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At least 1,711 records · Page 95Linked to original sources
PubMed2005

Lingual orthodontics: history, misconceptions and clarification.

Many frank misconceptions still exist surrounding the efficacy and clinical nature of lingual orthodontics, which were first introduced over 25 years ago in Japan and the United States. Despite early difficulties in the development of the technique, it has become a valid clinical option for patients in many parts of the world. Specific problems, for example concerning patient comfort and biomechanics, have been systematically solved over time. Continuing modification of clinical methods significantly increases options for clinicians and patients, especially adults who may be reluctant to accept traditional labial orthodontic appliances.

Adult↗
PubMed2006

An audit of the laboratory service provided to the Health Service Executive Orthodontic Department, St James Hospital, Dublin.

PURPOSE OF THE STUDY: To evaluate the service purchased from contracted orthodontic laboratories used by HSE (SWA) regional orthodontic unit, St. James's Hospital, Dublin and identify deficiencies in the current service. MATERIALS AND METHODS: A data collection questionnaire was designed and distributed to the departmental orthodontists for a period of three months (October-December 2004). Gold standards, drawn up based on the authors' ideal requirements and published guidelines, were supplied to grade the work returned. RESULTS: During the study period 363 items of laboratory work were requested. 20% of the laboratory work arrived late and most of the delayed work was delayed for more than 24 hours. Most laboratory delays occurred with functional appliances, retainers and study models. Prior to fit, 20% of the appliances required adjustments for more than 30 seconds. 65% of laboratory work returned to the department met all of the gold standards. 10% of appliances were considered unsatisfactory. Functional appliances were most often ill fitting accounting for almost half of the unsatisfactory laboratory work. CONCLUSIONS: The majority of the laboratory work returned to the department met our gold standards and arrived on time. Forty six percent of the appliances required adjustments. Functional appliances required the most adjustments; one in five of all functional appliances ordered were considered unsatisfactory.

Dental Audit↗
PubMed1991

[Preprosthetic orthodontics: technical aspects of mechanotherapy].

This paper describes the rationale as well as some of the therapeutic tools which may be used during simple preprosthetic orthodontic movements. First a typical bracket is examined: the overall design, the base, the slot and the tie-wings. All those components allow mechanical force transmission from the archwire to the tooth in all three orders of movement. In the classic "edgewise" form of treatment, final placement of the teeth is determined by the bends incorporated into the archwire. Conversely, in the more recent "straight-wire" approach, the angulation of the slot relative to the bracket base provides for an optimal positioning of each individual tooth on the dental arch. Mesio-distal angulation of the roots being referred to as "tip" and bucco-lingual angulation as "torque". The bracket also allows bodily bucco-lingual tooth placement relative to the dental arch as a whole (in-out). Prior to a comprehensive treatment, brackets are placed on teeth according to a standard set of criteria. They must be located midway mesio-distally on the buccal aspect in accordance with the true anatomic longitudinal axis of the root. Its occluso-gingival position however can be slightly adjusted according to the individual needs of the case. In more limited situations, where only a few teeth are moved, those rules have to be adapted since the anchorage teeth are kept stable. Examples are presented which illustrate the key features of limited orthodontic movements. Archwires present themselves in various sections and alloys. The most commonly used metals are stainless steels and the more recently introduced nickel-titanium superelastic alloys.(ABSTRACT TRUNCATED AT 250 WORDS)

Dental Bonding↗
PubMed2006

Magnetic forces on orthodontic wires in high field magnetic resonance imaging (MRI) at 3 tesla.

