Activator-headgear Combination Research Articles

Treatment effects of the MARA appliance and Activator-Headgear combined with fixed appliances in Class II division 1 malocclusion patients: A retrospective longitudinal study.

Class II division 1 malocclusion treatment with functional devices offers acceptable results. These devices can be removable or fixed, and the essential difference between them is the need for compliance. It is clinically important to investigate if there are differences in the treatment effects of these devices that present different characteristics. This retrospective longitudinal study compared the treatment effects of Class II correction with the MARA appliance, Activator-Headgear (AcHg) combination, both followed by multibracket fixed appliances, and an untreated control group. Each experimental group was composed of 18 patients, with a baseline mean age of 11.70 and 10.88 years, treated for 3.60 and 3.17 years. The control group consisted of 20 subjects with baseline mean age of 11.07 years. The groups were evaluated before (T1) and after (T2) treatment. Lateral radiographs were used to evaluate the treatment changes with treatment (T2-T1), compared to the control group. Intergroup comparisons were performed using repeated-measures analysis of variance (ANOVA), followed by Tukey's test. The AcHg group showed significantly greater maxillary growth restriction than the MARA, while the mandibular changes were due to natural growth. Both devices promoted significantly greater maxillary incisors retrusion, mandibular incisors labial inclination, and improvement of overjet and molar relationships, compared to the control. Both functional devices followed by multibracket appliances were effective to correct Class II malocclusion. Nonetheless, the AcHg combination presents superior skeletal effects, due to significantly greater maxillary growth restriction compared to the MARA appliance. Moreover, the appliances presented similar dentoalveolar effects.

A severe skeletal Class II correction by activator headgear combination

A severe skeletal Class II correction by activator headgear combination

A severe skeletal Class II correction by activator headgear combination

Skeletal Class II malocclusion with mandibular deficiency and maxillary excess is a severe skeletal problem encountered in growing individuals. Correction of mandibular deficiency and maxillary excess in a skeletal Class II patient with a vertical growth pattern poses a great challenge. The control of vertical dimension becomes very important as downward and backward rotation of mandible will exaggerate the facial convexity. The present case signifies the importance of functional jaw orthopedic treatment in a vertically growing female patient with mandibular deficiency and maxillary vertical excess. Activator headgear combination was used for skeletal correction which was followed by fixed mechanotherapy. Superimposition of pretreatment and posttreatment cephalometric tracings shows desired treatment outcomes.

Jasper Jumper and activator-headgear combination: A comparative cephalometric study

Aim: The aim of this study was to evaluate and compare the skeletal and dentoalveolar effects of Jasper Jumper (JJ) and activator-headgear (AcHg) combinations and an untreated control group. Materials and Methods: The sample comprised 37 Class II high-angle patients. Twenty of them (mean age: 12.4 ± 0.61 years) were treated with JJ and 17 of them (mean age: 10.9 ± 0.74 years) were treated with AcHg. Mean treatment time was 5 months for the JJ group and 11 months for the AcHg group. Control group consisted of 20 Class II high angle patients (mean age: 10.4 ± 0.41 years) and mean observation period was 10 months. Results: Co-A showed significant increase in the JJ and control groups while SNA angle decreased significantly in only JJ group. Increase in SNB angle in AcHg group was significantly greater than in the JJ and control groups. In the JJ group, mandibular incisors protruded significantly. Conclusion: Both the AcHg and JJ treatments had restraining effect on maxillary growth, but stimulated significant mandibular growth. Anteroposterior discrepancy was corrected in the AcHg group mostly by the mandibular growth compared to JJ treatment. Maxillary incisors were retroclined in the AcHg group while mandibular incisors were proclined in the JJ group.

Skeletal class II correction by activator-headgear combination

Skeletal Class II malocclusion with mandibular deficiency is one of the most common skeletal problems encountered in growing individuals. Correction of mandibular deficiency in a skeletal Class II patient with a vertical growth pattern poses a great challenge. The control of vertical dimension becomes very important as downward and backward rotation of mandible will exaggerate the facial convexity. This case report describes the functional jaw orthopedic treatment of a vertically growing female with mandibular deficiency. Activator-headgear combination was used for skeletal correction which was followed by fixed mechanotherapy.

