RU2113189C1 - Method for producing functional imprint of maxilla and mandible in cases of tooth loss - Google Patents

Abstract

FIELD: medical engineering. SUBSTANCE: method involves forming glossal surface of maxillary spoons at least 4 mm thick and manufacturing individual spoons on jaws using preliminarily made functional mold in making holes in it for molding mass to discharge. Central relation of jaws is repeatedly determined and final functional mold is produced under patient occlusion pressure. EFFECT: improved functional results. 2 cl

Description

 The invention relates to medicine, namely to orthopedic dentistry.

 In recent decades, methods for obtaining functional casts have been continuously developed and improved, significant results have been achieved in improving the fixation of prostheses on toothless jaws.

 Currently, functional casts are divided according to the degree of compression of the soft tissues of the prosthetic bed into compression ones obtained under the pressure of the fingers of the doctor’s hands or the patient’s bite; unloading, obtained without pressure on the tissue of the prosthetic bed, and differentiated, obtained by selective pressure on the tissue of the prosthetic bed, depending on their anatomical and functional features.

 Some authors consider it advisable in all cases to obtain compression casts, motivating that during the function of biting and processing food in the mouth, the mucous membrane experiences similar conditions. They also believe that the compression cast provides uniform pressure throughout the prosthetic bed.

 Other authors claim that compression casts lead to compression of the mucous membrane and change its true physiological state, disrupt blood and lymph circulation, impair its nutrition, as a result of which inflammatory and then atrophic processes can occur in it, and bone tissue atrophies. To avoid this, the authors recommend receiving decompression or unloading casts from toothless jaws that do not change the true state of the mucous membrane of the prosthetic bed, ensuring its normal function under the prosthesis.

 The experience of our clinic has shown that unloading tissues throughout the prosthetic bed does not provide a full fixation of the prosthesis made using a decompression or unloading cast. The mucous membrane of the prosthetic bed has a different thickness and compliance. Often there are bone protrusions, mobile crests of the alveolar process, alveolar part and other unfavorable features that require a selective approach to displaying them with a cast.

 In a number of modern works, it is recommended to use the principle of differential pressure on the tissue of the prosthetic bed. The authors recommend unloading low-compliance areas of painful, thin and atrophic mucous membranes, and display areas of the mucous membrane with great flexibility under pressure. This contributes to less injury to the mucous membrane and provides selective load on individual sections of the prosthetic bed, depending on their functional endurance.

 The methods for producing casts described above for orthopedic treatment of patients after complete loss of teeth in the upper and lower jaws are aimed at creating uniform pressure with the basis of the prosthesis on the mucous membrane of the prosthetic bed, but it should be recognized that today using any of the methods for producing a cast it is not possible to ensure complete functional representation of the prosthetic bed in a broad sense of this issue, especially when prosthetics of the toothless upper and lower jaws 3.4 and 5 degrees of atrophy of the alveolar o cane and alveolar part, including obtaining a functional impression.

 A known method of obtaining functional casts from toothless jaws, including the manufacture of individual wax spoons on the jaws (Vasiliev M.E. et al. Dental prosthetics. - M .: Medgiz, 1958, p.197-198).

 However, this method does not provide a selective approach to displaying the mucous membrane of the prosthetic bed having different thicknesses and suppleness, bone protrusions, mobile ridges of the alveolar ridge of the alveolar part, and does not at all affect aspects of the anatomical and topographic features of the prosthetic bed of the upper and lower jaws after complete loss of teeth, caused by periodontal disease.

 Closest to the proposed is a method of obtaining a functional impression of the upper and lower jaws after complete loss of teeth, including the manufacture of individual wax spoons on the jaws, and the subsequent manufacture of individual plastic spoons (Svirin B.V. et al. Prosthetics of patients with complete absence of teeth, Methodical allowance, Ministry of Health of the Russian Federation, M., 1982).

 However, this method allows to obtain functional casts under the pressure of the patient’s bite, i.e. It does not provide selective load on individual sections of the prosthetic bed, depending on their functional endurance.

 The aim of the invention is to develop an optimal way to increase the effectiveness of orthopedic treatment of patients after complete loss of teeth in the upper and lower jaws.

 This goal is achieved by providing, upon receipt of casts, a selective load on individual sections of the prosthetic bed.

 The method is as follows.

 Individual wax spoons are made directly in the patient's oral cavity. Occlusive wax rollers are formed on the occlusal surface of the spoons. The central ratio of the jaws is determined. Functional preliminary casts are obtained under the pressure of the patient’s bite. Gypsum models are cast and the boundaries of individual plastic spoons are drawn. Individual plastic spoons are made and occlusal wax rollers are formed. Redefine the central ratio of the jaws. Functional, “final” casts are obtained under the pressure of the patient’s bite.

