Joo-Young Ohe

Correlation Between Serum C-Terminal Cross-Linking Telopeptide of Type I Collagen and Staging of Oral Bisphosphonate-Related Osteonecrosis of the Jaws

PURPOSE The aim of the present study was to correlate the staging of bisphosphonate-related osteonecrosis of the jaws (BRONJ) with serum C-terminal cross-linking telopeptide of type I collagen (CTX), which is under debate as an index of risk prediction. Stage I BRONJ was defined as asymptomatic osteonecrotic bone. Stage II BRONJ includes infection, and stage III includes additional complications such as fracture or extraoral fistulas. PATIENTS AND METHODS The serum CTX values of 18 patients (mean age 74 years) who were diagnosed with osteonecrosis of the jaws caused by oral bisphosphonate were investigated. RESULTS The serum CTX values ranged from 10 to 262 pg/mL (mean 112 +/- 76.1). The mean duration of bisphosphonate therapy was 3.9 years, and 17 of the 18 patients had received once weekly 70 mg aldendronate and 1 patient once weekly 35 mg risedronate. The risk assessment was rated according to the CTX values of the individual patient (minimal risk, more than 150 pg/mL; moderate, 100 to 150 pg/mL; and high, less than 100 pg/mL). Next, the BRONJ scores were calculated according to the number of the BRONJ lesions and their stage. The risk assessment and BRONJ scores were correlated. The result was statistically significant (P = .019). CONCLUSIONS BRONJ is relatively rare but has been increasingly recognized in our clinic. The usefulness of the serum CTX value as an index of risk prediction continues to be debated. Considering the staging of lesions and the number of lesions, we found a significant correlation between the disease severity and the risk assessment using serum CTX.

Photo-cured hyaluronic acid-based hydrogels containing growth and differentiation factor 5 (GDF-5) for bone tissue regeneration

In this study we describe the generation and influences on in vitro and in vivo osteogenesis of photo-cured hyaluronic acid (HA) hydrogels loaded with growth and differentiation factor 5 (GDF-5). Prior to loading GDF-5, we characterized the release profiles from these hydrogels and tested their respective cell viability, differentiation and in vivo bone regeneration. The results from this testing indicated that GDF-5 was observed to release in a sustained manner from the HA hydrogels I-III. MTT and Live/Dead assays showed that the HA hydrogels I-III have good biocompatibility for use as scaffolds for bone tissue regeneration. In vitro cell tests showed a higher level of MC3T3-E1 cell proliferation and differentiation on HA hydrogels I-III than on HA hydrogel 0. Moreover, in vivo animal tests showed that the HA hydrogels I and III had a significant improvement on osteogenesis. Overall, our results suggest that the HA-based hydrogel is a good biomaterial to deliver osteogenic differentiation factors such as GDF-5, and GDF-5 can be useful as an effective alternative to aid new bone formation.

Retrospective study of two biochemical markers for the risk assessment of oral bisphosphonate‐related osteonecrosis of the jaws: can they be utilized as risk markers?

PURPOSE the purpose of this retrospective study was to examine the possibility of utilizing serum C-terminal telopeptide cross-link of type I collagen (s-CTX) and serum osteocalcin (s-OC) as risk markers for oral bisphosphonate-related osteonecrosis of the jaws (BRONJ). PATIENTS AND METHODS the s-CTX values and the s-OC values were measured from 23 patients (one male, 22 females) diagnosed with BRONJ using clinical and radiographic examinations. The two biochemical markers were evaluated during a regular checkup for osteoporosis management. For the control group of s-CTX study, s-CTX values were obtained from 61 independently recruited postmenopausal women who have been on bisphosphonate therapy for >6 months. The s-CTX values of the ONJ group and the control group were compared. Because of retrospective nature of this study, the control group for s-OC study could not be established. A single sample t-test was performed for the s-OC value from the ONJ group. RESULT twenty-three ONJ patients had taken alendronate for osteoporosis treatment, and the s-CTX testing results were low levels of 10-192 pg/ml (mean: 93.2 ± 49.4 pg/ml). Mean of s-CTX of the control (n=61) was 125 ± 85.7 pg/ml. The duration of BP therapy ranged between 1 and 10 years (4.82 ± 2.6). The s-OC level was estimated between 0.2 and 5.4 ng/ml (1.91 ± 1.51 ng/ml). The mean s-CTX value of the control group was higher but without significance (P=0.12). The s-OC values of the ONJ group were significantly lower than the lowest value of the reference range (P<0.001). CONCLUSION as a result of the s-CTX and s-OC testings at the diagnosis of BRONJ, the values of the two markers were decreased. The decrease of the s-OC values implies a problem during the bone-formation process. Therefore, we can assume that in this patient group, invasive dental surgery contributes to an increase in the risk of BRONJ incidence. This result may imply that, during bisphosphonate therapy, simultaneous consideration of s-CTX showing inhibition of bone resorption and s-OC indicating the degree of bone formation might be a set of risk markers assessing risk prediction for BRONJ before invasive dental surgery.

