RU2749042C1 - Method for temporary prosthetics of auricle for period of osseointegration of cranial implants - Google Patents

Abstract

FIELD: medicine; otorhinolaryngology; dentistry.

SUBSTANCE: in the preoperative period, a multi-spiral computed tomogram of the patient's head is performed. The computed tomography data is converted in the simulation program into a three-dimensional image of the stl extension. A three-dimensional image of the patient's existing ear is cut out and mirrored. A surgery is performed to install cranial retention implants in the temporal bone. At the end of the surgery, the surgical field with the installed cranial implants is scanned with an intraoral dental scanner or a laboratory scan of the alginate physical cast. According to the obtained optical cast of the temporal bone with the installed implants, a previously converted three-dimensional image of the auricle is adapted with the formation of a 1.5 mm thick cuff that overlaps the surgical field with the installed implants by 5 mm around the perimeter. At the same time, a dome-shaped gap of 1.5 mm is formed in the projection of the installed implants. After that, the file of the three-dimensional image of the formed epithesis of the auricle is opened in the program for preparing the object for 3D printing and enlarged in volume by 1 mm. The internal digital volume of the prosthesis is cut out, leaving a wall thickness of 1 mm. Holes with a diameter of 2 mm are formed in different poles of the object. The resulting image of the cuvette is printed on a 3D printer. Without removing the support of three-dimensional printing, through the holes in the polymer form of the epithesis of the auricle, medical silicone, dyed in a flesh color, is injected using a disposable medical syringe. The holes through which the silicone was injected are covered with a paint paper self-adhesive tape; and the cuvette is put in the furnace at a temperature of 82 degrees centigrade for 40 minutes. After vulcanizing the silicone, the polymer shell of the cuvette is broken and the silicone temporary ear epithet is removed without damage. The epithesis is fixed to the patient's skin on a silicone adhesive applied along the periphery of the ectoprosthesis, after first introducing a wound-healing drug into the gap above the implants.

EFFECT: method allows making a silicone prosthesis of the auricle, similar in shape to the natural patient's ear providing visual blockade of cranial retention implants and epithelization of the skin in the implanted area of the head.

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Description

The invention relates to medicine, namely to facial prosthetics, and can be used for temporary orthopedic rehabilitation of patients with an absent auricle for the period of osseointegration of cranial implants.

From the prior art, there is known a method for manufacturing an auricle prosthesis, which includes obtaining a wax template for an auricle prosthesis in a collapsible reusable stamp made of plaster, fitting a wax template of a prosthesis on the patient's face at the seat, subsequent processing of a wax template by forming an individual relief on it for obtaining a wax copy of the prosthesis, which is then gypsum into a cuvette, replace the wax with silicone, remove the obtained silicone prosthesis from the cuvette, grind (Patent No. 2421188 dated 20.06.2011).

Known ear endoprosthesis, which is a synthetic base made by digital prototyping with computer modeling of the cartilaginous structure of the external auricle and subsequent milling on a machine with numerical control; having a surface on the side of the congruent field of contact with a high accuracy of coincidence with the field of contact, as a result of which its base is individual, completely congruent to the receiving bed and plays the role of the inner frame of the auricle. An individual reconstructive endoprosthesis for otorhinolaryngology, made by digital prototyping, consists of a porous biosynthetic material and has a surface on the side of the congruent adjoining field with high accuracy, coinciding with the adjoining field. Thanks to the use of computer modeling and milling on a numerically controlled machine, the reconstructive individual endoprosthesis for otorhinolaryngology has a three-dimensional design. It repeats with high accuracy the cartilaginous base of the external auricle, the surface of the base of the endoprosthesis is completely congruent to the receiving field of contact. It not only allows you to completely restore the missing part of the outer ear or a completely lost auricle as a result of injuries, burns, and oncological diseases, but it is also reliably fixed, acting as the inner frame of the auricle. Does not require additional screw retainers (Education and science in modern conditions: materials of the VIII International scientific-practical conference (Cheboksary, June 26, 2016) / editorial board: ON Shirokov [and others]. - Cheboksary : CNS "Interactive plus", 2016. - No. 3 (8). - 31-34 p.).

