Search

The results of oral and maxillofacial surgery (OMS) significantly depend on the individual capabilities of surgeons. In this article, an autonomous surgical robot is proposed to automatically perform surgery according to a preoperative plan with the assistance of a surgeon. A 3-D computed tomography image of the subject's teeth was used to build an offline shape-based model by creating a large amount of 2-D contour data. A monochrome camera was mounted on a self-developed robot to capture the real-time image of the teeth for comparison with the offline 2-D contour to verify the teeth pose without using common markers. The data of the preoperative plan and the teeth pose were integrated to guide the movement of the robot during operation. Drilling experiments were conducted on the five 3D-printed mandible models, and a statistical analysis revealed highly accurate results. This autonomous robot provides a practical solution for robotically conducted OMS and has the potential to significantly reduce the workload of surgeons.

Manually surgical planning becomes an increasing workload of surgeons because of the fast-growing patient population. This study introduced a machine-learning-based approach to assist surgical planning in orthognathic surgery.Both preoperative and one-year-later postoperative computerised tomography images of 56 patients were collected. A 12-layers cascaded deep neural network structure with two successive models was proposed to yield an end-to-end solution, where the first model extracts landmarks from 2D patches of 3D volume and the second model predicts postoperative skeletal changes.The experimental results showed that the model obtained a prediction accuracy of 5.4 mm at the landmark level in 42.9 s. It also represented 74.4% of 3D regions at volume level when compared with the ground truth of human surgeons.This study demonstrated the feasibility of predicting postoperative skeletal changes for orthognathic surgical planning by using machine learning, showing great potential for reducing the workload of surgeons.

Impracticable workspaces and cumbersome hardware limit the practical application of the currently available orthognathic surgical robots in a clinical environment. In this study, a compact and lightweight six degree of freedom (DOF) robot with a workspace limitation mechanism (WLM) was developed, and this article reports on the technical specifications of the robot, as well as the details of the three experiments performed to validate it. This robot can be easily installed by a single individual and is able to mechanically protect important organs from unintended injury. The results show that this robot functionally limits the workspace travel of the osteotomy device by an average overshoot of 0.8 mm, with a drilling and cutting accuracy of 1 and 0.5 mm, respectively. This operational accuracy has the potential to be further improved, making this novel robot a potentially precise and safe medical equipment for orthognathic surgery.

Bilateral prosthetic replacement of the condylar head was performed via a transparotid approach without adverse events in a 42-year-old man suffering from ankylosing spondylitis with severe ankylosis of both temporomandibular joints and the whole spine. He was diagnosed with ankylosing spondylitis 7 years previously, and trismus was noted at the time of diagnosis. He also had a 28-year history of psoriasis vulgaris. He could not open his mouth and had a very limited range of motion in the spine, which was fixed in a kyphosis position. We encountered two general difficulties when attempting to perform condylar replacement. First, because of ankylosis of the whole spine and decreased mechanical bone strength, the risk of an intraoperative spinal injury was not negligible. We prevented this by repeated preoperative simulations and optimization of the intraoperative position with the cooperation of the medical staff. Second, because of the limited range of motion in the whole spine and temporomandibular joints, the operative field was not guaranteed, so intraoral and posterior approaches could not be performed. The extraoral transparotid approach was used in this patient, despite a risk of facial nerve paralysis. We achieved a final mouth-opening capacity of 45 mm without complications.

Introduction We have developed an implant-type tissue-engineered cartilage using a poly- l -lactide scaffold. In a clinical study, it was inserted into subcutaneous areas of nasal dorsum in three patients, to correct cleft lip–nose deformity. The aim of this study was to helping evaluation on the efficacy of the regenerative cartilage. Methods 3D data of nasal shapes were compared between before and after surgery in computed tomography (CT) images. Morphological and qualitative changes of transplants in the body were also evaluated on MRI, for one year. Results The 3D data from CT images showed effective augmentation (>2 mm) of nasal dorsum in almost whole length, observed on the medial line of faces. It was maintained by 1 year post-surgery in all patients, while affected curves of nasal dorsum was not detected throughout the observation period. In magnetic resonance imaging (MRI), the images of transplanted cartilage had been observed until 1 year post-surgery. Those images were seemingly not straight when viewed from the longitudinal plain, and may have shown gentle adaptation to the surrounding nasal bones and alar cartilage tissues. Conclusion Those findings suggested the potential efficacy of this cartilage on improvement of cleft lip–nose deformity. A clinical trial is now being performed for industrialization.

