Diagnosis is usually radiological.
However, definitive diagnosis is through biopsy.
Aspirational biopsy of odontogenic keratocysts contains a greasy fluid which is pale in colour and contains keratotic squames.
Protein content of cyst fluid below 4g% is diagnostic of odontogenic keratocysts.
Smaller and unilocular lesions resembling other types of cysts may require a biopsy to confirm the diagnosis.
On a CT scan, the radiodensity of a keratocystic odontogenic tumour is about 30 Hounsfield units, which is about the same as ameloblastomas.
However, ameloblastomas show more bone expansion and seldom show high density areas.

Radiographs of odontogenic keratocysts show well-defined radiolucent areas with rounded or scalloped margins which are well demarcated.
These areas can be multilocular or unilocular.
The growth pattern of the lesion is very characteristic from which a diagnosis can be made as there is growth and spread both forward and backward along the medullary cavity with little expansion.
No resorption of teeth or inferior dental canal and minimal displacement of teeth is seen.
Due to lack of expansion of the odontogenic keratocyst, the lesion can be very large when radiographically discovered.
Diagnosis is usually radiological. However, definitive diagnosis is through biopsy. Aspirational biopsy of odontogenic keratocysts contains a greasy fluid which is pale in colour and contains keratotic squames. Protein content of cyst fluid below 4g% is diagnostic of odontogenic keratocysts. Smaller and unilocular lesions resembling other types of cysts may require a biopsy to confirm the diagnosis. On a CT scan, the radiodensity of a keratocystic odontogenic tumour is about 30 Hounsfield units, which is about the same as ameloblastomas. However, ameloblastomas show more bone expansion and seldom show high density areas.
Radiographs of odontogenic keratocysts show well-defined radiolucent areas with rounded or scalloped margins which are well demarcated. These areas can be multilocular or unilocular. The growth pattern of the lesion is very characteristic from which a diagnosis can be made as there is growth and spread both forward and backward along the medullary cavity with little expansion. No resorption of teeth or inferior dental canal and minimal displacement of teeth is seen. Due to lack of expansion of the odontogenic keratocyst, the lesion can be very large when radiographically discovered.
Odontogenic keratocyst