Active Appliance Research Articles

新生児敗血症に継発した幼児顎関節強直症の１例

We report on a 3-year-old child with unilateral temporomandibular joint (TMJ) ankylosis caused by neonatal sepsis. The operative procedure involved agressive resection of the ankylotic segment and contralateral coronoid with an immediate costchondral graft intervening with a temporalis myofascial flap. An activator appliance was used postoperatively to induce maxillary down ward growth. Satisfactory results were obtained at 1-year follow-up with respect to restoration of TMJ function and aesthetic improvement.

The Early Secondary Gingivoperiosteoplasty

The Early Secondary Gingivoperiosteoplasty

Orthopédie, stabilité, récidive

The stability of orthopedic treatments has been studied in many ways, but conclusions are very divergent. Usually, the methodology is not reproducible and unfavourable to compare the results. The structural analysis, described by Lautou, Dunglas and Vermelin, help to distinguish the skeletal from the dental effects, during treatments using activators. Clinical cases treated with activator appliances show that the relapse appears when the orthopedic response is poor and when the dento-alveolar compensations are strong.

Intermaxillary forces during activator treatment

The mode of action of the activator appliance is still unclear. Apart from a possible mandibular growth enhancing effect, some investigators believe that orthopedic forces may be applied to the maxilla, contributing to Class II correction by inhibition of maxillary growth. In addition, orthodontic forces may arise that produce dentoalveolar changes. The purpose of this study was to measure the magnitude of anteroposterior intermaxillary forces during wear of the activator appliance. Ten consecutive patients with Class II dental and skeletal relationships were treated with a modified activator appliance. The appliance had maxillary and mandibular segments that could be detached from each other during the measuring session. A force transducer was placed at the anterior part of the maxillary segment, and the anteroposterior force exerted by the mandibular segment was measured. Measurements were taken in the upright and reclined position at every patient visit for a period of 6 months. Results indicated that intermaxillary forces were generally in the orthodontic range (median values of 100 gf at the upright position and 123 gf at the reclined position). A wide variation in force levels was noted, both between patients and for the same patient during the experimental period. No statistically significant change in force levels was observed during the 6 month period and no difference was noted between upright and reclined posture. (Am J Orthod Dentofacial Orthop 1999;115:133-7)

Spontaneous lower arch changes with and without second molar extractions

This study describes the spontaneous changes that occurred in the lower arches of 41 children in whom orthodontic treatment was restricted to the upper arch only. In one group, lower second molars were extracted ( n = 18), whereas in the other, these teeth remained in situ ( n = 23). A two-phase treatment involved distal movement of the buccal segments with an “en masse” appliance and extraoral traction, followed by edgewise mechanics to retract or align the anterior teeth. Only study casts were examined. The occlusal aspects of the lower casts were recorded with the reflex microscope. Models were examined at the start of treatment, at the completion of buccal segment retraction, and when active appliance therapy was complete. The following arch measurements were recorded: intercanine and intermolar width, arch length and perimeter, and the degree of crowding in both the labial segment and the arch as a whole. In the extraction sample, upper buccal segment retraction was associated with increases in all lower arch dimensions and a reduction of crowding. In the nonextraction group, the response was inconsistent. Although arch length and perimeter reduced, intercanine and intermolar dimensions enlarged with minimal alteration in the labial segment crowding. During the second stage of therapy, dimensions generally decreased: arch length, perimeter, and the intercanine width returned to their pretreatment values in the extraction group and were further reduced in the nonextraction sample. However, both arch length and perimeter remained significantly longer in the extraction group. Intermolar width remained stable in both groups, whereas crowding increased. Over the 2-year observation period, arch length, arch perimeter, and crowding exhibited statistically significant differences in behavior between the two groups.(Am J Orthod Dentofacial Orthop 1998;113:133-43)

Use of activator appliances in pediatric patients treated with costochondral grafts for temporomandibular joint ankylosis: Analysis of 13 cases