Oral pyogenic granuloma, also known as lobular capillary hemangioma, is a common benign lesion in the oral cavity. Although the etiopathogenesis of oral pyogenic granuloma remains to be determined, it is speculated to be one of the inflammatory hyperplasias that arise in response to stimuli such as traumatic injury or hormonal factors. We recently experienced a gingival lesion in a 49-year-old female that presented diagnostic difficulties and was finally diagnosed as an oral pyogenic granuloma. The lesion had been initially suspected to be a malignant tumor or arteriovenous malformation because of severe bone resorption of the maxilla or its throbbing. Due to the hypervascularization of this lesion, transarterial embolization was carried out, followed by surgical excision. Pyogenic granuloma with bone resorption is quite rare and to the best of our knowledge has never been reported with extensive maxillary bone resorption penetrating the maxillary sinus. With regard to possible etiologies of this lesion, chronic stimulation by unstable tooth root that was bridged to adjacent teeth and/or a hormonal imbalance caused by progestin, which the patient has taken for many years for the treatment of endometriosis were suspected to be involved.

Background Manual landmarking is a time consuming and highly professional work. Although some algorithm-based landmarking methods have been proposed, they lack flexibility and may be susceptible to data diversity. Methods The CT images from 66 patients who underwent oral and maxillofacial surgery (OMS) were landmarked manually in MIMICS. Then the CT slices were exported as images for recreating the 3D volume. The coordinate data of landmarks were further processed in Matlab using a principal component analysis (PCA) method. A patch-based deep neural network model with a three-layer convolutional neural network (CNN) was trained to obtain landmarks from CT images. Results The evaluating experiment showed that this CNN model could automatically finish landmarking in an average processing time of 37.871 seconds with an average accuracy of 5.785 mm. Conclusion This study shows a promising potential to relieve the workload of the surgeon and reduces the dependence on human experience for OMS landmarking.

Background Human-related factors affect the accuracy and safety of the oral and maxillofacial surgery (OMS). This study proposed an autonomous surgical system aiming to conduct the OMS under the assistance and surveillance of the surgeon. Methods A markerless navigation module and a compact OMS robot were seamlessly integrated into this system. The specifications of each module and the working concept of the system were elaborated in this paper. A drilling experiment was conducted on five 3D-printed mandible models to test the pose detecting capability and evaluate the operational performance. Results The experiment showed that this system could successfully guide the robot finishing the operation regardless of the mandible pose. The accuracy of software and hardware are acceptable and potential performance improvement can be achieved in positioning accuracy. Conclusion This system proposed a novel concept and a practical solution to decrease the human-related factors on the OMS, which may change the role of the surgeon in the future operating room and finally benefit the outcomes of OMS.

Inflammatory pseudotumor (IPT) is a rare benign non-neoplastic lesion. The etiology and the pathogenesis are yet to be understood. Aggressive progression, together with confusing radiological signs, is often mistaken as malignant. We report here a rare case of aggressive IPT in the mandible. In this case a neoplastic lesion or a systemic disease was initially suspected after incisional biopsy. Initial diagnostic treatment with steroids showed a little improvement, which indicated a reactive lesion, IPT. After steroid administration, the residual lesion was resected. Eighteen months postoperative follow-up showed neither recurrence nor progression.

