RU2826752C1 - Method of corticotomy with simultaneous directed bone regeneration in frontal part of lower jaw at stages of orthodontic treatment of patients with occlusion anomalies - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to maxillofacial reconstructive surgery, and can be used for corticotomy with simultaneous directed bone regeneration in frontal part of lower jaw at stages of orthodontic treatment of patients with occlusion anomalies. Method involves an arched incision of the oral mucosa under infiltration anaesthesia at 5.0 mm at the level of teeth 31 and 41 and by 7.0 mm at the level of teeth 32 and 42 from the border of the attached and movable mucosa, incision at angle of 45 degrees of the chin muscle to the periosteum. Periosteum is dissected and exfoliated apically. Alveolar portion of the lower jaw within teeth 34-44 and a chin portion of the lower jaw are skeletonised; an auto-bone chips are taken from the chin portion of the lower jaw by means of a scraper. Piezotome is used to dissect a cortical bone between roots of teeth 44, 43, 42, 41, 31, 32, 33, 34 to a depth of the cortical layer to a spongy substance. In the coronary direction, the corticotomy line does not reach the bone peak by 1 mm, in the apical direction – by 1 mm below the root apex. Produced auto-bone chips are mixed with the allograft at ratio of 1:1. Bone mixture is laid on the surface of the alveolar process in the area of the corticotomy with a layer thickness of at least 5 mm. Fibrin membrane is laid on top of the laid graft. Apically displaced periosteum is fixed to the coronary portion with a resorbable suture. Muscles and mucous membrane are closed.

EFFECT: method provides improved quality of orthodontic treatment due to increased volume of bone tissue around teeth roots with subsequent movement of roots into newly formed bone.

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Description

AREA OF TECHNOLOGY

The invention relates to the field of medicine, in particular to maxillofacial reconstructive surgery, namely to a method of corticotomy with simultaneous directed bone regeneration in the frontal section of the lower jaw at the stages of orthodontic treatment of patients with occlusion anomalies.

PRIOR ART

Various traditional methods of maxillofacial reconstructive surgery are known from the state of the art. Below are descriptions of the said methods, known from published sources.

Over the past decades, the number of patients seeking orthodontic treatment has increased, as have aesthetic demands and the need for shorter treatment times.

At the stages of most traditional orthodontic treatment methods, the orthodontist is faced with the problem of bone loss, insufficient bone around the roots of the teeth, which makes the planned movements difficult or impossible without preliminary surgical preparation.

Various methods, both surgical and non-surgical, are used as an adjunct to orthodontic treatment. Recently, one of the most commonly used is corticotomy. Corticotomy is defined as a surgical procedure in which the cortical bone is cut, perforated or mechanically altered without actually affecting the medullary bone. The purpose of this method is to enhance blood circulation, metabolism in the area of the intervention, accelerate tooth movement, and reduce treatment time.

From Periodontal Restorative Dentistry. 2021 Jan-Feb; 41(1):105-111. DOI: 10.11607/PRD.4562, the following is known: Orthodontic treatment can result in marginal bone resorption when teeth move beyond the bone cortex. The aim of this case series was to test corticotomy with guided bone regeneration (GBR) procedure to regenerate bone in the direction of movement beyond the original bone cortex. Ten adult patients (60 anterior teeth), all with severe anterior crowding, were included in the study. Orthodontic therapy at all study sites involved selective surgical corticotomy and simultaneous GBR procedure. CBCT scans were performed before the start of orthodontic treatment (T0) and at the end of treatment (T1; mean: 7 months; range: 6 to 9 months). Pre- and postoperative CBCT images were superimposed using a DICOM viewer (3D Slicer) and examined using image processing software (ImageJ, National Institutes of Health) to measure the region of interest of the buccal plate. The mean area was 0.58 ± 0.22 ^mm2 at T0 and 1.76 ± 0.4 ^mm2 at T1 with statistically significant difference (P < 0.05). The combination of corticotomy and regenerative procedure seems to be able to increase the original bony anatomy when the root is relocated beyond the original bony envelope.