Dentoskeletal changes induced by the Jasper jumper and the activator-headgear combination appliances followed by fixed orthodontic treatment

The aim of this study was to compare the dentoskeletal changes of patients with Class II Division 1 malocclusion treated with either the Jasper jumper appliance or the activator-headgear combination, both associated with fixed appliances. The sample comprised 72 subjects with Class II Division 1 malocclusion divided into 3 groups: group 1 included 25 subjects treated with fixed appliances and the force modules of the Jasper jumper at an initial mean age of 12.72 years, group 2 included 25 subjects treated with the activator-headgear combination followed by fixed appliances at an initial mean age of 11.07 years, and group 3 included 22 untreated subjects at an initial mean age of 12.67 years. Initial cephalometric characteristics and dentoskeletal changes were compared with analysis of variance. Both experimental groups had similar dentoskeletal changes: restrictive effect on the maxilla, clockwise mandibular rotation and a slight increase in anterior face height, retrusion of the maxillary incisors, distalization of the maxillary molars, protrusion of the mandibular incisors, extrusion of the mandibular molars, and significant improvements of the maxillomandibular relationship, overjet, overbite, and the molar relationship. The effects of the Jasper jumper and the activator-headgear combination followed by fixed orthodontic appliances were similar in Class II malocclusion treatment.

A Retrospective Cephalometric Evaluation of Dental Changes with Activator and Activator Headgear Combination in the Treatment of Skeletal Class II Malocclusion

The aims of this study were to evaluate the dental changes brought about by activator and activator headgear combination (ACHG) and to determine whether we can achieve control over the lower incisor proclination which is a side effect of using functional appliances; or not, while treating cases of skeletal class II malocclusions. Lateral cephalograms of 45 skeletal class II division 1 patients were selected for the study. Fifteen of them were successfully treated with an Andresen activator and the other 15 with an activator headgear combination. Fifteen class II subjects who had declined treatment served as the control group. Cephalometric landmarks were marked by one author to avoid interobserver variability. The results revealed that both the activator and the activator headgear combination significantly (p < 0.001) affected dental variables measured. The mandibular incisor proclination was effectively controlled in the activator headgear combination group. An activator headgear combination would offer itself as a better option compared with activator alone in the treatment of skeletal class II malocclusions especially in cases with proclined mandibular incisors. When one of the treatment goals is to achieve a greater control over mandibular incisor proclination in the treatment of Skeletal Class II malocclusions, employing a combination of activator and headgear may substantially improve clinical outcomes.

Effects of activator and activator headgear treatment: comparison with untreated Class II subjects

The aims of this study were to determine whether the activator and activator headgear encourage mandibular growth, and whether there is any superiority of one appliance over the other or if the resultant changes are due to normal growth. Forty-nine skeletal Class II division 1 patients were selected. Thirty-three (13 females, 20 males; mean age 12.52 +/- 1.42 years) were treated with an Andresen activator and the remaining 16 (7 females, 9 males; mean age 13.04 +/- 1.47 years) with an activator headgear combination. Twenty Class II subjects (9 females, 11 males; mean age 12.57 +/- 1.11 years) who had previously refused treatment served as a control group. Cephalometric landmarks were marked and digitized by one author to avoid inter-observer variability. Nine angular and 12 linear measurements were established and measured using Vistadent AT software. A paired-sample t-test and an ANOVA test were used to statistically evaluate the findings. The results revealed that both the activator and the activator headgear combination significantly (P < 0.001) encouraged mandibular growth, but had little restraining effect on the maxilla. The mandibular incisors were more controlled in the activator headgear combination group. The resultant skeletal, dentoalveolar and soft tissue changes differed significantly from those due to growth.

