The anatomic portion of the tooth that is covered by cementum and is located in the alveolus (socket) where it is attached by the periodontal apparatus; radicular portion of tooth.
When a dependent child’s parents both have dental coverage, this rule states that the primary program (the one which pays first) is the one covering the parent whose month and day of birth falls first in the calendar year. The birthday rule is the most common rule for determining primary v. secondary coverage, but it may be superseded by a court order such as a divorce agreement.