Highlights • Reported a case of maxillary retrusion by a bilateral cleft lip and palate. • Preoperative simulation was performed for positioning and fixation of plate. • Maxillary advancement by distraction technique and mandibular setback surgery. • 2-stage procedure with maxillary advancement was found to be accurate., Introduction Computer-assisted preoperative simulation surgery is employed to plan and interact with the 3D images during the orthognathic procedure. It is useful for positioning and fixation of maxilla by a plate. We report a case of maxillary retrusion by a bilateral cleft lip and palate, in which a 2-stage orthognathic procedure (maxillary advancement by distraction technique and mandibular setback surgery) was performed following a computer-assisted preoperative simulation planning to achieve the positioning and fixation of the plate. A high accuracy was achieved in the present case. Presentation of case A 21-year-old male patient presented to our department with a complaint of maxillary retrusion following bilateral cleft lip and palate. Computer-assisted preoperative simulation with 2-stage orthognathic procedure using distraction technique and mandibular setback surgery was planned. Discussion The preoperative planning of the procedure resulted in good aesthetic outcomes. The error of the maxillary position was less than 1 mm. Conclusion The implementation of the computer-assisted preoperative simulation for the positioning and fixation of plate in 2-stage orthognathic procedure using distraction technique and mandibular setback surgery yielded good results.

It is important that oral care is effective, efficient, and economical. Herein, we investigated the efficacy of intraoral wet sheets for oral care in comparison with sponge brushes.We completed a Plaque Control Record (PCR) after observing intraoral plaque using a plaque disclosure test in healthy volunteers. After the teeth were cleaned for 3 minutes using a wet sheet, the test was repeated and the PCR was completed. The same method was performed using a sponge brush on the same subject under the same conditions 1 week later. The t test was used to analyze PCR findings.Ten healthy subjects were enrolled (mean age, 28.6 years). The PCR values improved from 44.0% before to 30.9% after use of the wet sheet. The post-cleaning PCR was significantly lower. The PCR values improved from 55.0% before to 50.2% after use of the sponge brush.The PCR improvement was greater when using the wet sheet. In all cases, the wet sheet was highly effective at smoothing tooth surfaces. Intraoral wet sheets may be an option for oral care performed by nurses and caregivers. Compared to the sponge brush, the intraoral wet sheet can save time and reduce costs.

The nasolabial cyst, a rare lesion involving the soft tissues of the maxillofacial region, commonly occurs in middle-aged females. These cysts usually present as soft, fluctuating growths in the sublabial folds, and are seen as swellings between the upper lip and nostril. Modern radiographic methods aid in the diagnosis of these cysts. There is an ongoing debate regarding the origin of nasolabial cysts, as there are two schools of thought: some believe that these cysts originate from fissural cysts, while others are of the opinion that they originate from remnants of the nasolacrimal groove. Herein, we present a rare case of a nasolabial cyst occurring in a 13-year-old girl treated for unilateral cleft lip and alveolus, using bone grafts nearly 5 years after lip and nose revision surgery. This contradicts with the previous theory regarding the origin of nasolabial cysts from fissural cysts. Despite indications that the cyst may have originated from remnants of the nasolacrimal groove, in the present study, trauma, infection or other unknown factors may have contributed to the pathogenesis of the nasolabial cyst.

Occurrences of aneurysm caused by intraoral inflammation or infection are very rare. Osseous dysplasias (ODs), the most common fibro-osseous lesions (FOLs), occur in the jaw. However, osseous lesion very rarely occurs in association with impacted tooth. We present here the case of a 22-year-old female who developed aneurysm in the cavernous region of the internal carotid artery (ICA) because of the infection of the maxillary OD with impacted and semi-impacted teeth. The aneurysm was later confirmed by contrast enhanced magnetic resonance imaging (MRI). The ICA trapping was performed under general anesthesia, and postoperative magnetic resonance angiography (MRA) confirmed disappearance of aneurysm. Approximately 2 months after the surgery, we performed left maxilla tumor excision under general anesthesia; the patient showed satisfactory progress after the excision. Since inflammation/infection of the maxilla may lead to aneurysm as found in this case, we recommend physicians to pay serious attention in such cases to prevent rupture of aneurysm.

