• Journal of Periodontal and Implant Science
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• v.52 no.1
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• pp.3-27
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• 2022

Purpose: This study was conducted to evaluate and compare the effects of different graft materials used in alveolar ridge preservation on dimensional hard tissue changes of the alveolar ridge, assessed using cone-beam computed tomography (CBCT) scans. Methods: A systematic electronic search of MEDLINE and the Cochrane Central Register of Controlled Trials and a manual search were conducted from November 2019 until January 2020. Randomized controlled trials were included if they assessed at least 1 variable related to vertical or horizontal hard tissue changes measured using CBCT scans. After a qualitative analysis of the included studies, subgroups were formed according to the graft material used, and a quantitative analysis was performed for 5 outcome variables: changes in vertical alveolar bone height at 2 points (midbuccal and midpalatal/midlingual) and changes in horizontal (buccolingual) alveolar bone width at 3 different levels from the initial crest height (1, 3, and 5 mm). Results: The search resulted in 1,582 studies, and after an independent 3-stage screening, 16 studies were selected for qualitative analysis and 9 for quantitative analysis. The metaanalysis showed a significantly (P<0.05) lower reduction of alveolar ridge dimensions for the xenogenic subgroup than in the allogenic subgroup, both vertically at the midbuccal aspect (weighted mean difference [WMD]=-0.20; standard error [SE]=0.26 vs. WMD=-0.90; SE=0.22) as well as horizontally at 1 mm (WMD=-1.32; SE=0.07 vs. WMD=-2.99; SE=0.96) and 3 mm (WMD=-0.78; SE=0.11 vs. WMD=-1.63; SE=0.40) from the initial crest height. No statistical analysis could be performed for the autogenic subgroup because it was not reported in sufficient numbers. Conclusions: Less vertical and horizontal bone reduction was observed when xenogenic graft materials were used than when allogenic graft materials were used; however, the loss of alveolar ridge dimensions could not be completely prevented by any graft material.

• Journal of Periodontal and Implant Science
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• v.31 no.1
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• pp.57-74
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• 2001

The purpose of this study was to evaluate the adjunctive combined effect of demineralized freeze-dried bone allograft(DFDB) in guided bone regeneration on supra-alveo-lar peri-implant defect. Supra-alveolar perio-implant defects, 3mm in height, each including 4 IMZ titanium plasma-sprayed implants were surgically created in two mongrel dogs. Subsequently, the defects were treated with 1 of the following 3 modalities: Control) no membrane or graft application, Group1) DFDB application, Group2) guided bone regeneration using an expanded polytetra-fluoroethylene membrane, Group3) guided bone regeneration using membrane and DFDB. After a healing period of 12-week, the animals were sacrificed, tissue blocks were harvested and prepared for histological analysis. Histologic examination were as follows; 1. New bon formation was minimal in control and Group 1, but considerable new bone formation was observed in Group 2 and Group 3. 2. There was no osteointegration at the implant-bone interface in the high-polished area of group2 and Group 3. 3. In fluorescent microscopic examination, remodeling of new bone was most active during week 4 and week 8. There was no significant difference in remodeling rate between group 2 and group 3. 4. DFDB particles were observed, invested in a connective tissue matrix. Osteoblast activity in the area was minimal. The results suggest that guided bone regeneration shows promising results in supra-alveolar peri-implant defects during the 12 week healing period although it has a limited potential in promoting alveolar bone regeneration in the high-polished area. There seems to be no significant adjunctive effect when DFDB is combined with GBR.

• The korean journal of orthodontics
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• v.45 no.5
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• pp.245-252
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• 2015

Objective: To assess the labial and lingual alveolar bone thickness in adults with maxillary central incisors of different inclination by cone-beam computed tomography (CBCT). Methods: Ninety maxillary central incisors from 45 patients were divided into three groups based on the maxillary central incisors to palatal plane angle; lingual-inclined, normal, and labial-inclined. Reformatted CBCT images were used to measure the labial and lingual alveolar bone thickness (ABT) at intervals corresponding to every 1/10 of the root length. The sum of labial ABT and lingual ABT at the level of the root apex was used to calculate the total ABT (TABT). The number of teeth exhibiting alveolar fenestration and dehiscence in each group was also tallied. One-way analysis of variance and Tukey's honestly significant difference test were applied for statistical analysis. Results: The labial ABT and TABT values at the root apex in the lingual-inclined group were significantly lower than in the other groups (p < 0.05). Lingual and labial ABT values were very low at the cervical level in the lingual-inclined and normal groups. There was a higher prevalence of alveolar fenestration in the lingual-inclined group. Conclusions: Lingual-inclined maxillary central incisors have less bone support at the level of the root apex and a greater frequency of alveolar bone defects than normal maxillary central incisors. The bone plate at the marginal level is also very thin.