BACKGROUND: In a previous investigation we reported on magnetic forces in the static magnetic field of a 1.5 Tesla MRI system. The aim of the present investigation was to assess forces on orthodontic wires in a high field strength MRI system at 3 Tesla. MATERIALS AND METHODS: Thirty-two different orthodontic wires (21 archwires, eight ligature wires and three retainer wires) were investigated in a 3 Tesla high field strength MRI system (Intera, Philips Medical Systems, Best, The Netherlands). Translational forces were measured by the deflection angle test (ASTM F2052-02), and rotational forces assessed on a 5-point qualitative scale. RESULTS AND CONCLUSION: Translational forces ranged between 43.5 mN and 136.1 mN for retainer wires and between 0.6 mN (Noninium) and 208.4 mN (Orthos Stainless Steel) for steel archwires. Translational forces were up to 53.8 times as high as gravitational forces for retainer wires and up to 54.5 times as high for steel archwires, associated with marked rotational forces for the most part. Archwires manufactured from nickel-titanium, titanium-molybdenum and cobalt-chromium and different ligature wires showed no or negligible forces in the magnetic field. Carefully ligated wires should not present a risk due to translational and rotational forces in the high field MRI system at 3 Tesla.

Alloys↗
PubMed2000

Lingual orthodontics (Part 3): Intraoral sandblasting and indirect bonding.

Bracket loss is a severe complication in the course of orthodontic treatment, especially when using lingual appliances. High adhesive strength between bracket and tooth is therefore an important requirement for the successful integration of lingual orthodontics into everyday practice. The present article examines the influence of intraoral sandblasting prior to etching on the adhesive strength of indirect bonding. The shear bond strength of 20 cylinders made of composite were measured 24 hours after these had been bonded onto the enamel of bovine teeth. The enamel was prepared by sandblasting (Microetcher, 50 microns Al2O3) for 3 seconds prior to bonding, followed by 30 seconds of enamel etching with 37% phosphoric acid. Twenty specimens were tested without sandblasting in the control group. The results show that intraoral sandblasting prior to etching can significantly (p < 0.001) increase the adhesive strength between enamel and bonding material. Thus intraoral sandblasting is an integral part of the indirect bonding record described in the second section of this article.

Acid Etching, Dental↗
PubMed1990

Factors associated with orthodontic patient compliance with intraoral elastic and headgear wear.

Factors related to compliance with the wearing of headgear and intraoral elastics were explored in a sample of 100 university clinic orthodontic patients. Data were gathered by means of a questionnaire that comprised items presumed to be associated with orthodontic compliance. These items were not patient characteristics, but variables of beliefs, attitudes, perceptions, and reasons thought to be associated with compliance. The 58 questions were reduced through alpha factor analysis and the imposition of a coefficient alpha restriction to 12 factors. These 12 factors were named according to the questions they comprised. To assess whether these factors were indeed related to compliance, correlation coefficients were calculated between the factor scores (independent variables) and the criterion of compliance with headgear and elastics (dependent variable). Compliance was rated on a three-point scale. Four factors were found to be weakly, though significantly, correlated with compliance. These factors were combinations of personality type, negative motives (pain, inconvenience, and dysfunction), and positive motives (general health awareness, specific dental knowledge, and personal oral embarrassment). The findings were compared with existing theories of patient behavior.

Cooperative Behavior↗
PubMed1991

The pain experience and psychological adjustment to orthodontic treatment of preadolescents, adolescents, and adults.

Age-related changes in psychological measurements of pain and well-being were studied in patients undergoing full fixed appliance orthodontic treatment. A longitudinal series of four questionnaires was used to obtain measurements of these factors after the separation phase of treatment, banding (2 to 7 days after separation), the first adjustment visit (3 to 4 weeks after placement of full fixed appliances), and the second adjustment visit (3-4 months after banding was completed). The results suggest an interaction between the phases of treatment and reported pain and psychological well-being and significant differences in the response profiles of the adolescent age group (14 to 17 years) compared to the preadolescent (11 to 13 years) and adult groups (18 years and older). These findings did not appear to be due simply to group differences in the use of analgesics, class of malocclusion, or type of full fixed appliance used. The profile comparisons indicated that the adolescent age group generally reported lower levels of psychological well-being and higher levels of pain during the phases of treatment examined. Consistent with these results was the finding that the adolescents differed from the preadolescents and adults in the quality of the pain experience reported during treatment. The results indicate an age difference in adjustment to fixed orthodontic therapy, which suggests that adolescents are more vulnerable to undesirable psychological effects of treatment.