The described method is effective, but quite technically complex and financially expensive.

The closest to the invention is the method for increasing the volume of bone tissue of the alveolar process of the jaw (RU2551923C1, published 10.06.2015). In the frontal section, in the area of the fourth teeth, infiltration anesthesia is performed with partial hydropreparation of soft tissues, making a needle injection into the movable mucous membrane at a distance of 1-2 mm from the mucogingival line. At a distance of 1-2 mm from the said line, horizontal incisions of 10±2 mm in length are performed opposite teeth 3-4, on the right and left. Then, using a semi-blunt separator inserted through the said incisions, the periosteum is peeled off from the bone along the frontal group of teeth, forming in the projection of their roots, on the border of the attached mucous membrane, a subperiosteal tunnel of vertical size 15±1.5 mm. The bone-plastic material is introduced into the formed subperiosteal tunnel through the above-mentioned incisions, which is then evenly distributed by palpation. In this case, the bone-plastic material is introduced using tweezers with jaws 3÷5 mm wide, bent relative to the springy branches, while simultaneously widening the subperiosteal tunnel using a displacing spatula with a working blade part bent relative to the handle, 8±2 mm wide. The wound is sutured with the capture of the oral mucosa and periosteum.

The proposed analogue comes closest to solving the problems solved by the claimed invention, however, in the opinion of the applicant, the problem is not solved in the most effective way.

SUMMARY OF THE INVENTION

Accordingly, there is a need to eliminate at least some of the above-mentioned shortcomings.

The technical problem that this invention is aimed at solving is improving the quality of orthodontic treatment by increasing the volume of bone tissue around the roots of teeth, followed by moving the roots into the newly formed bone and improving (changing the phenotype) of the attached gum.

The set goals can be achieved using the method of corticotomy with simultaneous directed bone regeneration in the frontal part of the lower jaw at the stages of orthodontic treatment of patients with occlusion anomalies, including an arcuate incision of the oral mucosa under infiltration anesthesia at a distance of 5.0 mm at the level of teeth 31 and 41 and 7.0 mm at the level of teeth 32 and 42 from the border of the attached and movable mucosa, a 45-degree dissection of the mental muscle to the periosteum, the periosteum is dissected and peeled off apically, the alveolar part of the lower jaw within teeth 34-44 and the chin section of the lower jaw are skeletonized, autogenous bone chips are collected from the chin section of the lower jaw using a scraper, a corticotomy is performed using a piezotome - dissection of the cortical bone between the roots of teeth 44, 43, 42, 41, 31, 32, 33, 34 to the depth of the cortical layer to the spongy substance, taking into account the three-dimensional arrangement of the tooth roots, while in the coronal direction the corticotomy line does not reach the bone peak by 1 mm, in the apical direction - 1 mm below the apex of the tooth root, the resulting autogenous bone chips are mixed with the allogeneic graft in a ratio of 1:1, the resulting bone mixture is placed on the surface of the alveolar process in the corticotomy area with a layer thickness of at least 5 mm, a fibrin membrane is placed on top of the placed graft, the apically displaced periosteum is fixed to the coronary part with a resorbable thread, the muscles and mucous membrane are sutured.

In the preferred embodiment, the collection of autogenous bone chips from the chin region of the lower jaw is carried out at a rate of 0.3 ^cm3 per tooth.

In a preferred embodiment, Sure-oss cortical-cancellous chips are used as an allogeneic graft.

In a preferred embodiment, a PRGF membrane is used as the fibrin membrane.

The above and other objects, advantages and features of the present invention will become more apparent from the following non-limiting description of an exemplary embodiment thereof, given by way of example with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

The essence of the invention is explained by the drawings, which show:

Fig. 1-4 sequentially depict the stages of corticotomy with simultaneous guided bone regeneration in the frontal part of the lower jaw at the stages of orthodontic treatment of patients with occlusion anomalies.