• Restorative Dentistry and Endodontics
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• v.16 no.1
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• pp.133-150
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• 1991

To study the mechanical behavior depended on the restoration method and alveolar bone height at endodontically treated teeth. a finite element model was made which was applied by four types of restoration methods and alveolar bone height on upper central incisor and then 1 Kg force was applied on each model as follows; 1) $45^{\circ}$ diagonal load on incisal edge. 2) $26^{\circ}$ diagonal load on lingual surface. and 3) horizontal load on labial surface. The author analyzed the displacement and stress of teeth and their supporting tissue by finite element method according to three type of loading conditions. The results were as follows : 1. The displacement by restoration method and the stress in dentin was found greater in restoration without a post than in that with a post. 2. The displacement and stress was found about the same when compared : A) in Resin model and PFM model applied by restoration method without a post and B) in PRC model and CPC model applied by restoration method with a post. 3. The lower alveolar bone height was. the greater was the displacement and stress. 4. The lower alveolar bone height was. the greater slightly was the stress of restoration without a post than in that with a post. 5. The stress in loading condition was the greatest in P1 in dentin and post. and was greatest in P3 in alveolar hone. 6. In the restoration method without a post. stress concentration in labial dentin was distributed to a figure of long belt in adjacent part to periodontal ligament. while in restoration method with a post. it was distributed in adjacent part to post side. And in all types of restoration method stress concentration in alveolar bone was distributed along the compact bone of labial and lingual surface.

• The korean journal of orthodontics
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• v.46 no.3
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• pp.155-162
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• 2016

Objective: The aim of this study was to investigate whether labial tooth inclination and alveolar bone loss affect the moment per unit of force ($M_t/F$) in controlled tipping and consequent stresses on the periodontal ligament (PDL). Methods: Three-dimensional models (n = 20) of maxillary central incisors were created with different labial inclinations ($5^{\circ}$, $10^{\circ}$, $15^{\circ}$, and $20^{\circ}$) and different amounts of alveolar bone loss (0, 2, 4, and 6 mm). The $M_t/F$ necessary for controlled tipping ($M_t/F_{cont}$) and the principal stresses on the PDL were calculated for each model separately in a finite element analysis. Results: As labial inclination increased, $M_t/F_{cont}$ and the length of the moment arm decreased. In contrast, increased alveolar bone loss caused increases in $M_t/F_{cont}$ and the length of the moment arm. When $M_t/F$ was near $M_t/F_{cont}$, increases in Mt/F caused compressive stresses to move from a predominantly labial apical region to a palatal apical position, and tensile stresses in the labial area moved from a cervical position to a mid-root position. Although controlled tipping was applied to the incisors, increases in alveolar bone loss and labial tooth inclination caused increases in maximum compressive and tensile stresses at the root apices. Conclusions: Increases in alveolar bone loss and labial tooth inclination caused increases in stresses that might cause root resorption at the root apex, despite the application of controlled tipping to the incisors.

• The Journal of the Korean dental association
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• v.57 no.3
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• pp.149-160
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• 2019