Highlights • A relatively rare case of the cutaneous sinus tract in the submental region, derived from the lower second molar, was misdiagnosed as inverted follicular keratosis and thyroglossal duct cyst. • The patient previously underwent punch resection under local anesthesia, resulting in a histopathological diagnosis of inverted follicular keratosis. • Computed tomography (CT) and fistulography indicated that the cutaneous lesion was linked to the periapex of the left mandibular second molar. • Diagnostic imaging is essential in ensuring accurate assessment of the cause of cutaneous sinus tract., Introduction Odontogenic cutaneous sinus tract is a relatively rare occurrence that can be complicated to diagnose. The presence of a cutaneous lesion is often not even partly associated with a dental etiology because of the less frequency of occurrence in the case of dental symptoms. Consequently, the underlying dental cause is often missed leading to inappropriate diagnosis and treatment. Case presentation Here, we report the case of a 45-year-old man who presented with a persistent lesion of the cervical region. At the time of presentation, the lesion had been present for approximately one year with a gradual increase in size but no specific symptoms. The patient had previously undergone punch resection under local anesthesia, which resulted in a histopathological diagnosis of inverted follicular keratosis. A diagnosis was made of an odontogenic cutaneous sinus tract secondary to chronic apical periodontitis of the left mandibular second molar. Discussion Cutaneous sinus tract in the face and neck is most likely to develop intraorally. Root canal treatment or surgical extractions are the common treatment choices. A previously reported review of 137 cases found that 106 (77%) were treated by extraction and 27 (20%) were treated by surgical or conservative nonsurgical endodontic therapy. Conclusion Early diagnosis of cutaneous sinus tract using proper aid is responsible for shortening the treatment duration and avoiding unnecessary treatment.

Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare life threatening severe cutaneous adverse reactions, primarily caused by drugs and infection. Most of the cases of SJS are predominantly drug related. Drugs including antibacterial sulfonamides, non-steroidal anti-inflammatory drugs (NSAIDs) and anti-epileptic drugs have been identified to cause SJS/TEN. We report a case of 35 year old male, road accident victim, who suffered from mandibular fracture and a splenic injury, admitted to our hospital. Following the splenic embolization in Radiology Department he was administered cefazolin sodium and diclofenac sodium. The patient developed skin lesions characteristic of SJS, which was confirmed by skin biopsy. From the course of the skin lesions and its relation to diclofenac sodium administration and discontinuation, the drug was suspected to have caused SJS. The cefazolin sodium and diclofenac sodium were stopped one after another. Patient was successfully treated with prednisolone and was issued with drug card to prevent further attack of SJS by the same drug. We report the present case, in order to raise awareness that frequently prescribed NSAIDs diclofenac sodium has potential to cause rare skin disorder like SJS and prepare physician for the early intervention of any such future incidence.

The patient was a 78-year-old man with a chief complaint of dysphagia. Extrinsic displacement of the posterior hypopharyngeal wall was observed on upper endoscopy. The patient was diagnosed with ossification of the anterior longitudinal ligament (OALL) of the cervical spine according to lateral cervical spine radiographic findings. The OALL caused dysphagia. In swallowing endoscopic assessments of patients with dysphagia, OALL of the cervical spine should be differentiated from other possible diagnoses by using radiography when extrinsic displacement of the posterior oropharyngeal or hypopharyngeal wall is observed.

Background: Infections in the oral and maxillofacial region can sometimes extend beyond the oral cavity, with serious consequences. Most oral infections are odontogenic, occurring through the root apex of the tooth or the periodontal pocket. It thus makes sense that edentulous patients have a much lower risk of oral bacterial infection. For this reason, while there are many reports on systemic infections caused by oral infections, few of these describe such infections in edentulous patients. Case presentation: We present a case of oral and maxillofacial cellulitis followed by sepsis due to Streptococcus pyogenes infection in an 89-year-old Japanese edentulous woman. S. pyogenes was detected in the wound of left maxilla and the blood sample. S. pyogenes has been reported to be one of the most common and influential aerobic bacteria associated with deep neck infection and subsequent systemic infection. Left maxillary sinusitis was observed, and this could be the origin of the S. pyogenes infection. S. pyogenes derived from the sinusitis and leaked to the oral cavity might have caused systemic infection through wounding of the oral mucosa. Fortunately, intensive antibiotic therapy was effective, and the patient recovered without any surgical procedures. Conclusions: We experienced a rare case of oral and maxillofacial cellulitis followed by sepsis due to a Streptococcus pyogenes infection in an old edentulous woman. This result indicated that, while edentulous patients are considered to have no risk of odontogenic infection, they still carry a risk of bacterial infection.

