| intracoronal retainer | A retainer that depends upon components placed within the crown portion of a tooth for its retentive qualities. (05 Mar 2000) |
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| extracoronal retainer | A retainer that depends upon contact with the outer circumference of the crown of a tooth for its retentive qualities. (05 Mar 2000) |
| left main bronchus | It arises at the bifurcation of the trachea, passes in front of the oesophagus and enters the hilum of the left lung where it divides into a superior lobe bronchus and an inferior lobe bronchus. It is longer, of narrower caliber, and more nearly-horizontal than the right main bronchus, hence, aspirated objects enter it less frequently. Synonym: bronchus principalis sinister. (05 Mar 2000) |