Effect of lower third molars on the incidence of mandibular angle and condylar fractures.

Purpose:Numerous previous studies already have proven that mandibles with a third molar are significantly more susceptible to angle fracture by external force. Similarly, other data suggest that the absence of a third molar increases the risk of condylar fracture, while concurrently decreasing the risk of angular fracture. We attempt to characterize the effect of a third molar on the incidence of mandibular angle and condylar fractures. Methods:This retrospective study reviews data from 385 patients, all of whom were seen in our clinics between February 2006 and November 2009. All data were collected from clinical examination notes and panoramic radiographs, with third-molar state evaluated by the Pell and Gregory classification system. Results:Our results mirror those of previous studies. The incidence of mandibular angle fracture was significantly greater on sides with a third molar, whereas the condylar fracture rate significantly increased in mandibles lacking a third molar or without a fully erupted third molar. The rate of symphysis and mandibular angle fracture was also high in cases of multiple comorbid fractures. Conclusions:Both the presence and the state of the lower third molar affect the risk of future mandibular angle and condylar fracture.

Postoperative stability of 2-jaw surgery with clockwise rotation of the occlusal plane.

ObjectiveThe objective of this study was to investigate the skeletal stability after Le Fort I osteotomy with clockwise rotation and bilateral sagittal split osteotomy. Materials and MethodsThe sample consisted of 31 young Korean patients who were treated with Le Fort I osteotomy with clockwise rotation and setback bilateral sagittal split osteotomy. The lateral cephalographs were obtained before surgery (T1), right after surgery (T2), and on an average of 6.23 months after the operation (T3). The horizontal and vertical relations of landmarks to the reference line and soft tissue changes were evaluated. ResultDuring the T2 − T1 period, there was superior and anterior movement of the posterior part (PNS, UMD) and advancement and impaction of the anterior part (ANS, A point, UIE) of the maxilla. The mandible was moved superiorly and posteriorly. During the T3 − T2 period, maxillary segment showed counterclockwise rotational relapse. The posterior part was relatively stable especially in the vertical position and the anterior part moved in the posterior and superior directions. Mandibular landmarks showed forward relapse in the horizontal aspect and superior relapse in the vertical aspect. The posterior part (PNS and UMD) showed a significantly higher stability rate (>70%) in the vertical aspect and the anterior part of the maxilla (ANS, A point) demonstrated a significantly lower value (<30%) in the vertical aspect. According to the skeletal changes, the soft tissue of the lower facial profile is rotated clockwise. ConclusionsTwo-jaw surgeries involving clockwise rotation of the occlusal plane showed stable results especially in the maxillary posterior landmarks. The clockwise rotational movement can be beneficial to increase skeletal stability and facial aesthetics in Asians.

A CBCT study on positional change in mandibular condyle according to metallic anchorage methods in skeletal class III patients after orthognatic surgery

PURPOSE This study was to evaluate the postoperative stability of the mandibular condyle according to the number of screws in the proximal segment using cone beam computed tomography (CBCT). PATIENTS AND METHODS Thirty patients diagnosed with skeletal class III malocclusion and underwent sagittal split ramus osteotomy (SSRO) were enrolled in this study. In Group A, 4 screws and a 4-hole miniplate were used for the internal fixation of an osteotomy and 3 screws, only 1 screw in the proximal segment, and a 4-hole miniplate were used in Group B. We digitally measured anteroposterior, supero-inferior, and mediolateral positions and angles of the long axis of the mediolateral poles in CBCT scans pre-operatively, within 1 week postoperatively and 3, 6 months after surgery. RESULTS The condylar head angle in the axial plane showed consistent and significant changes. The condylar head angle in the coronal plane decreased in both groups, which shows that condylar heads bent inward. In the axial plane, Group A showed statistically significant differences while Group B did not in early stage (T0-T1-T2). The change in distance between condylar heads shows that these have moved outward in both groups. CONCLUSION The results show that a fixation method using 3 screws with a 4-hole miniplate did seemed preferable and may give some flexibility for condylar heads to be positioned in physiologic position during postoperative phase.

Volume stability of hydroxyapatite and β-tricalcium phosphate biphasic bone graft material in maxillary sinus floor elevation: a radiographic study using 3D cone beam computed tomography.

OBJECTIVES The purpose of this study was to confirm volume stability of biphasic calcium phosphate (BCP) through the changes of grafted volume over the time by 3D CT analyzing software program. PATIENTS AND METHODS Fifteen patients, 16 sinuses who were scheduled a staged implantation through sinus floor elevation (SFE)-lateral window technique from 2009 to 2011 were included in the study. Of the 15 patients, eight were male and seven were female (mean age 50.1). For sinus floor augmentation, BCP with local blood was packed loosely into the maxillary sinus and the grafted site was covered with a collagen membrane. For the evaluation of volume change, 3D CBCT scans were taken five times at pre-operatively (To), post-op 1 week (T1), 1 month (T2), 3 months (T3), and 6 months (T4). 3D image processing software (OnDemand3DTM software) was used for this study. The time sequential change was statistically evaluated. RESULT 84.32% grafted BCP is maintained until post-op 6 month (T4), and the average volume loss is 207.7 mm(3) (about 0.21 cc). Statistically, a significant volume change (decreasing) was observed in three groups (T2-T1, T3-T2, T4-T3). CONCLUSION Biphasic calcium phosphate, as a synthetic material, has high volume stability and is a predictable graft material for the successful SFE. Although some limitations of the 3D analyzing software program, it is a fast, simple, relatively accurate and promising approach to quantifying long-term changes in the grafted area.

