Galectin-3 Plays an Important Role in BMP7-Induced Cementoblastic Differentiation of Human Periodontal Ligament Cells by Interacting with Extracellular Components.

Human periodontal ligament stem cells (hPDLSCs) contain multipotent postnatal stem cells that differentiate into PDL progenitors, osteoblasts, and cementoblasts. Previously, we obtained cementoblast-like cells from hPDLSCs using bone morphogenetic protein 7 (BMP7) treatment. Differentiation into appropriate progenitor cells requires interactions and changes between stem or progenitor cells and their so-called environment niches, and cell surface markers play an important role. However, cementoblast-specific cell surface markers have not yet been fully studied. Through decoy immunization with intact cementoblasts, we developed a series of monoclonal antibodies against cementoblast-specific membrane/extracellular matrix (ECM) molecules. One of these antibodies, the anti-CM3 antibody, recognized an approximate 30 kDa protein in a mouse cementoblast cell line, and the CM3 antigenic molecule accumulated in the cementum region of human tooth roots. Using mass spectrometric analysis, we found that the antigenic molecules recognized by the anti-CM3 antibody were galectin-3. As cementoblastic differentiation progressed, the expression of galectin-3 increased, and it localized at the cell surface. Inhibition of galectin-3 via siRNA and a specific inhibitor showed the complete blockage of cementoblastic differentiation and mineralization. In contrast, ectopic expression of galectin-3 induced cementoblastic differentiation. Galectin-3 interacted with laminin α2 and BMP7, and these interactions were diminished by galectin-3 inhibitors. These results suggested that galectin-3 participates in binding to the ECM component and trapping BMP7 to induce, in a sustained fashion, the upregulation of cementoblastic differentiation. Finally, galectin-3 could be a potential cementoblast-specific cell surface marker, with functional importance in cell-to-ECM interactions.

Cell Surface Accumulation of Intracellular Leucine Proline-Enriched Proteoglycan 1 Enhances Odontogenic Potential of Human Dental Pulp Stem Cells.

Primary dental pulp cells can be differentiated into odontoblast-like cells, which are responsible for dentin formation and mineralization. Successful differentiation of primary dental pulp cells can be verified using a few markers. However, odontoblast-specific cell surface markers have not been fully studied yet. LEucine PRoline-Enriched Proteoglycan 1 (LEPRE1) is a basement membrane-associated proteoglycan. LEPRE1 protein levels are increased during odontoblastic differentiation of human dental pulp cells (hDPCs). Intracellular and cell surface accumulation of this protein completely disappeared during dentin maturation and mineralization. Cell surface binding of an anti-LEPRE1 monoclonal antibody that could recognize an extracellular region was gradually increased in the odontoblastic stage. Overexpression and knockdown experiments showed that accumulation of intracellular LEPRE1 could lead to inefficient odontoblastic differentiation and that the movement of LEPRE1 from intracellular region to the cell surface was required for odontoblastic differentiation. Indeed, when LEPRE1 already located on the cell surface was blocked by the anti-LEPRE1 monoclonal antibody, odontoblastic differentiation of hDPCs was inhibited. In this study, we looked at other aspects of LEPRE1 function as a cell surface molecule rather than its known intracellular hydroxylase activity. Our results indicate that this protein has potential as a specific cell surface marker in odontoblastic differentiation.

Minimal sedation using oral sedatives for multi-visit dental treatment in an adult patient with dental phobia.

In adult patients with dental phobia, dental treatment may be difficult, or may not be possible. Depending on the level of fear or anxiety, non-pharmacological or pharmacological behavior management techniques are used in the dental treatment of such patients. Among the pharmacological behavior management techniques, minimal sedation, that is, the lowest depth of sedation, can be easily obtained in adult patients using oral sedatives, does not require special equipment or tools, and does not affect ventilatory and cardiovascular function. Diazepam is an anxiolytic drug belonging to the benzodiazepine family that, in addition to relieving anxiety, produces muscle relaxation, and is a representative drug used in adult patients with fear of dental treatment. Herein, we report the case of a 50-year-old woman with severe dental fear who successfully underwent long-term dental treatment in approximately 20 visits with minimal sedation using oral diazepam. In addition, we reviewed the considerations for the use of benzodiazepines for minimal sedation.

