[Clinical application of bone regeneration by in vivo tissue engineering]

With regard to the graft materials, cortical bone block, vascularized bone flap and particulate cancellous bone and marrow (PCBM) have been used for the reconstruction of maxillofacial skeleton. Needless to say, the aim of cortical bone block and vascularized bone flap transfer is the transplantation of bony tissue of its own. On the other hand, the main objective of PCBM grafting is the transplant of osteogenic stem cells derived from uncommitted marrow mesenchymal cells. After PCBM grafting, active new bone formation occurs from osteogenic stem cells followed by bone remodeling and replacement of host bone. This process means that PCBM grafting is the method of bone regeneration that is based on in vivo tissue engineering. In this paper, clinical application of PCBM grafting for the reconstruction of maxillofacial skeleton is introduced by showing the repair of maxillary bony defect of cleft lip and palate patients, alveolar ridge augmentation and the reconstruction of large mandibular segmental defects.

Influence of arthroscopically observed fibrous adhesions before and after joint irrigation on clinical outcome in patients with chronic closed lock of the temporomandibular joint

The aim of this study was to investigate the changes in the state of arthroscopically observed fibrous adhesions (FA) after visually guided irrigation (VGIR) and the influence of FA on clinical outcome in patients with chronic closed lock of the temporomandibular joint (TMJ). Forty-eight TMJs of 48 patients with unilateral chronic closed lock were enrolled in this study. All 48 joints underwent VGIR twice. After the first VGIR (immediately before the second VGIR), clinical outcome was assessed as regards maximal interincisal opening (MIO) and self-evaluated TMJ pain (VAS). Thirty patients were symptom-free (good outcome group) and the remaining 18 patients had symptoms (poor outcome group). In each group, the changes of the MIO, VAS and severity of FA (FA score) after the first VGIR were studied. The influence of FA score in the first and second VGIR on clinical outcome was analyzed by logistic regression analysis. There was no joint with disappearance or reduction of FA after the first VGIR. In both groups, MIO and VAS were significantly improved after the first VGIR even though the state of FA became significantly worse. The multivariate logistic regression analysis showed that the risk of poor outcome for FA scores in the first and second VGIR were 0.89-times (95% CI: 0.33-2.40, P=0.82) and 1.76-times (95% CI: 0.54-5.73, P=0.35), respectively. The dose-response relationships between FA scores in the first or second VGIR were not significant. In conclusion, our results indicate that the presence of FA or a postoperative worsening of FA (including postoperative new FA formation) seems not to affect the clinical outcome as regards MIO and VAS in patients with chronic closed lock of the TMJ.

Comparison of intraoral radiography and computed tomography in evaluation of formation of bone after grafting for repair of residual alveolar defects in patients with cleft lip and palate

For one year we studied postoperative computed tomograms (CT) and intraoral radiographs for 29 patients with unilateral alveolar clefts. Interdental bone height and the bony boundary on the nasal side were assessed on intraoral films and compared with the evaluation by CT. Twenty-four cases had adequate interdental bone height as assessed by intraoral films. However, 10 of these 24 cases showed insufficient anteroposterior depth on CT. Two of the remaining five cases were also overestimated by the intraoral radiograph. All cases had sufficient bony boundary on the nasal side on intraoral radiography. However, CT showed that bone formation on the nasal side off two cases was significantly worse than that on the non-cleft side. Consequently, about 40% of surgical outcomes may be overestimated by intraoral radiographs. CT therefore seems to give a better assessment of the clinical outcome than intraoral radiographs and should be considered as an adjunct in difficult clinical cases.

Application of limited cone beam computed tomography to clinical assessment of alveolar bone grafting: a preliminary report

OBJECTIVES

The aim of this study was to demonstrate the clinical applicability of limited cone beam computed tomography (Dental 3D-CT) for assessment of bone-grafted alveolar cleft.

PATIENTS AND METHODS

Seventeen bone bridges were examined after alveolar bone grafting in 13 patients with cleft lip and palate. All bone bridges, including cleft-adjacent teeth, were examined by plain radiography and the Dental 3D-CT imaging system.

RESULTS

The plain radiographs showed the approximate condition of the bone bridge and cleft-adjacent teeth. The Dental 3D-CT images clearly showed precise three-dimensional (3D) morphology of the bone bridge, 3D relationships between the bone bridge and the roots of cleft-adjacent teeth, and their periodontal condition. In addition, the conditions surrounding dental implants installed in the bone bridge could be observed three-dimensionally.

CONCLUSIONS

The results indicate that the Dental 3D-CT imaging system is suitable for clinical assessment of alveolar bone grafting before and after installation of dental implants or orthodontic treatment of the cleft-adjacent teeth.