These drawings do not cover and, moreover, do not limit the entire scope of options for implementing this solution, but represent only illustrative material of a particular case of its implementation.

EMBODIMENT OF THE INVENTION

In accordance with the embodiment of the invention shown in Fig. 1-4, under infiltration anesthesia, we make an arcuate incision of the mucous membrane at a distance of 5.0 mm (at the level of teeth 31 and 41) and 7.0 mm (at the level of 32 and 42) from the border of the attached and movable mucous membrane.

The mentalis muscle is dissected at an angle of 45 degrees down to the periosteum. The periosteum is dissected and peeled off apically, the alveolar part of the lower jaw (within teeth 34-44) and the mental part of the lower jaw are skeletonized (Fig. 1).

Using a scraper, autogenous bone chips are collected from the chin area of the lower jaw in the required volume (at the rate of 0.3 ^cm3 ) per tooth.

Using a piezotome, a corticotomy is performed - an incision of the cortical bone between the roots of teeth 44, 43, 42, 41, 31, 32, 33, 34 to the depth of the cortical layer to the spongy substance, taking into account the three-dimensional arrangement of the roots of the teeth. In the coronal direction, the corticotomy line does not reach the bone peak by 1.0 mm, in the apical direction - 1 mm below the apex of the tooth root (Fig. 2).

The obtained autogenous bone chips are mixed with an allogeneic transplant (Sure-oss cortical-cancellous chips) in a 1:1 ratio (Fig. 3, 4).

The resulting bone mixture is placed on the surface of the alveolar process in the area of corticotomy with a layer thickness of at least 5.0 mm. A PRGF membrane is placed on top of the placed graft.

The apically displaced periosteum is fixed to the coronary part with a resorbable thread. The muscles are sutured. The mucous membrane is sutured.

Clinical case 1

Patient A., 32 years old, came to the orthodontist's clinic with complaints of crowding of teeth in the frontal part of the lower jaw, and rotation of tooth 32 along the axis.

On examination, the patient's teeth are occluded according to skeletal class 2. Distal bite. Sagittal gap is 3.0 mm. Crowding of the frontal group of teeth, rotation along the axis of tooth 32, protrusion of the lower jaw incisors are noted. Gum recession on teeth 31, 41.

The orthodontist has drawn up a treatment plan.

During the CBCT scan, a lack of bone tissue was revealed on the vestibular surface of the roots of teeth 31, 32, 41, 42 by 1/2 of the root length.

Based on the examination results and in accordance with the orthodontic treatment plan (elimination of crowding, protrusion, body movement of the incisors along the sagittal axis by 2.0 mm), it was proposed to perform a corticotomy in the frontal section of the lower jaw with simultaneous directed bone regeneration in the projection of the roots of teeth 31, 32, 41, 42.

In the preoperative period, the patient is fitted with an orthodontic system 3 weeks before surgery.

Operation protocol

Infiltration anesthesia was performed with a solution of Articaine with Epinephrine 1:100000 in the amount of 3.4 ml.

An arcuate incision was made in the mucous membrane at a distance of 5.0 mm (at the level of teeth 31 and 41) and 7.0 mm (at the level of 32 and 42) from the border of the attached and movable mucous membrane.

The mentalis muscle was dissected at an angle of 45 degrees down to the periosteum. The periosteum was dissected and peeled off apically, the alveolar part of the lower jaw (within teeth 34-44) and the mental part of the lower jaw were skeletonized.

Using a Micros scraper, we collected autogenous bone chips from the chin area of the lower jaw in the required volume - 2 ^cm3 (based on 0.3 ^cm3 ) per tooth.

Using a piezotome, a corticotomy was performed - a dissection of the cortical bone between the roots of teeth 44, 43, 42, 41, 31, 32, 33, 34 to the depth of the cortical layer to the spongy substance, taking into account the three-dimensional arrangement of the roots of the teeth. In the coronal direction, the corticotomy line does not reach the bone peak by 1.0 mm, in the apical direction - 1 mm below the apex of the tooth root.