Atrophic alveolar ridge of maxillary anterior area is commonly observed after the extraction of teeth in patients with severely compromised periodontal disease, causing difficulties with implant placement. Successful esthetics and functional implant rehabilitation rely on sufficient bone volume, adequate bone contours, and ideal implant positioning and angulation. The present case report categorized the ridge augmentation techniques using guided bone regeneration (GBR) on the maxillary anterior site by Seibert classification. Case I patient presented for implant placement in the position of tooth #11. The alveolar ridge was considered a Seibert classification I ridge defect. Simultaneous implant placement and GBR were performed. Eight months after implantation, clinical and radiological examinations were performed. Case III patient presented with discomfort due to mobility of the upper maxillary anterior site. Due to severe destruction of alveolar bone, teeth #11 and #12 were extracted. After three months, the alveolar ridge was considered a Seibert classification III ridge defect. A GBR procedure was performed; implantation was performed 6 months later. Approximately 1-year after implantation, clinical and radiological examinations were performed. During the whole treatment period, healing was uneventful without membrane exposure, severe swelling, or infection in all cases. Radiographic and clinical examinations revealed that atrophic hard tissues and buccal bone contour were restored to the acceptable levels for implant placement and esthetic restoration. In conclusion, severely resorbed alveolar ridge of the maxillary anterior area can be reconstructed with ridge augmentation using the GBR procedure so that dental implants could be successfully placed.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.1
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• pp.108-113
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• 2008

It would be desirable to regenerate bone vertically in a predictable way; such a technique would allow for more favorable implant - crown ratio and better esthetics for implant placement. Traditionally, several techniques has been proposed for this purpose including GBR with particulated bone and block bone graft using mandible or illium however, the efficacy of these techniques has not been firmly established because they have some week points or complications each other that it is difficult to draw firm conclusion for superiority. In recent years, We have treated 11-cases of vertical deficiency of alveolar bone using thin block and chip bone graft technique and the postoperative results showed good prognosis with few complications. So we report the results of its treatment and cases with review of literature.

• The Journal of the Korean dental association
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• v.53 no.1
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• pp.6-13
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• 2015

A new field in dental implantology is developing with the goal of finding new ways to improve the osteoconductivity of bone substitutes and to study new molecules able to dictate cellular differentiation and improve bone regeneration. The real future in bone regeneration seems to be in connection with the rhBMP-2s, currently obtained by synthesis using recombinant DNA. Since the first rhBMP-2 studies in humans by Boyne, There are many studies for bone regeneration at oral and maxillofacial area. The rhBMP-2 is widely used at sinus augmentation, alveolar bone defect, and socket preservation.

• The korean journal of orthodontics
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• v.32 no.5 s.94
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• pp.361-373
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• 2002

The purpose of this study was to evaluate the morphological changes of olveolar bone and mandibular symphysis of lower incisor by presurgical orthodontic treatment and orthognathic surgery in skeletal class III malocclusion. The sample consisted of 30 adult class III malocclusion patients who have received bilateral sagittal split mandibular osteotomy. Lateral cephalograms were taken before treatment, after presurgical orthodontic treatment and 3 months after orthognathic surgery. Skeletal and symphyseal measurements were compared and the relationships between them were analysed. The results were as follow : 1. The labial and lingual alveolar bone height in presurgical and postsurgical group were decreased than that of pretreatment group. 2. The vertical measurements of the craniofacial skeleton showed reverse correlationship with anteroposterior width of basal alveolar bone, but IMPA showed correlatiionship (p<0.01) 3. The craniofacial skeleton and the change of symphyseal measurements(symphyseal length, symphyseal width) showed no correlationship. 4. The labial alveolar bone height showed correlationship with lingual alveolar bone height(p<0.001), and negative correlationship with lingual alveolar crestal width(p<0.01). Labial and lingual alveolar crestal width has negative correlationship (p<0.05). Mandibular symphyseal length and width has positive correlationship(p<0.01). 5. IMPA, LISA showed negative correlationship with labiolingual alveolar bone height and lingual alveolar width and positive correlationship with labial alveolar base bone width.

• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.2
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• pp.161-171
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• 2006

Endosseous implants have restored normal function and dental health to many patients. When implants were introduced as an effective treatment modality, their efficacy was limited by the amount of available bone. Today, various grafting procedures can surgically create bone width and volume. Implants can be placed in more ideal locations for successful prosthetic reconstruction. The use of autogenous bone grafts represents the "gold standard" for bone augmentation procedures. Either intraoral or extraoral sites may be considered for donor sites. Alveolar ridge augmentation using autogenous bone block, can be done during implant placement or staged with implant placement, after bone graft healing. In the staged technique, a better implant positioning and the use of wide diameter implants are possible. Alveolar ridge augmentation using autogenous block graft is a predictable way of treatment, for the atrophic alveolar ridge before implant placement. The cases presented in this article clinically demonstrate the efficacy of using a autogenous block graft in generating effective new bone fill for dental implant placement.