Study of the mechanism of compensation is of great practical importance, for accounting overlap the upper teeth and lower teeth relationship between the depth of overlap, the slope of the articular path, height and curvature of the mounds Spee is important to stabilize the prosthesis. Bonneville said pattern between elements of the masticatory apparatus.
Bonneville laws are:
1. The distance between the centers of the articular heads and between them and the medial angle of the lower incisors form an equilateral triangle, each side of which is 10 cm
2. The depth at the site of overlap of incisors is not arbitrary or random, but depends on the height of the molars and premolars, the position of the teeth in the maxillary arch and the curvature of the entire dental arch. Height mounds gradually decreases from premolars to molars.
3. Incisors determine all movements of the lower jaw to the upper.
4. Vestibular surface of the front teeth lie in a circle, and the side - in a straight line.
5. Line clamping molars curved in the sagittal direction.
6. During movement of the lower jaw to the side on the working side of the same name turns, and on balancing - oppositely.
Bonneville laws emphasize the importance of the relationship between the various elements of articulated chain. The question of prime importance of a particular element in the articulation of the prosthetic clinic edentulous jaws is at the center of attention for many years.
GHISI (1930) and his school believe that the slope of the articular Road is the direction of movement of the lower jaw, and that its motion affects the size and shape of the articular tubercle. Saving multiple contacts at different shifts of the lower jaw is a basic requirement of the classical theory of balancing, the most prominent representatives are Gysi and Ghana. According Gysi papulose preservation and incisal contact is the most important factor in this theory.
The main requirements of the theory Gysi are:
1. The exact definition of joint path.
2. Record incisive way.
3. Determination of sagittal compensation curve.
4. The height of posterior teeth.
Any clinical form is the result of abnormal occlusion loss or weakening of any link in the overall system of articulation links. Since the leading role in this system is the slope of the articular path specified with the burin slip, then to characterize normal or abnormal bite are four corners formed by the intersection with the horizontal plane inclined plane incisive and articulate slip, namely
1. The angle of inclination of the articular path in the sagittal direction of 30-33 degrees.
2. Tilt angle tarnsverzalnom direction (angle Bennett) 15-17 degrees.
3. Sagittal incisal path angle of 40-50 degrees.
4. Transversal angle of 55-60 degrees incisive way.
These values according to different authors vary not only from person to person, but sometimes one and the same person on different halves of the jaw. But one thing is certain - between these angles and their values there is some internal patterns and changes in the relationship of one of them in one direction or another invariably cause a corresponding change in the other.
Chewing motion for Gysi is cyclically by a parallelogram, which is established by closing the sliding uninterrupted chewing surfaces of most of the teeth.
From the position of the central occlusion:
Phase 1 - lower jaw,
Phase 2 - misalignment of teeth to the side,
Phase 3 - interdigitation of the same name bumps on the working side and oppositely - for balancing,
Phase 4 - slip teeth to their original position of the central occlusion.
The theory is similar to the theory of Hanau Gysi, as she shared basis. Hanau analyzes the system of articulation and especially emphasizes the difference between the position of the articulator and the denture in the mouth because of the lack of consideration of the elastic tissue.
Of a series of articulating laws Hanau identified 5 major factors, calling them articulating the five:
1 - the slope of the articular path
2 - the depth of the compensation curve
3 - an estimated slope plane
4 - the slope of the upper incisors,
5 - height hills.
All five of these factors can be varied to change: joint path, approximate plane and cutting edge position - in tilt compensation curve - in depth, hills - in height. The dependence of the current can be represented, for example: increasing the depth of compensation curve leads to an increase in the slope and vice versa. It should be noted, however, that these elements of the complex articulation of the theory of balance is difficult to measure accurately and accounting. This applies not only to the slope of the articular route, but also to the slope hills, hillocks and occlusal plane.