The resulting autogenous bone chips were mixed with an allogeneic transplant (Sure-oss cortical-cancellous chips) in a 1:1 ratio.

The resulting bone mixture is placed on the surface of the alveolar process in the area of corticotomy with a layer thickness of 5.0 mm. A PRGF membrane is placed on top of the placed bone graft.

The apically displaced periosteum was fixed to the coronal part of the periosteum using resorbable Glycolon 4.0 thread. The stumps of the mentalis muscle were sutured using Glycolon 4.0. The edges of the wound on the mucous membrane were aligned and sutured together using Glycolon 4.0.

Hemostasis during surgery

The postoperative area was examined 30 minutes after the operation. The patient was prescribed antibacterial therapy and painkillers. It was recommended to use chlorhexidine bigluconate 0.02% solution as a local antiseptic 2 times a day.

A control CBCT study was conducted.

During the follow-up examination of the patient on the 5th day after the operation, the patient has no complaints. Minor swelling of the soft tissues of the chin area and along the transitional fold is noted. The sutures are sound. There is no discharge along the suture line.

Upon examination on the 10th day after the operation, the patient has no complaints. No soft tissue edema is noted, no discharge along the suture line. The sutures have been removed. Healing by primary intention.

It is recommended to continue orthodontic treatment.

Follow-up examinations were carried out 3 and 6 months after the operation.

CBCT 6 months after the operation shows restructuring of the bone graft. The newly formed bone completely covers the roots of the frontal teeth from the vestibular surface. The structure of the bone tissue is similar in structure to the bone of the alveolar process.

Corticotomy, directed bone regeneration, the use of PRGF leading to the formation of a complete regenerate allow for orthodontic movement of teeth in the required direction, improve bone support for tooth roots, lead to a change (improvement) in the attached mucosa, and reduce treatment time.

INDUSTRIAL APPLICATION

The proposed method is used in medicine, in maxillofacial reconstructive surgery.

Claims (4)

1. A method of corticotomy with simultaneous directed bone regeneration in the frontal section of the lower jaw at the stages of orthodontic treatment of patients with occlusion anomalies, including an arcuate incision of the oral mucosa under infiltration anesthesia, retreating 5.0 mm at the level of teeth 31 and 41 and 7.0 mm at the level of teeth 32 and 42 from the border of the attached and movable mucosa, dissection at an angle of 45 degrees of the mental muscle to the periosteum, characterized in that the periosteum is dissected and peeled off apically, the alveolar part of the lower jaw within teeth 34-44 and the chin section of the lower jaw are skeletonized, autogenous bone chips are collected from the chin section of the lower jaw using a scraper, a corticotomy is performed using a piezotome - dissection of the cortical bone between the roots of teeth 44, 43, 42, 41, 31, 32, 33, 34 to the depth of the cortical layer to the spongy substance; in this case, in the coronal direction, the corticotomy line does not reach the bone peak by 1 mm, in the apical direction - 1 mm below the apex of the tooth root, the resulting autogenous bone chips are mixed with the allogeneic graft in a 1:1 ratio, the resulting bone mixture is placed on the surface of the alveolar process in the corticotomy area in a layer thickness of at least 5 mm, a fibrin membrane is placed over the placed graft, the apically displaced periosteum is fixed to the coronary part with a resorbable thread, the muscles and mucous membrane are sutured. 2. The corticotomy method according to paragraph 1, characterized in that the collection of autogenous bone chips from the chin section of the lower jaw is carried out at a rate of 0.3 ^cm3 per tooth. 3. The corticotomy method according to paragraph 1, characterized in that Sure-oss cortico-spongy chips are used as an allogeneic transplant. 4. The method of corticotomy according to paragraph 1, characterized in that a PRGF membrane is used as the membrane.