Adolescent↗
PubMed2005

Evaluation of posttreatment changes in Class II Division 1 patients after nonextraction orthodontic treatment: cephalometric and model analysis.

BACKGROUND: The aim of this retrospective study was to evaluate changes in patients with Class II Division 1 malocclusions treated with cervical headgear and full fixed orthodontic appliances and without extractions. METHODS: Lateral cephalograms and dental casts of 18 patients were obtained at the beginning and the end of treatment and at the postretention period. Pretreatment records were taken at 11.9 +/- 2.6 years, and the mean treatment time was 2.8 +/- 1.2 years. All patients were asked to use maxillary and mandibular Hawley retainers for 1 year. The average postretention interval was 5.3 years. RESULTS: The assessment of cephalometric findings showed that maxillary growth was restricted; maxillary incisor inclination, overjet, and overbite were decreased; the mandibular incisors were proclined; and a slight mandibular posterior rotation occurred at the end of treatment. At the postretention period, the maxilla remained stable, the mandible moved anteriorly, and the overjet increased slightly (1.25 mm, P < .01). The dental cast changes indicated that both maxillary and mandibular irregularity index values decreased significantly during treatment but increased after 5 years. Mandibular intercanine width decreased 0.47 mm ( P < .01) during the postretention period. CONCLUSIONS: The redirection of maxillary growth remained stable in patients with Class II malocclusions treated with cervical headgear and fixed orthodontic appliances and without extractions, but treatment-induced mandibular rotations tended to return to their original patterns. Various dental changes occurred during the postretention period.

Cephalometry↗
PubMed1994

Evaluation of orthodontic treatment using the Dental Aesthetic Index.

This investigation evaluates dental esthetic differences of orthodontic patients before and after treatment. The orthodontic treatment provided for patients in this investigation involved the use of removable appliances in 85% of the cases, use of fixed appliances in 2% of the cases, and a combination of fixed and removable appliances in 13% of the cases. Records of patients treated at a dental school clinic between 1959 and 1984 were reviewed. Inclusion criteria for this study included complete patient records, and the presence of dental casts for estimation of the Dental Aesthetic Index (DAI). Of the 932 patients, 116 patient records were included. Fifty patients began treatment during the mixed dentition (age < or = 144 months), and 66 were treated during the permanent dentition (age > 144 months). Pretreatment DAI values and component factors were measured and compared with posttreatment values. The DAI scores improved significantly (p < or = 0.0001) in both age groups (paired t test; Bonferroni correction). However, 20% of the patients showed a worsening or no change in the DAI with treatment. In the mixed dentition group, maxillary anterior irregularities, diastema, and overjet showed statistically significant improvement after treatment (p < or = 0.0001). Patients in the permanent dentition showed statistically significant improvement in the crowding of lower incisors, maxillary anterior alignment, and overjet (p < or = 0.0001). Logistic regression analysis defined five statistically significant factors (p < or = 0.05) that could differentiate patients with successful and unsuccessful treatment outcomes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1997

Proximal alveolar bone level after orthodontic treatment with magnets, superelastic coils and straight-wire appliances.

Proximal alveolar bone level changes were radiographically determined in 20 subjects (mean age 14.3 years, SD 2.00) a short time after rapid orthodontic treatment with magnets and superelastic nickel-titanium coils succeeded by straight-wire appliances. The findings were compared with a matched control group of 20 individuals (mean age 14.3 years, SD 1.99) who had no history of orthodontic treatment. Proximal alveolar bone level changes were determined on bitewing radiographs as the distance between the cementoenamel junction (CEJ) and the alveolar bone crest (AC). The observation period was 2.7 years (SD 0.65) for the treatment group and 2.8 years (SD 0.65) for the control group. In the treatment group, a small mean increase of 0.2 mm (SD 0.29) in the CEJ-AC distance was found a short time after treatment. In the control group the increase in CEJ-AC distance was 0.1 mm. The difference between the groups was significant (P < 0.001). In the treatment group, sites in the maxilla showed significantly greater CEJ-AC distances than in the mandible (P < 0.001), 0.3 mm (SD 0.33) versus 0.1 mm (SD 0.24). The mesial sites of the maxillary first molars in the treatment group showed the highest average increase in distance between CEJ and AC, mean 0.5 mm (SD 0.33). Neither group had any sites with bone loss, i.e., CEJ-AC distance exceeding 2 mm. No significant difference was found in CEJ-AC distance between teeth moved with magnets succeeded by straight-wire appliances and teeth moved with superelastic coils succeeded by straight-wire appliances.

