Biomedical subjects

Biao Yi

Publications and source records attributed to Biao Yi.

6 recordsLinked to original sources

PubMed2002

[Distraction osteogenesis for treatment of temporomandibular joint ankylosis].

OBJECTIVE: To study the application of distraction osteogenesis in temporomandibular joint (TMJ) ankylosis patients. METHODS: 11 temporomandibular joint ankylosis patients (13 sides of TMJ) were treated by this technique. After removal of bony mass on the ankylosis area, a L-shape osteotomy of the ramus was performed to create the distraction transport disc which connected the mandible by distractor. Distractions were started on the 4 approximately 8th postoperative day. The distraction rhythm and rate were 0.25 mm 4 times a day. Distraction was stopped when contact was made between the transport disc and glenoid fossa. The patients underwent active mouth opening postoperatively. Distractor was kept in place for 3 approximately 4 months after completion of distraction and then removed under local anesthesia. RESULTS: Postoperatively, the range of mouth opening of the 11 patients (13 sides) was increased to normal (33 approximately 45 mm), bone formation in the gaps were perfect and the neocondyle was remodeling and approximated normal shape. No complications were found. CONCLUSION: Distraction osteogenesis for arthroplasty has many advantages compared with traditional methods. It is valuable in clinical practice as a new method for treatment of TMJ ankylosis.

Adolescent↗

PubMed2002

[Application of distraction osteogenesis in severe maxillary hypoplasia secondary to cleft palate].

OBJECTIVE: To evaluate the effect of distraction osteogenesis in correction of severe undeveloped maxilla secondary to cleft palate and to evaluate the selection of distraction modality. METHODS: Distraction osteogenesis was performed upon 8 patients, 6 males and 2 females, aged 11 to 25 years, one with incomplete cleft palate, 4 with unilateral complete left palate, and 3 with bilateral complete cleft palate, all accompanied with severe maxillary hypoplasia. The 7 adult patients were treated by modified high-stepped Le Fort I osteotomy, the other patient, a child, was treated by Le Fort I osteotomy followed by rigid external distraction. X-ray films of skull in lateral, frontal, or panoramic positions, and X-ray film of temporomandibular joint in Schiller's position were taken pre- and postoperatively. In model surgery the accurate distraction distance was measured and the direction of distraction designed. Orthodontic therapy was started immediately after the distraction was completed and the distractor was removed after a period of 4 months' consolidation. RESULTS: The designed distraction was achieved in a11 8 patients. Except in one case with a bone defect 1 cm x 0.5 cm at the osteotomy line in the lateral wall of the right maxillary sinus, dense new bone was formed in the area of distraction in the other cases. The postoperative occlusal relationship was good and stable. No infection and other complication was found. During an average of 20 months' follow-up, the maxilla and occlusion were stable, and no relapse was found. The distance of forward distraction of the maxilla reached an average of l2 mm (5 approximately 15 mm). The SNA angle increased from 71 degree on average preoperatively to an average of 79 degree postoperatively. Both the facial appearance and occlusal relationship returned to normal in a11 the patients. CONCLUSION: Without need of bone grafting and with a stable effect and little influence on platatopharyngeal competence, distraction osteogenesis is an effective method of correcting maxillary hypoplasia secondary to cleft palate and is worthy of spreading.

Adolescent↗

PubMed2002

[EMG activities of the head, neck and upper trunk muscles with mandibular movements in healthy adults and mandibular asymmetry patients].

OBJECTIVE: To study the activities of head, neck and upper trunk muscles during mandibular movements in healthy adults and mandibular asymmetry patients. METHODS: Electromyographic integrogram was used to record and analyze the electromyographic activities of the anterior temporal (Ta), posterior temporal (Tp), sternocleidomastoid (SCM), and trapezius (TRAP) muscles in rest position and during mandibular movement among 10 normal adults and 10 mandibular asymmetry patients. RESULTS: All the four muscles showed constant electromyographic activities when the mandible was in the rest position. The activities of Ta, Tp, and SCM muscles increased with protrusion of mandible, mouth opening, tapping, maximum clenching, and chewing. The activities of Ta and Tp muscles of the patients were 1.7 times greater than that of the normal adults during mandibular movement without occlusion, and were weaker by 50% during mandibular movement with occlusion. The difference between electromyographic activities during mandibular movement and in rest position was less among patients than among normal adults. The TRAP muscle of the patients showed constant electromyographic activities with the activity volume nearly 1.8 times that of the normal adults. The difference between the muscle and its namesake at the opposite side was greater among the patients (21%) than among the normal adults (8%). CONCLUSION: All the four muscles participate in the maintenance of rest position of mandible and the realization of mandibular movements. The coordination of muscular activities among mandibular asymmetry patients is poorer than that among normal adults.