From the prior art, there is a known method of manufacturing an auricle prosthesis, which consists in converting the image of a computer tomogram of the patient's existing ear into a digital format of a 3D model, mirroring it and carrying out correction in the adjacent area in the area of the missing ear with the formation of a 1 mm thick cuff to the tissues of the prosthetic bed, and with a diameter corresponding to the diameter of the external auricle, in the 3D-modeler program, displaying the obtained 3D model of the auricle prosthesis negatively in a rectangular shape, the digital model of the shape is divided lengthwise into two parts, on one side of the part of the shape a canal is modeled, for subsequent introduction of silicone, and with on the opposite side of the mold, two similar channels for the outflow of structural material and prevention of pore formation, each of the two halves is divided into three more fragments, so that the display of the ear in the form, having the greatest undercuts, remained in one of the fragments and the antagonist fragment, followed by modeling on each of the fragments of the shape on the end surface at the junction with the subsequent fragment along the diagonal of the rectangle of cylindrical protrusions, and on the subsequent fragment of the shape, depressions corresponding to the shape of the protrusions are modeled, similar mirrored protrusions and holes are modeled on the inner surfaces of the extreme fragments of the shape, 3D printing a physical model of a mold for the manufacture of an auricle prosthesis from a heat-resistant polymer, mechanical processing of the printed form, matching the fragments of the form and fixing them with a clamp, injecting silicone for the manufacture of an auricle prosthesis by means of a syringe into a previously modeled canal, polymerization of the prosthesis in a dry heat cabinet at a temperature of 82.5 degrees Celsius for one hour, removing the silicone ear prosthesis and its final processing (Patent No. 2699291 dated 09/05/2019).

The known method of prosthetics of the auricle consists in carrying out a computed tomogram of the head of a patient with an absent auricle, converting the resulting image of the existing ear into a digital CAD / CAM system module, followed by digital modeling of the absent auricle by mirror rotation and forming the border of adhesion to the prosthetic field, translating the resulting digital model of the auricle prosthesis into a physical polymer prototype model by means of 3D-printing, separation of the prototype of the auricle prosthesis with a diamond dental disk into two parts: "auricle" and "prosthesis base", then "auricle" and "prosthesis base" are separately installed into a dental cuvette and filled with duplicate dental silicone, after polymerization of which the prototype is removed and medical dental silicone is poured into the resulting mold under pressure under vacuum conditions, the resulting parts of the auricle prosthesis are processed from excess material and individualized with medical paints, then along the line of connection of the components of the prosthesis along the end surface, holes are drilled coaxially to each other to install fixing elements made of hard dental polymer, having a round flat base, a neck and a hemispherical head, the edges of the hemispherical head are made with the diameter of the holes is half the diameter of the heads and the base of the fixing elements, after which the "auricle" and the "base of the prosthesis" are connected by means of these fixing elements, then the auricle prosthesis is fixed to the tissues of the patient's prosthetic bed by means of medical glue (RF Patent No. 2637602 from 05.12.17).

