Evaluation of the Mid and Lower Face in Three Females With Myhre Syndrome: Objective Methods to Supplement Subjective Assessment

Abstract

Myhre syndrome is associated with a recognizable pattern of facial differences that develop after early childhood. Patients typically have midface hypoplasia, mandibular prognathism, narrow oral commissures with a short philtrum and thin upper lip vermillion. Other characteristics include deeply set eyes with short palpebral fissures, and small, widely spaced teeth. The aim of this study is to review the concept of prognathism in Myhre syndrome, describe the oral and maxillofacial surgery (OMS) evaluation of three females, and provide some preliminary data to propose more objective guidelines and diagnostic tools for facial evaluation in other patients. In addition to the dysmorphologic examination, maxillofacial imaging is recommended in many patients to evaluate the dentition, midface and mandibular anatomy. An orthopantomogram is useful to visualize the dentition, alveolar portion of the maxilla and the mandible. A lateral cephalogram can assess jaw relationships and allow cephalometric analyses to compare to published norms. With the common characteristics visualized, a checklist has been developed to serve as a guide when evaluating patients. OMS consultation can enhance the care provided by the medical geneticists who usually manage these individuals.

Keywords: SMAD4; Myhre syndrome; facial evaluation; mandibular prognathism; maxillary hypoplasia.