Tooth hypersensitivity associated with paresthesia after inferior alveolar nerve injury: case report and related neurophysiology.

Inferior alveolar nerve (IAN) injury is usually caused by stretching or crushing of the neurovascular structures and postoperative intra-alveolar hematoma or edema after dental procedures. This results in paresthesia in the ipsilateral chin, lip (vermilion border, skin, and mucosa), and labial or buccal alveolar mucosa of the mandibular anterior teeth. However, there are no reports of sensory alterations in the teeth, especially tooth hypersensitivity, after IAN injury. I report a case in which paresthesia of the lower lip and hypersensitivity of the lower anterior teeth occurred simultaneously after the removal of the third molar that was located close to the IAN. In addition, I discuss the reasons for the different sensory changes between the tooth and chin (skin) after nerve injury from a neurophysiological point of view. Since the dental pulp and periodontal apparatus are highly innervated by the inferior alveolar sensory neurons, it seems necessary to pay attention to the changes in tooth sensitivity if IAN injury occurs during dental procedures.

Delayed paresthesia of inferior alveolar nerve after dental surgery: case report and related pathophysiology.

Paresthesia is an altered sensation of the skin, manifesting as numbness, partial loss of local sensitivity, burning, or tingling. The inferior alveolar nerve (IAN) is the third branch of the trigeminal nerve and is very important in dental treatment. IAN paresthesia may occur after various dental procedures such as simple anesthetic injections, surgical procedures, and endodontic treatment, and is reported to range from 0.35% to 8.4%. The altered sensation usually follows immediately after the procedure, and reports of late onset of nerve involvement are rare. This report presents a rare case of delayed paresthesia after dental surgery and discusses the pathophysiology of IAN delayed paresthesia.

Pulseless electrical activity during general anesthesia induction in patients with amyotrophic lateral sclerosis.

Pulseless electrical activity (PEA) is a clinical condition characterized by unresponsiveness and lack of palpable pulse in the presence of organized cardiac electrical activity and is caused by a profound cardiovascular insult (e.g., severe prolonged hypoxia or acidosis, extreme hypovolemia, or flow-restricting pulmonary embolus). Amyotrophic lateral sclerosis (ALS) is a disease that is characterized by progressive degeneration of all levels of the motor nervous system. Damage to the respiratory system and weakness of the muscles may increase the likelihood of an emergency situation occurring in patients with ALS while under general anesthesia. We report a case of PEA during the induction of general anesthesia in a patient with ALS who presented for dental treatment and discuss the causes of PEA and necessary considerations for general anesthesia in patients with ALS.

Single-Tooth Osteotomy Using Piezoelectric Devices to Treat an Ankylosed Maxillary Molar.

Single-tooth osteotomy is a surgical technique in which the tooth and adjacent bone with sufficient soft tissue are repositioned in a single step or moved orthodontically. It is not used in the maxillary posterior region because of poor accessibility, bleeding complications, and anatomical limitations such as the maxillary sinus. However, the development of piezoelectric surgical devices and the popularization of the sinus floor elevation procedure have simplified the approach to the posterior maxillary area. This article reports two cases of single-tooth osteotomy of ankylosed teeth that were performed safely in the posterior maxilla with the use of a piezoelectric device and a sinus membrane elevation. In addition, several merits of this approach as compared with conventional osteotomy are described.

Denosumab-related osteonecrosis of the jaw: a case report and management based on pharmacokinetics.

Denosumab, a monoclonal antibody against the receptor activator for nuclear factor-kappa B ligand (RANKL), is a recently approved antiresorptive drug that suppresses osteoclast formation by targeting preosteclasts, in contrast to the traditional antiresorptive bisphosphonates that target mature osteoclasts. Osteonecrosis of the jaw (ONJ) is a well-known, if rare, side effect of bisphosphonate therapy; however, cases of ONJ have also been reported since 2010 in patients taking denosumab. We describe here a patient who developed ONJ while receiving denosumab; the pharmacokinetics of denosumab and bisphosphonates are discussed in the context of ONJ management.

Protective dental splint for oroendotracheal intubation: experience of 202 cases.

