EARLY TREATMENT OF SKELETAL CLASS II BY FRÄNKEL FUNCTIONAL REGULATOR
In this case 7-year-old boy with severe distal bite caused by mandibular retrognathism was treated by Fränkel functional regulator type Ic. Aim: The aim of this paper was to show main skeletal and dental effects of Fränkel functional regulator type I in early treatment of skeletal distal bite. Appropriate timing for usage of functional appliance can successfully correct mandibular retrognathism and avoid later prolonged orthodontic treatment. Material and method: In this case boy in early mixed dentition with skeletal Class II was treated. Before treatment clinical examinations, study cast analysis, intraoral and extraoral photos, orthopantomogram and lateral cephalogram have been done. Active phase of treatment lasted 18 months. During this period patient wore an appliance continuously for 24 hours except during meals. An appliance was made on the basis of registered construction bite in position of posterior teeth in Class I. Patient activated screws in appliance once in 10 days. Lateral cephalogram, intraoral and extraoral photos have been done on the end of active phase of orthodontic treatment. Results and conclusion: Before treatment patient had severe Class II with deep bite and overjet of 11mm. Parameters on lateral cephalogram were: SNA 83°, SNB 77°, ANB 6°, Wits apprasial 9mm, SpP/MP 27°, FMA 21°, FMIA 59°, IMPA 100°, I/SpP 117°, Bjork 390°, Jarabak ratio 68%. After active phase of treatment patient had stable occlusion in Class I, reduced overbite and overjet of 3mm. At the end of the treatment measured parameters on the lateral cephalogram were: SNA 83°, SNB 79°, ANB 4°, Wits apprasial 0mm, SpP/MP 25°, FMA 20°, FMIA 59°, IMPA 101°, I/SpP 115°, Bjork 390°, Jarabak ratio 68%. Fränkel functional regulator is very successfull appliance for early treatment of skeletal distal bite, before pubertal growth spurt. This appliance causes skeletal and dentoalveolar changes and contributes to the correction of swallowing and speech.