Type Of Orthodontic Appliance Research Articles

Pharmacological interventions for pain relief during orthodontic treatment.

Pain is a common side effect of orthodontic treatment. It increases in proportion to the amount of force applied to the teeth, and the type of orthodontic appliance used can affect the intensity of the pain. Pain during orthodontic treatment has been shown to be the most common reason for people wanting to discontinue treatment, and has been ranked as the worst aspect of treatment. Although pharmacological methods of pain relief have been investigated, there remains some uncertainty among orthodontists about which painkillers are most suitable and whether pre-emptive analgesia is beneficial. We conducted this Cochrane Review to assess and summarize the international evidence relating to the effectiveness of analgesics for preventing this unwanted side effect associated with orthodontic treatment. The objectives of this review are to determine:- the effectiveness of drug interventions for pain relief during orthodontic treatment; and- whether there is a difference in the analgesic effect provided by different types, forms and doses of analgesia taken during orthodontic treatment. Cochrane Oral Health's Information Specialist searched the following databases: the Cochrane Oral Health Trials Register (to 19 June 2017), the Cochrane Central Register of Controlled Trials (CENTRAL;the Cochrane Library 2016, Issue 7), MEDLINE Ovid (1946 to 19 June 2017), Embase Ovid (1980 to 19 June 2017) and CINAHL EBSCO (Cumulative Index to Nursing and Allied Health Literature; 1937 to 19 June 2017). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched on the 19 June 2017 for ongoing studies. We placed no restrictions on language or date of publication when searching the electronic databases. We included randomized controlled trials (RCTs) relating to pain control during orthodontic treatment. Pain could be measured on a visual analogue scale (VAS), numerical rating scale (NRS) or categorical scale. Two review authors independently screened the search results, agreed the studies to be included and extracted information from the included studies regarding methods, participants, interventions, outcomes, harms and results. We planned to resolve any discrepancies or disagreements through discussion. We used the Cochrane 'Risk of bias' tool to assess the risk of bias in the studies. We identified 32 relevant RCTs, which included 3110 participants aged 9 to 34 years, 2348 of whom we were able to include in our analyses. Seventeen of the studies had more than two arms. We were able to use data from 12 trials in meta-analyses that compared analgesics versus control (no treatment or a placebo); nine that compared non-steroidal anti-inflammatories (NSAIDs) versus paracetamol; and two that compared pre-emptive versus post-treatment ibuprofen for pain control following orthodontic treatment. One study provided data for the comparison of NSAIDs versus local anaesthetic.We found moderate-quality evidence that analgesics effectively reduced pain following orthodontic treatment when compared to no treatment or a placebo at 2 hours (mean difference (MD) -11.66 mm on a 0 to 100 mm VAS, 95% confidence interval (CI) -16.15 to -7.17; 10 studies, 685 participants), 6 hours (MD -24.27 mm on a VAS, 95% CI -31.44 to -17.11; 9 studies, 535 participants) and 24 hours (MD -21.19 mm on a VAS, 95% CI -28.31 to -14.06; 12 studies, 1012 participants).We did not find any evidence of a difference in efficacy between NSAID and paracetamol at 2, 6 or 24 hours (at 24 hours: MD -0.51, 95% CI -8.93 to 7.92; 9 studies, 734 participants; low-quality evidence).Very low-quality evidence suggested pre-emptive ibuprofen gave better pain relief at 2 hours than ibuprofen taken post treatment (MD -11.30, 95% CI -16.27 to -6.33; one study, 41 participants), however, the difference was no longer significant at 6 or 24 hours.A single study of 48 participants compared topical NSAIDs versus local anaesthetic and showed no evidence of a difference in the effectiveness of the interventions (very low-quality evidence).Use of rescue analgesia was poorly reported. The very low-quality evidence did not show evidence of a difference between participants taking ibuprofen and participants taking paracetamol (relative risk (RR) 1.5, 95% CI 0.6 to 3.6). Nor did we find evidence of a difference between groups in likelihood of requiring rescue analgesia when ibuprofen was taken pre-emptively compared to after treatment (RR 0.8, 95% CI 0.3 to 1.9).Adverse effects were identified in one study, with one participant developing a rash that required treatment with antihistamines. This was provisionally diagnosed as a hypersensitivity to paracetamol. Analgesics are more effective at reducing pain following orthodontic treatment than placebo or no treatment. Low-quality evidence did not show a difference in effectiveness between systemic NSAIDs compared with paracetamol, or topical NSAIDs compared with local anaesthetic. More high-quality research is needed to investigate these comparisons, and to evaluate pre-emptive versus post-treatment administration of analgesics.

