Biomechanical Analysis of the Kirschner-Wire Depth of the Modified Tension Band Wiring Technique in Transverse Patellar Fractures: An Experimental Study Using the Finite-Element Method

Background@#Modified tension band wiring is one of the most preferred surgical methods for transverse patellar fractures. However, the optimal depth or sagittal position of a Kirschner wire (K-wire) in modified tension band wiring has yet to be determined.The purpose of this study was to evaluate whether the depth of a K-wire affects the biomechanical characteristics of modified tension band wiring using the finite-element method. @*Methods@#A patella model was designed with a cuboid shape (length, 34.3 mm; width, 44.8 mm; and thickness, 22.4 mm) and divided into the cortical and cancellous bone parts. A transverse fracture line was formed on the midline of the cuboid shape model.The cuboidal model was applied to modified tension band wiring. The depth or sagittal position of the K-wire was divided into superficial, center, and deep. With the Abaqus v2017 program (Dassault System Inc.), the distal part of the model was fixed, and a tensile load of 850 N was applied to the proximal part of the model at an angle of 45°. The maximum pressures of the cortical and cancellous bones at the fracture plane were measured. The largest von Mises values of the K-wire and stainless steel wire were also measured. The fracture gap on the distracted or anterior side was measured. @*Results@#In deep K-wire placement, the highest peak von Mises values of the cortical and cancellous bones were observed. The Kwire and stainless steel wire showed the highest von Mises values in deep K-wire placement. The fracture gap was also largest in deep K-wire placement. @*Conclusions@#The depth of the K-wire affects the biomechanical characteristics of modified tension band wiring. Deep placement of the K-wire will be more favorable for bone union than the empirically known 5-mm anterior or center placement of the K-wire.

Biomechanical Analysis of the Kirschner-Wire Depth of the Modified Tension Band Wiring Technique in Transverse Patellar Fractures: An Experimental Study Using the Finite-Element Method

Background@#Modified tension band wiring is one of the most preferred surgical methods for transverse patellar fractures. However, the optimal depth or sagittal position of a Kirschner wire (K-wire) in modified tension band wiring has yet to be determined.The purpose of this study was to evaluate whether the depth of a K-wire affects the biomechanical characteristics of modified tension band wiring using the finite-element method. @*Methods@#A patella model was designed with a cuboid shape (length, 34.3 mm; width, 44.8 mm; and thickness, 22.4 mm) and divided into the cortical and cancellous bone parts. A transverse fracture line was formed on the midline of the cuboid shape model.The cuboidal model was applied to modified tension band wiring. The depth or sagittal position of the K-wire was divided into superficial, center, and deep. With the Abaqus v2017 program (Dassault System Inc.), the distal part of the model was fixed, and a tensile load of 850 N was applied to the proximal part of the model at an angle of 45°. The maximum pressures of the cortical and cancellous bones at the fracture plane were measured. The largest von Mises values of the K-wire and stainless steel wire were also measured. The fracture gap on the distracted or anterior side was measured. @*Results@#In deep K-wire placement, the highest peak von Mises values of the cortical and cancellous bones were observed. The Kwire and stainless steel wire showed the highest von Mises values in deep K-wire placement. The fracture gap was also largest in deep K-wire placement. @*Conclusions@#The depth of the K-wire affects the biomechanical characteristics of modified tension band wiring. Deep placement of the K-wire will be more favorable for bone union than the empirically known 5-mm anterior or center placement of the K-wire.

Long-term Follow-up of Patellar Nonresurfacing in Total Knee Arthroplasty

BACKGROUND: We aimed to confirm the long-term effect of patellar nonresurfacing (patellar decompression) in preventing anterior knee pain after total knee arthroplasty (TKA) and to investigate the possible complications.METHODS: Among patients who underwent primary TKA after being diagnosed as having advanced osteoarthritis (Kellgren-Lawrence grade 4) at our institution from January 2004 to December 2010, 121 patients who were followed up for more than 7 years were included in this study. Patients who underwent TKA with and without patellar decompression were classified as the study group and control group, respectively. A clinical knee rating score was used to compare the postoperative clinical outcomes between groups. To identify complications after patellar decompression, simple radiographs (weight-bearing anteroposterior and lateral views, patella in 30° and 45° axial views, and whole scanogram) were taken during follow-up.RESULTS: There were no complications such as patellar fracture, osteonecrosis, and subluxation. At 2 years after surgery, the prevalence of anterior knee pain was 12.7% and 18.0% in the study group and control group, respectively (p = 0.42), and the number of patients with patellofemoral osteoarthritis grade II or over was lower in the study group (p = 0.03). At 7 years after surgery, the prevalence of anterior knee pain was 18.3% and 24.0% in the study group and control group, respectively (p = 0.45), and there was no statistically significant intergroup difference in the number of patients with patellofemoral osteoarthritis grade II or over (p = 0.11).CONCLUSIONS: Patellar nonresurfacing TKA reduces anterior knee pain in the early postoperative period. The procedure can be considered a relatively safe option with fewer complications; however, its effectiveness appears to decrease over time.

