by v8.1m


Tiziano Baccetti, DDS, PhD
Assistant Profesor
Departmento of Orthodontics University of Florence Italy
Active member of Worlsd Federation of Orthodontics

51.)Twinblock /Bionator/Fränkel


The presentation will highlight the importance of the biology of the individual patient in treatment planning for Class II malocclusion . When stimulation of mandibular growth is the aim of Class II treatment , factors for a better and faster treatment can be identified .

The first factor is the level of skeletal maturity of the individual patient . Class II treatment by means of functional appliances (twin/block, Bionator, FR-2) is highly effective only when the peak in mandibular growth is included in the treatment period.

An improved version of the Cervical Vertebral Maturation method will be presented for the identification of the peak in growth . The new method is comprised of 5 stages and it allows for diagnosis on a single cephalogram.

The second factor for success is the individual morphology of the mandible in Class II patients undergoing functional jaw orthopedics . As an evolution of auxologic categories by Petrovic , anterior versus posterior growth rotation of the mandible can play a significant role in influencing treatment outcomes in terms of mandibular elongation . A simple method based on the measurement of the mandibular angle will be described to predict good responders to treatment of Class II malocclusion by means of functional appliances.

A rational treatment protocol for Class II malocclusions associated with mandibular retrusion includes rapid maxillary expansion and simulation of mandibular growth with functional/orthopedic devices . In facts, from a diagnostic point of view , a transverse deficiency of the maxilla of about 3 to 4 mm on average can be found in Class II patients.

The lecture will indicate optimal timing for both maxillary expansion and functional/orthopedic treatment of mandibular deficiency . The results apply not only to functional appliances , but also to distalizing appliances, headgears, Class II elastics, and orthopedics appliances such as the Herbst appliance.

The final part of the presentation will report the findings of a series of controlled longitudinal studies on the effects of the twin-block and Bionator appliances . Treatment with these functional appliances elongated the mandible of about 5 mm more than untreated controls when treatment is performed at the right time .The twin block is more efficient then the Bionator , because the effect is produced in half of the time (1 year versus 2 years ). Clinical management of the functional appliances will be described along.

Asociación Mexicana de ortopedia Maxilar, A.C.
9ª Reunión Anual AMOM. 24-28 de Noviembre del 2004.
Cancún, Quintana Roo. México.

AMOM 2015 © ® diseño web: