Sequential treatment from mandibulectomy to reconstruction on mandibular oral cancer – Case review II: mandibular anterior and the floor of the mouth lesion of basaloid squamous cell carcinoma and clear cell odontogenic carcinoma

Preoperative patient analysis for oral cancer involves multiple considerations that are based on multiple factors; these include TNM stages, histopathologic findings, and adjacent anatomical structures. Once the decision is made to excise the lesion, the margin of dissection and its extent should be considered along with the best form of reconstruction and airway management. Treatment methods include surgical resection, radiotherapy, and chemotherapy. Although the combined method of treatment is controversial, surgical resection is considered predominantly, and immediate reconstruction after surgical resection follows. The choice of treatment is dictated by the anticipated functional and esthetic results of treatment and also by the availability of a surgeon with the required expertise. Segmental mandibulectomy with primary reconstruction has been shown to have advantages in both functional and esthetic results. A 52-year-old male patient with basaloid squamous cell carcinoma of the floor of the mouth, and the anterior portion of the mandible was treated with surgical procedures that included segmental mandibulectomy with both supraomohyoid neck dissection (SOHND) at Levels I–III and mandible reconstruction with a left fibula free flap. A 55-year-old male patient with clear cell odontogenic carcinoma of the oral cavity underwent segmental mandibulectomy with both SOHND at Levels I–III and mandible reconstruction with a left fibula free flap. The purpose of this study was to review the anatomic and functional results of patients after immediate reconstruction with a fibula free flap following resection of carcinoma in the anterior portion of the mandible and floor of the mouth.

Sequential treatment from mandibulectomy to reconstruction on mandibular oral cancer – Case review I: mandibular ramus and angle lesion of primary intraosseous squamous cell carcinoma

Primary intraosseous squamous cell carcinoma (PIOSCC) is very rare type of squamous cell carcinoma (SCC) that occurs within the jaw and arises from remnants of odontogenic epithelium with no connection to the oral mucosa. This study reports two cases of PIOSCC of the mandible. Reported in this article are two cases of PIOSCC of the mandible that were treated with resection and reconstruction using a fibular free flap. The first case was a 36-year-old male patient who complained of right mandibular pain. Computed tomography (CT) and panoramic radiograph revealed a large radiolucency in the mandibular ramus area. At first, an odontogenic keratocyst was tentatively diagnosed, and an excision procedure was carried out at another clinic. A final biopsy after cyst enucleation revealed well-differentiated SCC, so we proceeded with segmental mandibulectomy and reconstruction using a fibular free flap. The second case was a 48-year-old male patient with left mandibular pain. CT and panoramic radiograph revealed irregular radiolucency in the mandibular angle area near tooth #38. At first, osteomyelitis was tentatively diagnosed, and a curettage was carried out. A later biopsy revealed well-differentiated SCC, so segmental mandibulectomy and reconstruction with a fibular free flap were secondarily performed. Our two cases have had no recurrence. The facial appearance of both patients is satisfactory, and the neo-mandibular body created using a fibular bone transfer displays adequate bony volume.

Sequential treatment from mandibulectomy to reconstruction on mandibular oral cancer – Case review II: mandibular anterior and the floor of the mouth lesion of basaloid squamous cell carcinoma and clear cell odontogenic carcinoma

Preoperative patient analysis for oral cancer involves multiple considerations that are based on multiple factors; these include TNM stages, histopathologic findings, and adjacent anatomical structures. Once the decision is made to excise the lesion, the margin of dissection and its extent should be considered along with the best form of reconstruction and airway management. Treatment methods include surgical resection, radiotherapy, and chemotherapy. Although the combined method of treatment is controversial, surgical resection is considered predominantly, and immediate reconstruction after surgical resection follows. The choice of treatment is dictated by the anticipated functional and esthetic results of treatment and also by the availability of a surgeon with the required expertise. Segmental mandibulectomy with primary reconstruction has been shown to have advantages in both functional and esthetic results. A 52-year-old male patient with basaloid squamous cell carcinoma of the floor of the mouth, and the anterior portion of the mandible was treated with surgical procedures that included segmental mandibulectomy with both supraomohyoid neck dissection (SOHND) at Levels I–III and mandible reconstruction with a left fibula free flap. A 55-year-old male patient with clear cell odontogenic carcinoma of the oral cavity underwent segmental mandibulectomy with both SOHND at Levels I–III and mandible reconstruction with a left fibula free flap. The purpose of this study was to review the anatomic and functional results of patients after immediate reconstruction with a fibula free flap following resection of carcinoma in the anterior portion of the mandible and floor of the mouth.

Sequential treatment from mandibulectomy to reconstruction on mandibular oral cancer – Case review I: mandibular ramus and angle lesion of primary intraosseous squamous cell carcinoma

Primary intraosseous squamous cell carcinoma (PIOSCC) is very rare type of squamous cell carcinoma (SCC) that occurs within the jaw and arises from remnants of odontogenic epithelium with no connection to the oral mucosa. This study reports two cases of PIOSCC of the mandible. Reported in this article are two cases of PIOSCC of the mandible that were treated with resection and reconstruction using a fibular free flap. The first case was a 36-year-old male patient who complained of right mandibular pain. Computed tomography (CT) and panoramic radiograph revealed a large radiolucency in the mandibular ramus area. At first, an odontogenic keratocyst was tentatively diagnosed, and an excision procedure was carried out at another clinic. A final biopsy after cyst enucleation revealed well-differentiated SCC, so we proceeded with segmental mandibulectomy and reconstruction using a fibular free flap. The second case was a 48-year-old male patient with left mandibular pain. CT and panoramic radiograph revealed irregular radiolucency in the mandibular angle area near tooth #38. At first, osteomyelitis was tentatively diagnosed, and a curettage was carried out. A later biopsy revealed well-differentiated SCC, so segmental mandibulectomy and reconstruction with a fibular free flap were secondarily performed. Our two cases have had no recurrence. The facial appearance of both patients is satisfactory, and the neo-mandibular body created using a fibular bone transfer displays adequate bony volume.

The effect of autogenous tooth bone graft material without organic matter and type I collagen treatment on bone regeneration / 대한악안면성형재건외과학회지

Objectives@#The aim of this study is to examine the effect of particulate autogenous tooth graft removed with organic matter and type I collagen addition on bone regeneration and to validate the possibility of useful allograft material for jaw defects.Material and methods: Autogenous tooth bone maker (Korean Dental Solution® KOREA) made particulate autogenous tooth not including organic matter. We used to the developed tooth grafts for experiment. Cell adhesion test with hemacytometer and energy dispersive X-ray spectroscopy (Supra40 VP®, Carl Zeiss, Germany) analysis about the particulate autogenous tooth and type I collagen were performed. Rabbits were divided into three groups: bone graft with organic matter (OM) removing particulate autogenous tooth group, bone graft with OM removing particulate autogenous tooth and type I collagen group, and a control group. Bone grafting was performed in rabbit’s calvaria. The rabbits were sacrificed at different interval at 1, 2, 4, and 6 weeks after bone grafting for the histopathologic observation and observed the effect of bone regeneration by SEM, H-E & Masson stains, osteocalcin IHC staining.Result: In vitro cytopathological study showed affinity for cells, cell attachment pattern, and cell proliferation in the order of control group, OM-removed and collagen-treated group, OM-removed particulate autogenous tooth group. The results of the degree of mineralization were opposite to those of the previous cell experimental results, and the OM-removed group, OM-removed group and collagen-treated group were relatively higher than the control group. Histopathologic analysis showed that vascularization and neonatal bone formation were higher in particulate autogenous tooth group with removing OM and with addition of collagen than control group and group of OM removed only. Immunohistochemical analysis showed that osteocalcin (OSC) expression was not observed in the control group, but at 4 weeks groups, OSC expression was observed the OM removed and OMremoved-collagen-treated particulate autogenous tooth, and the degree of expression was somewhat stronger in group of the OM removed and collagen additionally treated particulate autogenous tooth. @*Conclusion@#Particles that do not contain organic matter, the saint tooth, was responsible for sufficient bone graft material through the role of space maintenance and bone conduction, and further improved bone formation ability through additional collagen treatment. Therefore, research on various extracellular substrates and autologous bone grafting materials is necessary, and through this, it is possible to lay the foundation for a new type of autologous bone grafting material with excellent academic and technical utility.

