Expressed defects of alveolar crest are impeding an ideal implant setting. For restoring the crest parameters it's often necessary to use autoplasts. Methods of autoplast sampling from the chin or lower jaw branch provides an easy access, good quality of material for limited defect restoring, autoplast cortical spongiform morphology, a low probability of rejection and 
minimal autoplast resorption. Audi technique or technique of inverted Olympic rings is characterized with bone quality betterment and engraftment time decreasing comparing with other methods and techniques of ridge restoration.
minimal autoplast resorption. Audi technique or technique of inverted Olympic rings is characterized with bone quality betterment and engraftment time decreasing comparing with other methods and techniques of ridge restoration.During teeth row prosthetics with implants help we often face with the need of alveolar ridge parameters recovery. Bone defects as a result of trauma, congenital anomalies or other pathologic processes are much more pronounced and often require for more complicated treatment than defects appeared as a result of teeth extraction for dental evidences.
Recovery of lost hard and soft tissues is not only important from an aesthetic standpoint, but also for implant good biomechanical support providing. If not build up an anterior ridge, it could lead to unwanted load on implants installed in this part of the jaw. This is especially true when tissues deficit replacement is due to implant. When operation in order to build the ridge is planned, the correlation of implant length and crown height must be taken into account, as well as the location of incisal edge towards the implant axis. Tissue recovery for account of prosthesis can lead to the accumulation of food debris and plaque in the field of orthopedic construction, which in turn can bring tissues' inflammation.
Techniques of aimed bone regeneration (ABR) are used during or before implant installation. The best results of ABR techniques applying simultaneously with implant installation are achieved in circular defects treatment; in horizontal defects treatment the prognosis are much worse. Delayed implants installation after ABR conduction has the following advantages:
- the presence of a larger bone mass;
- allows to install implants in the preferred position;
- provides a better initial stability;
- bigger bone density provides better contact with the implant surface.
During elimination of significant bone defects it is preferable to use the technique of deferred implant installation, while during the replacement of small defects implants can be installed alongside with ABR techniques interference. The disadvantages of deferred method are a long healing period (9 months) before implants installation and worse quality of bone regeneration, if only cortical cancellous autoplast wasn't used for under-membrane defect replacement. One more technique's disadvantage is a high risk of early polytetrafluoroethylene (PTFE) membranes exposure. Techniques of aimed bone regeneration should be used in situations when the prognosis can be improved, but does not depend only from membranes usage.
Functional remodeling of regenerated bone under the load of implant may be different from the reaction of bone tissue in areas where the build-up wasn't conducted. Biomechanical stress-load distribution takes place in direct area of bone and implant contact. The denser the bone is, the better the load distribution goes.
Studies show that resorption of autoplast of membrane origin is less pronounced than resorption of autoplast of endochondral origin. Although sponge blocks revascularizing faster than cortical ones, cortical membrane autoplast revascularizing faster than endochondral blocks which have a prevailing spongy part. Most likely, that a fast revascularization of bone of membrane origin is a reason of excellent bone block conservation and explains good and rapid autoplast engraftment out of chin area (represented mainly by cortical substance with a small number of osteogenic cells).
Functional remodeling of regenerated bone under the load of implant may be different from the reaction of bone tissue in areas where the build-up wasn't conducted. Biomechanical stress-load distribution takes place in direct area of bone and implant contact. The denser the bone is, the better the load distribution goes.Before surgery and for autoplast parameters determination it is recommended to produce a diagnostic wax model with the defect reconstruction, as well as the surgical sample, which will help to make bone bloc and implant installation. For the donor bottom parameters estimate it is necessary to make an ortopanoramny picture. Lateral cephalometric image will help to determine the anterior-posterior distance in the lower jaw anterior. For the lower jaw roots length estimate, sighting picture should be done. A useful additional study technique during operation planning may be a tomography of the defect.
Auto transplantation
Autoplasts from the chin symphysis in the form of bone blocks are successfully used for the ridge build-up in the area of significant local defects for the future implant installation.
