Kyung-In Jeong

Clinical study of graft materials using autogenous teeth in maxillary sinus augmentation.

Purpose:The purpose of this study was to evaluate the effectiveness of autogenous tooth bone graft materials. Materials and Methods:Hundred implants in 51 patients were selected, and the patients received maxillary sinus augmentation and implant placement using autogenous tooth graft materials at the Chosun University Dental Hospital and Seoul National University Bundang Hospital between July 2009 and November 2010. Results:In cases using autogenous tooth bone graft alone, or together with other graft material, the implant survival rate was 96.15%. On histomorphologic examination, autogenous tooth bone graft materials showed gradual resorption and new bone formation through osteoconduction and osteoinduction. Conclusions:The results indicated that autogenous tooth bone graft materials are appropriate for use in maxillary sinus augmentation.

Influence of bone morphogenetic protein and proportion of hydroxyapatite on new bone formation in biphasic calcium phosphate graft: Two pilot studies in animal bony defect model

PURPOSE The purpose of these two pilot studies using animal bony defect models was to evaluate the influence of bone morphogenetic protein (BMP) and proportion of hydroxyapatite (HA)/beta-tricalcium phosphate (β-TCP) in biphasic calcium phosphate (BCP) graft on new bone formation. METHODS In this study, four kinds of synthetic osteoconductive bone materials known for bone growth scaffold, OSTEON™II(HA:β-TCP 30:70), OSTEON™III (HA:β-TCP 20:80), OSTEON™II Collagen, and OSTEON™III Collagen, were prepared as BCP graft materials. In pilot study 1, three BCP materials (OSTEON™II, OSTEON™III, and OSTEON™II Collagen) were grafted in rabbit calvarial defects after impregnating in rhBMP-2. OSTEON™II without the rhBMP-2 impregnation was included in the study as the control. The amount of new bone was examined and measured histologically at 2, 4, and 8 weeks. In pilot study 2, four BCP materials (OSTEON™II, OSTEON™III, OSTEON™II Collagen, and OSTEON™III Collagen) were grafted in beagle dog mandibular defects after soaking in the rhBMP-2. The amount of total bone and new bone were measured three-dimensionally using microCT and healing process was examined histologically at 2, 4, and 8 weeks. RESULTS In pilot study 1, rhBMP-2 impregnated groups showed more new bone formation than the rhBMP-2 free group. In pilot study 2, increased new bone formation was observed in time-dependent manner after graft of BCP and BCP-collagen (OSTEON™II, OSTEON™III, OSTEON™II Collagen, and OSTEON™III Collagen) impregnated with rhBMP-2. Also, BCP with a higher proportion of HA (30% HA) showed more favorable result in new bone formation and space maintenance, especially at the 8 weeks. CONCLUSION From the results of the pilot studies, rhBMP-2 played positive roles in new bone formation and BCP could become a scaffold candidate for rhBMP-2 impregnation to induce new bone formation. Moreover, BCP with a higher proportion of HA (30% HA) could be considered more appropriate for rhBMP-2 carrier.

Guided bone regeneration using autogenous tooth bone graft in implant therapy: case series.

Recently, techniques have been reported that involve the preparation of extracted teeth from patients used as particulated bone graft materials for bone graft purposes. For implant placement and bone graft, autogenous teeth bone graft materials were used in 15 patients, and clinically excellent results were obtained. In histological examination, favorable bony healing by osteoconduction was observed.

Consideration of various bone quality evaluation methods.

Purpose:Bone quality at the implant site has a significant effect on the success and prognosis of implants. The purpose of this article was to evaluate several methods used in evaluating bone quality and discuss the advantages and disadvantages. Methods:The search was made using PubMed database about quantitative computed tomography (QCT), and quantitative cone-beam computerized tomography (QCBCT), dual energy x-ray absorptiometry (DXA) scans, the resistance force against the hands of the surgeon, assessment of the effect of the torque of the drill, the initial fixed value of the implant, and fractal analysis according to the Lekholm and Zarb, and Misch classifications as the standard. Results:The method for measuring the resistance force and torque during implant placement and the method used to determine the implant’s initial implant fixed value were easy and simple. QCBCT was reported to involve less radiation and to be more objective than QCT. DXA and fractal analysis have limits when used to classify bone quality as Type II or Type III. Conclusion:Among the methods used to evaluate bone quality in implants, a method using computed tomography, measured in Hounsfield units, was found to be the most predictive.

Implants Displaced Into the Maxillary Sinus: A Systematic Review.

Objectives:Implant displacement into the maxillary sinus often results from features specific to the posterior maxillary teeth, including poor bone quality and insufficient remaining bone. This study reviews implants displaced into the maxillary sinus, the causes and complications of displacement, and how to remove them, according to when the displacement occurs. Materials and Methods:The PubMed, Ovid (MEDLINE), and EMBASE databases were searched using the keywords “displacement,” “implant,” “maxillary sinus,” and “removal” for articles published between January 2000 and July 2013. Results:Twenty-two journal articles were selected; these discussed 49 displaced implants. Most of the implants were displaced into the maxillary sinus during implantation, but resulted in a low incidence of complications, such as maxillary sinusitis. The displaced implants were removed using the Caldwell-Luc approach or a transoral or transnasal endoscopic approach. Conclusion:Implants displaced into the maxillary sinus have various causes according to when they are displaced. As displaced implants can cause several complications, transnasal endoscopy is recommended to remove them; however, the implants should be examined thoroughly before selecting the removal method.

