Final answer:
The division of a tooth's crown crosswise and parallel to the occlusal or incisal surface is between the incisal and cervical portions.
Step-by-step explanation:
The crown of a tooth divided crosswise with the division being parallel to the occlusal or incisal surface has the following divisions: incisal and cervical. The crown is the part of the tooth visible above the gum line, and it is covered with enamel, the hardest material in the body. Underneath the enamel is a layer of dentin that extends into the root around the innermost pulp cavity, which includes the pulp chamber in the crown and the pulp canal, or root canal, in the root. The term 'occlusal' refers to the chewing surface of the back teeth or molars, and 'incisal' refers to the biting edge of the front teeth or incisors. Therefore, when the crown is divided crosswise parallel to the occlusal/incisal surface, the division is between these surfaces: the incisal, which is the biting edge, and the cervical portion of the crown, which is closer to the root and gums.