Orthodontic Faculty Development Fellowship Award Synopsis

Sean Shih-Yao Liu
Indiana University

Department of Orthodontics and Oral Facial Genetics at Indiana University School of Dentistry. I also serve as the Director of the Mineralized Tissue and Histology Research Laboratory. The objective of my awarded project titled "A novel 3D superimposing technology to evaluate mandibular growth" is to establish a valid method of evaluating condylar growth, and based on this new technology to collect clinical preliminary data comparing the traditional Herbst appliance and the new mandibular anterior reposition appliance (MARA). The central hypothesis of the application is that the MARA guides greater mandibular advancement and condylar growth with lesser dental movement, compared to the Herbst appliance. The rationale for the proposed research is that, if mandibular deficiency is not corrected in the growing stage, patients will face greater difficulty in treatment with limited treatment options, such as surgery or camouflaged orthodontic treatment with tooth extraction, in their late adolescence or adulthood. Such options lead to higher invasiveness and medical expense. Based on our supportive preliminary data, this hypothesis will be tested by pursuing two specific aims:  1) Establish a means to measuring 3D morphological changes of the condyle; 2) Obtain pilot data for developing a larger study comparing treatment effectiveness of the traditional Herbst appliance and MARA. Under the first aim, a previously established 3D cone-beam computerized tomography (CBCT) superimposition technology in an adult case will be further developed to superimpose 3D digital models on natural stable structures of the anterior cranial base and the mandible in 3 growing patients, respectively. Under the second aim, 16 patients will be recruited, randomly allocated into two groups, and treated using the Herbst and MARA, respectively. Dental and skeletal landmark movement and condylar growth under both aims will be evaluated using newly developed 3D superimposition system and represented in 3D coordinate and color mapping systems. This study is innovative because it creates a new approach to understand craniofacial growth and evaluates effects of orthopedic growth modification while also investigating new treatment approaches for correcting mandibular deficiency. The proposed research is significant because it provides a new evidenced-based approach to assess growth and treatment outcomes in a 3D manner while also benefiting orthodontic education by virtually understanding the relationships between orthopedic treatment and craniofacial growth. The funding granted for this project will help our research team purchase necessary equipment and cover research personnel. The American Association of Orthodontists Foundation plays an essential and important role not only in developing novel technology but also to bring our field, Orthodontics and Dentofacial Orthopedics, a big step forward.