Cortical Perforation Misidentified with Medial Condylar Fracture of Femur in Total Knee Arthroplasty: Case Report

Intraoperative fracture in total knee arthroplasty (TKA) is a rare complication. However, when it happens, additional surgery to fix the fracture site is needed. Therefore, it is important to diagnose intraoperative fractures in TKA exactly. The authors experienced two cases of cortical perforation of medial femoral condyle misidentified as the fracture in TKA. Cortical perforation could be misdiagnosed as the fracture, which could lead to unnecessary surgery. This is the first report about cortical perforation in TKA. We report two cases of intraoperative cortical perforations and describe the radiological characteristics.

Anterior Dislocation of the Radial Head Combined with Plastic Deformity of the Ulnar Shaft in an Adult: A Case Report

A 25-year-old woman presented to the emergency room with a painful and swollen right forearm. She had just sustained an injury from an accident during which her arm was tightly wound by a rope as she was lowering a net from a fishing boat. Before being released, her arm was rigidly trapped in the rope for approximately ten minutes. Radiographs revealed anterior dislocation of the radial head that was accompanied by plastic deformation of the proximal ulna, manifested as a reversal of the proximal dorsal angulation of the ulna (PUDA); suggested a Monteggia equivalent fracture. With the patient under general anesthesia, we reduced the radial head by posterior compression at 90° of elbow flexion and at neutral rotation of the forearm. However, the reduction was easily lost and the elbow re-dislocated with even slight supination or extension of the arm. After the osteotomy of the ulnar deformity to restore the PUDA to normal, the reduction remained stable even with manipulation of the arm. We found that the patient could exercise a full range of motion without pain at the 3-month follow-up, and neither residual instability nor degenerative changes were observed at the final 3-year follow-up.

Flexor Pollicis Longus Reconstruction in Patient with the Linburg-Comstock Syndrome

Linburg-Comstock phenomenon is defined simultaneous flexion of thumb and other fingers. The coupling of the flexor pollicis longus and flexor digitorum profundus tendons is the main pathognomonic feature of this lesion. Typically, pain is noted at the distal level of the forearm at the site of the abnormal connection. We describe a case of flexor pollicis longus tendon rupture who undergoes a carpal tunnel release, and report the Linburg-Comstock syndrome after the flexor tendon reconstruction.

Evaluation of Clinical Applicability of Stress Radiography for Shoulder Instability: Correlation between the Degree of Displacement and the Physical Examinations / 대한정형외과학회잡지

PURPOSE: The purpose of this study is to examine the clinical applicability of stress radiography in patients presenting with shoulder instability. MATERIALS AND METHODS: Fifty-six patients diagnosed with shoulder instability and 20 healthy volunteers participated in the study. Degree of displacement of the humeral head as measured on stress radiography using a Telos GA-IIE device was compared with the results of the physical examinations. Four types of stress radiography were captured while applying 15 daN of force anteriorly (AER0 and AER60) and posteriorly (PER0 and PER60) at two different positions: (1) 90° of abduction combined with 0° of external rotation, and (2) 90° of abduction combined with 60° of external rotation. RESULTS: The degree of displacement of affected shoulders of 44 patients showed significantly larger displacement than normal shoulders (p<0.05), and the comparison between 56 affected shoulders of the patients and 40 normal shoulders of the volunteers showed significantly larger displacement only in PER0 and PER60 of the patients (p<0.05). Among the four radiographs of affected shoulders, AER60 showed significantly less displacement (p=0.046). The anterior drawer test under anesthesia of 16 patients who underwent surgery for anterior instability showed positive correlation with AER0 (Spearman's rho=0.56, p<0.024). Significantly larger anterior displacement of the load and shift test was observed in the subgroup with anterior displacement more than 3 mm (p=0.028), and higher positive frequency of the Kim's test was observed in the subgroup with posterior displacement more than 3 mm (p=0.005). CONCLUSION: Stress radiography using a Telos GA-IIE device could discriminate the affected shoulder. Although it could not replace individual physical examinations, the degree of displacement correlates with some physical examinations for shoulder instability.

