| dc.description.abstract | Introduction: There is currently no index that assesses the physical improvement in facial appearance in patients with Hemimandibular Hyperplasia following treatment from an asymmetry perspective. Aims: The primary aims were to develop and assess the applicability and reliability of an index to assess facial asymmetry correction for Hemimandibular Hyperplasia. Methods and Materials: A novel method for the assessment of a patient’s asymmetry using a frontal scan was developed: The Hemi-mandibular Hyperplasia Facial Asymmetry Improvement Index (HHFAII). Subsequently, an image of an adult male was manipulated to represent varying degrees of presentation and severity of Hemimandibular Hyperplasia. A total of 14 manipulations were produced to cover the breath of the condition. To assess the practical application and accuracy of the newly developed HHFAII, a cross-sectional observational study was conducted. Raters split between Consultant Maxillofacial Surgeons and Orthodontists were randomly allocated 6 manipulations each and asked to identify anatomical points within the manipulations and their markings were subsequently evaluated and scores calculated using the index. These were compared against the measurements to which the manipulations were produced, as well as the subsequent scores produced by the index, which served as the gold standard. Results: 20 raters completed the study and were split equally between Consultant Maxillofacial Surgeons and Orthodontists. After analysing the raters' measurements, 87% of measurements were within 1 millimetre (mm) deviation of the ideal measurement, whilst 13% were outside this range. Subsequently, 67% of index scores matched the gold standard. Of the 4 parameters measured in the study, evaluation of chin position was the most prone to error with 68% of measurements within 1mm of the ideal. In general, raters tended to underestimate the amount of facial asymmetry present. Furthermore, there was a group of 4 raters (20% of participants) who produced double the number of errors as the rest of the cohort combined. Conclusion: The Hemi-mandibular Hyperplasia Facial Asymmetry Improvement Index (HHFAII) can be applied to assess a patient’s asymmetry before and after treatment as well as record the outcome of their treatment. However, it needs further refinement to increase its reliability and reproducibility. | en_US |