Comparative study of intra-articular irrigation and corticosteroid injection versus closed reduction with intermaxillary fixation for the management of mandibular condyle fractures

OBJECTIVE

To evaluate the clinical outcome of a modified conservative treatment protocol involving intra-articular irrigation and corticosteroid injection into the superior joint compartment (SJC) of patients with fresh mandibular condyle fractures. Study design A total of 26 consecutive unilateral fresh condylar fractures in 26 patients were divided into the intra-articular irrigation (IR) group (14 patients, 14 joints) and the conventional conservative treatment (CC) group (12 patients, 12 joints). In the IR group, the SJCs of the fractured joints were irrigated with saline solution and injected dexamethazone sodium, followed by conventional rehabilitation. In the CC group, patients were treated by closed reduction with intermaxillary fixation (IMF) for 2 weeks, followed by conventional rehabilitation. Clinical outcome at 1 month, 3 months, 6 months, and 1 year after injury was determined by clinical examination of jaw motion, joint pain, and occlusal changes. The posttreatment results were compared with the pretreatment baseline data. Between-group differences in clinical parameters were analyzed.

RESULTS

There were significant between-group differences in the range of mandibular motion at 1 month and 3 months after injury (1 month, P=.0022; 3 months, P=.0022). In the IR group, joint pain was well relieved from the early stage of treatment. Occlusal changes were found in 1 patient in the IR group and 4 patients in the CC group at 1 year after injury.

CONCLUSIONS

The modified treatment protocol involving intra-articular irrigation and corticosteroid injection into the SJC is a more effective and quick-acting modality than conventional closed reduction with IMF for functional recovery and control of clinical symptoms of patients with unilateral fresh condylar fractures.

Immunohistochemical localization of cyclooxygenase-1 and -2 in synovial tissues from patients with internal derangement or osteoarthritis of the temporomandibular joint

This study examined the immunohistochemical expression and localization of cyclooxygenase-1 and -2 (COX-1 and COX-2) in synovial tissues from patients with internal derangement (ID) or osteoarthritis (OA) of the temporomandibular joint (TMJ). Synovial tissues from patients with condylar fractures of the mandible were studied as control. Synovial tissues from 13 TMJs of 10 patients with ID or OA and from 5 TMJs of 4 patients with fractures were examined for COX-1 and COX-2 expression by immunohistochemical staining using two monoclonal antibodies. In addition, whether the COX-2 expression grade correlated with the synovitis score and clinical findings was assessed. COX-2 was expressed in the synovial lining, infiltrating mononuclear cells, fibroblast-like cells, and blood vessels, including CD31-positive endothelial cells, in the synovium of patients with ID or OA. Expression levels of COX-1 in synovial lining cells and endothelial cells were similar in the specimens obtained from the patients with ID or OA and those obtained from the controls. The expression of COX-2 positively correlated with arthroscopic findings of synovitis (p = 0.55, P = 0.023) and with joint pain (p = 0.56, P = 0.021). These results suggest that up-regulation of COX-2 in synovium may play a part in the pathogenesis of synovitis in patients with ID or OA of the TMJ.

Implant-supported edentulous maxillary obturators with milled bar attachments after maxillectomy

PURPOSE

The purpose of this study was to evaluate the clinical results of implants and milled bar supported edentulous maxillary obturators following the surgical ablation of maxillary tumors.

PATIENTS AND METHODS

Seven patients with malignant tumors of the maxilla were studied. All patients underwent partial or total maxillectomy. Implants were installed in the remaining maxilla and milled bar supported obturators were fabricated. Masticatory efficiency, biting abilities, speech function, and changes in the marginal bone level around the implants were evaluated without the prostheses, with the previous prostheses, and with the implant-supported prostheses.

RESULTS

All implants were osseointegrated. All patients wore milled bar supported obturators and masticatory and speech functions markedly improved. There was no complication during the follow-up period.

CONCLUSIONS

These results suggest that a maxillary obturator supported by milled bar attachments is useful for oral rehabilitation in patients with resected edentulous maxilla.

Two-stage orthognathic treatment of severe class III malocclusion: report of a case

We report a two-stage orthognathic operation for a 16-year-old boy with a repaired isolated cleft palate. He had a severe class III malocclusion with an overjet of 20.4 mm. In the first stage, we did an anterior subapical segmental osteotomy with symphyseal ostectomy to reposition the mandibular anterior segment posteriorly and to reduce the transverse width of the mandible. During the second stage, we did a maxillary advancement by Le Fort I osteotomy, mandibular set-back by sagittal split osteotomy, reduction genioplasty, and shortening of the tongue. This unique two-stage surgical and orthodontic treatment considerably improved his overall facial aesthetics and occlusion.