Etanercept Treatment in Ankylosing Spondylitis Hip Lesions / 대한고관절학회지

PURPOSE: To evaluate the efficacy of etanercept in patients with an ankylosing spondylitis hip lesion. MATERIALS AND METHODS: Between March 2008 and December 2011, this study evaluated 13 patients with hip lesions who were refractory to conventional therapy. The general improvement was evaluated by the Harris hip score, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI), ESR, CRP, and complications. RESULTS: The mean Harris hip score changed from 55.6+/-3.4 to 87.2+/-4.3(P=0.01). The mean BASDAI/ BASFI decreased from 6.8+/-1.7/6.8+/-1.6 before treatment to 4.4+/-1.8(P=0.02)/4.3+/-1.1(P=0.02) after treatment. The mean ESR/CRP changed from 48.4+/-31.5/5.8+/-5.1 to 20.8+/-19.7(P=0.06)/3.1+/-4.2(P=0.03). No complications were encountered. CONCLUSION: These results suggest that etanercept can induce significant pain improvement in most ankylosing spondylitis hip lesions.

Parathyroid Hormone 1-34(Teriparatide) Treatment in Pelvic Insufficiency Fractures: A Report of Two Cases

As a result of aging population, the incidence of pelvic insufficiency fracture has been increasing. Pain-related immobility caused by pelvic insufficiency fractures may result in a serious dependency and high mortality with preexisting comorbidities. We present two cases of pelvic insufficiency fracture in elderly patients which had good clinical outcome by parathyroid hormone 1-34(teriparatide) treatment as well as a literature review.

A Comparison of Patella Retention versus Resurfacing for Moderate or Severe Patellar Articular Defects in Total Knee Arthroplasty: Minimum 5-year Follow-up Results

PURPOSE: The purpose of this study is to assess the clinical and radiological results of patients who underwent patellar retention or resurfacing for moderate or severe patellar articular defects during total knee arthroplasty and evaluate the clinical efficacy of patellar resurfacing according to the articular defect of the patella. MATERIALS AND METHODS: From May 2003 to March 2006, 252 patients (277 cases) underwent total knee arthroplasty by one surgeon. Intraoperatively, we divided these patients into a moderate articular defect group (50-75%: group I) and a severe articular defect group (75-100%: group II) and randomly performed patellar resurfacing. The average age was 67.2 years. There were 234 female and 17 male patients. The average follow-up period was 74.6 months. Clinical outcomes were analyzed using the Knee Society (KS) knee score. Functional score, Hospital for Special Surgery (HSS) score, Feller patellar score and range of motion (ROM). Radiological outcomes were analyzed using the congruence angle, Insall-Salvati ratio and patella tilt angle. RESULTS: The KS knee score and functional score at the last follow-up were 84.4/73.1 in the retention group and 85.2/71.8 in the resurfacing group (p=0.80, p=0.63) in group I. In group II, the values were 82.1/75.1 and 87.0/71.2, respectively (p=0.51, p=0.26). The HSS score and Feller patella score were 86.7/20.3 in the retention group and 84.3/21.7 in the resurfacing group (p=0.31, p=0.29) in group I. In group II, the values were 91.6/21.2 and 85.5/22.1, respectively (p=0.37/p=0.30). The knee ROM (p=0.36/p=0.41), congruence angle (p=0.22/p=0.16), Insall-Salvati ratio (p=0.16/p=0.21) and patella tilt angle (p=0.12/p=0.19) were not statistically different between the two groups. CONCLUSIONS: In this study, we could not find any correlations between the degree of patellar articular defect and patellar resurfacing in terms of the clinical and radiological results. Therefore, patellar articular defects is thought to be less meaningful in determining patellar resurfacing.

