Bone resorption caused by metabolism of acidic substances produced by cysts contributes to cyst growth. Such substances include Prostaglandin-2 and Interleukin-1 which are both produced by the cyst itself. Nutritional deficiency theory
Epithelial cells will form a mass inside the cavity and the innermost cells become deprived of nutrients because they are far from the source of nutrients (the blood vessels). The innermost cells die and form an aggregate of dead tissue. The inner cells undergo ischemic liquefactive necrosis which creates the cavity space surrounded by growing epithelial cells. This theory is unlikely in the absence of malignant transformation of epithelial cells as it does not follow the existing relationship between connective tissue and epithelium. Abscess theory
Epithelial cells have an inherent quality to reproduce and cover any connective tissue that is not already lined with epithelia. Formation of an abscess must precede the epithelial proliferation in order for the cells to carry out this tendency. This theory explains why cysts are lined in epithelia but not why the initial cysts itself forms. Diagnosis
A non-vital tooth is necessary for the diagnosis of a periapical cyst, meaning the nerve has been removed by root canal therapy. Oral examination
The surrounding intraoral anatomical structures should be palpated to identify the presence of bone expansion or displacement of tooth roots as well as crepitus noises during examination, indicating extensive bone damage. Bulging of the buccal or lingual cortical plates may be present.
Oculocerebrorenal syndrome (also called Lowe syndrome) is a rare X-linked recessive disorder characterized by congenital cataracts, hypotonia, intellectual disability, proximal tubular acidosis, aminoaciduria and low-molecular-weight proteinuria. Lowe syndrome can be considered a cause of Fanconi syndrome (bicarbonaturia, renal tubular acidosis, potassium loss and sodium loss). Signs and symptoms
Boys with Lowe syndrome are born with cataracts in both eyes; glaucoma is present in about half of the individuals with Lowe syndrome, though usually not at birth. While not present at birth, kidney problems develop in many affected boys at about one year of age. Renal pathology is characterized by an abnormal loss of certain substances into the urine, including bicarbonate, sodium, potassium, amino acids, organic acids, albumin, calcium and L-carnitine. This problem is known as Fanconi-type renal tubular dysfunction. Genetics
This syndrome is caused by mutations in the OCRL gene which encodes an inositol polyphosphate-5-phosphatase. At least one mechanism by which these mutations cause this syndrome is by loss of its Rab-binding domain.This protein is associated with the primary cilia of the retinal pigment epithelial cells, fibroblasts and kidney tubular cells. This suggests that this syndrome is due to dysfunction of the cilia in these cells.