Radiographic survey of third molar development in relation to chronological age among Japanese juveniles

The aim of the present study was to establish Japanese reference material on the third molar development of Japanese juveniles for forensic application. Observations were performed on the orthopantomograms of 1282 Japanese patients between the ages of 14.0 and 24.0 years. Demirjian formation stages of the maxillary and mandibular third molars were recorded for chronological evaluation of wisdom teeth and applied for further statistical analysis. Statistically significant differences were noted between the upper and lower jaws and genders. Accordingly, males achieved root developmental grades earlier than females. We assessed the mean ages for all formation grades and predicted the probability that a Japanese juvenile would be older than the relevant ages of 14, 16, and 20 as defined by Japanese Juvenile Law. We determined the likelihood that a Japanese youth is older than the relevant age of 18 as defined by legislation in the United States.

Vertical alveolar distraction osteogenesis with complications in a reconstructed mandible

We report here a case of vertical alveolar distraction osteogenesis with many complications that required further surgical interventions. A 54-year-old man underwent mandibular resection followed by iliac bone grafting as the result of large mandibular odontogenic keratocyst. Eleven months later, alveolar vertical distraction osteogenesis was applied to the patient for prosthetic rehabilitation. Fracture of the basal bone occurred in the consolidation period, and the fracture was fixed by the titanium miniplate system. Radiographic examination after completion of distraction osteogenesis confirmed a radiolucent area in half of the distracted area between the basal bone and the transport segment, and when the distractor was removed the radiolucent area was filled with fibrous granulation tissue. The granulation tissue was removed and endosteal implants were inserted together with a bone graft. Ultimately, all implants were osseointegrated, and adequate esthetics and function of the implant-supported prosthesis were achieved.

Regional differences of type II collagen synthesis in the human temporomandibular joint disc: immunolocalization study of carboxy-terminal type II procollagen peptide (chondrocalcin)

The purpose of this study was to determine the regional differences of distribution of the carboxy-terminal type II procollagen peptide (pCOL-II-C; chondrocalcin) as markers of cartilaginous expression in the human temporomandibular joint (TMJ) disc. Twelve human TMJ discs without morphologic abnormalities were obtained from 12 fresh cadavers. All specimens were analysed for pCOL-II-C expression using polyclonal rabbit anti-human pCOL-II-C antibody in avidin-biotin-peroxidase complex staining. The results were demonstrated that the percentage of pCOL-II-C immunoreactive disc cells was significantly higher in the outer part (the articular surfaces) than in the inner part (the deep central areas) of the disc. These findings suggest that the tissue heterogeneity of cartilaginous expression reflects the functional demands of the remodelling process in the human TMJ disc.

Magnetic resonance evaluation of the disk before and after arthroscopic surgery for temporomandibular joint disorders

OBJECTIVE

The purposes of this study were (1) to assess functional and pain outcomes after arthroscopic surgery on patients with temporomandibular joint disorders (TMD); (2) to evaluate postsurgical changes in disk position, mobility, and morphology on magnetic resonance imaging (MRI); and (3) to measure the association between changes in disk position, mobility, and morphology on MRI and clinical outcomes.

STUDY DESIGN

A retrospective analysis was conducted of temporomandibular joints with internal derangement and osteoarthritis that were refractory to nonsurgical treatments and underwent arthroscopic surgery and on which MRI was performed within 1 month after the initial visit and 1 year after arthroscopic surgery. Clinical findings were assessed on the basis of mandibular range of motion and joint pain level on a visual analog scale at the initial visit and 1 year after arthroscopic surgery. The disk position, mobility, and morphology on MRI were compared with clinical findings and were statistically analyzed before and after arthroscopic surgery. The treatment outcome was judged according to our success criteria. The associations between changes in disk position, mobility, and morphology and clinical outcomes after arthroscopic surgery were statistically analyzed.

RESULTS

Forty-three joints of 43 patients who underwent arthroscopic surgery were assessed in this study. After arthroscopic surgery, mandibular range of motion and visual analog scale results improved statistically. According to the criteria for clinical resolution, 32 surgeries were successful and 11 were unsuccessful. Preoperative and postoperative MRI showed that most joints had anterior disk displacement (ADD) without reduction. Postoperative MRI revealed that, statistically, the number of mobile disks had increased and deformity of the disks had progressed. In the successful group, postoperative MRI revealed that all joints had mobile disks. In both groups, most joints had ADD without reduction before and after arthroscopic surgery, and, statistically, deformity of the disks progressed after arthroscopic surgery.