Comparison of Drills Used in Endonasal Dacryocystorhinostomy

PURPOSE: To evaluate and compare two types of microdrills that are used in endonasal dacryocystorhinostomy. METHODS: We retrospectively analyzed medical records and video recordings of 51 patients with 65 affected eyes who underwent endonasal dacryocystorhinostomy for treatment of chronic dacryocystitis or primary acquired nasolacrimal duct obstruction at our hospital between 2005 and 2007. All procedures were performed by the same surgeon. The patients were randomly divided into two groups. For patients in group 1 the surgeon used the Diego powered dissector (Gyrus(R)), while patients in group 2 were treated using the Ossepro (Bein Air(R)) microdrill. RESULTS: The operation success rate of group 1 was 96.6% and of group 2 was 94.2%. This difference was not statistically significant (p>0.05). The mean operation time was longer in group 1 (45.6 min) than in group 2 (65.8 min). These values, along with the mean drill usage times for each group, were significantly different (p=0.03). The mean revolution per minute(RPMs)or the two groups were also significantly different (p=0.05). CONCLUSIONS: Our results suggest that microdrills used in endonasal dacryocystorhinostomy should have protective shields to minimize mucosal damage, and employ rapid RPMs to efficiently produce bony openings in the thick anterior processes of the maxilla. The tips of microdrills should also be exposed, to better visualize and acquire good operating fields.

Repeatability of Spectral Domain OCT (3D-OCT 1000) in Normal Subjects and Various Macular Diseases

PURPOSE: To evaluate the repeatability of macular thickness and total macular volume measurements made using spectral domain optical coherence tomography (OCT) in normal subjects and subjects with macular disease. METHODS: Among a total of 108 subjects, there were 50 normal subjucts, 20 patients with diabetic macular edema, 10 patients with retinal vein occlusion, 15 patients with age-related macular degeneration, and 13 subjects with other conditions. Two serial macular measurements were obtained from each subject by a single experienced examiner using spectral domain OCT. The repeatability of the measurements was evaluated by comparing two consecutive foveal and perifoveal thickness measurements and total macular volume measurements. The intraclass correlation coefficient was also calculated to evaluate the repeatability of measurements made in normal and macular disease subjects. Result: Spectral domain OCT measurements of macular thickness and macular volume were found to be consistent. Measurements of normal subjects were the most consistent, followed by measurements of patients with age-related macular degeneration, retinal vein occlusion, and diabetic macular edema. CONCLUSIONS: Although measurements made using spectral domain OCT were repeatable across all subjects, they were more consistent in normal subjects than in patients with macular disease. The differences in repeatability should be considered in the context of diseased pathologic anatomy. Physicians should remain cautious when using these measurements for clinical evaluation.

Dacryocystocele in Adult: A Report of Five Cases

PURPOSE: To report the clinical findings and the treatments of patients with dacryocystocele, presenting as an uncommon mass in the medial canthal area of adults. CASE SUMMARY: Five patients, diagnosed with dacryocystocele, complained of epiphora and mucopurulent discharge and were found to have a medial canthal mass. Four of these patients presented with symptoms of acute dacryocystitis. One patient underwent repeated endonasal dacryocystorhinostomy (endonasal DCR) with silicone implantation, but the epiphora returned a few months after the treatment. The patient then received external dacryocystorhinostomy (external DCR) with silicone implantation. Two patients experienced recurrence after the first endonasal DCR and, therefore, received repeat endonasal DCR with silicone implantation via a maximum excision of the enlarged lacrimal sac. One patient underwent external DCR with silicone implantation due to acute inflammation with chronic dacryocystitis, and one attempted conservative treatment after refusing any surgical procedure but suffered a relapse. In the surgical cases, no patients experienced recurrence after the final procedure, and they all had a favorable course during the 6 to 14 months of follow-up. CONCLUSIONS: Dacryocystocele in adults always requires a surgical procedure. Additional maximum excision of the lateral wall of an enlarged lacrimal sac could be performed to reduce the possibility of recurrence.

