RU2794833C1 - Method for fixing radiopaque markers under edentia for designing of surgical navigation guide - Google Patents

Abstract

FIELD: medicine; surgical dentistry.

SUBSTANCE: invention relates to medicine, specifically to surgical dentistry and can be used for treatment of patients using dental implants and navigational surgical guide. Method for fixing radiopaque markers when combining computed tomography images in the DICOM file format with intraoral scan of the jaw ridge bone in the STL file format for adentia for designing of surgical navigation guide includes drying oral mucosa, application of Diplen-Dent film on the immobile mucosa of jaw ridge bone, fixing of radiopaque markers from radiopaque liquid-flowing light-cured resin on the film and their polymerisation. Record STL-file by intraoral imaging of jaw ridge bone. Record DICOM file by cone beam computed tomography. They are combined using radiopaque markers, then surgical navigation guide is designed.

EFFECT: improved fixation of radiopaque markers in the oral cavity is approved, thereby minimizing the occurrence of errors when accurately combining computed tomography in the DICOM file format with an intraoral scan of jaw ridge bone in the STL file format under edentia, reducing the risk of radiopaque markers getting into food and the patient's airway.

1 cl, 6 dwg

Description

The invention relates to medicine, namely to surgical dentistry, and can be used in the treatment of patients using dental implants and a navigational surgical template.

Currently, navigational surgery is developing extremely rapidly. Surgical templates are becoming not just a “modern trend”, but a necessity in the surgical protocol when installing dental implants (N.E. Degtyarev, R.F. Mukhametshin, S. Mamedov et al. // HeadandNeck / Head and Neck. Journal of the All-Russian Public Organization Federation of Head and Neck Specialists - 2020). Their use determined the exact positioning of the implant in the bone, thereby reducing the occurrence of iatrogenic factors by an order of magnitude (patent No. 2758099, A61C 13/38, 10/26/2021. Navigation template for dental implantation with a channel for irrigation of the surgical field, authors A.V. Guskov, A. V. Kuznetsov, D. N. Mishin and others).

Diploin-Dent films are recommended and widely used in leading dental centers. Russian developers have proposed a fundamentally new type of Diplen-Dent polymer films, in which good adhesion to the mucous membrane is combined with the possibility of prolonged administration of drugs (registration certificate for a medical device FSR 2008/02392). Films "Diplen-Dent" consist of two layers - hydrophilic and hydrophobic, and depending on the location of the layer, two sides of the film are distinguished. The hydrophilic layer, or side, has the ability to adhere to the moist mucous membrane, the wound surface. [Electronic resource; Access mode: http://dentashop.ru/diplen.html].

There are a number of ways to combine cone beam computed tomography with oral topography to design surgical guidance templates for dental implant placement.

A known method of manufacturing a template for implant installation (patent RU No. 2369354, A61C 8/00, 03/27/2008), the essence of which is that using an X-ray contrast impression mass, an impression is taken from the patient's oral cavity, which acts as a template prototype, and due to this, the topology of the oral cavity is recorded. After that, the patient's oral cavity, together with the X-ray contrast impression mass, is scanned using a computed X-ray tomograph (CT) and an X-ray image is obtained, and the optimal spatial position of the implant in the patient's jaw bone tissue is modeled using the obtained digital images. Then, with the help of software, the impression mass is recognized in the three-dimensional image and, based on the image of the impression mass in contact with the patient's oral cavity, a surgical template is created.

The disadvantage of this method is the low accuracy of binding the topology of the oral cavity scan to the topology of bone tissues, the need to take an impression, and cast plaster models.

The disadvantages are due to errors in the re-installation of the impression in the patient's oral cavity, the non-optimal shape and location of the markers, as well as deformations of the impression during repeated use.

There is a known method of combining computed tomography with oral topography using intraoral scanning of the alveolar ridge of the jaw and radiopaque markers in adentia for designing a surgical navigation template, chosen by the authors as a prototype (patent RU No. 2778963, A61B 6/00, 29.08.2022). The method consists in the fact that after drying the mucous membrane of the oral cavity with a spacer, radiopaque markers of an individual shape and size are applied to the immovable mucosa of the alveolar crest of the jaw from a radiopaque liquid-flowing light-curing composite, then the applied radiopaque markers are polymerized with a dental lamp, the reliability of fixation of the radiopaque markers to the dried mucous membrane of the cavity is checked of the mouth with a dental probe, after which an intraoral scan of the alveolar ridge of the jaw is performed and an STL file is obtained, then a cone beam computed tomography is performed and a DICOM file is obtained, after which, using the software, the STL file and the DICOM file are combined using radiopaque markers, after of which a surgical navigation template is designed.

The disadvantages are due to the low adhesion of the composite to the soft tissues of the oral cavity. Possible changes in the location of radiopaque markers, which provokes errors when combining the topology of the oral cavity scan with the topology of bone tissues, as well as the possible ingress of radiopaque markers into the patient's food and respiratory tract.

The problem, which is not the solution of the present invention, is the creation of an accurate surgical navigation template in conditions of adentia, reducing the time of treatment of patients.

The technical result of the invention is to improve the fixation of radiopaque markers in the oral cavity, in connection with this, to minimize the occurrence of errors when accurately combining computed tomography (DICOM file) with an intraoral scan of the alveolar ridge of the jaw (STL file) in edentulous conditions, reducing the risk of getting radiopaque markers in the food and respiratory tract of the patient.

