Intricate relations and concepts of reference points in prosthodontics: A literature review

Oral rehabilitation presents a variety of clinical situations needing fabrication of prostheses that could satisfy the overall requirement of the patients. In various prosthodontic procedures, exact articulation of the maxillary cast to the articulator necessitates minimum three reference points that could decide the plane to which maxillary cast is mounted. Therefore, the correct choice of reference points in anterior and posterior areas is very crucial failing which one can end up with fabricating intolerable prosthesis. This reference plane is usually created by two points located posterior to the maxillae and one point located anterior to them. In general, the two posterior points are located by measuring prescribed distances from the skin surface landmarks. Literature has well evidenced various anterior and posterior points of reference used for mounting the maxillary cast on the different type of articulator systems. The most common reference plane is the Frankfort plane, which has been assumed to be horizontal when the patient is in the natural head position. However, this relationship is not simply opening or closing, but a complex relationship which exists in three dimensions. Variations may occur in any direction – superoinferior, anteroposterior, or mediolateral. Thus, it is essential to record this relationship with the least possible error to obtain a successful prosthesis.