Type: Process Essays
Sample donated: Janet Nguyen
Last updated: October 2, 2019
Improvement in facialprofile is the most important factor considered by most patients seekingorthodontic treatment. Therefore,, the focus of orthodontic treatment should beto achieve pleasing facial profile and soft tissue characteristics rather thanjust cephalometric norms. As a clinician, it is critical to identify and locatethe structures at fault with the help of cephalometric analysis, which aremainly contributing to the development of Class II malocclusion. The firstsimple step is to identify whether it is dental or skeletal Class IImalocclusion. Dental class II malocclusion is caused by tooth migration, whichmay be confined to the entitre arch or a segment of the arch following amissing tooth or abnormally displaced teeth. Skeletal malocclusion could be asa result of prognathic maxilla and normal mandible, retrognathic mandible andnormal maxilla or a combination of both- prognathic maxilla and retrognathicmandible.
The treatment of choicefor retrognathic mandible in a growing patient is to enhance the mandibulargrowth using a varierty of functional appliances. With improved patient co-operation and increased daily wear, the Twin Blockdeveloped by Clark in 1982, has proved to be a popular and clinically successful appliance. Comparative studiesdone by Illing et al in 1998 and McNamara in 1999 demonstrated that Twin Blockappears to be the most effective in producing sagittal and vertical changescompared to Bass appliance, Bionator and Frankel. The sagittal and verticalchanges are achieved through mandibularskeletal and dentoalveolar changes in addition to normal growth of themandible.
Perioral muscles have arestraining effect on dental arches. Frankel’s appliance is a passive appliancethat works by holding the perioral muscles away from the dental arches,expanding capsule and allows for new functional adaptation of muscles. The mechanicaleffect of the appliance directed to the capsular matrix and not to teeth / alveolar process. Buccalshields and lip pads exert periosteal pull that bring about the desired dentalchanges. One of the drawbacksof Twin Block is the inability to bringabout observable soft tissue changes compared to Frankel.
Incorporation of the buccal shields and lip pads into amodified Twin Block appliance can bring about the desired skeletal and soft tissue changes.This paper demonstratesa modification of Twin Block appliance for treatment of Class II division 1malocclusion with constricted maxillary arch and hyperactive perioral muscles.