A rare case of progressive osteolysis of mandible is discussed with clinicoradiological presentation. The purpose of the case report is to make the medical community aware of this rare and fascinating disorder in the maxillofacial region. The disease is characterised by spontaneous progressive osteolysis of one or more skeletal bones. Occurrence in maxillofacial region is rare with fewer than 35 reported cases affecting the facial and jaw bones. The present case report is about the mystery of bilaterally missing ascending rami. An attempt is made to draw attention of the medical fraternity to this unusual and rare entity which can induce instability, dysfunction and cosmetic disturbances.