CONCLUSIONS

Arthroscopic surgery was an effective treatment for TMD refractory to nonsurgical treatments. This study provides important information of clinical significance. Disk position remained ADD without reduction, disk mobility increased, and deformity of the disks progressed after arthroscopic surgery.

[Combination chemotherapy with nedaplatin and 5-fluorouracil for oral squamous cell carcinomas]

We used a new combination chemotherapy with nedaplatin (CDGP) and 5-fluorouracil (5-FU) in eleven fresh patients with oral squamous cell carcinomas. 5-FU was administered at a dose of 1,000 mg/body by continuous infusion for 24 hours on days 1 to 5. CDGP was administered at a dose of 80 or 100 mg/m2 by drip infusion for 120 minutes on day 5. The response rates of total (1- or 2-course) and 2-course group were 54. 5% and 83.3%, respectively. Adverse drug reactions were limited to two cases of grade 3 toxicity with anorexia. The combination chemotherapy with 5-FU and CDGP in place of cisplatin and 5-FU seemed to play an important role as neo-adjuvant chemotherapy for oral squamous cell carcinomas.

Suppression of the morphine-induced rewarding effect and G-protein activation in the lower midbrain following nerve injury in the mouse: involvement of G-protein-coupled receptor kinase 2

The present study was designed to investigate whether a state of neuropathic pain induced by sciatic nerve ligation could alter the rewarding effect, antinociception, and G-protein activation induced by a prototype of mu-opioid receptor agonist morphine in the mouse. The sciatic nerve ligation caused a long-lasting and profound thermal hyperalgesia. Under this neuropathic pain-like state, an i.c.v. morphine-induced place preference was observed in sham-operated mice but not in sciatic nerve-ligated mice. However, no differences in the antinociceptive effect of i.c.v.-administered morphine were noted between the groups. The increases in the binding of guanosine-5'-o-(3-[(35)S]thio)triphosphate induced by morphine in lower midbrain membranes including the ventral tegmental area, which contributes to the expression of the rewarding effect of opioid, were significantly attenuated in sciatic nerve-ligated mice. On the other hand, there were no differences in the stimulation of guanosine-5'-o-(3-[(35)S]thio)triphosphate binding to pons/medulla membranes, which plays an important role in the antinociception of mu-opioid receptor agonists, between the groups. In addition, no changes in levels of guanosine-5'-o-(3-[(35)S]thio)triphosphate binding by either the selective delta- or kappa-opioid receptor agonists were noted in membrane of the lower midbrain and limbic forebrain membranes obtained from sciatic nerve-ligated mice. Reverse transcription-polymerase chain reaction analysis showed that sciatic nerve ligation did not alter the mRNA product of mu-opioid receptors in the lower midbrain, indicating that a decrease in some mu-opioid receptor functions may result from the uncoupling of mu-opioid receptors from G-proteins. We found a significant increase in protein levels of G-protein-coupled receptor kinase 2, which causes receptor phosphorylation in membranes of the lower midbrain but not in the pons/medulla, obtained from mice with nerve injury, whereas there were no changes in the protein level of phosphorylated-protein kinase C in the lower midbrain. These results suggest that the uncoupling of mu-opioid receptors from G-proteins by G-protein-coupled receptor kinase 2 in the lower midbrain may, at least in part, contribute to the suppression of the rewarding effect of morphine under neuropathic pain.

Visually guided temporomandibular joint irrigation in patients with chronic closed lock: clinical outcome and its relationship to intra-articular morphologic changes

OBJECTIVE

The aim of this study was to evaluate the clinical outcome after visually guided irrigation (VGIR) of the temporomandibular joint (TMJ) and its relationship with postoperative arthroscopic changes.

STUDY DESIGN

Of the original 69 patients, thirty patients (30 TMJs) underwent VGIR of the TMJ a second time. After the first VGIR, the clinical outcome was assessed, and 18 patients were assigned to the good outcome group. The remaining 12 patients were assigned to the poor outcome group. The arthroscopic findings related to the articular surface, synovial lining, and fibrous adhesion scores were recorded. Then, the arthroscopic findings in the first and second VGIR were compared.

RESULTS

The intra-articular tissue status between the first and second VGIR was unchanged in approximately 40% of all joints. No significant differences with respect to an improvement in tissue status were found when the good outcome and poor outcome groups were compared.

CONCLUSIONS

In patients with chronic closed lock of the TMJ, a clinical improvement after VGIR does not seem to be accompanied by improved intra-articular tissue status.