Previous reports suggest that the most common location of the odontomas are in the maxilla. Among the ectopic odontoma, the nasal ectopic odontomas are rare, and are usually asymptomatic. Here, we present a rare case of an ectopic complex odontoma in the lower nasal turbinate causing nasal obstruction and bleeding, which was removed surgically. A 33-year-old male patient presented to our hospital with chief symptoms of nasal obstruction and bleeding from the nose. The Computed Tomography (CT) image of head and neck showed an irregular radio opaque mass in the lower nasal turbinate. The endoscopic examination revealed part of the tumor resembling toothlet. From the above findings, clinical diagnosis of odontoma was made. Histological examination of the mass confirmed the diagnosis of complex odontoma. The symptoms of obstruction and bleeding was averted by surgical removal of the mass.

Recently, there have been remarkable advances in regenerative medicine, and almost all disorders of the oral and maxillofacial region could be research targets of regenerative medicine. Meanwhile, treatment in this region has been well established using biomaterials, prostheses, and microsurgery. Therefore, to surpass such a conventional approach as an alternative, regenerative medicine should take an approach of being less invasive and/or more effective. In this report, we present our preclinical and clinical research on bone and cartilage regenerative medicine in the oral and maxillofacial region. Regarding bone regenerative medicine, we have tried to develop artificial bone that would maximize bone formation at the transplanted site, but would subsequently be replaced by autologous bone. We have made custom-made artificial bone (CT-Bone) using alpha-tricalcium phosphate (α-TCP) particles and an ink-jet printer, and have conducted clinical research and trials on 30 patients. To develop tissue-engineered cartilage with proper three-dimensional (3D) morphological form and mechanical strength, we have optimized the culture medium of chondrocytes and the scaffold. Following a preclinical study confirming efficacy and safety, we have conducted clinical research in three patients with nasal deformity associated with cleft lip and palate, and are now starting multicenter clinical research.

Computer-assisted oral and maxillofacial surgery (OMS) has been rapidly evolving since the last decade. State-of-the-art surgical navigation in OMS still suffers from bulky tracking sensors, troublesome image registration procedures, patient movement, loss of depth perception in visual guidance, and low navigation accuracy. We present an augmented reality navigation system with automatic marker-free image registration using 3-D image overlay and stereo tracking for dental surgery. A customized stereo camera is designed to track both the patient and instrument. Image registration is performed by patient tracking and real-time 3-D contour matching, without requiring any fiducial and reference markers. Real-time autostereoscopic 3-D imaging is implemented with the help of a consumer-level graphics processing unit. The resulting 3-D image of the patient's anatomy is overlaid on the surgical site by a half-silvered mirror using image registration and IP-camera registration to guide the surgeon by exposing hidden critical structures. The 3-D image of the surgical instrument is also overlaid over the real one for an augmented display. The 3-D images present both stereo and motion parallax from which depth perception can be obtained. Experiments were performed to evaluate various aspects of the system; the overall image overlay error of the proposed system was 0.71 mm.