A known method of temporary auricle prosthetics for the period of postoperative formation of the external auditory canal consists in obtaining a computer tomogram of the head, highlighting on it a volumetric image of the existing external and internal auditory canal of the patient's ear from the "healthy side", followed by converting the resulting file into a digital CAD module \ CAM system, modeling the absent auricle and the auditory canal by mirroring the image of the structures of the opposite side and forming a cuff of the border of adhesion to the prosthetic field, reducing the resulting image over the entire surface by 1-2 mm, followed by its 3D-printing from a medical polymer, coating the resulting polymer composition of an ear prosthesis with an auditory canal with a layer of medical silicone 1-2 mm thick by layer-by-layer application, the formation of a transmastoidal approach to the external auditory canal with a diameter corresponding to the diameter of the analogue of the auditory canal manufactured of the prosthesis with the laying of skin flaps to the bone edges of the trepanation cavity, and fixation of the temporary ear prosthesis, with the introduction into the formed operating channel of the part of the prosthesis corresponding to the patient's ear canal, by means of silicone glue applied to the cuff of the temporary prosthesis of the auricle adjacent to the skin. The use of computed tomography data of the patient's preserved natural auricle and auditory canal and the use of modern additive 3D printing technologies make it possible to accurately reproduce the planned anatomy of the auditory canal, with its congenital absence or acquired infection, which is physiological (RF Patent No. 2714119 dated 02/11/2020) ...

The closest to the proposed method is a method for the manufacture of facial prostheses, which consists in obtaining in the preoperative period a cone-beam computed tomography of the head and a 3D image of the face, comparing the obtained images in a computer modeling program into a single volumetric image, highlighting a part of the face planned for removal in the image, according to the boundaries of the proposed operation, clarification of the boundaries of the prosthesis adhesion during the completion of the operation at the stage of suturing, by the method of face scanning and comparison of the previously obtained image, highlighting the boundaries of the future prosthesis with refined boundaries, increasing the image volume by 0.5 mm and removing the internal volume of the prosthesis image with the formation of thickness of 0.5 mm, with the additional formation of two holes in the resulting volumetric object at different poles of the object, printing the resulting image on a 3D printer with a dental polymer, removing supports, light polymerization of the object, cc inserting a colored flesh-colored medical silicone into one of the holes of the object and removing the outer polymer shell, removing excess silicone from the facial prosthesis (RF Patent No. 2727741 dated 23.07.2020).

The problem to be solved by the invention is the temporary prosthetics of the auricle of patients with unilateral atresia or microtia of the ear, for the period of osseointegration of the cranial retention devices.

The technical result of the invention is the manufacture of a silicone auricle prosthesis, similar in shape to the patient's natural ear and providing visual blockade of cranial retention implants and promoting epithelialization of the postoperative wound in the implanted head area.

The technical result of the invention is provided by the fact that the method of temporary prosthetics of the auricle for the period of osseointegration of cranial implants is carried out as follows, in the preoperative period, a multispiral computed tomogram of the patient's head is carried out, the computed tomography data is converted into a volumetric image of the stl extension in the simulator program, a three-dimensional image is cut out the patient's existing ear and is mirrored, an operation is performed to install cranial retention implants in the temporal bone, upon completion of the operation, a scan of the operating field with installed cranial implants is performed with an intraoral dental scanner or laboratory scanning of an alginate physical impression, according to the obtained optical impression of the temporal bone with installed implants adapt the previously converted volumetric image of the auricle with the formation of a cuff 1.5 mm thick, overlapping the surgical software le with 5 mm implants installed around the entire perimeter, while a dome-shaped gap of 1.5 mm is formed in the projection of the installed implants, after which the volumetric image file of the formed auricle epithesis is opened in the program to prepare the object for 3D printing and is increased in volume by 1 mm, and the internal digital volume of the prosthesis is cut out, leaving a wall thickness of 1 mm, holes with a diameter of 2 mm are formed in different poles of the object, the resulting image of the cuvette is printed on a 3D printer, without removing the support of three-dimensional printing, through the holes in the polymer form of the ear epithesis the shells through a disposable medical syringe are injected with medical silicone painted in a flesh color, the holes through which the silicone was injected are closed with masking paper self-adhesive tape and placed in an oven at a temperature of 82 degrees Celsius for 40 minutes, after vulcanization of the silicone, the polymer shell of the cuvette is broken and the silicone temporary epithesis of the ear is removed without damage, fix uh pitez to the patient's skin on silicone glue applied along the periphery of the ectoprosthesis, having previously introduced a wound-healing drug into the gap over the implants.

