Vertical dystopia measurement
By definition, orbital dystopia is any type of abnormal displacement of the entire orbital cones and their contents that can occur in three different dimensional planes. Orbital dystopia in horizontal and vertical planes have been given the terminology orbital hypertelorism and vertical orbital dystopia (1,2). In defining orbital hypertelorbitism, Tessier (the father of craniofacial surgery) stressed the displacement of the entire orbital cones. The severity of the hypertelorism was based on the measurements of the intercantal distance and shape of frontal- orbital region (1). Following Tessiers principles, vertical orbital dystopia was defined as an abnormal displacement of the entire orbital cones in the vertical plane, not just displacement of one, two, or three orbital segments. Both orbital hypertelorism and vertical orbital dystopia initially referred to congenital conditions, but later were used to describe facial trauma, muscular torticollis, facial skeletal tumors, and iatrogenic and idiopatic causes (3). Nevertheless, it is extremely important to emphasize that the acute displacement of the orbital walls does not necessarily accompany the displacement of the orbital rims and should not be referred to as orbital hypertelorism or vertical orbital dystopia. In this line of thinking, facial trauma with a low impact force does not lead to orbital dystopia, mainly because there is not enough energy to provoke mobilization of the entire orbital cone. Therefore, it is our belief that, other than congenital and tumoral causes, only facial trauma with very high energy may cause displacement of the entire orbital cones. |