aÂ·pexÂ·iÂ·fiÂ·caÂ·tion. Induced tooth root development or closure of the root apex by hard tissue deposition. apexification. a process of promoting apical closure of the root in an endodontically treated tooth by placement of calcium hydroxide paste or other tissue-tolerant material in the root canal after an apicoectomy.
Supernumerary is an adjective which means exceeding the usual number. When used as a noun, supernumerary means a temporary employee, additional society member, or extra manpower, usually in a function which has a temporary contract. In aeronautical context, a flight deck may contain a supernumerary seat. 2  This is a place for someone who doesn't have anything to do with the take off, flying, or landing of the aircraft. 3  Just a place for an extra body to observe.
A hierarchy (from the Greek á¼±ÎµÏÎ±ÏÏÎ¯Î± hierarchia, rule of a high priest, from á¼±ÎµÏÎ¬ÏÏÎ·Ï hierarkhes, leader of sacred rites) is an arrangement of items (objects, names, values, categories, etc.) in which the items are represented as being above, below, or at the same level as one another. subsumptive containment hierarchy is a classification of objects from the general to the specific. Other names for this type of hierarchy are taxonomic hierarchy and  IS-A hierarchy. The last term describes the relationship between each levelâa lower-level object is a member of the higher class.