 The outer lingual surface of the spoon on the lower jaw is thickened with wax, and 1-1.5 mm of wax is removed from the inner surface at the place of attachment of m.mylohyoideus for free movement of m.mylohyoideus, however, the wax layer is not removed from the part of the inner surface of the spoon that corresponds to the non-muscular the triangle is the area behind the maxillary hyoid muscle (regio retromylohyoideus).

 On the occlusal surface of the spoon, an occlusal cushion is formed, respectively, in the middle of the alveolar ridge or focusing on the Pound triangle, if there are 3, 4 and 5 degrees of atrophy of the alveolar part. The inner lingual edge of the roller should not go beyond the jaw-hyoid crest. The height of the roller from the level of the frenulum of the lower lip is an average of 18 mm.

 In the field of moving tissues of the alveolar part, perforations are made to exit the excess impression mass.

 In the upper jaw in the area of the mucous-glandular zone (the so-called line “A”), in most cases, the mucous membrane has a significant compliance, therefore, its functional design when taking the impression helps to create a valve and better fixation of the prosthesis.

 To do this, a wax strip is applied to the distal portion of the spoon (it is advisable to use various thermoplastic and elastic materials), and, slightly softened, a spoon is introduced into the oral cavity and formed under bite pressure using functional tests.

 On the occlusal surface of the spoon, an occlusal cushion is formed from strong wax and modeled in accordance with the shape of the jaw (square, round or triangular). The front section of the upper roller should be located at a distance of 8 ± 2 mm anterior to the center of the incisal papilla. Its width here should not exceed 3 mm. At the level of the zygomatic process, the width of the roller is increased to 8-10 mm, then the roller is brought back to nothing and rounded. The occlusal roller ends at a distance of 5 mm from the middle of the maxillary tubercle. The height of the roller should be equal to an average of 22 mm (the starting point for the measurement is the bridle of the lip).

 In the field of moving tissues of the alveolar ridge, perforations are made to exit the excess impression mass.

 The creation of outflow for excess impression mass through the perforations, as well as the fluidity of the material used, create the prerequisites for obtaining on the cast of the relief the surface of the moving tissues in the region of the alveolar process and the alveolar part without displacement.

 The edges of the spoons in all departments of the valve zone are formed using moderate functional tests, after which they are shortened by 1-1.5 mm and edged with adhesive plaster.

 After making individual spoons with occlusal rollers, they begin to determine the central ratio of the jaws - the correct determination of the position of the lower jaw relative to the upper in three mutually perpendicular planes.

 The impression is taken with highly plastic impression materials (elastic, eugenolysine-zinc paste).

 Obtaining impressions under occlusion pressure is more appropriate, since the mucous membrane of the prosthetic bed is displayed under functional load, while at finger pressure it is difficult to calculate the force and ensure uniform pressure.

 When applying impression material on a spoon of the lower jaw, the latter should cover the front of the hyoid space, where it will be held due to the viscosity of the mass. When the impression mass becomes viscous, they begin to form the edges of the impression. The patient is asked to make minimal tongue movements: raise the tongue and touch the incisal papilla with it to release the frenum of the tongue; push the tongue forward, while raising the bottom of the oral cavity and the action of m.genioglossus is recorded. Then the patient performs swallowing movements to form the distal edge of the lingual surface of the cast, and the activity of the entire muscular system in this area is also displayed. The spoon should not be visible through the impression mass in the area m. mylohyoideus, since the displacement force of the prosthesis in this area is very high. However, slight pressure in a non-muscular triangle is usually acceptable.

 The model is cast carefully and immediately immediately after the impression is made with durable autoclaved gypsum, which preserves the microrelief of the mucous membrane of the prosthetic bed on the prosthesis, which naturally improves the fixation of prostheses.

 After obtaining the final functional casts and casting of gypsum models, the dental part of the manufacture of prostheses is carried out according to the usual accepted technique.

Claims (2)

 1. A method of obtaining a functional impression of the upper and lower jaws after complete loss of teeth, including the manufacture of individual wax spoons on the jaws and the subsequent manufacture of individual plastic spoons, characterized in that the lingual surface of the spoon is formed with a thickness of at least 4 mm, an occlusal surface is formed on the occlusal surface of the spoon a roller for determining the central ratio of the jaws, a layer of wax 1 - 1.5 mm is cut from the inner surface of the spoon, and the outer lingual surface of the spoon is thickened with wax by 1, 5 mm, perforated holes are made in places of bony protrusions and moving parts of the mucous membrane of the prosthetic bed, then the central ratio of the jaws is determined by functional tests, after which a preliminary functional impression is taken.  2. The method according to p. 1, characterized in that an individual plastic spoon is made according to a preliminary functional impression, making holes on it for the exit of excess impression mass in the area of moving tissues of the mucous membrane of the prosthetic bed, an occlusal wax roller is formed on the occlusal surface of the plastic spoon, the edges spoons are functionally formed with thermoplastic or elastic material, located in the buccal region of the edge of the spoon 1 - 1.5 mm above the oblique line, then re-determine the central stitching of the jaws and under the pressure of the patient’s bite remove the final functional cast.