Adolescent↗
PubMed2004

Vertical forces in labial and lingual orthodontics applied on maxillary incisors--a theoretical approach.

Theoretical and experimental biomechanical analyses explain most labial orthodontics (LaO); however, lingual orthodontic (LiO) biomechanical principles are rarely introduced. The objective of this study was to apply basic biomechanical considerations in understanding the influence of maxillary incisor inclination and to compare the effect of labial vs lingual intrusive/extrusive forces on tooth movement. Basic anatomic and geometric hypotheses were assumed, ie, tooth length (crown and root), location of the center of resistance, and crown thickness. Incisor inclination as related to a perpendicular line to the occlusal plane (OP) varied between -35 degrees (retroclination) and 45 degrees (proclination). A 0 degrees inclination was defined as a tooth position with its long axis perpendicular to the OP. The buccolingual moment for characterizing root movement was calculated for an applied force perpendicular to the OP. The results showed that when using LaO, an extrusion force resulted in labial root movement from a retroclination of 20 degrees up to a proclination of 45 degrees. In LiO, labial root movement occurred only when the tooth was proclined more than 20 degrees. In all other tooth inclinations, lingual root movement occurred. The opposite tooth movement occurred when an intrusive force was applied. Application of a vertical force has different clinical effects on tooth movement with labial and lingual appliances. Application of a lingual force is more complicated, and its effect on tooth movement depends on bracket position and initial tooth inclination.

Alveolar Bone Loss↗
PubMed2006

Galvanic corrosion behavior of orthodontic archwire alloys coupled to bracket alloys.

The purpose of this study was to provide a quantitative assessment of galvanic corrosion behavior of orthodontic archwire alloys coupled to orthodontic bracket alloys in 0.9% NaCl solution and to study the effect of surface area ratios. Two common bracket alloys, stainless steels and titanium, and four common wire alloys, nickel-titanium (NiTi) alloy, beta-titanium (beta-Ti) alloy, stainless steel, and cobalt-chromium-nickel alloy, were used. Three different area ratios, 1:1, 1:2.35, and 1:3.64, were used; two of them assumed that the multibracket appliances consists of 14 brackets and 0.016 inch of round archwire or 0.016 x 0.022 inch of rectangular archwire. The galvanic current was measured for 3 successive days using zero-impedance ammeter. When the NiTi alloy was coupled with Ti (1:1, 1:2.35, and 1:3.64 of the surface area ratio) or beta-Ti alloy was coupled with Ti (1:2.35 and 1:3.64 of the surface area ratio), Ti initially was the anode and corroded. However, the polarity reversed in 1 hour, resulting in corrosion of the NiTi or beta-Ti. The NiTi alloy coupled with SUS 304 or Ti exhibited a relatively large galvanic current density even after 72 hours. It is suggested that coupling SUS 304-NiTi and Ti-NiTi may remarkably accelerate the corrosion of NiTi alloy, which serves as the anode. The different anode-cathode area ratios used in this study had little effect on galvanic corrosion behavior.

Chromium Alloys↗
PubMed2001

Incorporating retained deciduous teeth in orthodontic therapy.

While patients with hypodontia of the permanent dentition constitute a relatively small portion of the general population, a significant percentage of these patients will require orthodontic therapy. This is a case report in which the family opted to maintain the retained deciduous teeth rather than seek combined orthodontic-prosthodontic treatment.