Speech and orthodontic appliances: a systematic literature review.

Various types of orthodontic appliances can lead to speech difficulties. However, speech difficulties caused by orthodontic appliances have not been sufficiently investigated by an evidence-based method. The aim of this study is to outline the scientific evidence and mechanism of the speech difficulties caused by orthodontic appliances. Randomized-controlled clinical trials (RCT), controlled clinical trials, and cohort studies focusing on the effect of orthodontic appliances on speech were included. A systematic search was conducted by an electronic search in PubMed, EMBASE, and the Cochrane Library databases, complemented by a manual search. The types of orthodontic appliances, the affected sounds, and duration period of the speech disturbances were extracted. The ROBINS-I tool was applied to evaluate the quality of non-randomized studies, and the bias of RCT was assessed based on the Cochrane Handbook for Systematic Reviews of Interventions. No meta-analyses could be performed due to the heterogeneity in the study designs and treatment modalities. Among 448 screened articles, 13 studies were included (n = 297 patients). Different types of orthodontic appliances such as fixed appliances, orthodontic retainers and palatal expanders could influence the clarity of speech. The /i/, /a/, and /e/ vowels as well as /s/, /z/, /l/, /t/, /d/, /r/, and /ʃ/ consonants could be distorted by appliances. Although most speech impairments could return to normal within weeks, speech distortion of the /s/ sound might last for more than 3 months. The low evidence level grading and heterogeneity were the two main limitations in this systematic review. Lingual fixed appliances, palatal expanders, and Hawley retainers have an evident influence on speech production. The /i/, /s/, /t/, and /d/ sounds are the primarily affected ones. The results of this systematic review should be interpreted with caution and more high-quality RCTs with larger sample sizes and longer follow-up periods are needed. The protocol for this systematic review (CRD42017056573) was registered in the International Prospective Register of Systematic Reviews (PROSPERO).

Practice and Attitude towards Orthodontic Services by Pedodontists and General Practitioners

Objective: The study aimed to evaluate the provision of orthodontic skills among general and pediatric dentists. Methods: The study included 344 subjects, who were given a questionnaire that included information like experience of practice, type of orthodontic appliances used, frequency of orthodontic patients treated yearly, etc. Mean scores of all the questions were calculated using student’s t test and one-way ANOVA test at p value <0.05. Results: In general, percentage of participants practicing orthodontics was 22.1%. It was observed that more number of pedodontists were involved in orthodontic treatment than general dentists. Removable appliances were frequently used for patients. The prevalence of practicing orthodontic treatment was mostly observed in more experienced practitioners. Conclusion: The frequency of providing orthodontic treatment was significantly higher amongst pediatric dentists. However, orthodontic courses should be made available for the dental practitioners for further excellence.

Changes on the Soft Tissues of the Oral Cavity during the Orthodontic Treatment Depending on the Type of Orthodontic Appliance

Introduction : Periodontal status and malocclusions are closely related. Retention places that enable for detention of food caused by various malocclusions, make selfcleaning and proper hygiene difficult and as such endanger the integrity of the soft tissues. Correctly applied orthodontic treatment has positive effects on periodontal tissues as it reduces the risk of damage and inflammations. One of the key factors for successful orthodontic therapy is adequate maintaining of the oral hygiene, which includes removal of dental plaque, the main cause of deterioration of the soft tissues of the oral cavity. Aim of the study: Establish the connection between changes in the soft tissues of the oral cavity and the type of used orthodontic appliance. Establish the time interval for appearance of changes on the soft tissues of the oral cavity. Patients and Methods: This research included 120 patients who were divided into three groups depending on the type of the orthodontic appliance used (mobile orthodontic appliance - active, mobile orthodontic appliances - functional and fixed orthodontic appliances). Examinations were performed three times: at the beginning of the treatment, after three months of therapy and after six months of therapy. In order to analyze the status of the soft tissues of the oral cavity and level of hygiene we used: Silness-Loe plaque index and Loe-Silness gingival index. Results: In patients divided by the type of orthodontic therapy, a statistically significant difference in the value of indexes after three and six months of wearing orthodontic appliances was found in patients who wore fixed orthodontic appliances. There was a difference in increased index values among this group when compared to subjects treated with mobile orthodontic appliances. Conclusion: During the orthodontic therapy, especially with fixed orthodontic appliances, patients must pay attention to adequate oral hygiene maintenance in order to avoid any unwanted changes on soft tissues of the oral cavity.