BACKGROUND: Dental injury as a result of oroendotracheal intubation during general anesthesia is very common. We report our experiences of using mouthguard to prevent dental injury during intubation based on our protocol. METHODS: This retrospective study enrolled patients referred for preanesthetic evaluation, those patients with a history of any of the dental treatments to their anterior teeth listed on our fabrication protocol from January 1, 2009 to June 30, 2010. RESULTS: No cases of dental trauma during oroendotracheal intubation were reported among the 202 patients who used a protective device. 66% of the patients had risk factors for hard tissue damage aged 10-40 years. At the ages of 40-70 years, the incidence of risk group for periodontal damage was higher. CONCLUSIONS: Preanesthetic consultation was effective for preventing dental injury, so preanesthetic questionnaire and proper dental consultation would be helpful.

Diplopia after inferior alveolar nerve block: case report and related physiology.

Although inferior alveolar nerve block is one of the most common procedures performed at dental clinics, complications or adverse effects can still occur. On rare occasions, ocular disturbances, such as diplopia, blurred vision, amaurosis, mydriasis, abnormal pupillary light reflex, retrobulbar pain, miosis, and enophthalmos, have also been reported after maxillary and mandibular anesthesia. Generally, these symptoms are temporary but they can be rather distressing to both patients and dental practitioners. Herein, we describe a case of diplopia caused by routine inferior alveolar nerve anesthesia, its related physiology, and management.

The influence of mandibular skeletal characteristics on inferior alveolar nerve block anesthesia.

BACKGROUND: The inferior alveolar nerve block (IANB) is the most common anesthetic techniques in dentistry; however, its success rate is low. The purpose of this study was to determine the correlation between IANB failure and mandibular skeletal characteristics. METHODS: In total, 693 cases of lower third molar extraction (n = 575 patients) were examined in this study. The ratio of the condylar and coronoid distances from the mandibular foramen (condyle-coronoid ratio [CC ratio]) was calculated, and the mandibular skeleton was then classified as normal, retrognathic, or prognathic. The correlation between IANB failure and sex, treatment side, and the CC ratio was assessed. RESULTS: The IANB failure rates for normal, retrognathic, and prognathic mandibles were 7.3%, 14.5%, and 9.5%, respectively, and the failure rate was highest among those with a CC ratio < 0.8 (severe retrognathic mandible). The failure rate was significantly higher in the retrognathic group than in normal group (P = 0.019), and there was no statistically significant difference between the other two groups. CONCLUSIONS: IANB failure could be attributable, in part, to the skeletal characteristics of the mandible. In addition, the failure rate was found to be significantly higher in the retrognathic group.

Mandibular metastasis of cholangiocarcinoma: A case report.

Tumors metastasizing from distant regions to the oral and maxillofacial region are uncommon, comprising only 1%-2% of all malignancies. Cholangiocarcinoma is a malignancy that arises from cholangiocytes, which are epithelial cells that line the bile ducts. These cancers are difficult to diagnose and have a poor prognosis. In this paper, we report a rare case of mandibular metastasis of cholangiocarcinoma diagnosed at the primary site and discuss the radiographic findings observed in this case.

Effect of premolar extraction and presence of the lower third molar on lower second molar angulation in orthodontic treatment.

OBJECTIVE: To evaluate the change in mandibular second-molar (M2) angulation in orthodontic treatment with premolar extraction and lower third molar (M3). STUDY DESIGN: Panoramic radiographs were evaluated in 3 groups of 129 participants: (1) control, no orthodontic treatment (n = 65); (2) extraction, orthodontic treatment with premolar extraction (n = 30); and (3) nonextraction, orthodontic treatment without premolar extraction (n = 34). The angular difference and ratio of M2 to the first molar (M1), the change in the angulation of M2 between pre- and postorthodontic treatment, and the distal bone level of M2 were assessed. RESULTS: The angular difference and ratio of M2 to M1, the angulation change of M2 between pre- and postorthodontic treatment, and the distal bone level of M2 were higher in the nonextraction group than in the control and extraction groups. CONCLUSIONS: The successful orthodontic alignment of the M2 may not be achieved in nonextraction cases when the M3s are present.

Morphogenesis of the peri-implant mucosa: a comparison between flap and flapless procedures in the canine mandible.

