Removable Orthodontic Appliances Research Articles

Book reviews

Book reviewed in this article:EQUILIBRATION IN THE NATURAL AND RESTORED DENTITION, by Hyman Smukler.ENAMEL MICROABRASION, by Theodore P. Croll.CORE CURRICULUM FOR PROFESSIONAL EDUCATION IN PAIN, edited by Howard L. Fields.INFECTION CONTROL FOR THE DENTAL TEAM, by L.P. Samaranayake, Flemming Scheutz, and James A. Cottone.RESIN‐BONDED BRIDGES. A PRACTITIONER'S GUIDE, by W.M. Tay.GENERAL ANAESTHESIA AND SEDATION IN DENTISTRY, by CM. Hill and P.J. Morris.THE DESIGN, CONSTRUCTION AND USE OF REMOVABLE ORTHODONTIC APPLIANCES, by C. Philip Adams and W. John S. Kerr.RUBBER DAM IN CLINICAL PRACTICE, by James S. Reid, Paul D. Callis, and Colin J.W. Patterson.

Application of Super-elastic NiTi Alloy Wire for Use in Removable Orthodontic Appliances : Studies on Heat Treatment Condition

Application of Super-elastic NiTi Alloy Wire for Use in Removable Orthodontic Appliances : Studies on Heat Treatment Condition

Zur Frage der Wachstumsinduktion durch Kondylusrekonstruktion beim Kind

Six children, presenting hypoplasia, ankylosis or agenesis of the temporomandibular joint, underwent autologous reconstruction of the condyle. At the time of surgery, the patients were at an age for four to 14 years. Postoperative follow-ups continued the following one to three years, whereby removable orthodontic appliances were used. In all cases postoperative function varied from good to very good and was free of pain. Additionally, in three cases, signs of growth in the area of transplantation were successively achieved. One case showed excessive growth. Regarding these cases of condylar hypoplasia, the rationale for the indication of surgical treatment as well as postoperative orthodontic treatment are discussed.

Vorstellung eines Tragezeitmessers zur Abklärung wissenschaftlicher Fragestellungen in der Kieferorthopädie

A timing device for removable orthodontic appliances is described. The measurement system includes a quartz digital clock at the timer. A reed switch serves as a sensor and is activated by a magnetic device fastened directly or by an orthodontic band to a molar tooth. A changeover reedswitch prevents manipulation by the patient. As a timing device the system provides great accuracy. The high-speed capability of the device permits further scientific application: Installation of two timing devices in a single Bionator permits selective timing (e.g. biting contact during wear of the appliance).

Erwachsenenbehandlung mit Abnehmbaren Apparaturen? Ein Beitrag zur Kieferorthopädisch-Prothetischen Zusammenarbeit

Request of adults for orthodontic treatment increases. In that cases requirements to the practitioner are of many kinds, especially if in consequence of secondary changes after lost of teeth the patient is not able, as in the past to accept his irregularities of teeth in relation to masticatory, physiognomic and phonetic function. Absolutely there is willingness to wear also removable orthodontic appliances. Possibilities and advantages of plates for orthodontic-prosthetic problems are discussed and examples of treatment demonstrated.

Orthodontic treatment of the primary dentition

Five patients were treated for corrections of problems in the primary dentition. Anterior and posterior crossbite, deep overbite malocclusion, and overbite malocclusion were treated with simple removable orthodontic appliances. Early orthodontic treatment for these patients helped resolve any functional problems that could interfere with later growth and development, such as health and function of the TMJ complex.

Demineralization and remineralization around orthodontic appliances: An in vivo study