Orthodontically induced external apical root resorption in patients treated with fixed appliances vs removable aligners.

To determine whether orthodontic treatment with removable aligners vs fixed orthodontic appliances is associated with a different frequency of orthodontically induced external apical root resorption (OIEARR) when genetic, radiographic, and clinical factors are accounted for. Three hundred seventy-two orthodontic patients treated with removable aligners (Invisalign) or fixed appliances were genetically screened for interleukin 1B gene (IL1B) (rs1143634), interleukin 1 receptor antagonist gene (IL1RN) (rs419598), and osteopontin gene (SPP1) (rs9138/rs11730582). Twelve clinical variables, potentially associated with OIEARR, were also considered. Subjects were divided according to the presence of radiographically determined OIEARR (>2 mm). The association between OIEARR and appliance type, and radiographic, clinical and genetic factors, was assessed using backward stepwise conditional logistic regression. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported. Reliability of the methods was adequate. Clinical case complexity (American Board of Orthodontics [ABO] Discrepancy Index) (OR: 1.032; 95% CI: 1.005-1.061; P = .021) and extent of incisor apical displacement in the sagittal plane (OR: 1.478; 95% CI: 1.285-1.699; P = .001) were associated with an increased OIEARR risk. After adjusting for associations between clinical/radiographic/genetic factors, there were no statistically significant differences with respect to OIEARR or type of orthodontic appliance used, whether removable aligners or fixed appliances (OR: 1.662; 95% CI: 0.945-2.924; P = .078). Only subjects homozygous for the T allele of IL1RN (rs419598) were more prone to OIEARR during orthodontic treatment (OR: 3.121; CI: 1.93-5.03; P < .001). A similar OIEARR predisposition was identified using either removable aligners (Invisalign) or fixed appliances.

The Prevalence, Intensity and Extent of Oral Impacts on Daily Performances among the Patients Wearing Orthodontic Appliances

Objectives: To evaluate the frequency, severity and extent of Oral Impact on Daily Performances (OIDP) in the patients wearing orthodontic appliances in relation to type of orthodontic appliances and sex of patients.&#x0D; Materials and method: This was a descriptive cross sectional study with 287 participants by convenient sampling aged 10-25 years, undergoing orthodontic treatment at the department of Orthodontics &amp; Dentofacial Orthopedics of Dhaka Dental College &amp; Hospital. Face-to-face structured interviews and clinical examination were done to collect information about impacts on quality of life related to wearing orthodontic appliances, using the OIDP.&#x0D; Results: Two hundred and eighty seven patients (31% male and 69% female) undergoing orthodontic treatment participated in the study. The prevalence of condition-specific impacts related to wearing orthodontic appliances was 30.7%. Among adolescents with impacts related to wearing orthodontic appliances, 16.8% reported impacts of severe intensity and 90.5% reported impacts on only one daily performance, commonly eating or speaking or cleaning mouth. The prevalence and the extent, but not the intensity of condition-specific impacts differed by type of orthodontic appliance (P =.023* and .0426* respectively).&#x0D; Conclusion: Less than one third participants undergoing orthodontic treatment reported side effects, specific impacts on daily living, related to wearing orthodontic appliances. Such impacts were higher among patients wearing fixed type of orthodontic appliances than removable type. This information could help to inform patients about the frequency, intensity &amp; extent of sociodental impacts during the course of their treatment and thereby increase the treatment compliance.&#x0D; Ban J Orthod &amp; Dentofac Orthop, April 2016; Vol-6 (1-2), P.6-12

Impact of orthodontic appliances on the quality of craniofacial anatomical magnetic resonance imaging and real-time speech imaging.