The advantages of the proposed technology are that the patient, right on the day of the operation, receives an auricle epithesis, which closes the installed implants and completely repeats the shape of his existing ear on the opposite side, which has a high medical and socio-psychological effect. And a high therapeutic effect is also achieved due to the fact that antiseptic and epithelizing agents, for example, solcoseryl ointment (gel), are introduced into the gap made in the prosthesis in the projection of the installed cranial implants?

The file of the volumetric image of the patient's face can be used an infinite number of times for the subsequent manufacture of an unlimited number of designs of ectoprostheses according to the proposed technology. Developed in the proposed method, the object in the form of a "shell" cuvette completely repeats the volumetric file of the auricle, cheap to manufacture and has a low cost due to the thickness of the "shell" cuvette of the prosthesis in 1 mm. The method is realized by the technical characteristics of 3D printers and worked out experimentally, which took into account the flexibility of the wall of the "shell" cuvette, the ability to keep its shape during silicone vulcanization and is easily removed at the final stage of ectoprosthesis manufacturing.

Prosthetics of the patient according to the proposed method is carried out as follows:

1. A multispiral computed tomogram of the patient's head is performed on the patient before the operation period.

2. In a modeling program, for example, InVesalius 3.1, the computed tomography data is converted into a volumetric image of the stl extension.

3. Next, in a program, for example, Meshmixer, a volumetric image of the patient's existing ear is cut out and mirrored.

4. An operation is performed to install cranial retention implants into the temporal bone.

5. An optical impression or a physical impression is poured with an intraoral dental scanner using traditional technology, followed by sanitizing with a laboratory scanner, the operating field with installed cranial retention implants.

6. The resulting image is opened in the program, for example, Meshmixer and the previously converted volumetric image of the auricle is adapted along the temporal bone with installed implants with the formation of a cuff 1.5 mm thick, overlapping the surgical field with installed implants by 5 mm around the entire perimeter.

7. In the projection of the installed implants, a dome-shaped gap of 1.5 mm is formed.

8. The volumetric image file of the formed auricle epithesis is opened in a program for preparing an object for 3D printing, for example, Anycubic Photon, and enlarged by 1 mm, and the internal digital volume of the prosthesis is cut out, leaving a wall thickness of 1 mm at different poles the object is formed by holes with a diameter of 2 mm.

9. The resulting image is printed on a 3D printer, for example, DLP 3D Anycubic Photon (Shenzhen Anycubic Technology Co., Ltd, China), processed in accordance with the recommendations of the manufacturer of the structural material, for example, Harzlabs for dental model (Harzlabs, Russia), without removing print support.

10. In the polymer form of the epithesis of the auricle by means of a disposable medical syringe, through the previously formed holes, medical silicone, painted in a flesh color, is injected.

11. The holes through which the silicone was introduced are covered with masking paper self-adhesive tape and placed in an oven at 82 degrees Celsius for 40 minutes to cure the silicone.

12. After curing the silicone, the polymer shell of the "shell" cuvette is broken and the temporary silicone ear epithesis is easily removed without damaging the surface.

13. The obtained silicone epithesis is fixed to the patient's skin on silicone glue applied along the periphery of the prosthesis, after having introduced a wound-healing drug, for example, solcoseryl ointment, into the gap above the implants.

Clinical example

A 29-year-old patient K. came to the clinic with complaints of an aesthetic facial defect associated with a congenital absence of the right auricle. Based on the results of anamnesis, examination and computed tomography, the diagnosis Q16.0 - Congenital absence of the auricle (ICD 10) was made. The decision was made to replace the missing auricle with silicone epithesis supported by cranial retention implants. Treatment:

According to the computed tomography data, carried out at the diagnostic stage, the head image was converted in the InVesalius 3.1 program into a volumetric image of the stl extension.