Surgical sample usage helps to determine the optimum position of the bone block for the future implant installation. The bottom is fully prepared for the donor block intake. Bone perforation with ultrasonosurgery scalpel facilitates the migration of osteogenic cells, accelerates revascularization and improves block and bone bottom matching. Besides this, remodeling of recipient-bottom is conducted for maximum contact with autoplast ensuring.
After intake, the autoplast is placed into the physiological salt solution and stays there during minimum of time before its installation in recipient bottom. Titanium screws of small diameter are used for fixation. The unit is attached onto the bottom, and then with the help of collected in donor area cancellous tissues the small spaces are fulfilling. Because the cortical-cancellous autoplast is almost completely fills the defect, there is no more need for membranes usage, which in case of its early exposure may lead to complications.
not shown during the membrane autoplast fitting, because such blocks are almost not absorbed. If the block size is not large enough or autoplast is used in the form of shavings, the membrane usage will help to keep and stabilize the autoplast and to improve the bone regeneration in the defect area.
During the work in aesthetically significant areas and a possibility to dispense without temporary removal prosthesis it is necessary to adapt it. Tooth denture processing is conducted in a way to exclude any pressure onto the autoplast. It is recommended not to use removable tooth prosthesis for eating.
Tissues in the defect area must be fully cured before auto transplantation starts. Alien particles removal, patchwork operations and / or teeth extraction should be performed at least 8 weeks before the surgery. A careful work with soft tissues is minimizing the possibility of trauma getting in the defect area. Beveled cut a little bit away from the middle of the crest (the lower jaw vestibular, the upper jaw palato) and divergent relaxing cuttings allows wound closure without any tension and adequate flap blood supply keeping. Cuts performance too much far into the palatal must be avoid because of the high probability of epithelial shedding in the postsurgical period.
Muco-periosteal flap in front area of upper jaw is reclining to the front nasal spine level, lower and lateral margin of the nasal cavity and to the upper jaw indentation in canines' projection. Complete wound closure without any tension is a basic condition for the successful autoplast engraftment. Before block installation, the periosteum at the base of the flap is gently incised with the help of fabric scissors and/or a scalpel for mucosa tension avoiding and free wound edges comparison.
Such complications as dehiscence and autoplast exposure are more often in smokers, that's why during the treatment period patients should refrain from smoking. Attempts to improve wound closure usually leads to attached gingiva zone and vestibule depth decreasing. Sometimes in such cases the use of patchwork operations is shown. In the reintervention the reposition of attached gingiva in the vestibular side can be conducted.
Very often patients are worrying about how would their chin and lower jaw branch look like after the surgery. Although in original studies of children roof of the mouth defects plastic the filling of donor section with anything wasn't conducted, and it didn't affect the aesthetics, still there are radiographic evidences of incomplete bone regeneration among adults. However, an incomplete recovery of chin bone does not significantly change the shape.
Donor section can be filled with demineralized freeze-dried bone and/or with resorbable hydroxyapatite of animal origin (osteography/N, Bio-Oss or absorbable hemomotatus). Chin retraction was not observed and can be prevented by gentle flap tilting on the lower jaw. The lower jaw boundary should remain intact, that's why it is necessary to make autoplast intake very carefully for avoiding a lingual cortical plate perforation.
The incision line varies depending on the topography of muscles and periodontal status of the lower jaw. Among patients with small vestibules or pronounced chin the incision is carried out lengthwise the lower jaw anterior.
The presence of marginal gingiva inflammation or alveolar bone around the lower incisors loss are usually leads to the need of vestibular incision performance. Vestibular incision below the muco-gingival connection provides better access, but also leads to stronger bleeding and the scar tissue formation. In limitation of vestibular incision distal border area a probability of temporary mental nerve paresthesia reducing up to 10%; for the moment there were no cases of permanent paresthesia reported.
The imposition of pressure bandage helps to reduce the degree of bruising, and to prevent dehiscence and infection. To reduce the degree of postsurgical hypostasis glucocorticoids appointments are shown. The average dose of dexamethasone before the surgery starting is 9 mg, followed by appointment within 2 days of decreasing. After surgery, the pain in donor section either of minimal or moderate level.