The aim of this work was to investigate the effects of commonly used orthodontic appliances on the magnetic resonance (MR) image quality of the craniofacial region, with special interest in the soft palate and velopharyngeal wall using real-time speech imaging sequences and anatomical imaging of the temporomandibular joints (TMJ) and pituitaries. Common orthodontic appliances were studied on 1.5 T scanner using standard spin and gradient echo sequences (based on the American Society for Testing and Materials standard test method) and sequences previously applied for high-resolution anatomical and dynamic real-time imaging during speech. Images were evaluated for the presence and size of artefacts. Metallic orthodontic appliances had different effects on image quality. The most extensive individual effects were associated with the presence of stainless steel archwire, particularly if combined with stainless steel brackets and stainless steel molar bands. With those appliances, diagnostic quality of magnetic resonance imaging speech and palate images will be most likely severely degraded, or speech imaging and imaging of pituitaries and TMJ will be not possible. All non-metallic, non-metallic with Ni/Cr reinforcement or Ni/Ti alloys appliances were of little concern. The results in the study are only valid at 1.5 T and for the sequences and devices used and cannot necessarily be extrapolated to all sequences and devices. Furthermore, both geometry and size of some appliances are subject dependent, and consequently, the effects on the image quality can vary between subjects. Therefore, the results presented in this article should be treated as a guide when assessing the risks of image quality degradation rather than an absolute evaluation of possible artefacts. Appliances manufactured from stainless steel cause extensive artefacts, which may render image non-diagnostic. The presence and type of orthodontic appliances should be always included in the patient's screening, so the risks of artefacts can be assessed prior to imaging. Although the risks to patients with fixed orthodontic appliances at 1.5 T MR scanners are low, their secure attachment should be confirmed prior to the examination.

Les appareils orthodontiques invisibles et presque invisibles

Patient demand for invisible esthetic orthodontic appliances is steadily increasing. Two types of orthodontic appliances have a high rate of patient acceptance. The lingual technique has continually evolved by offering both prefabricated brackets or custom-made brackets. The various techniques have been improved over time, and the results are better than ever. Thermoplastic aligners are an alternative to lingual devices and their use is rapidly growing. Their specific properties make it easier to assess their indications and limitations. A review of the literature, the development of these systems and a presentation of some clinical examples of treated cases will help us to provide some of the basics for understanding each of these two types of appliances and to demonstrate the advantages and disadvantages of each system.

Self-ligating brackets and their impact on oral health-related quality of life in Chinese adolescence patients: a longitudinal prospective study.

Introduction. Although the associations between orthodontic and oral health-related quality of life (OHRQOL) have been explored, little research has been done to address the influence of brackets type on perceived OHRQOL. The aim of this study was to assess whether the levels of OHRQOL in Chinese adolescence patients were influenced by the type of brackets. Materials and Methods. One hundred fifty Chinese orthodontic adolescence patients completed the 14-item Oral Health Impact Profile (OHIP-14, Chinese version) at five distinct intervals: after insertion of the fixed appliance at 1 week (T1), 1 month (T2), 3 months (T3), and 6 months (T4); and after treatment (T5). Results. Patients with self-ligating brackets were associated with less pain and discomfort at any intervals compared with conventional brackets, but no significant difference of overall OHIP-14 scores could be found between two groups. Moreover, in both groups, overall scores at T1 and T2 were significantly higher than the scores at any other intervals in both groups. Conclusions. The type of orthodontic appliance did not affect oral health-related quality of life in Chinese adolescence patients.

