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Region of interest
28, 38 and 48 (cyst around 48)
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Possible dentigerous cyst associated with tooth 48
There is a well-defined, corticated, oval radiolucency located pericoronal to the impacted tooth 48. Tooth 48 appears distally displaced. This entity appears to extend at least from the distal cemento-enamel junction region of tooth 48 to scallops on the buccal aspects of the mesial and distal root apices of tooth 47. No significant resorption is present on the roots of tooth 47. There are no signs of endodontic pathology involving tooth 47, despite this finding.
This lesion has caused expansion along the lingual cortex of the mandible in a "hydraulic fashion", and the contiguous lingual cortical plate is significantly thinned and may be partially dehiscent. The right inferior alveolar nerve canal appears to have been inferiorly displaced by this lesion, but its cortex appears intact. The alveolar crest located distal to tooth 47 appears partially dehiscent, which suggests communication with the oral cavity.
These findings suggest the presence of an odontogenic cyst associated with tooth 48, with the most likely interpretation being that of an asymmetric dentigerous cyst, but the possibility of similar cystic lesion, such as keratocystic odontogenic tumour should also be considered. Biopsy with histopathologic correlation is needed to reach a definitive diagnosis. The approximate dimensions of the lesion are noted.
Mesiodistal views of the cystic lesion without nerve tracking
These mesiodistal cross-sectional images demonstrate the inferior displacement of the mandibular nerve canal along the inferior surface of the cystic lesion, and intact superior border of the canal.
Right mandibular nerve inferior to tooth 48
The right mandibular nerve courses inferior to the horizontally impacted tooth 48. No signs of nerve compression are present. The periodontal ligament space is not visible around the roots, which suggests ankylosis is likely to be present. No resorption is evident on tooth 47.
Axial views of tooth 48
These axial cross sectional images of tooth 48 demonstrate the inferior passage of the nerve relative to tooth 48. Ankylosis should be considered.
Mesiodistal views of tooth 48
These mesiodistal cross-sectional images demonstrate the horizontal orientation of tooth 48 relative to the long-axis of tooth 47, and the distal displacement of the tooth due to the cystic lesion pericoronal to the tooth. There is no evidence of root resorption in tooth 47.
Impacted tooth 28: Probable ankylosis
Tooth 28 is vertically impacted and the crown is oriented in mild buccoversion. The follicle is hypoplastic, and communicates with the oral mucosa through the alveolar crest. The roots of the tooth appear fused and elevate the floor of the maxillary sinus. The sinus floor appears intact otherwise. The periodontal ligament space is poorly visible around the roots. These findings suggest ankylosis is likely present. There are no signs of associated pathology or resorption on tooth 27 at this time.
Axial views of tooth 28
These axial cross-sectional images demonstrate that the periodontal ligament space surrounding the root circumference of tooth 28 is not visible, which suggests that ankylosis is present.
Mesiodistal views of tooth 28
These mesiodistal cross-sectional images demonstrate the vertical and slightly mesioangular orientation of tooth 28 relative to the long-axis of tooth 27, and the slightly hypoplastic appearance of its follicle. This tooth has not caused any resorption of the adjacent tooth 27. The sinus floor overlying the roots of tooth 28 has been elevated and remains intact.
Left mandibular nerve lingual to tooth 38: severe nerve compression
The left mandibular nerve courses lingual to the apical third of the mesial root and the distal root apex of the horizontally oriented and partially impacted tooth 38. The nerve is severely compressed by the roots of tooth 38. The crown of the tooth is in buccoversion orientation and extends to the buccal surface of the apical third of the distal root of tooth 37. The residual follicle appears hypoplastic. The periodontal ligament space is not clearly visible around the root circumference, which suggests this tooth may be ankylosed. Tooth 38 has caused resorption on the distal root of tooth 37.
Axial views of tooth 38
These axial cross-sectional images demonstrate the buccal passage of the left inferior alveolar nerve canal relative to the root apices of tooth 38. The periodontal ligament space surrounding the root circumference of this tooth is not fully visualized, which suggests that this tooth is likely ankylosed. Note the buccoversion of the crown of the tooth and its position against the buccal surface of the apical third of the distal root of tooth 37.
Mesiodistal views of tooth 38
These mesiodistal cross-sectional images demonstrate the horizontal orientation of tooth 38 relative to the long-axis of tooth 37, and the hypoplastic appearance of its follicle.