OBJECTIVE: Although it has been shown that the exclusion of the mucoperiosteal flap can prevent postoperative bone resorption associated with flap elevation, there have been only a few studies on the peri-implant mucosa following flapless implant surgery. The purpose of this study was to compare the morphogenesis of the peri-implant mucosa between flap and flapless implant surgeries by using a canine mandible model. STUDY DESIGN: In six mongrel dogs, bilateral edentulated flat alveolar ridges were created in the mandible. After 3 months of healing, 2 implants were placed in each side by either the flap or the flapless procedure. Three months after implant insertion, the peri-implant mucosa was evaluated by using clinical, radiologic, and histometric parameters, which included the gingival index, bleeding on probing, probing pocket depth, marginal bone loss, and the vertical dimension of the peri-implant tissues. RESULTS: The height of the mucosa, length of the junctional epithelium, gingival index, bleeding on probing, probing depth, and marginal bone loss were all significantly greater in the dogs that had the flap procedure than in those that had the flapless procedure (P < .05). CONCLUSION: These results indicate that gingival inflammation, the height of junctional epithelium, and bone loss around nonsubmerged implants can be reduced when implants are placed without flap elevation.

Vertical alveolar ridge augmentation using autogenous bone grafts and platelet-enriched fibrin glue with simultaneous implant placement.

OBJECTIVE: The aim of this study was to evaluate the combined use of autogenous bone and platelet-enriched fibrin glue as grafting material for vertical alveolar ridge augmentation with simultaneous implant placement in a canine alveolar ridge defect model. STUDY DESIGN: In 6 mongrel dogs, bilateral vertical alveolar ridge defects were created in the mandible. After 3 months of healing, 2 dental implants were placed in each defect of the mandible, creating 6-mm supra-alveolar peri-implant defects. The 2 implants per defect were subjected to surgical treatments involving either a combination of autogenous bone grafts and platelet-enriched fibrin glue, or a conventional flap procedure only (control). After a healing period of 6 months, the dogs were humanely killed for histological and histometric analyses. RESULTS: Implant placement alone produced limited vertical alveolar height (0.6 +/- 0.4 mm). However, alveolar augmentation including a combination of autogenous bone grafts and platelet-enriched fibrin glue with simultaneous implant placement resulted in alveolar ridge augmentation amounting to 4.2 +/- 1.0 mm, comprising 63% of the defect height. New bone-implant contact was 40.5% in the defects treated with combined autogenous bone grafts and platelet-enriched fibrin glue, and was 48.4% in the resident bone; this difference was not statistically significant. CONCLUSION: The present study demonstrates that vertical alveolar ridge augmentation using autogenous bone grafts and platelet-enriched fibrin glue with simultaneous implant placement might effectively increase vertical alveolar ridge height and allow for an acceptable level of osseointegration.

Platelet-enriched fibrin glue and platelet-rich plasma in the repair of bone defects adjacent to titanium dental implants.

PURPOSE: The aim of this study was to compare the effects of platelet-enriched fibrin glue and platelet-rich plasma (PRP) on the repair of bone defects adjacent to titanium dental implants. MATERIALS AND METHODS: In 6 mongrel dogs, 3 screw-shaped titanium dental implants per dog were placed into the osteotomy sites in the tibia. Before implantation, a standardized gap (2.0 mm) was created between the implant surface and the surrounding bone walls. Six gaps were left empty (control group), 6 gaps were filled with autogenous particulate bone mixed with PRP (PRP group), and 6 gaps were filled with autogenous particulate bone mixed with platelet-enriched fibrin glue (fibrin glue group). RESULTS: After 6 weeks, the bone-implant contact was 59.7% in the fibrin glue group, 29.2% in the PRP group, and 10.2% in the control defects; this difference was statistically significant (P < .05). DISCUSSION AND CONCLUSION: Greater bone-implant contact was achieved with platelet-enriched fibrin glue than with PRP. The results indicate that platelet-enriched fibrin glue can induce a stronger peri-implant bone reaction than PRP in the treatment of bone defects adjacent to titanium dental implants.

Maxillary sinus floor augmentation using autogenous bone grafts and platelet-enriched fibrin glue with simultaneous implant placement.

