Abnormal mandible morphology Obtuse angle of mandible Steep mandibular plane angle High mandibular plane angle UMLS:C4038738 Abnormally flat (obtuse) angle of the mandible. The angle of the mandibular, located at the junction between the body and the ramus of the mandible, is normally close to being a right angle. This terms describes an abnormal increase of this angle such that the mandible appears flatter than normal. SNOMEDCT_US:709997007 HP:0005446 See PMID:17213440 Figure 1G for an example of an obtuse mandibular angle.