CHANGES IN DENTAL ARCH DIMENSIONS BY USE OF AN ORTHOPEDIC CERVICAL HEADGEAR IN CLASS-II CORRECTION

Orthopedic cervical headgears are commonly used in Finland for early t reatment of the Class II malocclusion, but there is a lack of follow-u p studies on the effect of this treatment. We have evaluated the effec ts of the cervical headgear therapy with an expanded inner bow to trea t Class II malocclusion and dental arches. Forty children, 20 boys and 20 girls, with Class II, Division 1 malocclusion, were treated with t he orthopedic cervical headgear. No other appliances were used. The me an age of the subjects in the beginning of the treatment was 9.3+/-1.3 years (range 6.6 to 12.4 years). The mean treatment time was 1.8+/-0. 6 years (range 0.8 to 3.1 years). The cervical headgear was used with a 10 mm expanded inner bow and a 15 degrees upward bend of the long ou ter bow, 12 to 14 hours a day with a force of 500 gm per side. Class I relationships were achieved in all subjects. At the same time, the ma xillary and mandibular dental arches were widened. The annual incremen t in the intercanine and intermolar distances was significantly greate r than in healthy control subjects (literature data), except for the m andibular intercanine distance in boys. The maxillary arch lengths wer e also significantly increased; there were no consistent changes of th e mandibular arch lengths. Class II malocclusion may be treated with t he orthopedic cervical headgear. The treatment results in increased gr owth of the dental arch widths by expansion of the inner bow of the he adgear. The widening of the maxilla is followed by spontaneous widenin g of the mandible.