undergraduate students. METHODS: Pre- and post-test assessments of undergraduate dental students (n = 30) who either studied a learner-control multimedia learning environment courseware package (n = 15) or a program-control version (n = 15) on equivalent material of the orthodontic appliances curriculum. Both groups were evaluated by means of multiple-choice questions covering knowledge, understanding and application. A one-way ANOVA was carried out in order to check for statistical difference between the two groups. The P-value was set at 0.05. RESULTS: There was no difference in prior knowledge between both groups at baseline. Although, both groups significantly improved their scores after having studied the course, no significant difference was found between both groups in relation to answers to questions about knowledge, understanding and application. CONCLUSIONS: In this study, the learner-control instructional multimedia program was found to be as effective as the program-control version when teaching principles of the orthodontic appliances to undergraduate students. The focus needs to be on improving the value of CAL. Comparative evaluations of how different CAL approaches compare with or complement one another are certainly needed.

Comprehension↗
PubMed1994

A study of forces originating from orthodontic appliances for splinting of teeth.

Management of dental trauma in children sometimes requires the use of a dental splint. This can be constructed with composite materials, kevlar, fiberglass, wire and composite or orthodontic wires and brackets. However, there have been no studies of the control of dental movement when orthodontic materials are used for a dental splint. The purpose of this study was to determine the forces exerted by an orthodontic appliance used as a dental splint. To measure such forces, a transducer with a detection of 0.01 N (+/- 5%) was inserted into a maxillary dental arch model. The results showed that the orthodontic wire was rarely passive and the forces developed ranged from 0 to 27 x 10(-2) N. The force developed was independent of the length of the dental splint (p < 0.05) and wire size (p < 0.05). The mean force developed by nickel-titanium wires (14.27 x 10(-2) N) was significantly greater (p < 0.05) than the mean force developed by stainless steel and cobalt-chromium wires. Moreover, the mean force developed by rectangular wires (12.07 x 10(-2) N) was significantly greater (p < 0.05) than the mean force developed by square and round wires. The results suggested that stainless steel or cobalt-chromium, square or round wires should be used for construction of a dental splint.

Analysis of Variance↗
PubMed2005

Localized sequential use of resilient lining to generate orthodontic force in thermoformed active removable appliances.

A new modality of orthodontic treatment based on the thermoformed appliance was developed and trialled clinically. A light-cured resilient lining material commonly used for denture relining was placed locally and sequentially in thermoformed appliances to generate orthodontic forces. The new method appeared to be effective. All the presented cases showed substantial improvement in dental alignment. A number of orthodontic movements were demonstrated. Localized use of resilient lining in thermoformed orthodontic appliances appeared to be a promising alternative to other thermoformed active removable appliance (TARA) treatments. Further studies are required to optimize the procedures and explore its full potential.

Acrylic Resins↗
PubMed1991

A study of adult orthodontic patients and their treatment.

This retrospective epidemiological study was undertaken to assess factors related to adult orthodontic treatment and to identify any associated trends. Case records of all patients (676) aged 18 years or over at the start of active orthodontic treatment at the Eastman Dental Hospital, London were examined. Variables associated with patients and their treatment (age, sex, source of referral, malocclusion, type of appliance, and interdisciplinary treatment including orthognathic surgery) were studied and the data analysed statistically. Findings revealed that the number of adult patients undergoing orthodontic treatment has increased significantly, especially since 1985. The age of the patients treated was also found to increase in recent years. The percentage of female patients (72 per cent) Class III malocclusions (21.6 per cent) and Class III skeletal bases (26.2 per cent) was higher than found in studies on children. Most of the treatments required fixed appliances and over half involved interdisciplinary treatment, with an increase in the percentage of orthognathic surgical cases. Surgery was significantly more common in males (P less than 0.01) and highly significantly associated with Class III malocclusions and skeletal III bases (P less than 0.001). Twenty-five per cent of adult patients were found to have had a previous course of orthodontic treatment though these patients were not significantly different from adult patients presenting for the first course of treatment.

Adolescent↗
PubMed2000

A survey of the delegation of orthodontic tasks and the training of chairside support staff in 22 European countries.

This paper reports on a survey which was undertaken to investigate the delegation of orthodontic tasks and the training of chairside support staff in Europe. Two questionnaires were posted to all members of the EURO-QUAL BIOMED II project together with an explanatory letter. The first dealt with the delegation of nine clinical tasks during orthodontic treatment. The second with the types of chairside assistant employed in each country and the training that they are given. Completed questionnaires, which were subsequently validated, were returned by orthodontists from 22 countries. They indicated that there was no delegation of clinical tasks in six of the 22 countries and delegation of all nine tasks in five countries. The most commonly delegated tasks were taking radiographs (in 14 of the 22 countries) and taking impressions (in 13 of the 22 countries). The least commonly delegated tasks were cementing bands (in five of the 22 countries) and trying on bands (in six of the 22 countries). Seven of the 22 countries provided chairside assistants with training in some clinical orthodontic tasks. Eighteen of the 22 countries provided general training for chairside assistants and offered a qualification for chairside assistants. Four of these 18 countries reported that they only employed qualified chairside assistants. Of the four countries which reported that they did not provide a qualification for chairside assistants, two indicated that they employed chairside assistants with no formal training and two that they did not employ chairside assistants. It was concluded that there were wide variations within Europe as far as the training and employment of chairside assistants, with or without formal qualifications, and in the delegation of clinical orthodontic tasks to auxiliaries was concerned.

Cementation↗
PubMed1992

[Numerical analysis of orthodontic treatment elements of pseudo-elastic NiTi alloys].

In orthodontic treatment malpositions of teeth are often corrected by fixed appliances, consisting, in part, of loops made by the orthodontist. The most important alloys in use are steel, cobalt-chromium, or titanium-molybdenium alloys. The static force systems of fixed appliances made of these materials are well known from experimental and numerical studies, but as they may change during tooth movement, we are often confronted with problems in therapy. The introduction of pseudoelastic nickel titanium alloys (NiTi) into orthodontic treatment, offers the chance of improving the effectiveness and reliability of orthodontic devices. In the present paper a plane finite element (FE) for the analysis of orthodontic loops is presented. It enables the determination of the nonlinear behaviour of pseudoelastic NiTi-alloys and is capable of simulating large structural displacements and rotations accompanied by moderate strains. A comparative numerical and experimental study shows the efficiency of this element. The associated results reflect pseudoelastic effects on certain loop designs, and reveal the benefits for the orthodontist and his patients.

Computer Simulation↗
PubMed2006

Enhancing the regenerative potential of guided tissue regeneration to treat an intrabony defect and adjacent ridge deformity by orthodontic extrusive force.

BACKGROUND: The biologic potential of the periodontal ligament (PDL) can be harnessed to solve complex clinical problems involving several dental disciplines. The purpose of this case report is to demonstrate that orthodontic extrusive force can enhance the regenerative potential of guided tissue regeneration (GTR) to eliminate an intrabony defect and augment a ridge deformity. METHODS: Regenerative therapy by open debridement with particulate anorganic cancellous bovine-derived bone xenograft (BDX), bioabsorbable membrane, and minocycline root conditioning was carried out. Eight weeks after the initial surgery, orthodontic extrusion and uprighting simultaneously were initiated. RESULTS: Radiographs and reentry documentation demonstrated that orthodontic extrusive force could enhance the regenerative potential of GTR. Consequently, the intrabony defect and alveolar ridge were successfully treated. CONCLUSION: This case report demonstrates that orthodontic-regenerative combined therapy can resolve complex clinical problems involving several dental disciplines.

Alveolar Ridge Augmentation↗