Comparison of time and cost between conventional surgical planning and virtual surgical planning in orthognathic surgery in Korea / 대한악안면성형재건외과학회지

Background@#The purpose of this study was to measure the time of the conventional surgical planning (CSP) and virtual surgical planning (VSP) in orthognathic surgery and to compare them in terms of cost.Material and method: This is a retrospective study of the patients who underwent orthognathic surgery at the OOOOO University Dental Hospital from December 2017 to August 2018. All the patients were analyzed through both CSP and VSP, and all the surgical stents were fabricated through manual and 3-dimensional (3D) printing. The predictor variables were the planning method (CSP vs. VSP) and the surgery type (group I: Le Fort I osteotomy+bilateral sagittal split osteotomy [LFI+BSSO] or group II: only bilateral sagittal split osteotomy [BSSO]), and the outcomes were the time and cost. The results were analyzed using paired t test. @*Results@#Thirty patients (12 females, 18 males) met the inclusion criteria, and 17 patients were excluded from the study due to missing or incomplete data. There were 20 group I patients (LFI+BSSO regardless of genioplasty) and 10 group II patients (BSSO regardless of genioplasty). The average time of CSP for group I was 385±7.8 min, and that for group II was 195±8.33 min. The time reduction rate of VSP compared with CSP was 62.8% in group I and 41.5% in group II. On the other hand, there was no statistically significant cost reduction. @*Conclusions@#The time investment in VSP in this study was significantly smaller than that in CSP, and the difference was greater in group I than in group II.

Langerhans cell histiocytosis of the mandible: two case reports and literature review

Langerhans cell histiocytosis (LCH) is a rare disorder characterized by the proliferation of dendritic cells resulting in local or systemic symptoms. The clinical symptoms of patients with Langerhans cell histiocytosis depend on the site and the degree of involvement. This article describes two case histories of unifocal bony Langerhans cell histiocytosis with mandibular involvement and further discusses the appropriate management of such via a review of the literature.

Misdiagnosis of ameloblastoma in a patient with clear cell odontogenic carcinoma: a case report

Clear cell odontogenic carcinoma (CCOC), a rare tumor in the head and neck region, displays comparable properties with other tumors clinically and pathologically. In consequence, an incorrect diagnosis may be established. A 51-year-old male patient who was admitted to the Department of Oral and Maxillofacial Surgery at Pusan National University Dental Hospital was initially diagnosed with ameloblastoma via incisional biopsy. However, the excised mass of the patient was observed to manifest histopathological characteristics of ameloblastic carcinoma. The lesion was ultimately diagnosed as clear cell odontogenic carcinoma by the Department of Oral Pathology of Pusan National Dental University. Therefore, segmental mandibulectomy and bilateral neck dissection were performed, followed by reconstruction with fibula free flap and reconstruction plate. Concomitant chemotherapy radiotherapy was not necessary. The patient has been followed up, and no recurrence has occurred 6 months after surgery.

Induction of Melanoma Cell-Selective Apoptosis Using Anti-HER2 Antibody-Conjugated Gold Nanoparticles

PURPOSE: This study was conducted to verify the induction and mechanism of selective apoptosis in G361 melanoma cells using anti-HER2 antibody-conjugated gold nanoparticles (GNP-HER2). MATERIALS AND METHODS: Following GNP-HER2 treatment of G361 cells, cell cycle arrest and apoptosis were measured by WST-1 assay, Hemacolor staining, Hoechst staining, immunofluorescence staining, fluorescence-activated cell sorting analysis, and Western blotting.

