A Clinical Study to Investigate the Occlusal Plane According to the Coronoid Notch in Removable Complete Dentures

الملخص

Statement of problem: Occlusal plane is the average plane established by the incisal and occlusal surfaces of the teeth; it is not a plane but represents the planar mean of the curvature of the surfaces. Boucher noticed that artificial teeth should be placed in the positions previously occupied by the natural teeth. So in edentulous patients we lose the occlusal plane, therefore it is necessary to  restore the height and angulation of the occlusal plane for functions and health of the stomatognathic system.

The Aim of the study:  The purpose of this clinical study was to determine the lost occlusal plane in dentulous patients depending on the coronoid notch (CN) as  a relative stable intra-oral bony landmark  and try to use it  in edentulous patients to determine the correct occlusal plane (OP).

 Material and methods:  Forty (40)  subjects were selected and they were between 18 and 22 years. All subjects had natural maxillary and mandibular teeth and exhibited Class I skeletal and dental relationship with physiological occlusion. The sample also included twenty (20) edentulous patients. All subjects with natural maxillary and mandibular teeth were examined to determine the distance from the left and right coronoid notch to the position of the mandibular buccal cusps tips   We located the coronoid notch on the mucous membrane -by indelible pencil-  by passing the finger through the anterior border of the ramus to find the greatest concavity, and then measured the distance from the CN to the proposed OP. We used this bony landmark in determining the occlusal plane in edentulous patients.

 Results. The mean of the distance between the CN and the proposed OP ranged from 6-8 mm.

 Conclusions. The distance between the Coronoid Notch and the proposed occlusal plane can be used in determining the lost occlusal plane in the edentulous patients.