Depending on the necessary block size the osteotomy may be performed before the canines projection or even going beyond their borders.
Between the upper limit of osteotomy and tops of teeth roots there must be at least 3, 45-5mm. Even having such a stock, a temporary minor change of lower teeth sensitivity is a usual postsurgical symptom
Implants installation
Because the autoplast is exposed to a minimal resorption (from 0 to 25% of amount), it is usually possible to achieve the required bone amount for implant installation. Implants are installed after a period of engraftment (4-6 months). Autoplasts in the upper jaw maintain the architecture and density of the anterior mandible.
Implant installation alongside with bone block grafting may be associated with an autoplast fracture, dehiscence with the block and implant exposure and a higher percentage of implants rejection compared with the delayed installation. At the same time, there is an insufficient contact between the implant and the bone during the implant, alongside with autoplast out of the iliac crest, installation. Delayed implant installation gives an opportunity to set them in a better position relating to proposed prosthesis without the need of additional block fixation. Because the ridge size increasing is quite often very significant, it permits to install implants of larger diameter. However, during the osteotomy forming for implant installation one must be very careful, because as a result of osteotomy production at the autoplast-recipient border a break can occur.
Sometimes, in order to make a noninvasive implant imposition, the osteotomy opening is made of a larger diameter than a diameter of the intended implant itself.
Technique of auto transplantation of bone block from the chin and lower jaw branch for local alveolar crest defects removal and for the future implants installation has several advantages: ease of donor section access; possibility to obtain a block of bigger size comparing with other donor sections; good terms of engraftment. Bigger bone density makes terms of engraftment shorter comparing with directed bone regeneration techniques. Disadvantages of this technique are a limited number of donor bones and the possibility of mandibular nerve and anterior lower jaw damage. Auto transplantation of bone blocks from the chin area is an effective alternative method for ridge reconstruction on purpose of future implants' installation.
Auto transplantation
Autoplasts from the chin symphysis in the form of bone blocks are successfully used for the ridge build-up in the area of significant local defects for the future implant installation.
Surgical sample usage helps to determine the optimum position of the bone block for the future implant installation. The bottom is fully prepared for the donor block intake. Bone perforation with ultrasonosurgery scalpel facilitates the migration of osteogenic cells, accelerates revascularization and improves block and bone bottom matching. Besides this, remodeling of recipient-bottom is conducted for maximum contact with autoplast ensuring.
After intake, the autoplast is placed into the physiological salt solution and stays there during minimum of time before its installation in recipient bottom. Titanium screws of small diameter are used for fixation. The unit is attached onto the bottom, and then with the help of collected in donor area cancellous tissues the small spaces are fulfilling. Because the cortical-cancellous autoplast is almost completely fills the defect, there is no more need for membranes usage, which in case of its early exposure may lead to complications.
not shown during the membrane autoplast fitting, because such blocks are almost not absorbed. If the block size is not large enough or autoplast is used in the form of shavings, the membrane usage will help to keep and stabilize the autoplast and to improve the bone regeneration in the defect area.
During the work in aesthetically significant areas and a possibility to dispense without temporary removal prosthesis it is necessary to adapt it. Tooth denture processing is conducted in a way to exclude any pressure onto the autoplast. It is recommended not to use removable tooth prosthesis for eating.
Tissues in the defect area must be fully cured before auto transplantation starts. Alien particles removal, patchwork operations and / or teeth extraction should be performed at least 8 weeks before the surgery. A careful work with soft tissues is minimizing the possibility of trauma getting in the defect area. Beveled cut a little bit away from the middle of the crest (the lower jaw vestibular, the upper jaw palato) and divergent relaxing cuttings allows wound closure without any tension and adequate flap blood supply keeping. Cuts performance too much far into the palatal must be avoid because of the high probability of epithelial shedding in the postsurgical period.
