RU2827452C1 - Method for elimination of acquired vertical deformations of alveolar process of jaws - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to maxillofacial surgery. Cone-beam computed tomography of the alveolar process is performed in a lateral projection. Size of the resected bone block is determined. Points A, B, C, D, E required for calculation are marked according to Fig. 1, 2. First, upper point B is determined, then points D, A and C. Then point E is marked at distance X from point D, calculated using mathematical formula X(CE)=[CD×AB]:CB, where X is the length of the segment CE, mm, CE is the side of the base of the pyramid of the resected bone block, point A is the intersection of the horizontal line drawn from the apex of the alveolar process, and the vertical line drawn from the beginning of the deformation on the inner side of the alveolar process, point B is an apex of an alveolar process, point C is an apex of the beginning of deformation from the outer side of the alveolar process, point D is an apex of the beginning of deformation from the inner side of the alveolar process, section CD – width of base of deformed section of alveolar process, segment AB is the distance by which it is necessary to move the apex of the alveolar process. Further, under conduction anaesthesia, a mucous membrane of the upper or lower jaw is incised along the mucous-gingival line. Mucous membrane, a submucous layer and a periosteum are dissected. Then the mucoperiosteal flap is displaced upwards, the alveolar process is skeletonised. Circular saw is used to make two vertical cuts for the entire thickness of the alveolar process, limiting the deformed portion of the alveolar process. At the base of the deformed section between the vertical cuts, a horizontal cut is made for the entire thickness of the alveolar process perpendicular to the axis of the deformed alveolar process. Formed bone block is separated while maintaining the connection with the periosteum and the mucous membrane of the occlusal and inner surfaces of the alveolar process. Bone block is formed in the form of pyramid with base on external surface of upper or lower jaw and apex on internal surface of alveolar process. Bone block is removed. Separated alveolar process is placed vertically and fixed to the body of the upper or lower jaw with a microplate with the help of screws. Wound is washed with an aqueous solution of chlorhexidine. Periosteum and mucous membrane are closed tightly.

EFFECT: method enables eliminating vertical deformation of the alveolar process of the jaws, giving the anatomically correct position of the alveolar process of the jaws, and then placing cylindrical implants in the alveolar process and performing orthopaedic rehabilitation on dental implants.

1 cl, 2 dwg, 2 ex

Description

The invention relates to medicine, namely to maxillofacial surgery, and can be used in otolaryngology.

The problem of eliminating vertical deformations of the alveolar process of the upper and lower jaws, which occurs as a result of partial or complete loss of teeth, with subsequent prosthetics on dental implants, is extremely relevant. Since the known methods of increasing the alveolar process do not fully allow achieving the anatomical spatial location of the alveolar process in order to install dental implants and achieve orthodontic rehabilitation of patients on artificial supports.

A method of targeted osseointegration with allogeneic materials is known, which allows to increase the volume of the alveolar process in the horizontal and vertical directions and eliminate defects by creating a framework of titanium foil or mesh over the augment and fixing it to the alveolar process with pins or microscrews (Kulakov A.A. National Guide to Dental Implantation. - GEOTAR-Media. - 2018. - 400 p., Kulakov A.A. National Guide to Maxillofacial Surgery. - GEOTAR-Media. - 2019. - 692 p., Immediate loading. Guide to successful implantology. - International Implantat Fondation Pablishing. Munich. Germany. - 2013. - 400 p. pp. 182-187).

A method is known in which the increase in the vertical size of the alveolar process consists of three-dimensional plastic surgery of the alveolar ridge by fixing two lateral bone blocks (monocortical autogenous transplants) one opposite the other with restoration of the original height of the alveolar ridge. The space between the blocks is carefully filled with bone chips. The monocortical graft is collected from the inner part of the ilium (Fouad Kuri, Hanser T., Kuri C., Neugebauer J. Regenerative methods in implantology. Translated by Yablonsky B. - M. - 2013. - 514 p. P. 230-290; Use of various methods of vertical and horizontal augmentation in case of atrophy of the alveolar process of the upper and alveolar part of the lower jaw. - Scientific Journal "ScienceRise" No. 3/4 (8) 2015).

Disadvantages of this method:

1. Does not imply a change in the position of the alveolar process;

2. The use of autogenous material causes additional trauma (donor site);

3. The use of allogeneic material in 12-15% of cases results in an increase in the alveolar process of only 20-30% of the planned amount;

4. High cost of surgical treatment.

The method of increasing the vertical size of the alveolar process by vertical transplantation of a bone block and three-dimensional reconstruction was chosen as a prototype. The technique involves horizontal osteotomy with the formation of a defect and its filling with autogenous or allogeneic materials (Fouad Kuri, Hanser T., Kuri Ch., Neugebauer J. Regenerative methods in implantology. Translation by Yablonsky B. - M. - 2013. - 514 p.)