The presence of clinically detectable areas of decalcification (observable as whitened areas) following the removal of orthodontic appliances is well recognized. The aim of the present study was to determine quantitatively (1) the amount of demineralization and (2) the ability of commercially available products to inhibit or reverse orthodontically related demineralization. Twenty orthodontic patients scheduled to have premolars extracted were randomly divided into four groups-one control and three test groups. The extracted premolars (numbering 58) were bracketed using an acid-etch composite system; each patient was given precise oral hygiene instructions and supplied with a sodium fluoride (1,100 ppm fluoride) dentifrice and an orthodontic toothbrush. The control group brushed only with the supplied dentifrice. In addition to brushing with the dentifrice, those in test group I rinsed once each night with a sodium fluoride (0.05%) mouthrinse; group II received a weekly topical APF treatment (1.2% fluoride); and Group III received a weekly topical APF treatment and rinsed once each night with the sodium fluoride mouthrinse. All premolars were extracted after 1 calendar month. Mineral profiles were determined on cross-sectioned teeth 50 to 75 μm occlusal and cervical to the brackets, directly underneath the brackets, and 500 μm away from the brackets. The control teeth (dentifrice only) demonstrated up to 15% demineralization to a depth of 50 μm. All of the test teeth produced rehardening and/or inhibition of demineralization ( P < 0.01). Those in test group III showed a particularly hard outer layer. The study demonstrated that (1) measurable demineralization occurred around orthodontic appliances after only 1 month and (2) this demineralization can be completely inhibited and/or reversed by the use of commercially available fluoride products.

Candidal carriage and plaque distribution before, during and after removable orthodontic appliance therapy.

Candidal counts at 6 mucosal sites in 33 subjects were estimated by imprint culture before, during and after removable orthodontic appliance therapy. Additionally, dental plaque scores and salivary pH were measured at each stage. Whole mouth and site prevalence of candida rose significantly during therapy before falling to levels approximating initial values. A similar pattern was seen for candidal counts for the whole mouth and at individual mucosal sites, although post-treatment densities were usually lower than originally seen. The number of sites colonised by candida and salivary pH also increased significantly during treatment and fell significantly afterwards. Only the upper palatal plaque scores rose during therapy and most other dental sites showed a gradual decrease in value during the course of the study. This could be attributed to regular monitoring of the patient's oral hygiene procedures. This investigation demonstrated a direct relationship between the presence of an acrylic appliance, candida and low salivary pH levels. Furthermore, removable appliance therapy had a positive, though transient influence upon the prevalence and density of oral candidal carriage, suggesting that the appliance may initiate the carrier state.

The role of removable orthodontic appliances in the investigation and management of patients with hypernasal speech.

The hospital-based orthodontist is involved with the management of cleft palate patients. Removable orthodontic appliance therapy as an adjunct to speech problems is described and discussed. The literature is reviewed and the investigation and management of speech problems related to palate-pharyngeal incompetence and hypernasal speech is outlined.

Book reviews

SummaryBook reviews in this article: Orthopedic Gnathology By J. A. Hockel. Pathways of the Pulp Edited by S. Cohen and R. C. Burns Immunology of Oral Diseases By I. M. Roitt and T. Lehner. Removable orthodontic appliances By T. M. Graberand B. Neuman.

The development of removable appliances in the United Kingdom.

The evolution since 1900 of the removable orthodontic appliance is described. The effects upon this evolution of political and economic events, the introduction of new materials and the British approach to orthodontic treatment are discussed. Present opinion favours the increased use of fixed appliances but it seems likely that removable appliances will still be suitable in about half those cases requiring active treatment.

Proximal Caries Increment in Connection with Orthodontic Treatment with Removable Appliances

The progression of proximal caries on canines, premolars and molars has been studied among 129 children treated with removable orthodontic appliances. The registration of carious lesions was performed on posterior bitewing radiographs taken before and after the orthodontic treatment. The children in this investigation showed a higher proximal caries progression than children treated with fixed orthodontic appliances where bands had been used. However, in comparison with caries data from epidemiological investigations in children of similar ages from the same area no difference was noted.

A Preliminary Report into the Development and use of Soluble Controlled-release Glass Timing Discs Implanted into Orthodontic Appliances

An investigation is reported into the development and use of soluble controlled-release glass timing discs as a possible method of assessing patient co-operation in the wearing of removable orthodontic appliances.

The mechanics of buccal canine retraction springs for removable orthodontic appliances.

The force-displacement characteristics of three types of buccal-canine retraction spring to both horizontal (normal) and vertical displacements is derived from simple beam theory. The analyses are used to examine theoretically the effect of variations in the geometry of a given type of spring and also to compare the merits of three designs in terms of the force applied on activation, and their stability to vertical displacement. Experimental measurements on enlarged models of the force-displacement behaviour were in good agreement with the values predicted by the derived equations.