Calcium, amylase, glucose, total protein concentrations, flow rate, pH and buffering capacity of saliva in patients undergoing orthodontic treatment with fixed appliances

OBJECTIVE: To evaluate qualitative and quantitative changes in the saliva of individuals undergoing orthodontic treatment with fixed appliances. METHODS: Salivary samples were collected from 50 individuals divided in two groups: Experimental Group - patients with fixed orthodontic appliances (n=25); and Control Group - subjects with no orthodontic appliances (n=25). Salivary flow rate, pH, buffering capacity, amylase activity, concentrations of total proteins, calcium and glucose were measured in all salivary samples. RESULTS: There was a reduction in salivary pH and buffering capacity and an increase in the concentration of calcium ions in the experimental group (p<0.05); there was also an increase in glucose, amylase and protein concentrations in the saliva of the Experimental Group, but the differences were insignificant. There was insignificant correlation between calcium ion concentration and salivary flow or between buffering capacity and salivary flow. CONCLUSION: The saliva of individuals with fixed orthodontic appliances had lower pH, buffering capacity and calcium concentration than that of individuals without any type of orthodontic appliance. These oral changes are enough to cause tooth demineralization. Patients with orthodontic appliances should adopt additional oral hygiene procedures.

Adult patients' adjustability to orthodontic appliances. Part I: a comparison between Labial, Lingual, and Invisalign

This prospective study examined the adult patient's perception of recovery after insertion of three types of orthodontic appliances: Buccal, Lingual and Invisalign. The sample consisted of sixty-eight adult patients (45 females and 23 males) who comprised three groups: 28 Buccal, 19 Lingual, and 21 Invisalign patients. After appliance insertion, patients completed a Health-Related Quality of Life questionnaire daily for the first week and again on day 14, in order to assess patients' perception of pain and analgesic consumption. In addition, four areas of dysfunction were assessed: oral dysfunction, eating disturbances, general activity parameters, and oral symptoms. Lingual appliance was associated with more severe pain and analgesic consumption, the greatest oral and general dysfunction, and the most difficult and longest recovery. The Invisalign patients complained of relatively high levels of pain in the first days after insertion; however this group was characterized by the lowest level of oral symptoms and by a similar level of general activity disturbances and oral dysfunction compared to the Buccal appliance. Many Lingual and some Buccal patients did not reach a full recovery from their eating difficulties by the end of the study period. The present study provides information to adult patients and clinicians assisting them in choosing the most appropriate treatment modality in relation to Health-Related Quality of Life parameters.

Prevalence of Banding and Bonding Molar Brackets in Orthognathic Surgery Cases

Orthodontic treatment in the orthognathic surgical patient commonly involves banding or bonding of erupted molars. Appliance displacement during surgery is a potentially serious complication. However, limited data exist about the prevalence of banding or bonding and the frequency of appliance failure in this patient population. The purpose of this study was to determine the prevalence of banding and bonding and appliance failure in a large cohort of patients undergoing orthognathic surgery at a single institution. All patients who underwent orthognathic surgery from 2004 to 2006 at Kaiser Permanente Oakland Medical Center were identified, and preoperative and postoperative radiographs were retrospectively reviewed. Study variables included age at time of surgery, gender, date and type of surgery, Angle classification of occlusion, type of orthodontic appliance (band or bond) on erupted molar teeth, and failure as detected from postoperative imaging. In the 1,003 patients there was a greater overall prevalence of molar bands (74.3%) than bonds (19.2%) with the vast majority (84.4%) of first molars and fewer (64.2%) second molars having banded appliances. The prevalence of bonded first and second molars was lowest in 2004 and highest in 2006. Appliance failure occurred in 19 patients (1.9%), most often involving maxillary second molars, and all were bonds. Of the 19 failed bonds, 2 were displaced into the mandibular osteotomy site and 1 was displaced into the posterior pharynx. The prevalence of bonded molars in surgical patients increased from 2004 to 2006. Appliance malfunction occurred most often in bonded maxillary second molars. Although rare, failure and displacement of bonded appliances may have significant consequences.