Comparative study on the osseointegration of implants in dog mandibles according to the implant surface treatment

Objectives This study compared the impact of implant surface treatment on the stability and osseointegration of implants in dog mandibles. Materials and Methods Six adult dogs received a total of 48 implants that were prepared using four different surface treatments; resorbable blast media (RBM), hydroxyapatite (HA), hydrothermal-treated HA, and sand blasting and acid etching (SLA). Implants were installed, and dogs were separated into 2- and 4-week groups. Implant stability was evaluated via Periotest M, Osstell Mentor, and removal torque analyzers. A histomorphometric analysis was also performed. Results The stability evaluation showed that all groups generally had satisfactory values. The histomorphometric evaluation via a light microscope revealed that the HA surface implant group had the highest ratio of new bone formation on the entire fixture. The hydrothermal-treated HA surface implant group showed a high ratio of bone-to-implant contact in the upper half of the implant area. Conclusion The hydrothermal-treated HA implant improved the bone-to-implant contact ratio on the upper fixture, which increased the implant stability.

Alveolar Cleft Restoration Using Autogenous Tooth Bone Graft Material for Implant Placement: A Case Report

R estoration of an alveolar cleft with bone grafting is necessary to stabilize alveolar segments, close oronasal fistulas, and provide bony support and volume for future implant placement where necessary. However, choosing appropriate bone grafting materials for the rehabilitation of cleft alveolus is not simple. Several studies have evaluated the available therapeutic choices to treat inadequate alveolar bone quantity and or quality to enable implant placement in cleft alveolar ridges. With the development of biomaterials and tissue engineering, implant therapy has been a reliable choice of treatment— even in alveolar cleft patients—due to the variety of available bone augmentation materials. Autogenous bone is considered to be the gold standard bone graft due to its osteoconductivity, osteoinductivity, and osteogenicity. Nonetheless, autogenous bone grafting typically requires extensive surgeries with possible complications, such as postoperative pain and infection. Studies have attempted to identify an autogenous graft without the limitations of known autogenous grafts, and some researchers have become interested in the use of human dentin from extracted teeth in this context. Dentin consists of inorganic and organic components that are very similar to human bone. In dentin, the inorganic content is near 75%, whereas the organic content is approximately 20%. Type I collagen composes up to 90% of the organic contents in dentin, and it plays a critical role in bone formation and mineralization. Dentin also contains bone morphogenetic proteins (BMPs), which promote the differentiation of mesenchymal stem cells into osteocytes and thus enhance bone formation. In addition, both alveolar bones and teeth are derived from neural crest cells, and their organic and inorganic contents are therefore very similar to each other. Based on previous studies of rabbit and human dentin researchers have developed an autogenous bone graft material made from extracted human teeth. Studies have demonstrated that autogenous tooth bone (AutoBT) graft material has potential osteoconductive, osteoinductive, and bone remodeling capabilities. Recently, clinicians have explored the option of using this novel AutoBT in alveolar cleft restoration. Here, we present a clinical case of restoration of an alveolar defect using AutoBT for site preparation prior to implant placement.

Displaced implants into maxillary sinus: report of cases.

Although the number of implant placement in the edentulous maxillary region is increasing, there are often some cases in which implants accidentally get displaced into maxillary sinus because of low bone quality, insufficient bone height, bone resorption after surgery, and improper treatment plan. Implants displaced into the maxillary sinus can cause some complications, including mucosal thickening and sinusitis; however, there are also many cases causing no symptoms at all. Treatment procedures for implants displaced into maxillary sinus are observation, removal of implants through intraoral approach, and removal through nasal cavity using endoscope. But treatment may vary according to the presence of sinusitis, ostium obstruction, and oroantral fistula. In this study, 4 patients with present illness of implants displaced into maxillary sinus were selected, and appropriate evaluation and treatment for these cases were studied.

Histologic analysis of resorbable blasting media surface implants retrieved from humans: a report of two cases

The purpose of this study is to evaluate the degree of osseointegration of resorbable blasting media (RBM) surface implants retrieved from humans. Three implants in the mandibular molar region that were surface-treated with RBM were retrieved from two patients. The implants were used to manufacture specimens in order to measure the bone-implant contact (BIC) ratio. The BIC ratios of the three implants were found to be an average of 69.0%±9.1%. In conclusion, that RBM surface implants are integrated into the host environment with histological significance and the BIC ratio of the RBM surface-treated implant was not significantly different from that of other surface-treated implants.

Osteoradionecrosis of Jaw in Head and Neck Cancer Patient Treated with Free Iliac Bone and Umbilical Fat Pad Graft.

Osteoradionecrosis is one of the most serious complications of patients receiving radiation therapy. It is characterized by hypovascularity, hypocellularity, and hypoxia-inducing necrosis of bone and soft tissue following delayed healing. In this case, a 72-year-old man was referred to the Department of Oral and Maxillofacial Surgery complaining of trismus following extraction three months before first visit. He had a history of right tonsillectomy, radical neck dissection and radiotherapy performed due to right tonsillar cancer seven years prior. After the diagnosis of osteoradionecrosis on right mandibular body and angle, conservative antibiotic therapy was used first, but an orocutaneous fistula gradually formed, and extensive bony destruction and sequestrum were observed. Sequestrectomy, free particulated iliac bone and umbilical fat pad graft were performed via a submandibular approach under general anesthesia. Preoperative regular exams and delicate wound care led to secondary healing of the wound without vascularized free flap reconstruction.