The specified technical result in the claimed method of combining computed tomography with the topography of the oral cavity using intraoral scanning of the alveolar ridge of the jaw of radiopaque markers in adentia for designing a surgical navigation template is achieved by applying a film "Diplen-Dent" to the immobile mucosa of the alveolar ridge of the jaw. Next, radiopaque markers of individual shape and size from a radiopaque liquid-flowing light-cured composite are fixed onto the Diplen-Dent film. Then the applied radiopaque markers are polymerized with a dental lamp, the reliability of fixation of the radiopaque markers to the film "Diplen-Dent" on the immovable mucosa of the alveolar ridge with a dental probe is checked, after which intraoral scanning of the alveolar ridge of the jaw is performed and an STL file is obtained. Then, a cone beam computed tomography is performed and a DICOM file is obtained, after which, using software, the STL file and the DICOM file are combined using radiopaque markers, and then a surgical navigation template is designed.

This method is illustrated with images reflecting

the sequence of implementation of the proposed method, where:

Fig. 1 - radiopaque markers on the Diplen-Dent film in the oral cavity;

Fig. 2 - intraoral scanning of the alveolar crest of the jaw (obtaining an STL file);

Fig. 3 - cone beam computed tomography (obtaining a Dicom file);

Fig. 4 - merging STL-file and DICOM-file;

Fig. 5 - merging STL-file and DICOM-file;

Fig. 6 - design of a navigational surgical template.

In practice, the method is carried out as follows.

On the immobile mucosa of the alveolar ridge of the jaw, a film of "Diplen-Dent" is applied. Next, radiopaque markers of individual shape and size are fixed on the film "Diplen-Dent" from a radiopaque liquid-flowing light-curing composite, then the applied radiopaque markers are polymerized with a dental lamp (Fig. 1). The reliability of fixation of radiopaque markers to the film "Diplen-Dent" on the immovable mucosa of the alveolar ridge with a dental probe is checked, after which an intraoral scan of the alveolar ridge of the jaw is performed to obtain an STL file (Fig. 2). The patient is then subjected to a cone beam computed tomography and a Dicom file is obtained (FIG. 3). Next, in a special program, the STL file and the DICOM file are compared using X-ray contrast markers (Fig. 4), (Fig. 5), after which a surgical navigation template is designed (Fig. 6).

The method proposed by the authors allows to achieve improved fixation of radiopaque markers in the oral cavity, in this regard, the occurrence of errors is minimized when accurately combining computed tomography (DICOM-file) with an intraoral scan of the alveolar ridge (STL-file) in edentulous conditions, the risk of hitting radiopaque markers in the food and respiratory tract of the patient.

The essence of the invention is illustrated by clinical examples.

Clinical example 1.

Patient S., 65 years old, came to the clinic on January 27, 2022 with a complaint of missing teeth in the upper jaw. A comprehensive survey has been carried out. With the help of computed tomography, a sufficient amount of bone tissue was determined for the installation of dental implants. The immovable mucosa of the alveolar ridge of the jaw was covered with a film of "Deeplen-Dent". Next, radiopaque markers of individual shape and size from a light-cured composite were fixed on the Diplen-Dent film, polymerized with a dental lamp, and the reliability of fixing individual radiopaque markers to the Diplen-Dent film on the fixed mucosa of the alveolar ridge with a dental probe was checked. An intraoral scan of the alveolar ridge of the jaw was performed (obtaining an STL file), then a cone beam computed tomography (learning a DICOM file) was performed on the patient, then a special program was used to compare the STL file with the DICOM file using X-ray contrast markers, after which they started designing surgical navigation template.

Clinical example 2 .

Patient F., 74 years old, came to the clinic on 03/09/2022 with a complaint of missing teeth in the lower jaw. A comprehensive survey has been carried out.

With the help of computed tomography, a sufficient amount of bone tissue was determined for the installation of dental implants. On the immobile mucosa of the alveolar crest of the jaw, a film of "Diplen-Dent" was applied. Next, radiopaque markers of individual shape and size from a light-cured composite were fixed on the Diplen-Dent film, polymerized with a dental lamp, and the reliability of fixing individual radiopaque markers to the Diplen-Dent film on the immobile mucosa of the alveolar ridge with a dental probe was checked. An intraoral scan of the alveolar ridge of the jaw was performed (obtaining an STL file), then a cone beam computed tomography (obtaining a DICOM file) was performed on the patient, then a special program was used to compare the STL file with the DICOM file using X-ray contrast markers, after which they started designing surgical navigation template.

Claims (1)

A method for fixing radiopaque markers when combining computed tomography images in the DICOM file format with an intraoral scan of the alveolar ridge in the STL file format in case of adentia for designing a surgical navigation template, which consists in the fact that after drying the oral mucosa with a emptyer, radiopaque markers are applied to the individual shapes and sizes from a radiopaque liquid light-curing composite, then the radiopaque markers are polymerized with a dental lamp, the reliability of the fixation of the radiopaque markers with a dental probe is checked, after which an intraoral scan of the alveolar ridge of the jaw is performed and an STL file is performed, a cone beam computed tomography is performed and a DICOM file is obtained, then, using software, they combine the STL file and the DICOM file using radiopaque markers, after which a surgical navigation template is designed, characterized in that, after drying the oral mucosa with a emptyer, a film "Diplen- Dent”, on which radiopaque markers of individual shape and size are then fixed from a radiopaque fluid light-curing composite.

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