Hemifacial microsomia – a review of the literature of current hypotheses of pathogenesis, and possible therapeutic methods

Abstract

<b>Introduction:</b> Hemifacial microsomia (HFM) is the second most common congenital craniofacial anomaly.<b>Aim:</b> The aim of this study is to review data related to HFM.<b>Materials and methods:</b> Materials for the review were selected based on an analysis of publications published in the last 10 years.<b>Results:</b> There are three possible models of pathogenesis – vascular abnormalities, Meckel’s cartilage damage, and abnormal development of cranial neural crest cells – caused by genetic, maternal, and external factors. Symptoms results from disorders of structures originating from the first, and second branchial arches, most commonly resulting in mandibular hypoplasia, microtia or anotia, hypoplasia of the auditory ossicles, facial nerve paralysis, and soft tissue deficiency. The severity of the disorder varies greatly, depending on the number of structures involved, and the degree of penetration. The most common classification system (Orbit, Mandible, Ear, Nerve, Soft tissue; OMENS) has recently been proposed to assess the temporomandibular joint disc, and to assess disturbances originating from another structures. Other classifications such as FACIAL or ICHOM criteria have also been developed. The approach to treating each case should be individualized, primarily focusing on reconstructing the underdeveloped mandible, orthodontic treatment, creating the external ear, and filling soft tissue deficiencies.<b>Discussion:</b> The complexity of the condition is noted, as well as the need for interdisciplinary patient care.<b>Conclusions:</b> Through analysis of existing research, and clinical data, significant information regarding etiology, symptoms, possible classification systems, and therapeutic options has been gathered.