Muco-periosteal flap in front area of upper jaw is reclining to the front nasal spine level, lower and lateral margin of the nasal cavity and to the upper jaw indentation in canines' projection. Complete wound closure without any tension is a basic condition for the successful autoplast engraftment. Before block installation, the periosteum at the base of the flap is gently incised with the help of fabric scissors and/or a scalpel for mucosa tension avoiding and free wound edges comparison.
Such complications as dehiscence and autoplast exposure are more often in smokers, that's why during the treatment period patients should refrain from smoking. Attempts to improve wound closure usually leads to attached gingiva zone and vestibule depth decreasing. Sometimes in such cases the use of patchwork operations is shown. In the reintervention the reposition of attached gingiva in the vestibular side can be conducted.
Very often patients are worrying about how would their chin and lower jaw branch look like after the surgery. Although in original studies of children roof of the mouth defects plastic the filling of donor section with anything wasn't conducted, and it didn't affect the aesthetics, still there are radiographic evidences of incomplete bone regeneration among adults. However, an incomplete recovery of chin bone does not significantly change the shape.
Donor section can be filled with demineralized freeze-dried bone and/or with resorbable hydroxyapatite of animal origin (osteography/N, Bio-Oss or absorbable hemomotatus). Chin retraction was not observed and can be prevented by gentle flap tilting on the lower jaw. The lower jaw boundary should remain intact, that's why it is necessary to make autoplast intake very carefully for avoiding a lingual cortical plate perforation.
The incision line varies depending on the topography of muscles and periodontal status of the lower jaw. Among patients with small vestibules or pronounced chin the incision is carried out lengthwise the lower jaw anterior.
The presence of marginal gingiva inflammation or alveolar bone around the lower incisors loss are usually leads to the need of vestibular incision performance. Vestibular incision below the muco-gingival connection provides better access, but also leads to stronger bleeding and the scar tissue formation. In limitation of vestibular incision distal border area a probability of temporary mental nerve paresthesia reducing up to 10%; for the moment there were no cases of permanent paresthesia reported.
The imposition of pressure bandage helps to reduce the degree of bruising, and to prevent dehiscence and infection. To reduce the degree of postsurgical hypostasis glucocorticoids appointments are shown. The average dose of dexamethasone before the surgery starting is 9 mg, followed by appointment within 2 days of decreasing. After surgery, the pain in donor section either of minimal or moderate level.
Depending on the necessary block size the osteotomy may be performed before the canines projection or even going beyond their borders.
Between the upper limit of osteotomy and tops of teeth roots there must be at least 3, 45-5mm. Even having such a stock, a temporary minor change of lower teeth sensitivity is a usual postsurgical symptom
Implants installation
Because the autoplast is exposed to a minimal resorption (from 0 to 25% of amount), it is usually possible to achieve the required bone amount for implant installation. Implants are installed after a period of engraftment (4-6 months). Autoplasts in the upper jaw maintain the architecture and density of the anterior mandible.
Implant installation alongside with bone block grafting may be associated with an autoplast fracture, dehiscence with the block and implant exposure and a higher percentage of implants rejection compared with the delayed installation. At the same time, there is an insufficient contact between the implant and the bone during the implant, alongside with autoplast out of the iliac crest, installation. Delayed implant installation gives an opportunity to set them in a better position relating to proposed prosthesis without the need of additional block fixation. Because the ridge size increasing is quite often very significant, it permits to install implants of larger diameter. However, during the osteotomy forming for implant installation one must be very careful, because as a result of osteotomy production at the autoplast-recipient border a break can occur.
Sometimes, in order to make a noninvasive implant imposition, the osteotomy opening is made of a larger diameter than a diameter of the intended implant itself.
Technique of auto transplantation of bone block from the chin and lower jaw branch for local alveolar crest defects removal and for the future implants installation has several advantages: ease of donor section access; possibility to obtain a block of bigger size comparing with other donor sections; good terms of engraftment. Bigger bone density makes terms of engraftment shorter comparing with directed bone regeneration techniques. Disadvantages of this technique are a limited number of donor bones and the possibility of mandibular nerve and anterior lower jaw damage. Auto transplantation of bone blocks from the chin area is an effective alternative method for ridge reconstruction on purpose of future implants' installation.
