A<unk> is a pathological epithelial lined cavity that fills with fluid or soft material and usually grows from internal pressure generated by fluid being drawn into the cavity from osmosis (hydrostatic pressure). The bones of the<unk> , the mandible and maxilla, are the bones with the highest prevalence of<unk>  in the human body. This is due to the abundant amount of epithelial remnants that can be left in the bones of the<unk> . The enamel of teeth is formed from ectoderm (the precursor germ layer to skin and mucosa), and so remnants of epithelium can be left in the bone during odontogenesis (tooth development). The bones of the<unk>  develop from embryologic processes which fuse together, and ectodermal tissue may be trapped along the lines of this fusion. This "resting" epithelium (also termed cell rests) is usually dormant or undergoes atrophy, but, when stimulated, may form a<unk>  The reasons why resting epithelium may proliferate and undergo<unk> c transformation are generally unknown, but inflammation is thought to be a major factor. The high prevalence of tooth impactions and dental infections that occur in the bones of the<unk>  is also significant to explain why<unk>  are more common at these sites.<unk>  that arise from tissue(s) that would normally develop into teeth are referred to as odontogenic<unk> . Other<unk>  are termed non-odontogenic<unk> . Non-odontogenic<unk>  form from tissues other than those involved in tooth development, and consequently may contain structures such as epithelium from the nose. As the<unk> grows from hydraulic pressure it causes the bone around it to resorb, and may cause movement of teeth or other vital structures such as nerves and blood vessels, or resorb the roots of teeth. Most<unk>  do not cause any symptoms, and are discovered on routine dental radiographs. Some<unk>  may not require any treatment, but if treatment is required, it usually involves some minor surgery to partially or completely remove the<unk> in a one or two-stage procedure.
Cysts of the jaws
Osteomyelitis of the jaws
Omphalolith
Hemifacial hypertrophy
Black hairy tongue
Chattering teeth
Blue nails
Enamel hypoplasia