Purpose: The long-term outcomes and clinical results of costochondral transplants used for the treatment of condylar ankylosis of the mandible in children with and without application of postoperative activator appliances are evaluated and compared. Materials and Methods: A nonrandomized, retrospective clinical study of 13 cases of condylar ankylosis (16 joints) of the mandible surgically treated during a 9year period from 1988 to 1997 was performed. All 13 patients were treated by condylectomy and immediate costochondral rib grafts. Nine of these patients underwent long-term postoperative therapy using removable activator appliances. Four patients did not undergo activator therapy postoperatively. Casts, radiographs, photographs, computed tomography (CT) scans, magnetic resonance imaging (MRI) and 99Tc bone scans were used postsurgically to evaluate graft take, condylar growth and function, occlusion, and facial and condylar symmetry. Results: The postoperative and long-term clinical results in both groups showed costochondral growth center transplants to be effective in restoring mandibular growth of the affected side. However, symmetry, arch coordination, correction of occlusal canting, mandibular deviation, facial growth, and prevention of reankylosis were obtained and better controlled only in those cases that underwent long-term orthodontic activator therapy postoperatively and were followed closely. Conclusions: Children with long-standing condylar ankylosis of the mandible and its resultant facial asymmetry and occlusal canting (secondary to a nonfunctional joint and maxillary compensation) treated with condylectomy and immediate costochondral rib graft reconstruction of the affected joint were treated more favorably when activators were used postsurgically. The patients that failed to comply with or continue activator therapy postsurgically developed complications relating to mandibular deviation, occlusal dysharmony, asymmetry and, in one case, reankylosis of the temporomandibular joint (TMJ).

Use of activator appliances in pediatric patients treated with costochondral grafts for temporomandibular joint ankylosis: Analysis of 13 cases

Use of activator appliances in pediatric patients treated with costochondral grafts for temporomandibular joint ankylosis: Analysis of 13 cases

Effectiveness of three different types of electric toothbrushes compared with a manual technique in orthodontic patients

Patients undergoing orthodontic treatment with fixed appliances are at risk of developing carious white spot lesions and gingival inflammation because of the challenge of oral hygiene. The purpose of this study was to evaluate under home conditions the effectiveness of three different types of electric toothbrushes during active appliance therapy: Interplak (Bausch & Lomb, Berlin, Germany), Rota-dent (Rota-dent, Kusnacht, Switzerland), and Braun Oral-B Plaque Remover (Braun/Oral-B, Kronberg, Germany). A manual technique, which included normal toothbrush, interdental brush, and dental floss, served as reference. The study was structured as a single-blind "Latin square design" study. Thirty-eight orthodontic patients were randomly allocated to groups who, within the test period, alternately used the toothbrushes. Before getting a new toothbrush that was to be used for a period of 4 weeks, each patient received video and written instructions. For another 4 weeks, the patient returned to the usual oral hygiene procedures before receiving the next new toothbrush. Oral hygiene was evaluated at the start of a new test period and after 2 and 4 weeks. Clinical scores included a modified O'Leary Plaque Index and Ainamo Gingival Bleeding Index. Wilcoxon rank testing for aggregated surfaces revealed statistically significantly lower plaque scores for Rota-dent than for the manual technique (p < 0.01). For all other toothbrushes, no differences were found in comparison to the manual technique. For Plaque Indices of specific sites, statistical analysis revealed all electric toothbrushes to be equal to the manual technique. No differences in Gingival Bleeding Indices were found after 4 weeks with either toothbrush. Patients with poor oral hygiene who used Rota-dent and Braun Oral-B Plaque Remover OD5 had statistically significantly lower plaque scores compared with the manual technique (p < 0.01; p < 0.05); for patients with good oral hygiene, these differences were neutralized. It may be concluded that electric toothbrushes of the new generation are a real alternative to the often laborious manual tooth cleaning procedures used during active appliance therapy. Patients with poor oral hygiene may benefit from them especially because plaque removal can be achieved easier and faster.