In the Meshmixer modeler, the volumetric image of the patient's existing ear was highlighted using the "virtual scissors" function and mirrored to the opposite side of the skull from the side of the missing ear.

Under an adequate operation anesthesia, 3 planned implants were installed in the patient's temporal bone, for the subsequent retention of the silicone epithesis of the auricle.

Upon completion of the operation, an intraoral dental scanner was scanned on the surgical site with the implants installed. The previously converted volumetric image of the auricle was adapted from the image obtained as a result of scanning in the Meshmixer program. On the image of the auricle, a 1.5 mm thick cuff was formed, overlapping the surgical field with installed implants by 5 mm along the entire perimeter. A dome-shaped gap of 1.5 mm was formed in the projection of the installed implants.

The volumetric image file of the formed auricle epithesis was transferred to the Anycubic Photon software for preparing the object for 3D printing and increased in volume by 1 mm, and the internal digital volume of the prosthesis was cut out, leaving a wall thickness of 1 mm. Holes with a diameter of 2 mm were formed at different poles of the object.

The resulting image was printed on a DLP 3D Anycubic Photon 3D printer (Shenzhen Anycubic Technology Co., Ltd, China) and processed in accordance with the recommendations of the structural material manufacturer Harzlabs (Russia), without removing the print support.

Medical silicone, painted in flesh color, was injected into the polymeric form of the auricle epithesis by means of a disposable medical syringe through previously formed holes.

The openings through which the silicone was introduced were covered with masking paper self-adhesive tape and placed in an oven at 82 degrees Celsius for 40 minutes.

After vulcanizing the silicone material, the polymer shell was destroyed and the silicone temporary ear epithesis was removed.

The obtained silicone epithesis is fixed to the patient's skin on silicone glue, having previously introduced wound-healing ointment, solcoseryl into the gaps above the implants. The prosthesis was removed once a day, washed with warm soapy water, and fixed back on glue with preliminary application of solcoseryl ointment to the postoperative wound. Solcoseryl ointment was used within 14 days after the operation.

After 5 months, a final silicone ectoprosthesis of the auricle was fabricated with support on cranial implants of a magnetic beam design for effective retention of the epithesis.

Claims (1)

The method of temporary prosthetics of the auricle for the period of osseointegration of cranial implants is carried out as follows: in the preoperative period, a multispiral computed tomogram of the patient's head is performed, the computed tomography data are converted into a volumetric image of the stl extension in the modeling program, a three-dimensional image of the patient's existing ear is cut out and mirrored, an operation is performed to install cranial retention implants in the temporal bone, upon completion of the operation, a scan of the operating field with installed cranial implants is performed with an intraoral dental scanner or laboratory scanning of an alginate physical impression, according to the obtained optical impression of the temporal bone with installed implants, a previously converted volumetric image of the auricle with formation cuffs 1.5 mm thick, overlapping the surgical field with installed implants by 5 mm around the entire perimeter, at the same time, a dome-shaped gap of 1.5 mm is formed in the projection of the installed implants, after which the volumetric image file of the formed auricle epithesis is opened in the program for preparing the object for 3D printing and increased in volume by 1 mm, and the internal digital volume of the prosthesis is cut out, leaving wall thickness of 1 mm, holes with a diameter of 2 mm are formed in different poles of the object, the resulting image of the cuvette is printed on a 3D printer, without removing the support for three-dimensional printing, medical silicone, colored in flesh-colored, the holes through which the silicone was injected are closed with a masking paper self-adhesive tape and placed in an oven at a temperature of 82 degrees Celsius for 40 minutes, after vulcanization of the silicone, the polymer shell of the cuvette is broken and the silicone temporary ear epithesis is removed without damage, the epithesis to the patient's skin is fixed on silicone glue applied on the periphery of the ectoprosthesis, having previously introduced a wound-healing drug into the gap over the implants.