Investigation of Long-Term Craniofacial Growth and Treatment Modalities in Patients with Craniofacial Microsomia

Hemifacial microsomia (HFM) or craniofacial microsomia (CFM) was described as a broad spectrum of congenital malformations resulting from the variable dysmorphogenesis of craniofacial structures which derived mainly from the first and second brachial arches. Most of the HFM affect unilateral craniofacial skeleton and its overlaying soft tissue, it is asymmetric in disease nature. The clinical features of CFM were complex because of multiple involvement of facial structures with large variations in clinical presentation in each patient. The classification and management of CFM was based on the Kaban-Pruzansky Classification, which categorize the severity of mandibular and condylar defects. Early multiplanar mandibular distraction osteogenesis (DO) was proved to be an effective treatment for correcting asymmetry of facial skeleton and lip canting in young children with CFM. However, the result regressed over time. The aims of the study are to 1) analyze the long-term 3D dentofacial features after early mandible DO in patients with CFM and investigate the anatomical benefits of early DO for definitive facial correction after growth completion; 2) elucidate the ultimate effective treatment modalities for CFM in long-term. The research project will be conducted for 2 years. This is a retrospective cohort study. The study includes 2 parts to answer the questions raised in the “aims”: 1) longitudinal craniofacial growth of CFM for patients with and without early mandible distraction; 2) analysis of the current treatment modalities among these patients and evaluate the treatment outcomes. The sample includes the consecutive adult patients with CFM who received definitive orthodontic and orthognathic treatments during 2012 to 2015. The patients are grouped according to their previous treatment: with early mandible DO (DO group) and without early mandible DO (NDO group). The longitudinal facial growth is measured using panoramic and lateral cephalometric radiographs. To evaluate the 3D craniofacial morphology, the CBCT was obtained at time before definitive treatment. The mandible is segmentalized to evaluate its form and shape. The cross-sectional area located between ramus and body are also measured at affected and unaffected sides. For the treatment outcome assessment, the time points of data collection are: T1, before OGS; T2, one week after OGS; and T3, completion of orthodontic treatment. The data included CBCT and dental models. The simulated 3D OGS plan (Ts) is also acquired if patient received 3D planning. The secondary outcome will be the patients who received OGS with or without 3D simulation. The initial treatment outcome and the ultimate treatment result will be compared to investigate the difference of roll, pitch and yaw direction/dimension.

Project ID:PC10507-0255
External Project ID:MOST105-2314-B182-029