There are numerous commonly used terms of relationship and comparison that refer to different aspects of teeth and are frequently utilized in articles about dentistry. Many of them are included below as a sort of glossary to assist with understanding the many articles that include these types of words.
Anterior refers to the direction towards an individual's lips, as opposed to posterior, which refers to the directions towards the back of an individual's head. The term anterior teeth refers to incisors and canines, as opposed to premolars and molars, which are posterior teeth.
Apical refers to the direction towards the root tip(s) of a tooth, as opposed to coronal, which refers to the direction towards the crown. It may also refer to something relating to the roots, such as apical support. This term is nearly synonymous with both cervical and gingival.
Axial refers to a plane parallel to the surface of a tooth. For example, if a drill bur would be inserted into a tooth from any side (proximal, facial or lingual), the depth of the hole is defined by the axial wall of the hole.
Buccal refers to the side of a tooth that is adjacent to (or the direction towards) the inside of the cheek, as opposed to lingual or palatal, which refer to the side of a tooth adjacent to (or the direction towards) the tongue or palate, respectively. Although technically referring only to posterior teeth (where the cheeks are present instead of lips, use of this term may extend to all teeth, anterior and posterior), this term may be employed to describe the facial surface of (or directions in relation to) anterior teeth as well.