Medical Emergencies in a Dental Office: Inhalation and Ingestion of Orthodontic Objects

<h2>ABSTRACT</h2><h3>Background</h3> The authors reviewed the literature regarding inhalation and ingestion of orthodontic appliances and suggest ways to manage and prevent these events. <h3>Types of Studies Reviewed</h3> The authors conducted literature searches of free text and Medical Subject Headings terms by using PubMed and Embase databases and selected appropriate studies. They analyzed retrieved articles according to several parameters: inhalation or ingestion event, number of cases, patient's sex and age, type of orthodontic appliance, in-office event or out-of-office event, and medical treatment. <h3>Results</h3> The authors found a total of 2,279 articles in their preliminary search. Eighteen reports of 24 cases from this search met all of the search criteria (that is, clinical studies, case reports or reviews limited to English, Hebrew or Arabic on any form of aspiration or inhalation of orthodontic appliances). Most cases (67 percent) involved ingested objects, and of those cases, the majority (57 percent) occurred in female patients. Most cases (85 percent) occurred outside the orthodontist's office. Seventeen patients (71 percent) had been treated with a fixed orthodontic appliance. In 60 percent of cases, the maxilla was involved. With one exception, no severe complications were reported (only seven patients were examined in a hospital emergency department), and patients were discharged uneventfully from the orthodontic office or emergency department. <h3>Clinical Implications</h3> Orthodontists and team members should participate in medical emergency management courses that emphasize the use of guidelines in cases of inhalation or ingestion of orthodontic objects. Each orthodontist's office should develop written emergency protocols for out-of-office events and present them to patients and their parents at the start of treatment.

Clinical and microbiological findings at sites treated with orthodontic fixed appliances in adolescents

Fixed orthodontic appliances can alter the subgingival microbiota. Our aim was to compare the subgingival microbiota and clinical parameters in adolescent subjects at sites of teeth treated with orthodontic bands with margins at (OBM) or below the gingival margin (OBSM), or with brackets (OBR). Microbial samples were collected from 33 subjects (ages, 12-18 years) in treatment more than 6 months. The microbiota was assessed by the DNA-DNA checkerboard hybridization method. Bacterial samples were taken from 83 OBR,103 OBSM, and 54 OBM sites. Probing pocket depths differed by orthodontic type (P <0.001) with mean values of 2.9 mm (SD, 0.6) at OBSM sites, 2.5 mm (SD, 0.6) at OBM sites, and 2.3 mm (SD, 0.5) at OBR sites. Only Actinomyces israelii (P <0.001) and Actinomyces naeslundii (P <0.001) had higher levels at OBR sites, whereas Neisseria mucosa had higher levels at sites treated with OBSM or OBM (P <0.001). Aggregatibacter actinomycetemcomitans was found in 25% of sites independent of the appliance. Different types of orthodontic appliances cause minor differences in the subgingival microbiota (A israelii and A naeslundii) and higher levels at sites treated with orthodontic brackets. More sites with bleeding on probing and deeper pockets were found around orthodontic bands.

Impacts on Daily Performances Related to Wearing Orthodontic Appliances

To assess the prevalence, intensity, and extent of the impacts on daily performances related to wearing different types of orthodontic appliances. A total of 1657 students, 15 to 16 years old, were randomly selected from those attending all secondary schools in Bauru, São Paulo, Brazil. Only those wearing orthodontic appliances at the time of the survey were included. Face-to-face structured interviews were done to collect information about impacts on quality of life related to wearing orthodontic appliances, using the Oral Impact on Daily Performances (OIDP). Adolescents were also clinically examined to assess the type of orthodontic appliance they were wearing. Comparisons, by type of orthodontic appliance and covariables, were performed using nonparametric statistical tests. Three hundred fifty-seven adolescents (36.1% boys and 63.9% girls) undergoing orthodontic treatment participated in the study. The prevalence of condition-specific impacts related to wearing orthodontic appliances was 22.7%. Among adolescents with impacts related to wearing orthodontic appliances, 35.8% reported impacts of severe or very severe intensity and 90.1% reported impacts on only one daily performance, commonly eating or speaking. The prevalence, but not the intensity or the extent, of condition-specific impacts differed by type of orthodontic appliance (P = .001). One in four Brazilian adolescents undergoing orthodontic treatment reported side effects, specific impacts on daily living, related to wearing orthodontic appliances. Such impacts were higher among adolescents wearing fixed rather than removable or a combination of fixed and removable orthodontic appliances. This information could help to inform patients about the frequency and intensity of sociodental impacts during the course of their treatment.

The provision of orthodontic services by general dental practitioners. 2. Factors influencing variation in service provision.

