Biomedical subjects

Li Teng

Publications and source records attributed to Li Teng.

At least 19 recordsLinked to original sources

PubMed2006

[Analysis of the complications following mandibular distraction using internal distractors].

OBJECTIVE: To investigate the causes and the prophylactic for the complications following mandibular distraction osteogenesis using internal distractors. METHODS: From 1997 to 2004, a total of 46 patients (61 sides) suffering from malformations or defects of mandible who underwent mandibular distraction osteogenesis were analyzed. The diseases included hemifacial microsomia in 27 cases, congenital or acquired mandibular hypoplasia and micrognathia bilateral in 8 cases and unilateral in 4 cases, electronical injury or postoperative mandibular defects in 3 cases, Treacher Collins syndrome in 2 cases, obstructive sleep apnea syndrome in 2 cases. RESULTS: Of them, 9 patients had postoperative complications, which included 3 patients had complications associated with distractors, local infection occurred in 2 cases, apertognathia of anterior teeth in 2 case, 2 patients had sinus of the skin of the lower lip. 9 patients had been aggressivly managed and obtained satisfactory results. CONCLUSIONS: The pivotal points to reduce complications are to understand the mechanism of mandibular distraction osteogenesis completely, and to be familiar with the anatomy of mandible and adjacent tissues. It is necessary to treat with it preoperatively and postoperatively.

Adolescent↗

PubMed2006

[The surgical management of unilateral Craniofacial Atrophy and Hypoplasia].

OBJECTIVE: To study the surgical reconstruction of unilateral Craniofacial Atrophy and Hypoplasia. METHODS: According to the etiological factors and severity of the facial deformities, different methods are employed, including bone framework reconstruction, soft tissue transplantation, orthognathic surgery. RESULTS: From September 1998 to August 2004, 42 cases were treated, Include: Hemifacial Microsomia 22 cases, Hemifacial Atrophy 16 cases, unilateral facial hypoplasia due to radiation 4 cases. Miniplate and transplants extrusion occurred on 2 post radiation patients due to poor soft tissue coverage, infection occurred on 1 patient after mandibular ramus reconstruction using autogenous rib and contralateral mandibular outer cortex. The leaving patients recovered well and the facial asymmetry were improved greatly. CONCLUSIONS: Facial asymmetry due to unilateral Craniofacial Atrophy or Hypoplasia is a common and complex condition for surgical management, The surgical plan should be delicated made individually according to the severity of the soft tissue and the underlying bone framework.

Adolescent↗

PubMed2006

[High level Le Fort I osteotomy and bone grafting for correction of secondary mid-face deformities in cleft patients].

OBJECTIVE: To explore the feasibility of combining high level Le Fort I osteotomy with bone grafting in the same operation for correction of secondary mid-face deformities in cleft patients. METHODS: From January 2002 to January 2005, 10 patients suffering from secondary mid-face deformities were treated. There were 4 males and 6 females, aged from 16 to 32 years. The unilateral cleft was involved in 8 patients and the bilateral cleft in 2 patients. All patients received combining high level Le Fort I osteotomy with bone grafting in the same operation. The horizontal corticotomy of high level Le Fort I osteotomy on anterior wall of maxillary bone is higher than that of traditional Le Fort I osteotomy, it is only 5 mm close to infraorbital foramen. RESULTS: All 10 patients were satisfied with their appearances after operation. Dental articulation was improved greatly in 9 patients. With an X-ray re-examination, maxillary was returned to normal position in all patients. After a follow up from 6 months to 2 years, dental arch had good appearance. The X-ray films showed no obvious bone absorption. The density of grafting bone was approximation to the normal bone. CONCLUSION: High level Le Fort I osteotomy can make not only maxillary advance, but also regions of lateral and floor of nose and partial infraorbital region advance. Combining with bone grafting in the same operation can decrease the frequency of operation, save the treatment expense and obtain an ideal effect. So it is an effective method for correction of the secondary mid-face deformities in cleft patients.

Adolescent↗

PubMed2006

[Contrast analysis of different sagittal split ramus osteotomy methods in correcting mandibular prognathism].