Adult↗

PubMed2002

[Development of internal distractors for jaws: experimental and clinical studies].

OBJECTIVE: To introduce a series of internal distractors developed by the authors and results of experimental study and clinical trials. METHODS: Based on the demand of clinical use and experimental studies, 7 kinds and 17 types of internal distractors were developed. Required biomechanics were evaluated and animal studies were undertaken in 16 Rhesus monkeys and 12 goats with 40 distractors. Clinically, 68 Patients with 7 kinds of severe dento-gratho-facial deformities were treated with 82 distractors and the histocompatibility, stability, influence on new bone formation were evaluated. RESULTS: The 7 kinds of distractors were State-approved products made of Titanium alloy and permitted for use in human. The pull and twist force tests demonstrated that the loading capability of them were larger than 7.8 kgf and 5.0 kgf respectively. The domestic made Grade II screw was used to transmit the moving, it was nimble, without dead point, and with a forward-backward space of < 0.1 mm. The horizontal space in between the two fixing parts was < 0.1 mm. The parallel degree of the two direction-guide rods was within 0.05 mm. Animal and clinical studies demonstrated that there was no rejection response of the tissues. There were fractures of the direction-guide rods in two early cases, the design was improved then. Other results both experimentally and clinically were satisfactory with good osteogenesis. CONCLUSIONS: This series of domestic made internal distractors can be used satisfactorily in distraction osteogenesis for various kinds of jaw deformities. The successful production of these distractors will provide a good foundation to popularize the internal distraction osteogenesis of the jaws.

Animals↗

PubMed2002

Mandibular functional reconstruction using internal distraction osteogenesis.

OBJECTIVE: To study the potential and advantages of internal distraction osteogenesis in mandibular functional reconstruction. METHODS: Three types of mandibular distractors were used in eight patients with various mandibular defects due to tumor or cyst resection. The average age of the patients was 31.5 years old (ages ranged from 8 to 54 years). For two patients with ramus defects, specially designed distractors were used to restore the normal ramus height. In two other patients, specially designed trifocal distractors were used. In three patients, vertical distractors were used. RESULTS: All the mandibles were successfully reconstructed in accordance with the direction and distance designed before operation except in one patient. In that patient the distal 23 mm defect failed to be corrected because of loosening of transport block fixation screws. CONCLUSIONS: Mandibular defects can be successfully corrected using internal distraction osteogenesis. Performing mandibular reconstruction using distraction osteogenesis is best done at the time of tumor or cyst resection.

Adult↗

PubMed2000

Composite mandibular allografts in canines.

OBJECTIVE: To evaluate the feasibility of transplanting composite mandibular allografts to repair large mandibular defects. METHODS: Three composite mandibular trans-plantation models were established. The first model consisted of hemimandible with the attached teeth, muscle and skin,and oral mucosa. The second model was transplanted in the same way with the first one excluding oral mucosa and some teeth, and third one excluding the oral mucosa and all dental crowns. Fourteen transplanting operations were performed in canines. Cyclosporine A and methylprednisone were given for immunosuppression. RESULTS: The composite mandibular organs had an effective and closed return circuit. Transplantation of vascularized allograft of mandibular compound organs was feasible. Two longest time survivors of 67 d and 76 d were in the third model group. Cyclosporine A was successful in suppressing rejection of transplanted composite allograft and prolonging survival time of transplantation models. CONCLUSIONS: The composite mandibular allografts were available with large block of living composite tissue, and helpful in restoration of appearance and function for severe mandibular defects.

Journal Article↗