Previous work has shown that variations exist amongst general dental practitioners in the volume and type of orthodontic services provided, the type of orthodontic appliances used, and the objectives of the orthodontic treatment. The aims of this survey were to identify practitioner characteristics that account for variations in the level of orthodontic services provided and which distinguish providers and non-providers of orthodontic services. Multiple regression analysis revealed that four practitioner characteristics explained 41 per cent of the variance in the number of orthodontic patients treated. Dentists who treated more orthodontic patients: 1) treated more general practice patients; 2) frequently used multiple sources to keep up to date in orthodontics; 3) perceived their patient base to contain more children; and 4) were likely to have attended a Truitt course. Eleven variables best distinguished providers from non-providers of orthodontic treatment; 1, 2 and 3 above had the highest correlation with the discriminant function. The Null Hypothesis that selected characteristics of dentists providing orthodontic services were no different from those of dentists not providing orthodontic services was rejected. The provision of orthodontic services was associated with a higher level of continuing orthodontic education as well as treating more general practice patients, especially children.

Resorption of permanent teeth.

The varying extent of permanent tooth resorption attributable to different types of orthodontic appliances is a continuing cause for concern. This paper reviews recent researches which contribute to an improved understanding of the origin and behaviour of osteoclasts; and considers the structure and behaviour of the periodontal ligament and its relationship to the cementum and bundle bone of the tooth socket. Permanent tooth resorption is identified as a normal phenomenon. A simple explanation is offered as to why under normal circumstances the bone of the tooth socket is more likely to be resorbed than the tooth itself. With this knowledge treatment procedures can be selected which will reduce tooth resorption risks to a minimum.

Clinical treatment with the Begg appliance

The standard procedures in the three stages commonly used in the Begg method have been illustrated step by step in a comprehensive series of intraoral photographs. Correction of overbite and overjet and the resolution of the anchorage problem have been described in detail, with due attention given to the fact that all necessary anchorage can be obtained entirely from within the dental arches. 4 However, the Begg technique is not a religion, nor is it a “snap” method to use in cases where every other method has failed. 9 Nonorthodontic factors, partly beyond the control of the operator, may also make it difficult to achieve stable, functionally adequate, and esthetically satisfying treatment results. 10 These precautions should be kept firmly in mind, since Begg treatment is a time-consuming procedure to start and work with, just as is true with other types of orthodontic appliances if failure is to be avoided. The frequent necessity of minor and sometimes even major deviations from the three standard stages of Begg treatment has also been stressed, but these stages should constantly be kept in mind and observed accurately if treatment results are to be satisfactory.

Reference charts for controlled extraoral force application to maxillary molars

A lthough headgear appliances were originally designed by Norman William Kingsley in 1892, half a century elapsed before orthodontists began to employ extraoral force extensively. 1 Kloehn’$ results with the cervical neckstrap actually provided the impetus to preserve extraoral traction from near obliteration. Subsequently, a va-riety of methods have been developed to employ extraoral force in conjunction with almost every type of orthodontic appliance. Yet extraoral force is primarily used for two purposes: (1) to correct dental arch relationships and (2) as anchorage to support teeth that would be displaced while other movements are being carried out. The most commonly used extraoral devices are the neckstrap for cervical pull and headcaps for straight pull and for higher pull. Force delivery to the teeth is usually accomplished by means of a face-bow attached to an intraoral bow which is inserted into buccal tubes on the maxillary molar ba.nds or by direct attachment of the headgear arms to hooks on the maxillary arch wire itself. Extraoral traction has many advantages when used properly, but it may produce unfavorable tooth movements and treatment results when basic biomechanical principles governing the direction of the applied force are disregarded. The most common adverse effects are extrusion and tipping of molar teeth. Furthermore, Schudy3 stressed that molar elongation must be avoided in persons with retrognathic facial profiles since extrusion of posterior teeth tends to rotate the mandible dorsally, thereby aggravating their facial disfigurement. Poulton* warned particularly against the indiscriminate use of the cervical neckstrap because it harbors a considerable vertical force component. Kuhn5 considered the control of posterior tooth eruption a major factor in attempts to modify or maintain lower face height. Whatever the merits of these concepts and critiques may be, an understand-

Modification of the fixed removable type of orthodontic appliance

Modification of the fixed removable type of orthodontic appliance