Congenital
Congenital lung cavities, or lung cavities present at birth, include bronchogenic cysts, congenital pulmonary airway malformation, and pulmonary sequestration. These congenital lesions are the most common cause of lung cavities in infants, children, and young adults. Bronchogenic cysts are due to abnormal budding of the bronchial tree. About 70% are found in the mediastinum, which is the central part of the chest where the heart is. Another 15 to 20% are intrapulmonary (within the lung), usually in the lower lobes. Congenital pulmonary airway malformation, formerly called congenital cystic adenomatoid malformation, is a benign tumor the results in the formation of single or multiple cysts. Pulmonary sequestration refers to abnormal lung tissue that gets its blood supply from the systemic circulation instead of the pulmonary circulation, like the rest of the lung. This lung tissue is also not connected to the trachea. See also
Focal lung pneumatosis, article comparing lung blebs, bullae, cysts, and cavities


== References ==
Trismus, commonly called lockjaw as associated with tetanus, is a condition of limited jaw mobility. It may be caused by spasm of the muscles of mastication or a variety of other causes. Temporary trismus occurs much more frequently than permanent trismus. It is known to interfere with eating, speaking, and maintaining proper oral hygiene. This interference, specifically with an inability to swallow properly, results in an increased risk of aspiration. In some instances, trismus presents with altered facial appearance. The condition may be distressing and painful. Examination and treatments requiring access to the oral cavity can be limited, or in some cases impossible, due to the nature of the condition itself. Definition
Trismus is defined as painful restriction in opening the mouth due to a muscle spasm, however it can also refer to limited mouth opening of any cause. Another definition of trismus is simply a limitation of movement. Historically and commonly, the term lockjaw was sometimes used as a synonym for both trismus and tetanus.Normal mouth-opening ranges from 35 to 45 mm. Males usually have slightly greater mouth opening than females. (40–60 mm, average of 50 mm). The normal lateral movement is 8–12 mm, and normal protrusive movement is approximately 10 mm. Some have distinguished mild trismus as 20–30 mm interincisal opening, moderate as 10–20 mm and severe as less than 10 mm.Trismus is derived from the Greek word trigmos/trismos meaning "a scream; a grinding, rasping or gnashing".