Langerhans cell histiocytosis of the mandible: two case reports and literature review

Langerhans cell histiocytosis (LCH) is a rare disorder characterized by the proliferation of dendritic cells resulting in local or systemic symptoms. The clinical symptoms of patients with Langerhans cell histiocytosis depend on the site and the degree of involvement. This article describes two case histories of unifocal bony Langerhans cell histiocytosis with mandibular involvement and further discusses the appropriate management of such via a review of the literature.

Misdiagnosis of ameloblastoma in a patient with clear cell odontogenic carcinoma: a case report

Clear cell odontogenic carcinoma (CCOC), a rare tumor in the head and neck region, displays comparable properties with other tumors clinically and pathologically. In consequence, an incorrect diagnosis may be established. A 51-year-old male patient who was admitted to the Department of Oral and Maxillofacial Surgery at Pusan National University Dental Hospital was initially diagnosed with ameloblastoma via incisional biopsy. However, the excised mass of the patient was observed to manifest histopathological characteristics of ameloblastic carcinoma. The lesion was ultimately diagnosed as clear cell odontogenic carcinoma by the Department of Oral Pathology of Pusan National Dental University. Therefore, segmental mandibulectomy and bilateral neck dissection were performed, followed by reconstruction with fibula free flap and reconstruction plate. Concomitant chemotherapy radiotherapy was not necessary. The patient has been followed up, and no recurrence has occurred 6 months after surgery.

Reconstruction of cheek mucosal defect with a buccal fat pad flap in a squamous cell carcinoma patient: a case report and literature review / 대한악안면성형재건외과학회지

BACKGROUND: Squamous cell carcinoma (SCC) is the most commonly occurring malignant tumor in the oral cavity. In South Korea, it occurs most frequently in the mandible, tongue, maxilla, buccal mucosa, other areas of the oral cavity, and lips. Radial forearm free flap (RFFF) is the most widely used reconstruction method for the buccal mucosal defect. The scar of the forearm donor, however, is highly visible and unsightly, and a secondary surgical site is needed when such technique is applied. For these reasons, buccal fat pad (BFP) flap has been commonly used for closing post-surgical excision sites since the recent decades because of its reliability, ease of harvest, and low complication rate. CASE PRESENTATION: In the case reported herein, BFP flap was used to reconstruct a cheek mucosal defect after excision. The defect was completely covered by the BFP flap, without any complications. CONCLUSION: Discussed herein is the usefulness of BFP flap for the repair of the cheek mucosal defect. Also, further studies are needed to determine the possibility of using BFP flap when the defect is deep, and the maximum volume that can be harvested considering the changes in volume with age.

Mandibular reconstruction with a ready-made type and a custom-made type titanium mesh after mandibular resection in patients with oral cancer / 대한악안면성형재건외과학회지