Long-term stability of Angle Class II, Division 1 malocclusions with successful occlusal results at end of active treatment

The purpose of this study was to examine long-term stability of Angle Class II, Division 1 malocclusions with successful occlusal results at the end of active appliance therapy, search for predictors of relapse, and look for characteristics associated with successful treatment. Records taken before and after treatment and a mean of 14.0 years postretention of adolescent patients treated for a significant Angle Class II, Division 1 malocclusion both with and without tooth extraction were evaluated. The sample was limited to successfully treated cases as judged by subjective evaluation of intercuspation and incisor occlusion of posttreatment study models and included 78 patients. Cephalometric characteristics or postretention occlusion was not considered in sample selection. The mode response was no change postretention for molar, premolar, and canine relationships and relapse of 0.5 mm for overjet and overbite. Maximum relapse was 3.5 mm for molar, premolar, and canine relationship, 3 mm for overjet, and 4.5 mm for overbite. Stepwise backward multiple regression analyses revealed no associations between either pretreatment characteristics or skeletal and dental treatment changes and relapse of overjet. However, relapse of overjet was associated with relapse of molar, premolar, and canine relationships, postretention increase in overbite, postretention proclination of maxillary incisors, and postretention retroclination of mandibular incisors. Active treatment changes included redirection or inhibition of maxillary growth and retraction of maxillary incisors. Mandibular incremental growth was favorable both during and after treatment. It was concluded that successful correction of Angle Class II, Division 1 malocclusions through differential growth adaptation and tooth movement appears to be very stable. (A M J O RTHOD D ENTOFAC O RTHOP 1995;107:276-85.)

Non-completion of active orthodontic treatment.

Over a 1-year period, all patients attending a consultant orthodontist's new patient clinics in North Derbyshire and whose treatment plans involved active appliance treatment, were accepted into a prospective longitudinal study. In all 294 patients were included in the study. Subsequent to the consultant's new patient clinic the patients' active treatments were undertaken in the Hospital, General, or Community Dental Services. Four years after the commencement of the study, 207 patients had completed active treatment and 50 had non-completed during active treatment. This gave an overall non-completion rate (NCR) of 19.5 per cent for the study. Of the 50 patients who did not complete treatment during active treatment 23 (46 per cent) non-completed during the first 6 months of active treatment. A predictive model of non-completion of active orthodontic treatment (NCT) over time is suggested.

Early orthodontic treatment

Interception by definition means stop, deflect, or interrupt the progress or intended course. The objective of interceptive orthodontic supervision is to create a more normal dentofacial environment as early as possible to prevent the adaptations and limitations that are often associated with a significant malocclusion in late adolescence. The question is not what can be treated early? but rather what shotdd be treated early? There are hidden pitfalls associated with interceptive treatment that may include long treatment times, maintenance of appliances, inability to accurately anticipate the changes associated with dentofacial growth and development, and the necessity to closely monitor treatment progress to avoid irreversible occlusal changes while evaluating the treatment response. The clinician must be prepared to evaluate and to alter the original plan of treatment if patient response is not coincident with treat ment objectives. Problem list and treatment plan development in the young patient is demanding as there are many variables to consider, many of which are difficult to predict or control. The clinician must have an understanding of the dentofacial changes associated with various growth patterns to identify the cause of the malocclusion, to determine treatment objectives and options, and to select the appropriate appliance to reach those objectives. One goal of early intervention should be the prevention of progressive, irreversible soft iissue or bony changes. In developing arch length deficiency malocclusions, for instance, serial extraction procedures, guidance of eruption, or active appliance therapy can be instituted early to create or to preserve arch length with' the objective of encouraging the dentition to erupt into a more ideal arch form. There is evidence, for instance, to suggest that teeth that erupt ectopically, out of attached gingival tissue, will exhibit long-term decreases in both attached tissue thickness and alveolar bone height when compared with normally erupting controls. Another example of a potentially progressive change is a functional mandibular deviation from rest

Analysis of activator treatment changes

Abstract The effects of functional appliance treatment have been reported in numerous studies in the literature with great variability in the findings. It is generally agreed that they can be used successfully to treat Class II malocclusions in growing and cooperative patients. However, there is a lack' of consensus regarding the relative orthodontic and orthopedic correction obtained by functional appliances in Class II correction. Lateral cephalometric radiographs from a sample (n=36) of patients who had undergone a phase of treatment with activator appliances were measured and analysed for changes using a modified version of the method described by Johnston (Hashim and Godfrey 1990). In this method, the treatment changes were broken down into: tooth movement relative to basal bone; and the translatory growth of the jaws, both with respect to the cranial base and to each other. The results show that the treatment effects were mainly dentoalveolar. There was a slight orthopedic effect on the maxilla, but no significant mandibular growth was observed, above that which can be expected from normal growth.