Activator Appliances↗
PubMed1998

Functional occlusion after fixed appliance orthodontic treatment: a UK three-centre study.

This study aimed to assess the prevalence of functional occlusal contacts in cases treated to a Class I incisor relationship by upper and lower fixed appliance therapy. Helkimo's dysfunction indices were used by one examiner to assess mandibular mobility, clinical dysfunction and occlusal status. One-hundred-and-eighty-eight subjects participated in three UK orthodontic centres; Cardiff, Newport and Liverpool. The results show that RCP (CR)-ICP (CO) discrepancies occurred in 33 (18 per cent) cases, non-working side contacts were present in 31 per cent and posterior contacts on protrusion occurred in 44 (23 per cent) subjects. These interferences were significantly more frequent in cases treated by postgraduate students compared with those treated by staff clinicians (P < 0.05). An overbite greater than 2.4 mm resulted in a highly significant reduction in the occurrence of non-working side contacts and posterior protrusive contacts (P < 0.001). The prevalence of functional occlusal discrepancies in this UK sample of orthodontic cases is similar to that reported in the American literature.

Adolescent↗
PubMed2000

Safe orthodontic bonding for children with disabilities during general anaesthesia.

General anaesthesia (GA) may be employed to overcome management difficulties in the orthodontic treatment of disabled children. This report introduces the application of a rubber dam as a useful aid for a high quality bonding and as an effective safeguard in bonding of brackets in general anaesthesia, in the handicapped in particular. GA was used in 12 patients, of a cohort of 49 disabled patients, to facilitate the placing of the fixed appliance. The first seven were bonded solely with the use of an oropharyngeal pack and a high velocity suction to prevent aspiration, and the last five additionally underwent placement of a rubber dam. The use of a rubber dam to facilitate the safe and reliable bonding of orthodontic brackets in handicapped children under general anaesthesia is highly recommended.

Adolescent↗
PubMed1999

A medico-legal review of some current UK guidelines in orthodontics: a personal view.

This article is a critical analysis from a medico-legal perspective of some current authoritative UK clinical guidelines in orthodontics. Two clinical guidelines have been produced by the Royal College of Surgeons of England and four by the British Orthodontic Society. Each guideline is published with the analysis immediately following it. Following recent UK case law (Bolitho v City & Hackney Health Authority, 1997) which allows the courts to choose between two bodies of responsible expert medical opinion where they feel one opinion is not 'logical', it is likely that the UK courts will increasingly turn to authoritative clinical guidelines to assist them in judging whether or not an appropriate standard of care has been achieved in medical negligence cases. It is thus important for clinicians to be aware of the recommendations of such guidelines, and if these are not followed the reasons should be discussed with the patient and recorded in the clinical case notes. This article attempts to highlight aspects of the guidelines that have medico-legal implications.

Adolescent↗
PubMed2006

Effects of low-level laser therapy on the rate of orthodontic tooth movement.

OBJECTIVES: To test the hypothesis that mechanical forces combined with low-level laser therapy stimulate the rate of orthodontic tooth movement. STUDY DESIGN: This study was a double blind, randomized placebo/control matched pairs clinical trial to test the efficacy of GaAlAs low-level laser therapy (LLLT) on 12 young adult patients who required retraction of maxillary canines into first premolar extraction spaces using tension coil springs with fixed edgewise appliance. LLLT was applied on the mucosa buccally, distally and palatally to the canine on the test side and using a pseudo-application on the placebo side. Dental impressions and casts were made at the commencement of the trial and at the end of the first, second and third months after starting the trial. Measurement of tooth movements was made on each stage model using a stereo microscope. RESULTS: There was no significant difference of means of the canine distal movement between the LLLT side and the placebo side for any time periods (p-value = 0.77). CONCLUSION: The energy density of LLLT (GaAlAs) at the surface level in this study (25 J/cm(2)) was probably too low to express either stimulatory effect or inhibitory effect on the rate of orthodontic tooth movement.

Adult↗