Disadvantages of this method:

1. Using a donor site is an additional trauma (two surgical wounds)

2. Long periods from surgery to implantation

3. Creating absolute stability of transplants in some cases is impossible.

The purpose of the invention is to create a method for eliminating acquired vertical deformations of the alveolar process of the jaws, imparting an anatomically correct position to the alveolar process of the jaws in the event of its vertical deformation, which allows for the subsequent installation of cylindrical implants in the alveolar process and the implementation of orthopedic rehabilitation on dental implants.

The purpose is achieved by eliminating acquired vertical deformations of the alveolar process of the jaws, in which the volume of the removed area is calculated based on the results of cone-beam computed tomography, osteotomy of the alveolar process in the horizontal plane according to the formula, excision of a bone fragment, vertical movement of the alveolar process and fixation to the body of the jaw with microplates on screws.

Cone beam computed tomography is performed, the dimensions of the resected bone block are determined in the lateral projection of the alveolar process, points A, B, C, D, E necessary for the calculation are marked: first, the upper point B is determined, then point D, A and C are marked on the side opposite to point D, segments are measured on the deformed alveolar process AB, CD, CB, point E is found at a distance X, calculated using the mathematical formula X (CE) = [CDxAB]: CB, thereby calculating the bone area to be removed, where X or segment CE is the side of the base of the pyramid of the resected bone block, point A is the intersection of the horizontal line drawn from the apex of the alveolar process and the vertical line from the beginning of the deformation from the inner side, point B is the apex of the alveolar process, point C is the apex of the beginning of the deformation from the outer side of the alveolar process, point D is the apex of the beginning deformations on the inner side of the alveolar process, segment CD is the width of the base of the deformed section of the alveolar process, segment AB is the distance by which the apex of the alveolar process must be moved. Next, under conduction anesthesia, an incision is made in the mucous membrane of the upper jaw along the mucogingival line, the mucous membrane, submucous layer, periosteum are dissected, the mucoperiosteal flap is displaced upward, the alveolar process is skeletonized, two vertical cuts are made using a circular saw along the entire thickness of the alveolar process, limiting the deformed area of the alveolar process, at the base of the deformed area between the vertical cuts, a horizontal cut is made along the entire thickness of the alveolar process, perpendicular to the axis of the deformed alveolar process, the formed bone block is separated, maintaining the connection with the periosteum and the mucous membrane of the occlusal and inner surface of the alveolar process, a bone block is formed with a base on the outer surface of the upper or lower jaw and a apex on the inner surface to the height of the base calculated by formula, the bone block is removed, the separated alveolar process is installed vertically and fixed to the body of the upper or lower jaw with a microplate using screws, the wound is washed with an aqueous solution of chlorhexidine, the periosteum and mucous membrane are sutured tightly.

Novelty of the invention:

1. For the first time, a mathematical model was developed and implemented for calculating the volume and shape of the removed area of the alveolar process to eliminate vertical deformation of the jaws.

2. Cone beam computed tomography (CBCT) is performed to determine the size of the resected bone block in the lateral projection of the alveolar process, the points A, B, C, D, E necessary for the calculation are marked, the segments on the deformed alveolar process AB, CD, CB are measured and, using a mathematical formula, the bone area to be removed is calculated according to the formula X (CE) = [CDxAB]: CB.

3. The points are marked as follows. First, the upper point B is determined, which is the apex of the deformed alveolar process, then point D is marked, which will correspond to the apex of the beginning of the deformation on the inner side of the alveolar process. Then point A is determined - the intersection of the horizontal line drawn from the apex of the alveolar process and the vertical line from the beginning of the deformation on the inner side. Then point C is marked - the apex of the beginning of the deformation on the outer side of the alveolar process. On the opposite side from point D. Point E is located at a distance X, calculated using the formula X (CE) = [CDxAB]: CB. Which corresponds to the base of the pyramid of the resected (osteotomized) bone block.

4. At the base of the deformed area, between the vertical cuts, a horizontal cut is made across the entire thickness of the alveolar process, perpendicular to the axis of the deformed alveolar process, the formed bone block is separated, maintaining the connection with the periosteum and the mucous membrane of the occlusal and lingual surfaces of the alveolar process. A bone block is formed with a base from the vestibular surface of the upper jaw and a top from the lingual surface to the height of the base calculated by the formula. The bone block is removed, the separated alveolar process is installed vertically and fixed to the body of the upper/lower jaw with a microplate using screws.

The combination of essential features allows us to obtain a new technical result: to eliminate the vertical deformation of the alveolar process of the jaws using calculations based on CBCT data of the removed bone area (osteotomized) using the developed mathematical formula and without using additional materials.