OBJECTIVE: The aim of this study was to evaluate the use of autogenous bone in combination with platelet-enriched fibrin glue as a grafting material for maxillary sinus augmentation with simultaneous implant placement in dogs. STUDY DESIGN: The mucous membranes of 12 sinuses in 6 dogs were elevated bilaterally. In the right sinus, autogenous bone mixed with platelet-enriched fibrin glue was grafted into the space between the membrane and the sinus wall. In the left sinus, autogenous bone alone was grafted as a control. At the same time, 2 dental implants were inserted into the grafting material through the maxillary sinus floor. The animals were killed 6 months after surgery. RESULTS: The mean bone-implant contact was 40.5% on the fibrin glue side and 32.3% on the control side (P < .05). The mean height of newly formed bone in the augmented area was 12.2 mm on the fibrin glue side and 10.7 mm on the control side (P < .05). CONCLUSION: The results indicate that the use of autogenous bone mixed with platelet-enriched fibrin glue can achieve results superior to those for grafts of autogenous bone alone. The specific improvements of this technique include enhanced osseointegration of dental implants and increased height of new bone.

The effect of platelet-rich plasma on bone healing around implants placed in bone defects treated with Bio-Oss: a pilot study in the dog tibia.

OBJECTIVE: The aim of this study was to examine the influence of platelet-rich plasma (PRP) used as an adjunct to Bio-Oss for the repair of bone defects adjacent to titanium dental implants. STUDY DESIGN: In 6 mongrel dogs, 12 screw-shaped titanium dental implants were inserted into the osteotomy sites in the dogs' tibias. Before implantation, a standardized gap (2.0 mm) was created between the implant surface and the surrounding bony walls. The gaps were filled with either Bio-Oss cancellous granules alone or Bio-Oss cancellous granules mixed with PRP. RESULTS: After 4 months, the Bio-Oss-treated defects revealed a significantly higher percentage of bone-implant contact than the defects treated with Bio-Oss and PRP (60.1% vs. 30.8%; P < .05). CONCLUSION: The results indicate that when PRP is used as an adjunct to Bio-Oss in the repair of bone defects adjacent to titanium dental implants, PRP may decrease periimplant bone healing.

Treatment of experimental peri-implantitis using autogenous bone grafts and platelet-enriched fibrin glue in dogs.

OBJECTIVE: The purpose of this study was to evaluate the effects of autogenous bone grafts and platelet-enriched fibrin glue in the treatment of peri-implantitis. STUDY DESIGN: Thirty-six screw-type commercially pure titanium implants with rough acid-etched surfaces were inserted into 6 mongrel dogs 3 months after extraction of mandibular premolars. After 3 months of healing, peri-implantitis was induced by placing gauze and wire around the implants. Once peri-implantitis was created, surgical treatments involving a combination of autogenous bone grafts and platelet-enriched fibrin glue, autogenous bone grafts alone, or a conventional flap procedure only (control) were carried out. Six months later, biopsies of the implant sites were taken and prepared for ground sectioning and analysis. RESULTS: The amount of reosseointegration was significantly higher in peri-implantitis defects treated with combined autogenous bone grafts and platelet-enriched fibrin glue as compared with the other 2 treatment procedures. A mean bone-to-implant contact of 50.1% was obtained in the peri-implantitis lesions treated with combined autogenous bone grafts and platelet-enriched fibrin glue. The corresponding values for the autogenous bone grafts and control groups were 19.3% and 6.5%, respectively. CONCLUSION: The present study demonstrates that surgical treatment involving the combined use of autogenous bone grafts and platelet-enriched fibrin glue might effectively promote reosseointegration in lesions resulting from peri-implantitis.

The effects of exposing dental implants to the maxillary sinus cavity on sinus complications.

OBJECTIVE: The aim of this study was to investigate whether dental implant exposure to the maxillary sinus cavity increases the risk of maxillary sinus complications. STUDY DESIGN: An implant was placed bilaterally in the maxillary sinus of 8 adult female mongrel dogs in a way that it penetrated the bone and mucous membrane of the maxillary sinus floor to the extent of 2 mm, 4 mm, or 8 mm. The implants were left in place for 6 months. RESULTS: Radiographic and histologic examinations did not show any signs of pathologic findings in the maxillary sinus of the 8 dogs. CONCLUSION: This study indicates that implant protrusion into the maxillary sinus cavity is not related to the development of sinus complications in canines.