The differential diagnosis of embryonal rhabdomyosarcoma (RMS), pleomorphic sarcoma, and leiomyosarcoma remains a challenge because of their overlapping histological presentations, with serious implications on the choice of treatment. We report a rare case of a tumor confined to the tongue in a 22-year-old woman. Clinical, histological, and immunohistochemical data confirmed the diagnosis of a composite tumor of embryonal RMS and leiomyosarcoma based on the presence of spindle-shaped cells within a myxoid background of spherical cells and immunoreactivity to muscle-specific markers (desmin, smooth-muscle actin, muscle-specific actin, myoglobin, and vimentin), RMS-specific myogenin, and leiomyosarcoma-specific h-caldesmon. The lack of immunoreactivity to S-100 and cytokeratin antibodies suggested the absence of melanoma and pleomorphic sarcoma, respectively. Presurgical treatment with a single round of broad-spectrum MAID (mesna, pirarubicin, ifosfamide, and dacarbazine) adjuvant therapy for the advanced soft tissue sarcoma allowed the growth of the tumor from 45 mm × 38 mm × 25 mm to 45 mm × 40 mm × 40 mm. Thereafter, subtotal glossectomy was performed. Based on the strong immunoreactivity of the tumor to myogenin, the patient received RMS-specific VAC (vincristine, actinomycin D, and cyclophosphamide) chemotherapy over 6 months. However, metastases to the lungs led to the patient's death. This case highlights the danger of “overdiagnosing” a patient, and the need to select a broad-spectrum adjuvant whenever a diagnosis of composite sarcoma is suspected.

Noncontact operation of a cycloid motor by means of a magnetic force has been realized. The fabricated motor has a cycloid reduction system with an internal gear as a stator and an external gear as a rotor. A cylindrical permanent magnet encloses the internal gear. The internal gear generates a wobbling motion due to attractive and repulsive magnetic forces produced by external permanent magnets. An output shaft attached to an external gear is rotated by the wobbling motion of the internal stator gear. This motor can be operated by means of magnetic fields applied to one side of the device. This feature allows the device to be used in medical procedures such as bone distraction osteogenesis, in which the actuator must be inside the human body for a long period of time. Such noncontact operation of the actuator reduces the burden on the patient. The fabricated motor exhibited a maximum torque of 4.1 mN·m and a maximum linear output of 4.9 N using a screw-nut system when the gap between the outer magnets and the motor was 2mm.

A 2-day-old girl was diagnosed with an oral epignathus teratoma and an uncommon combination of orofacial malformations including cleft palate; tongue, mandible, cranial base, cervical vertebrae, lower lip, and pituitary gland duplications; and fistula of the glabella and lower lip. Computed tomography revealed that the mass within the nasal cavity had tooth-like calcifications and protruded into the nasopharynx and oral cavity. It was implanted on the anterior wall of the body of the sphenoid bone and was accompanied with mandibular duplication. Magnetic resonance imaging detected duplication of the pituitary gland and confirmed the absence of intracranial communication of the nasopharyngeal mass. The teratoma did not cause respiratory obstruction; however, the patient required continuous nasogastric tube feeding. Usually, an epignathus teratoma is associated with few midline defects and can be corrected with multiple interventions at different time points. The current study describes the surgical procedure comprising excision of the tumor along with reconstructive surgeries of the mandible, tongue, and fistulae undertaken when the infant reached 7 months of age. The cleft palate was repaired at 18 months of age using the Kaplan buccal flap method. Histopathologic examination confirmed a grade 0 teratoma covered with keratinized skin and containing pilosebaceous and sweat glands, adipose tissue, and smooth muscle. The long-term success of this intervention was determined at the follow-up examination conducted at 3 years of age, with no signs of the teratoma recurrence observed.

Oral and maxillofacial surgery has not been benefitting from image guidance techniques owing to the limitations in image registration.A real-time markerless image registration method is proposed by integrating a shape matching method into a 2D tracking framework. The image registration is performed by matching the patient's teeth model with intraoperative video to obtain its pose. The resulting pose is used to overlay relevant models from the same CT space on the camera video for augmented reality.The proposed system was evaluated on mandible/maxilla phantoms, a volunteer and clinical data. Experimental results show that the target overlay error is about 1 mm, and the frame rate of registration update yields 3-5 frames per second with a 4 K camera.The significance of this work lies in its simplicity in clinical setting and the seamless integration into the current medical procedure with satisfactory response time and overlay accuracy. Copyright © 2016 John WileySons, Ltd.

