(Odontogenic cyst (periapical
.Periapical cyst develops from a preexisting granulomaIt is a focus of chronically inflamed granulation tissue.in apex of non vital tooth
Cyst formation occurs as result of epithelial.proliferation
It is initiated and maintained by the degradation
products of necrotic pulp tissue stimulation of
the resident epithelial rest of Malassez
occurs in response to the products of
Developing of preiapical cyst
Death of dental pulp
Apical bone inflammation
Stimulation of epithelial rest of Malassez
Most common cyst of the jaw .
Age 3-6 decades .
More located in maxilla , ant. then post.
then mand. post, finally lower ant.
Non vital tooth .
with a narrow opaque margin
It can not be differentiated
Round or oval shape
Cyst range from mm to 1.5cm
by non keratinized stratified squamus
Polymorphonuclear transmigrated through
the epithelium .
Connective tissue with mixed inflammatory
cell population .
Foci of dystrophic calcification, cholesterol
and giant cell .
with curettage .
RCT with apicoetomy .
IF NOT TREATED :
Weekness of the jaw
be classified to :
Def. : acute inflammation of the bone and bone
marrow of the mandible and maxilla.
- extension of periapical abscess .
- Physical injury
- Bacteremia .
Clinical features :
Parasthesia of lower lip
Lesion must have resorb or demineralize
approximately 60% of the bone to be shown
in a radiograph .
-Purulent exudates occupies the marrow spaces.
-Bony trabeculae show reduced octeoblastic
activity and increased octeoclastic resorbtion.
.Mandible > Maxilla(.Pain ( varies in intensity, not related to the extent Duration of the symptoms is generally
.proportional to the extent of the disease
Chronic osteomylitis appear primarily
radiolucent lesion , that may show focal
.zones of opacification
: In mild cases
.similarities to fibrousseous lesion.Few Infiltration of chronic inflammatory cells : In advanced cases
.necrotic bone.reversal lines of deposition and resorption -
Antibiotics, combination may be relatively- 1
.Surigical removal- 2