Forced eruption in restoring severely fractured teeth using removable orthodontic appliances

The literature documents the benefits of orthodontic extrusion of teeth and its supportive role in restorative dentistry. Forced eruption is often overlooked in treating teeth that are difficult to restore. A method is described utilizing a removable acrylic resin orthodontic appliance and a temporary stainless steel post and acrylic resin processed crown. The advantages and disadvantages of this treatment are presented, including the need to restore cosmetics.

Gingival response to removable orthodontic appliances

The gingival state of twenty-four young patients (mean age 9.4 years) wearing simple removable orthodontic appliances was assessed and followed at monthly intervals for 4 months. In nine of the patients intentional relief of the appliance was made in the upper right area. The plaque index levels were similar in both “relief” and “no-relief” groups and reached a similar score at 4 months. The gingival index was significantly higher in the “relief” group, and all five cases that showed gingival hyperplasia of the experimental area belonged to this group.

The effects of orthodontic treatment on periodontal tissues in patients with reduced periodontal support.

The effects of orthodontic treatment on periodontal tissues in patients with severely reduced periodontal support were studied. A prerequisite for tooth movement was a reduction of periodontal inflammation by regular scaling and a high standard of oral hygiene. Surgical elimination of deepened periodontal pockets was not performed before orthodontic tooth movement. 20 patients took part in the study. The reduction of maxillary overjet was performed with light forces by elastics from removable orthodontic appliances. Oral hygiene, gingival inflammation, pocket depth and the alveolar bone level were recorded before hygiene treatment and before and after orthodontic treatment. As a result of the hygiene treatment, the Plaque Index and Gingival Index scores were markedly reduced. The values for pocket depth showed no major change. When comparing mean values for proximal bone level measurements before and after orthodontic tooth movement no difference could be seen. The individual proximal bone level values remained unchanged for every second surface. The maximum deterioration in bone level, measured as a percentage of tooth length, during orthodontic treatment was 10% in 9 surfaces out of 142. Provided careful preorthodontic hygiene treatment of the existing advanced periodontal disease is given and the forces are kept within physiological limits, the results from this clinical study show that no increased progression of marginal periodontitis will occur due to orthodontic tooth movement.

Removable Orthodontic Appliances

One of the goals of this article has been to emphasize the limitation of removable appliances. It is also stressed that if the right preconditions are present, the removable appliance is a tool that should be used by a general dentist as well as by the orthodontist. Interceptive treatment carried out with removable appliances at the correct time may save the patient from a more complicated treatment at a later stage. Minor tooth movements can often facilitate the fabrication of a bridgework and should therefore be included in reconstruction. It has been pointed out that the construction and design of the appliance may be of crucial importance. A careful treatment plan and detailed description of the appliance should therefore precede treatment.

Reliable assessment of morphological changes resulting from orthodontic treatment

An investigation was carried out on pre-treatment, post-retention and follow-up casts of 200 patients treated with removable orthodontic appliances. Approximately half of the patients had dental extractions as part of their treatment. The evaluation of morphological features demonstrated a number of cases in which abnormal characteristics became apparent only at the post-retention and follow-up stage. These findings indicate the problem of defining relapse. To supplement the morphological assessment the efficiency of orthodontic treatment was also evaluated and the variations occurring during treatment and during the follow-up period became evident.

The orthodontic center of rotation of the maxillary central incisor

The cephalometric records of sixty-four Class II, Division 1 cases treated exclusively with removable orthodontic appliances have been used in a study of the manner in which maxillary central incisors tilt. The center of rotation was most frequently located in the middle third of the incisor root. The longer the time interval between the pre- and posttreatment cephalograms, the more apical was the rotation axis likely to be, an effect ascribed to growth changes in the maxilla. If the effects of growth are taken into account, it seems that the maxillary central incisor seldom, if ever, tilts about the apical third of its root when force levels customarily recommended for tipping movements are employed. The results suggest that the instantaneous and orthodontic centers of rotation are one and the same and support the view that the manner in which incisor teeth move in response to a single applied force depends principally on the physical properties of the tooth root, supporting bone, and periodontal membrane. An unexplained correlation was found between the rate of incisor movement measured at the cervical margin of the tooth and the level of the rotation center.