This report proposes a miniaturized non-contact actuation mechanism for a surgical device for bone extension operation. The device is embedded inside the body, and the device controls the gap between the bones cut by operation. A small permanent magnet is attached to the outer gear of a cycloidal reducer that rotates a screw of the screw-nut mechanism. This magnet is forced by the external magnetic flux density controlled by the outer permanent magnets’ position. In this research, two pairs of permanent magnet bar were rotated by stepping motors outside the device. The outer gear is constrained in As a result, ring gear of the cycloidal reducer is driven in translational wobbling motion the inner gear is connected to the screw and the output nut position is driven linearly with screw rotation. The dimensions of the fabricated device were 7 mm in diameter and 39.7 mm in length. The output thrust of this device was 2 N.

In the oral and maxillofacial region, conditions such as bone fracture, trauma-induced bone or cartilage defects, and tumor or birth defects are common, and it is necessary to elucidate the molecular mechanisms that control the differentiation of cells to establish new treatment strategies for these conditions. Therefore, numerous studies have investigated the role or involvement of factors that are thought to be crucial for differentiation of cells, including cell cycle factors, transcription factors, and growth factors. One of these types of factors, the cell cycle factors, critically influence the differentiation of cells, since a temporal arrest in the G 1 phase of the cell cycle or withdrawal from the cell cycle is thought to be a prerequisite for cell differentiation. In a previous attempt to identify cell cycle factor(s) controlling the commitment for differentiation of cells, we discovered that cyclin-dependent kinase (Cdk)6, one of the G 1 cell cycle factors, is a critical regulator of the differentiation efficiency of osteoblasts, osteoclasts, and chondrocytes. In addition, individual groups have also reported the importance of Cdk6 in differentiation in other cell types. Herein, we review the role of Cdk6 in differentiation of cells with a particular focus on osteoblast, osteoclast, and chondrocyte differentiation and discuss the potential of Cdk6 as a target of bone regenerative medicine.

Introduction Hepatocellular carcinoma (HCC) is a common neoplasm worldwide, with more than half of the tumors associated with regional metastasis. Extrahepatic metastasis is also common, and the most frequently affected sites are the lungs, abdominal lymph nodes, diaphragm, and bone. However, HCC metastasis to the mandible is rare, with approximately 50 cases reported in the literature. Methods In this report, we describe a case of HCC metastasis to the mandible at the apex of #18 root in a 62-year-old man. This patient had already been diagnosed with metastasis to pancreatic caput lymph node. The radiographic features of the mandible resembled radicular cyst and did not show typical findings of malignancy. Results Under the first diagnosis of radicular cyst, root canal treatment was initially performed, and then surgical treatment of the removal of the cystic lesion and #18 extraction were performed. Finally, the lesion was diagnosed as HCC metastasis from pathological examination. Consequently, he received constitutional chemotherapy in the hepatitis unit and is now in remission. Conclusion This case shows the importance of considering the differential diagnosis of malignancy.

Objective: To investigate the effects of transforming growth factor-β1 (TGF-β1) in combination with fibroblast growth factor-2 (FGF-2) and insulin-like growth factor-I (IGF-I), on the properties of chondrocytes after proliferation culture. Materials and Methods: The chondrocytes were obtained from remnant auricular cartilage during microtia operations and cultured with various growth factors. The proliferation and differentiation of cultured chondrocytes and the risk for malignant transformation of cells were evaluated. Results: A combination of FGF-2, IGF-I, and TGF-β1 was more effective than that of FGF-2 and IGF-I in terms of cell proliferation. Real-time quantitative polymerase chain reaction analysis revealed that FGF-2, IGF-I, and TGF-β1 strongly induced chondrocyte hypertrophy, suggesting that FGF-2, IGF-I, and TGF-β1 combined were inferior to FGF-2 and IGF-I in maintaining permanent cartilage phenotype. There was no significant difference in telomerase activities between cells cultured with FGF-2 and IGF-I and those with FGF-2, IGF-I, and TGF-β1. There was a slight increase in the S phase of the cell cycle in cells cultured with FGF-2, IGF-I, and TGF-β1 compared with those with only FGF-2 and IGF-I. There were also some alterations in the retinoblastoma pathway of the chondrocytes cultured with FGF-2, IGF-I, and TGF-β1. Conclusion: The results indicate that a combination of FGF-2 and IGF-I may be superior to one of FGF-2, IGF-I, and TGF-β1 for permanent cartilage regeneration. These analyses are useful for evaluating the properties of cultured chondrocytes.