There is no additional surgical wound that is used to take the autogenous bone block. No osteoplastic material is used, which in some cases can cause unwanted allergic reactions and increase the cost of the operation.

10 people were treated using this method, and good results were achieved; examples are given below.

The method is illustrated by the drawings shown in Fig. 1, 2.

Fig. 1 - calculation of the volume of the osteotomized area of the alveolar process of the lower jaw

Fig. 2 shows the calculation of the volume of the osteotomized section of the alveolar process of the upper jaw.

In Fig. 1-2: 1 - alveolar process, 2 - resected bone block, 3 - microplate, 4 - screws.

The method is carried out as follows.

The patient undergoes cone beam computed tomography (CBCT) to determine the size of the resected bone block in the lateral projection of the alveolar process, the points A, B, C, D, E necessary for the calculation are marked, the segments on the deformed alveolar process AB, CD, CB are measured and, using a mathematical formula, the bone area to be removed is calculated according to the formula X (CE) = [CDxAB]:CB.

X (segment CE) - the base of the pyramid of the resected (osteotomized) bone block,

point A - the intersection of the horizontal line drawn from the apex of the alveolar process and the vertical line from the beginning of the deformation on the inner side,

point B - apex of the alveolar process,

point C is the apex of the beginning of deformation from the outer side of the alveolar process,

point D - the apex of the beginning of deformation from the inner side of the alveolar process,

segment CD - the width of the base of the deformed section of the alveolar process,

segment AB is the distance by which the apex of the alveolar process must be moved.

The points are marked as follows. First, the upper point B is determined, which is the apex of the deformed alveolar process, then point D is marked, which will correspond to the apex of the beginning of the deformation on the inner side of the alveolar process. Then point A is determined - the intersection of the horizontal line drawn from the apex of the alveolar process and the vertical line from the beginning of the deformation on the inner side. Then point C is marked - the apex of the beginning of the deformation on the outer side of the alveolar process. On the opposite side from point D. Point E is located at a distance X, calculated by the formula X (CE) = [CDxAB]: CB. Which corresponds to the base of the pyramid of the resected bone block.

Under conduction anesthesia, an incision is made in the mucous membrane of the upper jaw along the mucogingival line. The mucous membrane, submucous layer, and periosteum are dissected. The mucoperiosteal flap is shifted upward, the alveolar process is skeletonized. Using a circular saw, two vertical cuts are made across the entire thickness of the alveolar process 1, limiting the deformed area of the alveolar process. At the base of the deformed area between the vertical cuts, a horizontal cut is made across the entire thickness of the alveolar process, perpendicular to the axis of the deformed alveolar process, the formed bone block is separated, maintaining the connection with the periosteum and the mucous membrane of the occlusal and inner surface of the alveolar process. A bone block 2 is formed with a base on the outer surface of the upper or lower jaw and a top on the inner surface at the height of the base calculated by the formula. The bone block 2 is removed, the separated alveolar process 1 is installed vertically and fixed to the body of the upper or lower jaw with a microplate 3 using screws. The wound is washed with antiseptic solutions, the periosteum and mucous membrane are sutured tightly. Standard medication and hygiene procedures are prescribed after the operation.

Clinical examples.

Example 1. Patient K, 56 years old, complained of missing teeth 26 and 27. CBCT revealed a deformation of the alveolar process of the upper jaw that prevented the installation of standard implants. A decision was made to perform an operation to eliminate the deformation of the alveolar process in segments 26-27. The removed bone area was calculated using the formula X=[CDxAB]:CB. The dimensions of the osteotomized area are calculated using cone beam computed tomography data, where X is the side of the base of the pyramid of the resected (osteotomized) bone block, C is the apex of the onset of deformation, CD is the width of the base of the deformed area of the alveolar process, AB is the distance by which the apex of the alveolar process must be moved.

X = [CD (7.8 mm) x AB (8.2 mm)] : CB (9.5 mm) = 6.7 mm side of the pyramid base of the required area to be removed to eliminate the deformation.

Under conduction anesthesia, an incision of the mucous membrane of the upper jaw was made along the mucogingival line in segment 26-27, measuring 2.5 cm. The mucous membrane, submucous layer, and periosteum were dissected. The mucoperiosteal flap was shifted upward, the alveolar process was skeletonized. Using a circular saw, 2 vertical cuts were made across the entire thickness of the alveolar process, limiting the deformed area of the alveolar process. At the base of the deformed area between the vertical cuts, a horizontal cut was made across the entire thickness of the alveolar process, perpendicular to the axis of the deformed process, the formed bone block was separated, maintaining the connection with the periosteum and the mucous membrane of the occlusal and inner surface of the alveolar process. A bone block was formed with a base on the outer surface of the upper jaw and a apex on the inner surface at the height of the base calculated using the formula X=[CDxAB]:CB. The bone block was removed, the separated alveolar process was installed vertically and fixed to the body of the upper jaw with microplates on screws, 2 screws on each side of the cut. The wound was washed with a solution of aqueous chlorhexidine, the periosteum and mucous membrane were tightly sutured. The sutures were removed on the 10th day. CBCT was repeated after 3 months. An operation was performed to remove the microplate and install an implant.