Analysis of Failure Cause of Acetabular Components Among Total Hip Replacement Arthroplasties Using RB Wagner Acetabular Cup

PURPOSE: The purpose of this study was to analyze the cause of failure of acetabular component cases after metal-on-metal primary total hip arthroplasty using RB Wagner acetabular cup. MATERIALS AND METHODS: Between January 1993 and January 2005, we retrospectively studied failure cause of 27 patients who underwent acetabular revision surgery among 468 consecutive cementless total hip arthroplasties using RB Wagner acetabular component. The duration of primary arthroplasty to revision ranged from 5.1 years to 11.5 years (mean 9.2 years). The clinical evaluation was performed using preoperative and last follow-up modified Harris hip scores. The radiological evaluation was performed in terms of the stability, such as inclination, anteversion, cup size, acetabular bone coverage, osteolysis, radiolucency and gap. RESULTS: The average Harris hip scores was 49.6 preoperatively and 91.3 at the most recent follow-up. In revision cases, the score was 41.2 to 51.7. Among 468 cases, 27 patients underwent revision surgery (7%, 27/468) and there was no osseointegration in all cases. The radiological evaluation in revision cases revealed inclination (46.04+/-5.328, p=0.0031), anteversion (14.14+/-2.95, p=0.584), cup size (54 mm+/-2.5, p=0.042) and acetabular bone coverage (67.9%+/-4.77, p=0.003). Focusing on the relation between disease entities, there was relatively high risk in patients with hip dysplasia (Fisher's exact test, p=0.0095). CONCLUSION: Although Wagner acetabular cup relatively showed as high survival rate as 93%, failure rate is significantly high in dysplastic hip patients.

Avascular Necrosis of the Hallucal Sesamoid: Three Cases Report / 대한족부족관절학회지

Although avascular necrosis of the hallucal sesamoid has not been frequently addressed in the literature, it should be considered in the differential diagnosis of persistent forefoot pain. We experienced 3 cases of avascular necrosis of the hallucal sesamoid with sclerosis of the sesamoid bone on radiograghs and computed tomograghy images. T1 and T2-weighted MRI images in 2 patients showed low signal intensity in the sesamoid bone, which suggested osteonecrosis and confirmed by histology. We report 3 cases of avascular necrosis of sesamoid with a review of the literature.

A Case of Simultaneous Orbital Cellulitis and Intracranial Complication

PURPOSE: To report a case of simultaneous orbital cellulitis and intracranial complications of acute sinusitis in a young patient. CASE SUMMARY: The 11-year-old male presented with a one-day history of left periorbital erythematous swelling, fever and headache. He was diagnosed with acute sinusitis at the department of otorhinolaryngology, and endoscopic sinus drainage of pus was performed. However, the patient's symptoms did not improve. The next day, a subdural abscess was found on brain computed tomography. He was treated by external drainage of the periosteal abscess via a subbrow incision and systemic antibiotics, as well as anticonvulsant medication. CONCLUSIONS: Twenty days after external drainage and beginning systemic antibiotics and anticonvulsant treatment, he was discharged with improved orbital cellulitis symptoms and a resolved subdural abscess.

The Effect of Intravitreal Bevacizumab Injection in Eales' Disease

PURPOSE: To report on 2 cases of Eales' disease that were successfully regressed with laser photocoagulation and intravitreal bevacizumab (Avastin; Genetech, Inc, San Francisco, California, USA) injection. CASE SUMMARY: Two male patients (30 years and, 40 years of age,) with a history of recurrent vitreous hemorrhage were diagnosed with Eales' disease. The 2 patients had peripheral retina neovascularization and active phlebitis in fundus fluorescein angiography. No other findings were observed in their eyes in the general examination. Scatter laser photocoagulation and intravitreal bevacizumab injection were performed. After 1 month follow-up, neovascularization completely regressed. There was no complication or recurrent vitreous hemorrhage at the 1 year follow up. CONCLUSIONS: Intravitreal bevacizumab injection, as combination treatment of laser photocoagulation, may be helpful in the regression of neovascularization due to Eales' disease.

Autologous Chondrocyte Implantation for Treating Chondral Defects of the Femoral Condyle