Objective: For regeneration of bone in a clinical setting, an adequate number of committed osteoblasts is required. Bone marrow mesenchymal stromal cells could provide a source of osteoblasts for bone regeneration. In addition, it is well known that mesenchymal cell condensation plays an important role in the early stages of membranous osteogenesis, and dynamic flow can positively influence and enhance osteodifferentiation of mesenchymal stromal cells. Therefore, to imitate bone development, we adopted a rotation culture method rather than a static culture method. Materials and Methods: Osteogenic differentiation was evaluated by histological, immunochemical and reverse transcriptase-polymerase chain reaction analyses. Results: Cell condensation and a 3-dimensional dynamic environment in a rotation culture may enhance osteoblastic phenotype development and mineralised matrix synthesis in vitro. The extracellular matrix of cell aggregates was endogenously synthesised in an entirely natural manner by the cells themselves. The cell aggregates by rotation culture showed mineral deposition and osteocalcin expression at 7 days, whereas these effects were not detected in the static culture until 14 days. Conclusion: These findings indicate that, compared with static culture in well plates, rotation culture provides a more suitable culture environment that is much closer to the actual cellular environment in vivo.

Necrotising ulcerative stomatitis is a very rapid, destructive disease of the alveolar bone and gingiva. The rapid destruction leads to devastating facial defects and death, if it is not treated promptly. Candida albicans and Pseudomonas aeruginosa are frequent causes of disseminated infections among patients who are immunocompromised. This report is of a 72-year-old woman with dose large B-cell lymphoma, who developed acute necrotising ulcerative stomatitis and septic shock together with histopathological and microbiological evidence of C. albicans and P aeruginosa infections. Gingival necrosis was managed by debridement to remove slough and irrigation with povidone iodine. All oral symptoms subsided following the initiation of antimicrobial therapy and debridement. The patient completed chemotherapy and achieved prompt remission. This report highlights the importance of prompt recognition, debridement, teeth extraction, scrupulous oral hygiene, appropriate antibiotic therapy, and nutritional support for immunocompromised patients with necrotising ulcerative stomatitis.

The reconstruction of the soft palate following resection of a tumour remains a challenge to this day. We recently reconstructed the soft palate by a procedure using the palatal mucoperiosteal flap, with blood supply from the greater palatine vessels. This operative procedure is simple, easy to perform and minimally invasive, and has been used on 2 patients with satisfactory results and good postoperative function.

Mesenchymal stem cell (MSC) condensation contributes to membrane ossification by enhancing their osteodifferentiation. We investigated bone regeneration in rats using the human bone marrow-derived MSC-spheroids prepared by rotation culture, without synthetic or exogenous biomaterials. Bilateral calvarial defects (8 mm) were created in nude male rats; the left-sided defects were implanted with MSC-spheroids, β-tricalcium phosphate (β-TCP) granules, or β-TCP granules + MSC-spheroids, while the right-sided defects served as internal controls. Micro-computed tomography and immunohistochemical staining for osteocalcin/osteopontin indicated formation of new, full-thickness bones at the implantation sites, but not at the control sites in the MSC-spheroid group. Raman spectroscopy revealed similarity in the spectral properties of the repaired bone and native calvarial bone. Mechanical performance of the bones in the MSC-implanted group was good (50 and 60 % those of native bones, respectively). All tests showed poor bone regeneration in the β-TCP and β-TCP + MSC-spheroid groups. Thus, significant bone regeneration was achieved with MSC-spheroid implantation into bone defects, justifying further investigation.