BACKGROUND: After the resection at the mandibular site involving oral cancer, free vascularized fibular graft, a type of vascularized autograft, is often used for the mandibular reconstruction. Titanium mesh (T-mesh) and particulate cancellous bone and marrow (PCBM), however, a type of non-vascularized autograft, can also be used for the reconstruction. With the T-mesh applied even in the chin and angle areas, an aesthetic contour with adequate strength and stable fixation can be achieved, and the pores of the mesh will allow the rapid revascularization of the bone graft site. Especially, this technique does not require microvascular training; as such, the surgery time can be shortened. This advantage allows older patients to undergo the reconstructive surgery. CASE PRESENTATION: Reported in this article are two cases of mandibular reconstruction using the ready-made type and custom-made type T-mesh, respectively, after mandibular resection. We had operated double blind peer-review process. A 79-year-old female patient visited the authors’ clinic with gingival swelling and pain on the left mandibular region. After wide excision and segmental mandibulectomy, a pectoralis major myocutaneous flap was used to cover the intraoral defect. Fourteen months postoperatively, reconstruction using a ready-made type T-mesh (Striker-Leibinger, Freibrug, Germany) and iliac PCBM was done to repair the mandible left body defect. Another 62-year-old female patient visited the authors’ clinic with pain on the right mandibular region. After wide excision and segmental mandibulectomy on the mandibular squamous cell carcinoma (SCC), reconstruction was done with a reconstruction plate and a right fibula free flap. Sixteen months postoperatively, reconstruction using a custom-made type T-mesh and iliac PCBM was done to repair the mandibular defect after the failure of the fibula free flap. The CAD-CAM T-mesh was made prior to the operation. CONCLUSIONS: In both cases, sufficient new-bone formation was observed in terms of volume and strength. In the CAD-CAM custom-made type T-mesh case, especially, it was much easier to fix screws onto the adjacent mandible, and after the removal of the mesh, the appearance of both patients improved, and the neo-mandibular body showed adequate bony volume for implant or prosthetic restoration.

Retrospective clinical study of multiple keratocystic odontogenic tumors in non-syndromic patients

OBJECTIVES: A keratocystic odontogenic tumor (KOT) is a type of odontogenic tumor that mainly occurs in the posterior mandible. Most KOTs appear as solitary lesions; however, they sometimes occur as multiple cysts. This study analyzed the clinical features of multiple KOTs. MATERIALS AND METHODS: The participants were diagnosed with KOT by biopsy with multiple surgical sites, and were patients at the Pusan National University Hospital and the Pusan National University Dental Hospital from January 1, 2005 to March 31, 2016. Charts, records, images and other findings were reviewed. RESULTS: A total of 31 operations were conducted in 17 patients. The mean patient age was 28.4±20.1 years. Multiple KOTs were found to occur at a young age (P<0.01). The predominant sites were in the posterior mandible (28.6%). Most cases of multiple lesions appeared in both the upper and lower jaw, and 40.3% of lesions were associated with unerupted and impacted teeth. The overall recurrence rate measured by operation site was 10.4% (8/77 sites). No patients were associated with nevoid basal cell carcinoma syndrome. CONCLUSION: The pure recurrence rate was lower than estimated, but there was a higher possibility of secondary lesions regardless of the previous operation site; therefore, long-term follow-up is necessary.

Comparison of time and cost between conventional surgical planning and virtual surgical planning in orthognathic surgery in Korea / 대한악안면성형재건외과학회지

BACKGROUND@#The purpose of this study was to measure the time of the conventional surgical planning (CSP) and virtual surgical planning (VSP) in orthognathic surgery and to compare them in terms of cost.MATERIAL AND METHOD: This is a retrospective study of the patients who underwent orthognathic surgery at the Pusan National University Dental Hospital from December 2017 to August 2018. All the patients were analyzed through both CSP and VSP, and all the surgical stents were fabricated through manual and three-dimensional (3D) printing. The predictor variables were the planning method (CSP vs. VSP) and the surgery type (group I: Le Fort I osteotomy + bilateral sagittal split osteotomy [LFI+BSSO] or group II: only bilateral sagittal split osteotomy [BSSO]), and the outcomes were the time and cost. The results were analyzed using the paired t test.@*RESULTS@#Thirty patients (12 females, 18 males) met the inclusion criteria, and 17 patients were excluded from the study due to missing or incomplete data. There were 20 group I patients (LFI+BSSO regardless of genioplasty) and 10 group II patients (BSSO regardless of genioplasty). The average time of CSP for group I was 385 ± 7.8 min, and that for group II was 195 ± 8.33 min. The time reduction rate of VSP compared with CSP was 62.8% in group I and 41.5% in group II. On the other hand, there was no statistically significant cost reduction.@*CONCLUSIONS@#The time investment in VSP in this study was significantly smaller than that in CSP, and the difference was greater in group I than in group II.