A cephalometric evaluation of anterior openbite correction with the magnetic active vertical corrector.

The purpose of this study was to evaluate treatment effects of the magnetic active vertical corrector appliance (AVC) when used to treat anterior openbites in a sample of growing patients. Twenty-five patients with a mean age of 10 years 8 months underwent AVC treatment for an average of almost 8 months. They had an average of 3 mm of anterior openbite closure during the treatment period, primarily due to maxillary and mandibular molar intrusion. Additional contributions to correction of the openbite were related to maxillary incisor eruption and lingual tipping combined with mandibular incisor lingual movement. A small amount of mandibular rotation with closure of the bite and decrease in anterior force height was observed. Anteroposterior skeletal change attributed to the AVC therapy was minimal.

The duration of orthodontic treatment with and without extractions: A pilot study of five selected practices

Contemporary orthodontic practice is diverse, both in the variety of clinical problems treated and in the methods used. Practices differ with respect to their patient composition as well as in many variables relative to treatment protocols. Such heterogeneity makes it difficult to make valid generalizations concerning the characteristics of orthodontic treatment procedures or outcomes; yet data and methods are required for assessment of issues of efficacy and utility. The frequency of orthodontic extractions is an objective criterion that distinguishes practices and may also be related to differences in treatment outcome variables, such as duration. Following a telephone survey to estimate extraction rates in the practices of 238 Michigan orthodontists, five practices with very high or low reported rates were chosen for this pilot study. Our primary aim was to determine whether a systematic relationship existed between the relative frequency of extraction treatments and the duration of active appliance therapy. Records of 438 patients from these practices were examined. The extraction rates of the practices ranged from a low of 25% to a high of 84%. Treatment duration was affected by several variables, such as the number of arches treated, the number of treatment phases, and the practice selected. When the data for all five practices were pooled, and all of the extraction versus nonextraction treatments were compared, the mean durations of treatment were 31.2 and 31.3 months, respectively. Data from individual practices, however, indicated that extraction treatment in each of the practices was of longer duration than nonextraction therapy. These differences in duration were 3.0, 6.6, 2.4, 3.0, and 7.3 months in the five practices.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of orthodontic treatment on periodontal bone support in patients with advanced loss of marginal periodontium

Loss of periodontal bone support was examined in 24 patients orthodontically treated for pathologic tooth migration in one jaw. Prior to orthodontic realignment of the front teeth, the patients had received periodontal treatment. Active appliance therapy was not given until inflammation was eliminated and the patients demonstrated a high level of oral hygiene. A 0.020-inch spiral wire was bonded to each adjacent realigned tooth for retention. The levels of marginal bone of the front teeth in the treated and untreated jaws were measured in percentage of “maximum bone height” on periapical radiographs made before and after treatment. Relpase was evaluated from study models. Mean averaged loss of periodontal bone from the period before to after orthodontic treatment was 4.94% (SD 4.03, P < 0.001) and 2.69% (SD 3.66, P < 0.001) of the treated and untreated front teeth, respectively. The mean difference in averaged loss between treated and untreated front teeth was 2.24% (SD 3.28, P < 0.01). The majority of the sites showed little or no loss. Maximum loss (35%) was observed in one site only. No association was found between initial bone loss and bone loss during orthodontic treatment. Spaces from 0.1 to 1.8 mm opened up adjacent to the retainer in seven patients. Relapse within the retained segment was associated with failures of the retainer. Of the 19 patients who had been in retention for more than 4 months (mean 16.0, SD 12.1), ten failures were recorded in nine patients. The failure mode was loosening of one or two teeth between wire and composite.