Example 2. Patient B, 58 years old, complained of missing teeth 44, 45 and 46. CBCT revealed a deformation of the alveolar process of the lower jaw, which prevented the installation of standard implants. A decision was made to perform an operation to eliminate the deformation of the alveolar process in segments 46-47. The removed bone area was calculated using the formula X=[CDxAB]:CB. The dimensions of the osteotomized area are calculated using cone beam computed tomography data, where X is the side of the base of the pyramid of the resected bone block, C is the apex of the onset of deformation, CD is the width of the base of the deformed area of the alveolar process, AB is the distance by which the apex of the alveolar process must be moved.

X = [CD (5.2 mm) x AB (9.2 mm)] : CB (7 mm) = 6.9 mm side of the pyramid base of the required area to be removed to eliminate the deformation.

Under conduction torus anesthesia, an incision of the mucous membrane of the lower jaw was made along the mucogingival line in segments 44-46, measuring 2.3 cm. The mucous membrane, submucous layer, and periosteum were dissected. The mucoperiosteal flap was shifted upward, the alveolar process was skeletonized. Using a circular saw, 2 vertical cuts were made across the entire thickness of the alveolar process, limiting the deformed area of the alveolar process. At the base of the deformed area between the vertical cuts, a horizontal cut was made across the entire thickness of the alveolar process, perpendicular to the axis of the deformed process, the formed bone block was separated, maintaining the connection with the periosteum and the mucous membrane of the occlusal and inner surface of the alveolar process. A bone block was formed with a base on the outer surface of the lower jaw and an apex on the inner surface at the height of the base calculated using the formula X=[CDxAB]:CB. The dimensions of the osteotomized area were calculated using cone beam computed tomography data. The cone-shaped bone block was removed, the separated alveolar process was installed vertically and fixed to the body of the lower jaw with microplates on screws, 2 screws on each side of the cut. The wound was washed with an aqueous chlorhexidine solution, the periosteum and mucous membrane were tightly sutured. The sutures were removed on the 10th day. CBCT was repeated after 3 months. An operation was performed to remove the microplate and install an implant.

Claims (3)

A method for eliminating acquired vertical deformations of the alveolar process of the jaws, characterized by the fact that cone-beam computed tomography (CBCT) of the alveolar process is performed in the lateral projection, then, based on the CBCT results, the dimensions of the resected bone block are determined, for this purpose, the points A, B, C, D, E necessary for the calculation are marked according to Fig. 1, 2, wherein first the upper point B is determined, then point D, then points A and C, then point E is marked at a distance X from point D, calculated using the mathematical formula X(CE)=[CD×AB]:CB, where X is the length of segment CE, mm, CE is the side of the base of the pyramid of the resected bone block, point A is the intersection of the horizontal line drawn from the apex of the alveolar process and the vertical line drawn from the beginning of the deformation from the inner side of the alveolar process, point B is the apex of the alveolar process, point C is the apex of the beginning of the deformation from the outer side of the alveolar process, point D is the apex of the beginning of the deformation from the inner side of the alveolar process, segment CD is the width of the base of the deformed section of the alveolar process, segment AB is the distance by which it is necessary to move the apex of the alveolar process; then, under conduction anesthesia, an incision is made in the mucous membrane of the upper or lower jaw along the mucogingival line, the mucous membrane, submucous layer, periosteum are dissected, then the mucoperiosteal flap is shifted upward, the alveolar process is skeletonized, two vertical cuts are made across the entire thickness of the alveolar process using a circular saw, limiting the deformed section of the alveolar process, at the base of the deformed section between the vertical cuts a horizontal cut is made across the entire thickness of the alveolar process perpendicular to the axis of the deformed alveolar process, the formed bone block is separated, maintaining the connection with the periosteum and the mucous membrane of the occlusal and inner surfaces of the alveolar process, a bone block is formed in the form of a pyramid with a base on the outer surface of the upper or lower jaw and a apex on the inner surface of the alveolar process, the bone block is removed, the separated alveolar process is installed vertically and fixed to the body of the upper or lower jaw with a microplate using screws, the wound is washed with an aqueous solution of chlorhexidine, sutured periosteum and mucous membrane tightly.

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