PURPOSE: We wanted to evaluate the clinical and objective results of autologous chondrocyte implantation (ACI) on a femoral chondral defect of the knee. MATERIALS AND METHODS: We evaluated 14 patients who had been operated on with ACI on the chondral defect of the knee between December 2000 and December 2005. There were 11 males and 3 females with the average age of 33 years (range: 17~44 years) and the mean size of the defect was 5.9 cm2 (range: 2.0~10 cm(2)). Seven cases were due to osteochondritis dissecans, and others were due to traumatic defect. The mean follow-up period was 26 months (range: 12~42 months). Lysholm's and Tegner's scores were used for evaluation. A 2nd look arthroscopic examination and a biopsy were carried out in 6 cases and MRI was done in 3 cases for evaluating cartilage regeneration. RESULTS: The mean Lysholm's and Tegner's scores were improved 60 to 84, and 2.4 to 4.1, respectively. According to the ICRS (International cartilage repair society) assessment, the gross appearance of the regenerated cartilage was graded as the following: 1 normal, 1 nearly normal, 3 abnormal and 1 severely abnormal. MRI demonstrated cartilage regeneration in 2 out of 3 cases. There were 2 cases of graft hypertrophy and 1 case of graft adhesion as complications. CONCLUSION: The clinical results were significantly improved according to Lysholm's and Tegner's scores. However, the gross appearances and histological results gave less satisfactory results. We conclude that a more sophisticated surgical technique and the long term follow-up results are necessary.

Clinical Outcome of Dacryocystorhinostomy with Septal Deviation

PURPOSE: Septal deviation has few subjective symptoms. However, a difficulty remains in doing DCR (dacryocystorhinostomy) in these patients. We investigate the clinical course of DCR in patients with a septal deviation. METHODS: Acquired nasolacrimal duct-obstructed patients who had undergone DCR with septal deviation from 2003 to 2006 in our hospital were retrospectively analyzed. We measured the septal distance using paranasal computed tomography taken preoperatively and compared the sex and age of patients, the kinds of operations, outcome of surgery, and ocular and nasal complications in our analysis. RESULTS: Twenty-two eyes of 22 patients with a mean age of 55.3 years (range 29~74) were analyzed (4 males, 18 females). Mean septal distance was 4.84 mm (range 2.18~6.99 mm). Nineteen eyes had endonasal DCR, and three had external DCR. Two had DCR combined with septoplasty. Three had septoplasty as a secondary operation, Nasal complication was synechiae in 9 eyes. DCR success was seen in 15 eyes, and DCR failure in 7 eyes. Septal distance was not correlated with DCR success but was correlated with nasal complication (Mann-Whitney test, p=0.003) CONCLUSIONS: In the case of DCR with septal deviation, the surgical technique used will need to minimize the mucosal injury and ensure appropriate nasal correction to prevent future complications.

Regulation of cementoblast differentiation and mineralization using conditioned media of odontoblast / 대한치주과학회지

For the regeneration of periodontal tissues, the microenvironment for new attachment of connective tissue fibers should be provided. At this point of view, cementum formation in root surface plays a key role for this new attachment. This study was performed to figure out which factor promotes differentiation of cementoblast. Considering anatomical structure of tooth, we selected the cells which may affect the differentiation of cementoblast - Ameloblast, OD11&MDPC23 for odontoblasts, NIH3T3 for fibroblsts and MG63 for osteoblasts. And OCCM30 was selected for cementoblast cell line. Then, the cell lines were cultured respectively and transferred the conditioned media to OCCM30. To evaluate the result, Alizarin red S stain was proceeded for evaluation of mineralization. The subjected mRNA genes are bone sialoprotein(BSP), alkaline phosphate(ALP), osteocalcin(OC), type I collagen(Col I), osteonectin(SPARC ; secreted protein acidic and rich in cysteine). Expression of the gene were analysed by RT-PCR. The results were as follows: 1. For alizarin red S staining, control OCCM30 didn't show any mineralized red nodules until 14 days. But red nodules started to appear from about 4 days in MDPC-OCCM30 & OD11-OCCM30. 2. For results of RT-PCR, BSP mRNAs of control-OCCM30 and others were expressed from 14 days, but in MDPC23-OCCM30 & OD11-OCCM30 from 4 days. Like this, the gene expression of MDPC23-OCCM30 & OD11-OCCM30 were detected much earlier than others. 3. For confirmation of odontoblast effect on cementoblast, conditioned media of osteoblasts(MG63) which is mineralized by producing matrix vesicles didn't affect on the mineralized nodule formation of cementoblasts(OCCM30). This suggest the possibility that cementoblast mineralization is regulated by specific factor in dentin matrix protein rather than matrix vesicles. Therefore, we proved that the dentin/odontoblast promotes differentiation/mineralization of cementoblasts. This new approach might hole promise as diverse possibilities for the regeneration of tissues after periodontal disease.