Biomedical subjects

Cheng Liang

Publications and source records attributed to Cheng Liang.

10 recordsLinked to original sources

PubMed2005

[Effects of maxillary distraction osteogenesis on the velopharyngeal configuration of cleft palate patients].

OBJECTIVE: To study the effects of internal maxillary distraction osteogenesis(DO) on the velopharyngeal configuration of cleft palate patients. METHODS: Ten patients with severe maxillary hypoplasia secondary to cleft lip and palate patients (7 males and 3 females, average age 20.1 years old) had undertaken high step LeFort I osteotomy, and internal maxillary distraction devices were applied to advance the maxilla. Before surgery, when DO was completed and 6 months after DO was completed, oriented lateral cephalograms at rest position of each patient were taken, and 6 measure indexes of velopharyngeal configuration were collected and analyzed. RESULTS: All patients had successfully accomplished maxillary DO and the maxilla had been averagely advanced 11.3 mm. PNS-PhW, C-PhW, UL and ANS-PNS-T had all significantly increased, and UD had significantly decreased when DO was completed and 6 months after DO was completed as compared with pre-surgery. No significant linear correlation was found between maxilla advancement distance and velopharyngeal configuration changes. CONCLUSION: Correction of maxillary hypoplasia secondary to cleft palate surgery by using internal maxillary DO can increase the velopharyngeal cavity depth, and may impair velopharyngeal competence, but the compensatory changes of velopharyngeal soft tissue can alleviate this impairment to certain extent.

Adolescent↗

PubMed2005

Internal midface distraction in correction of severe maxillary hypoplasia secondary to cleft lip and palate.

BACKGROUND: Maxillary hypoplasia is a familiar deformity in patients with cleft lip and palate. A large amount of maxilla advancement is often needed to correct the severe deformity, but local soft-tissue scars around the maxilla restrict maxilla advancement and increase the relapse rate. By gradually lengthening both the bones and the soft tissues, midface distraction can greatly increase postoperative stability and lower the relapse rate. METHODS: Ten patients with severe maxillary hypoplasia secondary to cleft lip and palate were treated with midface distraction using three kinds of internal distraction devices. Among them, six patients received an alveolar bone graft from the iliac crest during their Le Fort I osteotomy, and a bilateral sagittal split ramus osteotomy was performed simultaneously to push back the mandible in five patients with prognathia, to obtain a normal soft-tissue profile and occlusal relationship. RESULTS: Successful maxillary advancements ranging from 5 to 15 mm were measured from preoperative and postoperative cephalograms. Patients' sella-nasion-point A angles increased from an average of 71.25 degrees preoperatively to 79.05 degrees postoperatively. Orthodontic therapies were adopted before and/or after midface distraction. After the consolidation period, dense new bone was found to have formed in the distraction gap. During the follow-up period, the position of the maxilla and the final occlusal relationship were stable and acceptable, and no obvious relapses were seen. CONCLUSION: Midface distraction is an ideal choice for the correction of severe maxillary hypoplasia secondary to cleft lip and/or palate.

Adolescent↗

PubMed2005

[Orthognathic surgery and distraction osteogenesis for treatment of obstructive sleep apnea hypopnea syndrome].

OBJECTIVE: To discuss the indication and protocol of surgical therapy when treating mandibular micrognathism accompanying obstructive sleep apnea-hypopnea syndrome (OSAHS) using distraction osteogenesis and orthognathic surgery. METHODS: A total of 17 patients with mandibular micrognathism accompanying moderate to severe OSAHS, aged 11 to 59 years, 15 men and 2 women, were reviewed. Four of them were treated with orthognathic surgery, 5 of them were treated with distraction osteogenesis, and the other 8 patients were treated with an integrated procedure combining distraction osteogenesis with orthognathic surgery. Cephalometric analysis and polysomnography studies were obtained pre- and postoperatively. RESULTS: SNB angle changed from 64.6 degrees to 71.9 degrees, post airway space (PAS) from 5.4mm to 13.2 mm, apnea and hypopnea index (AHI) from 58.4 to 7.6, lowest saturation of oxygen (LSAT) from 66% to 87%. All the differences showed statistical significance (P < 0.001). The average mental horizontal advancement (MHA) was 14.3 mm and its correlation coefficients with deltaSNB, deltaPAS, deltaAHI, and deltaLSAT were 0.36, 0.62, 0.34, and -0.14, respectively. CONCLUSIONS: Both distraction osteogenesis and orthognathic surgery can be effectively used to treat patients with mandibular micrognathism accompanying OSAHS with slightly different indications. A combination of these two operations may be preferred.