Maxillary control with functional appliances: some clinical observations

Abstract Accepting that the activator appliance can be used successfully to correct the occlusion by modifying the relationship of the dentitions and modifying growth characteristics of maxilla and mandible, what are the limitations of the appliance in the treatment of Class II division I cases? How can we overcome these limitations to avoid the undesirable sequelae? Clinical experience with the Classical European Activator leads to the conclusion that this appliance does not provide adequate control of the position of the maxilla, and of the maxillary dentition. Unfavourable mandibular rotation may be induced. Excessive display of upper incisors may be increased. Similarly anterior high pull headgear attached to fixed appliances may also produce undesirable rotation of maxillary structures, particularly in patients showing dolichofacial characteristics. A combination of these two treatment modalities has been developed by Dr. U. Teuscher of Zurich. This article in essence represents an analysis of clinical results in which the activator with anterior high pull headgear was used in patients chosen from the author’s practice. The aim is to help the clinician appreciate the far reaching potential of the Teuscher appliance. Because the objective of this article is motivational, references are provided that should enable the clinician to manufacture and use the appliance, and to integrate the concept into their overall management of our Class II division 1 cases.

Response to activator treatment in Class II malocclusions

A clinical study was designed to disclose the effects of activator treatment in the correction of Class II malocclusions. The rationale for the use of the activator appliance was based on the premise that correction of distocclusion can be achieved by (1) inhibition of forward growth of the maxilla, (2) Inhibition of mesial migration of maxillary teeth, (3) inhibition of maxillary alveolar height increase and extrusion of mandibular molars, (4) increased growth of the mandible, (5) anterior relocation of the glenoid fossa, (6) mesial movement of mandibular teeth, and (7) combinations of these effects. The appliance, as designed for this study, could potentially have an effect on all of these factors. Measurements were obtained from cephalometric head films obtained at 6 month intervals. Matched-pairs analyses of control versus treatment change after 6 months and after 1 year of treatment were done on 36 and 29 pairs, respectively. Pretreatment versus treatment changes were analyzed on 33 subjects by means of the spline regression analysis posttreatment versus treatment changes were analyzed on 18 subjects by means of the Student Newman-Keuls multiple comparison test. The matched-pairs analyses of mean values demonstrated significant reduction in forward growth of the maxilla; uprighting of the maxillary incisors, reduced overjet, leveling of the mandibular occlusal plane, improved molar relationship, downward and forward relocation of the glenoid fossae, increased advancement of all mandibular structures, increased face profile angle, and increased lower face height. The two longitudinal analyses yielded similar findings, but some differences were noted. Because rather severe dental malocclusions were corrected, the slight average inhibition of maxillary growth and the anterior relocation of glenoid fossae alone could not account for the correction of the Class II dental arch relationship. It was therefore concluded that, in addition to the statistically significant changes, smaller changes occurred in several areas without being consistent enough or of a large enough magnitude to become statistically significant in the analyses of mean values. Comparison of group averages may mask treatment effects that significantly contribute to the correction of malocclusions in individual cases.

An Investigation into Factors Which May Deter Patients from Undergoing Orthodontic Treatment

A survey of a sample of patients and their respective parents attending the Orthodontic Department at the Leeds Dental Hospital was undertaken to assess some of the socio-economic factors which may mitigate against the provision and successful completion of a course of active appliance therapy. It emphasizes that for many families an appreciable degree of inconvenience and cost is incurred and makes it essential that treatment needs are justified for each individual patient in order to reduce lack of co-operation.

Changes in length and torque of the masticatory muscles produced by the activator appliance: J. Ahlgren and M. BendeusSwed. Dent. J. Supp. 15, pp. 15–35, 1982

Changes in length and torque of the masticatory muscles produced by the activator appliance: J. Ahlgren and M. BendeusSwed. Dent. J. Supp. 15, pp. 15–35, 1982

Morphologic evidence of muscle influence on dental arch width

Tests on hypotheses to explain changes in arch width during correction of distoclusion with the activator appliance used in this study showed that statistically significant increases occurred in both maxillary and mandibular arch widths during treatment. The increase was substantially larger in the maxilla than in the mandible. The arch width showed no statistically significant decrease after completion of treatment. The activator designed for this study affected orofacial muscle balance. The findings suggest that there were changes in the influence of tongue and cheek muscles on the maxilla. Available experimental as well as clinical data support the assumption that the tongue had taken a higher and more anterior position in the palatal area and that the tension of the cheek muscles was reduced relative to the posterior part of the maxillary dental arch.