Abnormal helix morphology Abnormal incisura morphology 2017-07-02T12:57:09Z An abnormal shape of the incisura, defined as the narrowed downward continuation of the conchal space bounded anteriorly by the borders of the tragus, posteriorly by the antitragus, and along its lower lateral margins and inferior boundary by the connection between the first two. The upper boundary is a somewhat arbitrary line crossing from the apices of the antitragus and the tragus.