February’s Tip

A Class II growing patient with a mandibular deficiency is presented. Treatment began on 8/07/85.  First, determine the mandibular growth direction of the patient. Growth pattern was Clockwise/Neutral.  The question then becomes whether to use a Bionator or a Twin Block appliance to advance the mandible.  The growth direction determines whether to make a neutral appliance, a bite opening appliance or a bite closing appliance. This case called for a neutral type Bionator.  

A Bionator does not depend upon teeth for retention. A Twin Block depends upon teeth for its retention.  Therefore, if the patient is from 6 to around 9 years of age a Bionator may be the appliance of choice. An older child with  more erupted permanent teeth may do better with a Twin Block. 

Please note this patient was originally a mouth breather and was treated with a Bionator for correction of the Class II.  

The Bionator was used for approximately 18 months to achieve a stable Class I molar relationship.  Next, upper and lower Schwarz appliances were used to gain expansion of the upper and lower arches.   

Next, full bracketing and banding was accomplished using the straight wire technique with a Ron Ross prescription. The case was completed on 2/21/91 and retention appliances fabricated.  Please note the patient’s eyes appear tired in the original photos and note the large diastema between his upper central incisors and the patient prefers to breathe through his mouth.

In his final photos he is no longer a mouth breather and instead is a nose breather. His eyes are now wide open and he appears much healthier.  The diastema closed naturally and a frenectomy was not needed.

Dr. Milton E. Pedrazzi DDS