Heights of Contour and the CEJ:
Facial heights of contour are most prominent on mandibular posterior teeth. They are least prominent on mandibular anterior teeth.
All teeth have facial heights of contour in the cervical third, except for mandibular molars (which have facial heights of contour at the junction of the cervical and middle thirds).
Anterior teeth have lingual heights contour in the cervical third of the crown. Posterior teeth have lingual heights contour in the middle third of the crown EXCEPT for the mandibular second pre-molar (which has a lingual height of contour in the occlusal third).
The CEJ dips deeper on:
-anterior teeth than posterior teeth
-the mesial side of a tooth than the distal
-maxillary teeth than mandibular teeth