Project 467170

Hemifacial Microsomia (HFM) is one of the most common congenital craniofacial disorders. Among many other features, microtia is present in the large majority of these patients. However, mainly due to the unilateral hypoplastic anatomy, microtia reconstruction among this patient population remains a challenge. This is especially true regarding accurate placement of the constructed auricle, as its classical relationships to the face cannot be used. As many consider that the auricle is truly located on the cranium and some propose the skulls dimensions are completely unaffected in HFM, we hypothesize that the appropriate location of the construct can be derived from the skull rather than from the face. In this regard, a retrospective review of all HFM patients and respective age-matched controls at our institution will be conducted, with a focus on measurements from their CT scans. The position of the tragus in relation to the skull base (Basion, Opisthion), and measurements of the cranial vault in general and in relation to the auricle, will be computed. These will then be compared using independent sample t-tests. Results from these analyses will be used to determine if firstly, the skull (skull base and cranial vault) can be used as an accurate predictor of ear position in controls. Second, to determine if skull base-derived measurements of the ears position and dimensions of the cranial vault are similar between HFM patients and their controls. Third, to determine if a simple cranial vault-based measurement is correlated with the skull base-derived construct position in HFM. If successful, a simple and reliable manner of positioning the constructed auricle based on the skull would be proposed, which would greatly improve the quality of care received by HFM patients.