A retrospective analysis of risk factors of oromaxillofacial infection in patients presenting to a hospital emergency ward / 대한악안면성형재건외과학회지

BACKGROUND@#The purpose of this study was to review the clinical features of oromaxillofacial infections in patients presenting to a hospital emergency ward, to identify the key factors affecting the requirement for hospitalization, and the potential risk factors predisposing to a prolonged length of hospital stay.@*METHODS@#A retrospective medical record review of the 598 patients treated for oromaxillofacial infection from 2013 to 2017 at the oral and maxillofacial surgery department, Yangsan Pusan National University Hospital, was conducted. The following information was collected from each patient: sex, age, past medical history, site of infection, etiology, admission or outpatient care, level of C-reactive protein (mg/dL), fascial spaces involved, treatment method, and duration of hospitalization. Chi-squared tests were used to identify risk factors, which were further analyzed using multivariable logistic regression.@*RESULTS@#A total of 606 patients were eligible for inclusion in the study, of which eight were excluded due to having incomplete charts; thus, 598 patients were included: 55% were male, mean patient age was 47.1 ± 19.9 years, and 12.9% of patients were diabetic. Furthermore, 71.2% of patients had infection originating in the mandible; the most common tooth of origin was lower posterior, and 29.8% of patients were hospitalized. Risk factors for hospital admission were elderly patients with concurrent disease, elevated C-reactive protein level, and multiple-space infection in the oromaxillofacial area. The duration of hospitalization was correlated with both diabetes and age.@*CONCLUSIONS@#The requirement for hospital admission is determined by the severity of the infection; even severe infections, once treated with appropriate surgery, have no relation to the length of hospital stay. The important risk factors for increased duration of hospitalization are diabetes mellitus and older age. The understanding of risk factors associated with a prolonged hospital stay during the treatment of oromaxillofacial infection will aid in treatment planning as well as highlight the importance of adequate diabetes control in patients at risk of such infection.

Versatility of the pedicled buccal fat pad flap for the management of oroantral fistula: a retrospective study of 25 cases / 대한악안면성형재건외과학회지

PURPOSE@#Maxillary bone grafts and implantations have increased over recent years despite a lack of maxillary bone quality and quantity. The number of patients referred for oroantral fistula (OAF) due to implant or bone graft failure has increased, and in patients with an oroantral fistula, the pedicled buccal fat pad is viewed as a robust, reliable option. This study was conducted to document the usefulness of buccal fat pad grafts for oroantral fistula closure.@*MATERIALS AND METHODS@#We retrospectively studied 25 patients with OAF treated with a buccal fat pad graft from 2015 to 2018. Sex, age, OAF location, cause, duration, presence of systemic disease, smoking, previous dental surgery, and side effects were investigated.@*RESULTS@#A total of 25 patients were studied. Mean patient age was 54.8 years, and the male to female ratio was 19:6. Causes of oroantral fistula were cyst enucleation, tumor resection, implant removal, bone graft failure, and extraction. Excellent results were obtained in 23 (92%) of the 25 patients. In the other two patients that both smoked, a small fistula was observed during follow-up. No recurrence of oroantral fistula was observed after 2 months to 1 year of follow-up.@*CONCLUSIONS@#The incidence of oroantral fistula is increasing due to implant and bone graft failures. Oroantral fistula closure using a pedicled buccal fat pad was found to have a high success rate.

The Effect of Autogenous Demineralized Dentin Matrix and Interleukin-6 on bone Regeneration