Adolescent↗

PubMed2005

[The transformation of fibroblast-like cells originating from different tissue into osteoblasts].

OBJECTIVE: To discuss whether fibroblast-like cells can transform into osteoblasts under specific condition during distraction osteogenesis. METHODS: Fibroblast-like cells were cultured in vitro. BMP-2, TGF-beta(1), BMP-2 and TGF-beta(1) were added into the medium, and the cellular change were observed by histochemistry and immunohistochemistry methods. The distraction was given on the membrane of fibroblast-like cells, and the cellular change were observed under the distraction. RESULTS: fibroblast-like cells from the joint could transform into osteoblasts under the effect of BMP-2 or BMP-2 with TGF-beta(1). Fibroblast-like cells from other regions could not transform into osteoblasts. CONCLUSION: The osteoblasts during distraction osteogenesis are multi-origin.

Animals↗

PubMed2004

[The effect of platelet-rich plasma on the distraction osteogenesis].

OBJECTIVE: To observe the effect of the platelet-rich plasma (PRP) on osteogenesis during bone distraction. METHODS: The osteoblasts were cultured in vitro. The rabbits were used as the animal model of distraction osteogenesis. The proliferation of osteoblasts was analysed through MTT methods. The osteogenesis was observed by histochemical and histoimmunochemical methods. RESULTS: PRP stimulated the proliferation of osteoblasts and facilitated distraction osteogenesis. CONCLUSIONS: PRP could accelerate the osteogenesis during bone distraction. The application of PRP in clinical practice might shorten the period of distraction osteogenesis.

Animals↗

PubMed2003

Distraction osteogenesis in correction of micrognathia accompanying obstructive sleep apnea syndrome.

To evaluate the effect of distraction osteogenesis in correction of micrognathia accompanying obstructive sleep apnea syndrome, a total of 28 patients with different severities of obstructive sleep apnea syndrome underwent mandibular distraction osteogenesis. A total of 51 distraction devices were placed for bilateral distraction in 23 patients and for unilateral distraction in five patients. The mean age of patients was 21.2 years (range, 3 to 60 years). Eleven patients had micrognathia accompanying obstructive sleep apnea syndrome secondary to bilateral temporomandibular joint ankylosis, and 10 patients had micrognathia accompanying obstructive sleep apnea syndrome secondary to unilateral temporomandibular joint ankylosis. Three patients had developmental micrognathia accompanying obstructive sleep apnea syndrome. The other four patients had micrognathia and concomitant obstructive sleep apnea syndrome induced by trauma, infection, or tumor resection. Each patient had been evaluated preoperatively and postoperatively with cephalometry and polysomnography. Mandible advancement ranged from 9 to 30 mm (average, 20.4 mm) and was successfully achieved after distraction. Fine new bone formed in the distraction gap when the distraction devices were removed 3 to 4 months after distraction was completed. No infection or other complications occurred in any patients. Complete curative effects were achieved in nine severe, six moderate, and eight mild obstructive sleep apnea syndrome patients after distraction, and the other five patients had been improved to the mild level. After distraction was completed, the posterior airway space was increased on average from 4.6 mm to 12.5 mm and the sella-nasion-point B angle was increased on average from 66 degrees to 75 degrees on cephalometric studies. The polysomnographic examination showed that the apnea hypopnea index was lowered on average from 58.0 to 3.15, and the lowest oxygen saturation was increased on average from 77 percent to 90.3 percent after distraction was completed. The follow-up period was 3 to 61 months (average, 18.1 months). The curative effect was stable and no relapse occurred. Therefore, the authors conclude that mandibular distraction osteogenesis is an effective method for correcting micrognathia accompanying obstructive sleep apnea syndrome. Compared with other current routine surgical procedures, it has many advantages, such as low risk, simple manipulation, high curative rate, low relapse rate, and stable result. It is presently the most effective method for the treatment of this difficult and complicated disorder.

Adolescent↗

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

[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↗

PubMed2002

[Instrumentation and techniques in bone density measurement].

Manifold methods for bone mineral density analyses are introduced in this paper, and the characteristics of precision, accuracy, position, convenience, sensitivity and the radiation hazards of these methods are also discussed here.

Absorptiometry, Photon↗