Gysi method found many supporters. A number of foreign textbooks Prosthodontics recommends it as one of the most accurate methods for the establishment of the mandible in centric relation.
AK Nedergin about this method writes that "it is very accessible and valuable because it allows you to properly install a central occlusion with control in the sagittal and transversal direction."
Kemeny proposed methodology fixing the mandible in centric relation with two perforated aluminum rods 8-10 cm long and 1 mm thick. These rods are heated and is embedded in the side of the lower parts of the wax cylinders of six teeth. Part of the rod inside the shaft, perforated, so they are better kept in wax. Part of the rods, which are 6-8 mm above the roller, pointed. The bars are set at an angle of approximately 80 degrees to the occlusal plane. This angle corresponds to the average path of the incisors and molars in the lower jaw move up and it depends on the rotational axis of the joint heads of the mandible. In these areas the top roller is heated wax and after the introduction of bases with rollers in the mouth offering the patient close his jaw. Since the bite bases fixed with rods, their further strengthening is required.
Kemeny suggests that the metal rods contribute to the closing of the jaws in centric, prevent displacement of the lower jaw forward and encourage the best fixing bases, as press them to the alveolar process and palate. The main disadvantage of Kemeny method is that the verification of the correctness of the central occlusion when it is excluded. Orthopedic clinics in the country use the method of fixation of the mandible in centric relation with precisely designed occlusal wax cylinders through triangular depression on the upper roller and the corresponding projections on the lower platen.
These projections are obtained by applying strips of heated wax on the lower roller, followed by closing the jaws in centric. This technique allows you to:
a) control the accuracy centric;
b) in the event of an error immediately eliminate it;
c) separately to strengthen the upper and lower models in the articulator.
Validation of the central occlusion:
1. Wax bases shall fit the model. The space between the model and the oral edge of the base is a sign of deformation. The space between the model and the back edges of the lower base is a sign of the deformation of the lower wax base.
2. With the re-introduction of bases with occlusal ridges in the mouth should be repeated in the same order all the manipulations that have been conducted to determine the centric, apply the same force when moving the lower jaw back and up.
To prevent displacement of the lower jaw to the back of occlusion, should:
a) the thumb, index and middle fingers of both hands to hold and push the base to the top of the upper jaw and the lower - to the bottom;
b) to offer to the patient's mouth opened slightly (within 3-4 mm), and then close it. Closing of the jaws occurs without the active intervention of a doctor, without the active movement of the lower jaw back. If at 3-4 times the closing and opening of the jaws wax projections fall in triangular grooves, this is a sign that the central occlusion is defined correctly.
To prevent displacement of the mandible in the front or the side of occlusion, close his offer several times and open the jaw. If at 3-4 times the closing and opening of the jaws triangular protrusions lower occlusal wax roller fall deeper into triangular top roller, it is a sign of correctness of the central occlusion. Otherwise, the contours of these projections are deformed. In addition, the displacement of the lower jaw forward and the right steps are formed between the upper and lower rollers. As we move to the left jaw steps are formed on the bottom roller on the left and on the upper roller to the right, and vice versa, the displacement of the lower jaw to the right steps are formed on the lower roller to the right and on the top - left. The same step turns on the upper roller in the front section of the erroneous setting of the lower jaw in front occlusion.
3. Next, check to see if a discharge of wax bases of the mucosa of the alveolar process and palate. The tip of a spatula is introduced alternately in front and side portions of the upper and lower occlusal ridges and trying to shift them to the side of the alveolar processes. The mobility of the basis in one or another area of divergence is a sign of its mucous membrane in determining the centric.
4. Parallel test whether the uniform contact occlusal ridges whether compression alveolar mucosa in one or other part of the jaw. Thumb and forefinger of his left hand is placed on the occlusal surface of the vestibular rollers offer the patient opened his mouth again and close his mouth. In the presence of compression fingers feel the tension. In addition, the compression of the mucous membrane appears balancing of bases at the closing of the occlusal ridges.
5. The correctness of the central occlusion test for voltage temporal symmetry and proper chewing muscles. Check out this is relative, as the muscles tense and symmetrical front occlusion.
Topic 85.1. Functional harmony chewing system.
GENERAL PURPOSE: study the features of construction, with full dentition by the presence of the teeth to the laws of articulation.
- Chewing system components and their functional interaction, functional harmony;
- The laws of articulation Bonneville, Ghana, Gysi, Monson.
ACADEMIC INFORMATION NECESSARY FOR THE STUDY OF THE TOPIC:
1. Prosthetic treatment of the edentulous patient. Fourth edition. R.Basker, J.Davenport. Blackwell. 2002 – 316 p.
2. Complete Denture. Manual. Robert W. Loney, DMD, MS. 2009.- 99 p.
ORGANIZATIONAL STRUCTURE OF THE practical CLASSES
Movement of the lower jaw is the result of a complex interaction of the masticatory muscles, the temporomandibular joints and teeth, coordinated and controlled by the central nervous system. Reflex and voluntary movement of the lower jaw are governed by the neuro-muscular system. Temporo-mandibular joint allows the distal mandibular fixed position relative to the top and create a guide plane for its motion forward, sideways and down within the limits of its movement. Stable vertical and distal interaction with the upper mandible is provided intercusps contact teeth antagonists. Teeth also form guides the plane to move the jaw forward and sideways within the contact between the teeth. When these two functions of joints and teeth are in a state of harmony, is the optimal functioning of the neuromuscular system. When the normal function of chewing chewing muscles work consistently and coherently. This allows the lower jaw to perform arbitrary and reflex movements within the limits of its movement. Within these limits, the functions are performed as chewing, swallowing, pronunciation of sounds. The most common cause of functional harmony violation of this system are the teeth. Intercusps correct contact between the teeth with a stable vertical and horizontal position of the lower jaw is a prerequisite for functional harmony. Violation of this contact may prevent or limit the closure of the lower jaw to the stability of the central relationship, in addition, it can interfere with the smooth movement of the lower jaw forward and to the side within the contact between the teeth. This condition is called "occlusion disharmony" in the result of which can be changed and disturbed functional coherence of the neuromuscular system. Disharmony occlusion in complete dentures leads to a violation of their stabilization in the functional and non-functional loading. The second cause of functional impairment can defeat neuromuscular system as a result of physiological responses to stress, which leads to muscle tension, changes in reflex movements of destructive and dysfunctional habits. These factors, combined with the lack of harmony in the occlusion can lead to unpleasant neurological segments as well as a negative impact on the natural teeth and periodontal tissue, stabilization of complete dentures. So disharmony occlusion caused by the presence of such contacts teeth, which breaks the agreed roles of dentition, the joints and the neuromuscular system. This is not just a physical disharmony, discord and interoperability. For functional harmony need physical harmony between the teeth and joints. This harmony is provided by the laws of the structure and biomechanics of the masticatory system.