The aim of this study was to evaluate the role of demineralized and particulate autogenous tooth, and interleukin-6 in bone regeneration. A demineralized and particulate autogenous tooth was prepared and human osteoblast-like cells (MG63) and human osteosarcoma cells were inoculated into the culture. The rate of cell adhesion, proliferation and mineralization were examined, and the appearance of cellular attachment was observed. An 8 mm critical size defect was created in the cranium of rabbits. Nine rabbits were divided into three groups including: An experimental group A (3 rabbits), in which a demineralised and particulate autogenous tooth was grafted; an experimental group B (3 rabbits), in which a demineralized, particulate autogenous tooth was grafted in addition to interleukin-6 (20 ng/mL); and a control group. The rabbits were sacrificed at 1, 2, 4 and 6 weeks for histopathological examination with H-E and Masson's Trichrome, and immunohistochemistry with osteocalcin. The cell-based assay showed a higher rate of cell adhesion, mineralization and cellular attachment in the experimental group A compared with the control group. The animal study revealed an increased number of osteoclasts, newly formed and mature bones in the experimental group A compared with the control group. Eventually, a higher number of osteoclasts were observed in the experimental group B. However, the emergence of newly formed and mature bone was lower than in the experimental group A. The current results suggest that treatment with demineralized and particulate autogenous tooth and interleukin-6 is not effective in stimulating bone regeneration during the bone grafting procedure.

Relationship between disease stage and renal function in bisphosphonate-related osteonecrosis of the jaw

OBJECTIVES: Bisphosphonate is the primary cause of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Bisphosphonates are eliminated from the human body by the kidneys. It is anticipated that bisphosphonate levels in the body will increase if the kidney is in a weak state or if there is systemic disease that affects kidney function. The aim of this study was to analyze the relevance of renal function in the severity of BRONJ. MATERIALS AND METHODS: Ninety-three patients diagnosed with BRONJ in Pusan National University Dental Hospital from January 2012 to December 2014 were included in this study. All patients underwent a clinical exam, radiographs, and serologic lab test, including urine analysis. The patient's medical history was also taken, including the type of bisphosphonate drug, the duration of administration and drug holiday, route of administration, and other systemic diseases. In accordance with the guidelines of the 2009 position paper of American Association of Oral and Maxillofacial Surgeons, the BRONJ stage was divided into 4 groups, from stage 0 to 3, according to the severity of disease. IBM SPSS Statistics version 21.0 (IBM Co., USA) was used to perform regression analysis with a 0.05% significance level. RESULTS: BRONJ stage and renal factor (estimated glomerular filtration rate) showed a moderate statistically significant correlation. In the group with higher BRONJ stage, the creatinine level was higher, but the increase was not statistically significant. Other factors showed no significant correlation with BRONJ stage. There was a high statistically significant correlation between BRONJ stage and ‘responder group’ and ‘non-responder group,’ but there was no significant difference with the ‘worsened group.’ In addition, the age of the patients was a relative factor with BRONJ stage. CONCLUSION: With older age and lower renal function, BRONJ is more severe, and there may be a decrease in patient response to treatment.

The effect of biomechanical stimulation on osteoblast differentiation of human jaw periosteum-derived stem cells / 대한악안면성형재건외과학회지

BACKGROUND: This study was to investigate the effect of biomechanical stimulation on osteoblast differentiation of human periosteal-derived stem cell using the newly developed bioreactor. METHODS: Human periosteal-derived stem cells were harvested from the mandible during the extraction of an impacted third molar. Using the new bioreactor, 4% cyclic equibiaxial tension force (0.5 Hz) was applied for 2 and 8 h on the stem cells and cultured for 3, 7, and 14 days on the osteogenic medium. Biochemical changes of the osteoblasts after the biomechanical stimulation were investigated. No treatment group was referred to as control group. RESULTS: Alkaline phosphatase (ALP) activity and ALP messenger RNA (mRNA) expression level were higher in the strain group than those in the control group. The osteocalcin and osteonectin mRNA expressions were higher in the strain group compared to those in the control group on days 7 and 14. The vascular endothelial growth factor (VEGF) mRNA expression was higher in the strain group in comparison to that in the control group. Concentration of alizarin red S corresponding to calcium content was higher in the strain group than in the control group. CONCLUSIONS: The study suggests that cyclic tension force could influence the osteoblast differentiation of periosteal-derived stem cells under optimal stimulation condition and the force could be applicable for tissue engineering.