Tooth impaction
Encyclopedia
Impacted and embedded teeth are the two main types of unerupted teeth found in the mouth
, and can sometimes be confused with each other.
In cases of both impacted and embedded teeth, the teeth remain below the surface of the gum
and sometimes bone
, rather than erupting into an exposed position within the mouth; however, the reason for the failure to erupt differs. Impacted teeth result from a situation in which an unerupted tooth is wedged against another tooth or teeth or otherwise directed so that it cannot erupt normally. In contrast, an embedded tooth is an unerupted tooth that is covered, usually completely, with bone
. The former is "physically" blocked in its path of eruption, while the latter is compromised by its lack of eruptive force often without known etiology. Certain systemic and local pathologic conditions may be associated with both (i.e., cleidocranial dysostosis
).
; the former would be termed bony impaction, while the latter would be termed soft-tissue impaction, and both classifications may present as partial or complete.
Mandibular third molars are the most commonly found unerupted teeth, while maxillary third molars are second most common.
Mouth
The mouth is the first portion of the alimentary canal that receives food andsaliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth....
, and can sometimes be confused with each other.
In cases of both impacted and embedded teeth, the teeth remain below the surface of the gum
Gingiva
The gingiva , or gums, consists of the mucosal tissue that lies over the mandible and maxilla inside the mouth.-General description:...
and sometimes bone
Bone
Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...
, rather than erupting into an exposed position within the mouth; however, the reason for the failure to erupt differs. Impacted teeth result from a situation in which an unerupted tooth is wedged against another tooth or teeth or otherwise directed so that it cannot erupt normally. In contrast, an embedded tooth is an unerupted tooth that is covered, usually completely, with bone
Bone
Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...
. The former is "physically" blocked in its path of eruption, while the latter is compromised by its lack of eruptive force often without known etiology. Certain systemic and local pathologic conditions may be associated with both (i.e., cleidocranial dysostosis
Cleidocranial dysostosis
Cleidocranial dysostosis, also called Cleidocranial dysplasia, is a hereditary congenital disorder due to haploinsufficiency caused by mutations in the CBFA1 gene also called Runx2, located on the short arm of chromosome 6....
).
Impaction classifications
There are numerous classification systems used to identify the specific manner in which a tooth is impacted. One of the most simple distinctions made is whether a tooth is impacted completely within bone or whether it has broken through the bony cortex and is partially or completely covered in gingival tissueGingiva
The gingiva , or gums, consists of the mucosal tissue that lies over the mandible and maxilla inside the mouth.-General description:...
; the former would be termed bony impaction, while the latter would be termed soft-tissue impaction, and both classifications may present as partial or complete.
Mandibular third molars are the most commonly found unerupted teeth, while maxillary third molars are second most common.