Original Article
Growth and treatment changes in patients treated with a headgear-activator appliance*,**,*,**

https://doi.org/10.1067/mod.2002.122177Get rights and content

Abstract

The aim of this study was to investigate growth and treatment changes in patients with Class II Division 1 malocclusion treated with a combined headgear-activator appliance. The sample consisted of 20 consecutive male patients treated with headgear-activator. Their compliance was checked after 2 months of treatment, and 3 patients dropped out. Lateral cephalograms, obtained 6 months before treatment, at the start of treatment, after 6 and 12 months of treatment, and 24 months after treatment, were analyzed by the method of Pancherz. The results disclosed that during growth, on average, overjet, molar relationship, and jaw-base relationship improved, and the mandibular incisors became retruded; the changes were statistically significant over a 2-year period. There was no significant change in the overbite. During the 12 months of treatment, there was no maxillary forward growth, and the jaw relationship improved (P <.001) because of forward growth of the mandible (P <.001). The molar relationship and the overbite improved (P <.001). Significant treatment effects included reduction in overjet (P <.001) and overbite (P <.01), and improvement of jaw-base (P <.05) and molar (P <.001) relationships. There was significant restraint of maxillary forward growth (P <.05). The eruption of the maxillary incisors and molars was restrained (P <.05). The average basic growth pattern in Class II Division 1 malocclusion resulted in small favorable changes in overjet, molar relationship, and jaw-base relationship. The main effect of the headgear-activator appliance was a favorable dental change, limited to restraint of maxillary forward growth but not affecting the vertical dimension. (Am J Orthod Dentofacial Orthop 2002;121:376-84)

Section snippets

Material and methods

The primary sample comprised 20 consecutive white male patients with skeletal Class II malocclusion and increased overjet who were treated with the headgear-activator appliance devised by van Beek.15, 16 The selection criteria were mixed dentition, fair shape of the dental arches, mild-to-moderate skeletal Class II (ANB 4.5° ≤ 8°), mandibular plane angle (NSL/ML > 39.0°), no previous orthodontic treatment, and acceptable cooperation (evaluated after 2 months). The initial average overjet and

Results

Table IV shows the changes due to growth during the 12-month treatment period (T1-T3). Both overjet (not significant [NS]) and molar relationship (P <.05) improved. The maxilla grew forward by 1.3 mm (P <.05) and the mandible by 2.2 mm (P <.01), resulting in a significant improvement of the jaw-base relationship (P <.05). The dental changes, with the exception of uprighting the mandibular incisors by 0.7 mm (P <.05), were insignificant. Mandibular length increased by 2.5 mm (P <.001). The

Discussion

In the present study, consecutive young males with skeletal Class II malocclusions were treated with a simple headgear-activator removable appliance15, 16 by 1 operator (M.B.). The compliance rate (85%) was near that of earlier studies for similar appliances.18, 23 The cephalometric characteristics of our sample were similar to a reference sample of Class II Division 1 subjects,21, 22 except for a tendency for larger lower facial height in our sample (Table III). The study included only

Conclusions

It was concluded that:

  • 1.

    On average, there were small, favorable, normal, skeletal growth changes in subjects with Class II Division 1 malocclusion.

  • 2.

    The skeletal effect of the headgear-activator appliance was primarily limited to restraint of forward maxillary growth.

  • 3.

    There was a modest enhancement of mandibular growth during the initial phase of treatment only.

  • 4.

    The vertical dental effect of the headgear-activator appliance was to restrain the eruption of the maxillary molars and incisors; the

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      Citation Excerpt :

      When comparing the 3 groups regarding treatment and growth changes, there was a similar restriction of maxillary forward displacement in both experimental groups (Table VII). These results agree with previous studies that also found significant restrictions of maxillary growth during Jasper jumper35-39 and activator-headgear combination therapies.21,28,40-43 Since these 2 modalities of orthopedic appliances were used to stimulate and redirect mandibular growth, when we compared changes in the mandibular components (SNB and Co-Gn), there were no significant differences between the experimental groups and the control group (Table VII).

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    *

    aAssistant professor.

    **

    bChair professor.

    *

    cAssociate professor.

    **

    Reprint requests to: Dr Margareta Bendeus, Orthodontics, Faculty of Dentistry, The University of Hong Kong, 34 Hospital Road, Hong Kong, SAR China; e-mail, [email protected].

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