Initial effects of treatment of Class II malocclusion with the Herren activator, activator-headgear combination, and Jasper Jumper

The initial effects of treatment of Class II, Division 1 malocclusion with an activator, according to Herren (27 patients), with an activator-headgear combination (20 patients), or with the Jasper Jumper appliance (25 patients) were studied on lateral cephalograms from before and after 6 to 8 months of treatment. The patients' ages ranged from 9 to 12 years. At the end of the period of observation, the correction in overjet and molar relationship was more complete in the patients with the Jasper Jumper than in the patients with the activator. Whereas all the patients with the Jasper Jumper showed neutral occlusion, this was the case in only 20 of the 47 patients with the activator. The correction of the distal occlusion occurred through a combination of skeletal and dentoalveolar adaptations. Skeletal changes accounted for 42%, 35%, and 48% of the overjet correction by the Herren-type activator, the headgear-activator, and the Jasper Jumper, respectively. The correction of the molar relationship occurred to 55%, 46%, and 38% by skeletal changes in the respective groups. Dentoalveolar compensation (distal movement of the upper molars, mesial movement of the lower molars) appeared to be inversely related to skeletal adaptation. The patients with the Jasper Jumper showed a marked intrusion of the lower incisors with a consequent reduction in overbite. (Am J Orthod Dentofac Orthop 1997;112:19-27.)

Orthodontic and orthopedic effects of Activator, Activator-HG combination, and Bass appliances: A comparative study

The orthodontic and orthopedic effects of the Activator, Activator-Headgear Combination (ACHG) and the Bass appliance systems were compared by analyzing the cephalometric records of 64 subjects, who were treated for skeletal Class II malocclusion, with both conventional and Pancherz's methods. Differences between observations on the different occasions (starting and ending values) were tested with Wilcoxon's matched pairs rank test. Kruskal-Wallis nonparametric analysis of variance was carried out in different situations among all three groups. If a level of significance less than 0.05 was observed, Scheffè's method of multiple comparisons was used to determine differences among groups. The results of this study showed that greater improvement in sagittal skeletal relationship (ANB angle) was obtained in both Bass and ACHG groups than in the Activator group. The differences between the groups were most pronounced for dental variables. The Bass appliance was found to be more effective in the control of the unwanted side effects (proclination of lower incisors, retroclination of upper incisors). Unfavorable labial tipping of the lower incisors was also prevented with the ACHG appliance. (Am J Orthod Dentofac Orthop 1996;110:36-45.)

A growth-related concept for skeletal Class II treatment

The use of a combined activator-high-pull headgear appliance for treatment of Class II, Division 1 malocclusion is presented as a preliminary report. The activator itself is equipped with a palatal bar, lower lip pads, and torque-control auxiliaries for the upper incisors. The face-bow is mounted directly on the activator, and the extraoral force vector is equivalent to that of an anterior high-pull vector. During bite registration the vertical displacement of the mandible is restricted to a minimum, and the anterior displacement should not exceed 6 mm. On the basis of current knowledge of the growth of the bony facial structures, treatment objectives and a specific approach for skeletal Class II correction are defined. Following these objectives, the therapy aims at correcting the malocclusion without diverting the anterior landmarks of the bony face from their specific lines of growth. This is brought about by the corresponding mechanics of the activator-headgear combination. The corrective effect of this appliance may be assumed to be the result of several different factors. The maxillary dentition is restrained in a posterior cranial direction, and an inhibitory effect on the maxilla counter to its line of development is attained. The mandibular dentition is influenced in an anterior downward direction by means of the bite registration, and the occlusion is unlocked during treatment. Any transfer of distally directed headgear forces from the maxilla to the mandible is prevented. Temporary stimulation of condylar growth, possibly combined with temporary posterior deflection of condylar growth, may also be induced. In this way it is possible to take maximum advantage of condylar growth in the sagittal dimension. Thus, not only is the malocclusion corrected but, at the same time, decisive profile improvement is achieved by anterior development of the mandible. From the experience gained so far with a Class II, Division 1 sample undergoing treatment with the activator-headgear combination, it would appear that skeletal control of the direction of facial growth during treatment is possible. A quantitative report on this group of approximately forty patients, some of whom are still receiving treatment, is in preparation.