Retrospective clinical study of mandible fractures

Objectives The purpose of this article is to analyze the incidence, demographic distribution, type, and etiology of mandible fractures that were treated by the Department of Oral and Maxillofacial Surgery in Kyung Hee University Dental Hospital from January 2002 to December 2012. Materials and Methods This was a descriptive and analytic retrospective study that evaluated 735 patients that were treated for mandible fracture. Results This study included 1,172 fractures in 735 patients. The ratio of male to female patients was 5.45 : 1; the maximum value was in patients between 20 and 29 years (38.1%) and the minimum in patients over 70 years old. The monthly distribution of facial fractures peaked in the fall and was lower during winter. No specific correlation was identified based on the annual fracture distribution. Among the 735 fracture patients, 1.59 fracture lines were observed per patient. The most frequent site was the symphysis, which accounted for a total of 431 fractures, followed by the angle (348), condyle (279), and body (95). The symphysis with angle was the most common site identified in combination with fracture and accounted for 22.4%, followed by symphysis with condyle (19.8%). The angle was the most frequent site of single fractures (20.8%). The major cause of injury was accidental trauma (43.4%), which was followed by other causes such as violence (33.9%), sports-related accidents (10.5%), and traffic accidents (10.1%). Fracture incidents correlated with alcohol consumption were reported between 10.0%-26.9% annually. Conclusion Although mandible fracture pattern is similar to the previous researches, there is some changes in the etiologic factors.

Differential Expression of Osteo-Modulatory Molecules in Periodontal Ligament Stem Cells in Response to Modified Titanium Surfaces

This study assessed differential gene expression of signaling molecules involved in osteogenic differentiation of periodontal ligament stem cells (PDLSCs) subjected to different titanium (Ti) surface types. PDLSCs were cultured on tissue culture polystyrene (TCPS), and four types of Ti discs (PT, SLA, hydrophilic PT (pmodPT), and hydrophilic SLA (modSLA)) with no osteoinductive factor and then osteogenic activity, including alkaline phosphatase (ALP) activity, mRNA expression of runt-related gene 2, osterix, FOSB, FRA1, and protein levels of osteopontin and collagen type IA, were examined. The highest osteogenic activity appeared in PDLSCs cultured on SLA, compared with the TCPS and other Ti surfaces. The role of surface properties in affecting signaling molecules to modulate PDLSC behavior was determined by examining the regulation of Wnt pathways. mRNA expression of the canonical Wnt signaling molecules, Wnt3a and β-catenin, was higher on SLA and modSLA than on smooth surfaces, but gene expression of the calcium-dependent Wnt signaling molecules Wnt5a, calmodulin, and NFATc1 was increased significantly on PT and pmodPT. Moreover, integrin α2/β1, sonic hedgehog, and Notch signaling molecules were affected differently by each surface modification. In conclusion, surface roughness and hydrophilicity can affect differential Wnt pathways and signaling molecules, targeting the osteogenic differentiation of PDLSCs.

Bone-regenerative activity of parathyroid hormone-releasing nano-hydroxyapatite/poly(L-lactic acid) hybrid scaffolds

We developed a bone-regenerative scaffold based on systematic combination of porous organic-inorganic hybrid scaffolds and recombinant human parathyroid hormone (rhPTH). The hybrid scaffold was fabricated by immobilization of polyphosphate-functionalized nano-hydroxyapatite (PP-n-HAp) on the surface of porous poly(L-lactic acid) (PLLA) scaffolds, which was followed by rhPTH loading on the polyphosphates of n-HAp surfaces. The surface polyphosphate functionalities of PP-n-HAp enabled the stable chemical immobilization of n-HAp on the amine-treated pore surface of the PLGA scaffolds. rhPTH with a positive charge was bound at a high efficiency of 98.1~99.5% onto the anionic polyphosphates of PP-n-HAp immobilized on PLLA surfaces and was sustainably released for up to 50 days. The release rate was manipulated by adjusting the amount of loaded rhPTH, and the release data were moderately fitted to the Higuchi’s diffusion model. Four types of scaffolds were tested in rabbit calvarias models (PLLA only, PP-n-HAp-PLLA, rhPTH (2 µg) loaded PP-n-HAp-PLLA, and rhPTH (10 µg) loaded PP-n-HAp-PLLA). After 5 weeks, rhPTH-loaded PP-n-HAp-PLLA (2 and 10 µg of rhPTH) displayed higher bone growth than the control (PLLA only) group. Nano-HAp and sustained release of rhPTH might be synergistically able to enhance the bone healing in the animal model.