In the mandible, buccal or lingual cortical expansion and thinning are noted.On MR imaging, the contents of the cyst display low to intermediate signal intensity on T1-weighted images and high signal intensity on T2-weighted images. The tooth itself is a zone of signal void. The lining of the cyst is thin with regular thickness and may show slight enhancement after contrast injection. Treatment and Prognosis
The treatment of choice for dentigerous cyst is enucleation along with extraction of the impacted teeth. If eruption of the unerupted tooth is considered feasible, the tooth may be left in place after partial removal of the cyst wall. Orthodontic treatment may subsequently be required to assist eruption. Similarly, if displacement of the associated tooth by the cyst has occurred and extraction may prove to be difficult, orthodontic movement of the tooth to a more advantageous location for extraction may be accomplished. Marsupialization may also be used to treat large dentigerous cysts. This permits the decompression of the cyst, with a resulting decrease in the size of the bone defect. The cyst can then be excised at a later date, with a less extensive surgical procedure. The prognosis for the dentigerous cyst is excellent, and recurrence is rare. This is related to the exhausted nature of the reduced enamel epithelium, which has differentiated and formed tooth crown enamel before developing into a cyst. Nevertheless, several potential complications must be considered. The possibility that the lining of a dentigerous cyst might undergo neoplastic transformation to an ameloblastoma has been well-documented.
Research has indicated that teratogens (substances known to cause birth defects), trypan blue (a stain used to color dead tissues or cells blue), and arsenic may damage the developing fetus and cause encephaloceles.Proper levels of folic acid have been shown to help prevent such defects when taken before pregnancy, and early in pregnancy.Occipital encephaloceles are frequently accompanied by hydrocephalus, as seen in 60-90% of patients. Diagnosis
Usually encephaloceles are noticeable deformities and are diagnosed immediately after birth, but a small encephalocele in the nasal or forehead region can go undetected. Various physical and mental developmental delays can indicate the presence of encephaloceles. Classifications
Encephaloceles of the face are generally classified as nasofrontal, nasoethmoidal, or naso-orbital, however, there can be some overlap in the type of encephalocele. They can also appear along any part of the cranial vault, as they result from abnormal closure of cranial bones; the most common location for encephaloceles is the occipital region. If the bulging portion contains only cerebrospinal fluid and the overlying membrane, it may be called a meningocele. If brain tissue is present, it may be referred to as a meningoencephalocele. When the head size or occipitofrontal circumference is smaller than the herniating sac, then it is termed as giant encephalocele.Separation of the neural and surface ectoderm causes apoptosis in the midline. A disturbance in this separation process at the final closure due to the lack of apoptosis is considered to be a critical aspect of nasofrontal and nasoethmoidal encephalocele.