OBJECTIVE: To explore the indication, advantage and disadvantage of modified or classical technique of intraoral sagittal split ramus osteotomy (SSRO) for correction of mandibular prognathism. METHODS: From January 1997 to January 2005, 95 patients suffering from mandibular prognathism or accompanied by other deformities were treated with modified or classical technique of intraoral SSRO. Of 95 cases, there were 34 males and 61 females, aging 15 to 44 years, including 53 cases of single mandibular prognathism, 28 cases accompanied with mandibular deviation, 11 cases accompanied with maxillary retrognathism, 2 cases accompanied with glossacele and 1 case accompanied with malar protrusion. X-ray cephalometry showed: sella-nasion-A point (SNA) 80-83 degrees, sella-nasion-B point (SNB) 80-84 degrees, A point-nasion-B point (ANB)--3-1 degrees. Forty-three cases were corrected by modified SSRO and 52 cases by classical SSRO. RESULTS: The face appearance and dental articulation of all the patients were improved greatly. In patients by classical SSRO, disorder of local sensibility occurred in 9 cases, mandibular fracture during the cleavage of the ascending ramus in 1 case, significant bleeding in 1 case, postoperative infection in 1 case and postoperative relapse in 3 cases. In patients by modified SSRO, disorder of local sensibility occurred in 2 cases and postoperative relapse in 1 case; no mandibular fracture, significant bleeding, postoperative infection and other complications occurred. With a follow-up of 3 months to 7 years, X-ray cephalometry showed SNA 81-83 degrees, SNB 78-81 degrees and ANB 1-4 degrees. CONCLUSION: Modified SSRO is an ideal method of correcting mandibular prognathism, especially severer mandibular prognathism accompanied by mandible deviation deformity.

Adolescent↗

PubMed2006

[Simultaneous occlusal orthodontics during mandibular distraction osteogenesis].

OBJECTIVE: To study the significance and principle of simultaneous orthodontics during mandibular distraction osteogenesis. METHODS: Totally 11 patients simultaneously underwent occlusal orthodontic treatment for 3-4 months during mandibular distraction osteogenesis. Square-wire and elastic loops were adapted to perform the orthodontics by ways of more frequent adjustment of orthodontic device than routine method. RESULTS: All 11 patients with mandibular micronathia obtained the improved occlusion with their mandibular expected elongation, for instance, their open-bite and teeth displacement were partially corrected. CONCLUSION: Simultanous orthodontics with mandibular distraction osteogenesis may improve the malocclusion, decrease the orthodontic time, and lead the mandibular distraction direction.

Adolescent↗

PubMed2006

[Experiment of using distraction osteogenesis to repair skull defect].

OBJECTIVE: To explore the possibility of using distraction osteogenesis to repair skull defect. METHODS: 17 goats with one year age were chosen randomly. The animals were divided to 3 groups. Group A includes 7 goats, a 3.0 cm x 2.2 cm rectangle skull defect is created on both sides of parietal area. Group B includes 5 goats, a 2.2 cm x 2.2 cm square skull defect was created on right side of parietal area. Group C includes 5 goats, a 3 cm x 1 cm rectangle skull defect was created on both sides of parietal area. Accordingly, different size of transport discs were created on right side of skull and the distraction apparatus is implanted. 3-D CT was done to measure the skull defect on group A. Biomechanical test was done on group B. Process of bone formation illustrated by histological stain, scan and transparent electric microscope was observed on group C. RESULTS: Group A measured by 3-D CT showed that skull defect of experimental side have been repaired by distraction osteogenesis. There was definitely difference between experimental and control side (P < 0.01). Group B measured by biomechanical test showed no definitely difference between experimental and normal side (maximum load P = 0.235 > 0.05, rigidity P = 0.213 > 0.05). Group C showed that the process of bone formation was typical intramembranous. CONCLUSIONS: The evidence showed that skull defect of goat can be repaired by distraction osteogenesis.

Animals↗

PubMed2005

Finding dominant sets in microarray data.

Clustering allows us to extract groups of genes that are tightly coexpressed from Microarray data. In this paper, a new method DSF_Clust is developed to find dominant sets (clusters). We have preformed DSF_Clust on several gene expression datasets and given the evaluation with some criteria. The results showed that this approach could cluster dominant sets of good quality compared to kmeans method. DSF_Clust deals with three issues that have bedeviled clustering, some dominant sets being statistically determined in a significance level, predefining cluster structure being not required, and the quality of a dominant set being ensured. We have also applied this approach to analyze published data of yeast cell cycle gene expression and found some biologically meaningful gene groups to be dug out. Furthermore, DSF_Clust is a potentially good tool to search for putative regulatory signals.

Algorithms↗

PubMed2005

Correction of inverted nipple: an alternative method using continuous elastic outside distraction.

Inverted nipple, which is defined as a nipple located on a plane lower than the areola, presents both functional and cosmetic problems. It is a source of repeated irritation and inflammation and interferes with nursing. In addition, its abnormal appearance may cause psychologic distress. With consideration of its underlying pathophysiologic components and severity, a number of techniques have been introduced for correction of this anomaly. Most of these techniques involve extensive skin incision around the nipple that may jeopardize the blood and nerve supply to the nipple or create much scar tissue that is esthetically objectionable. For correcting the inverted nipple, the authors introduce an alternative, simple method using continuous elastic outside distraction. Compared with other methods using outside distraction, the authors used an adjustable elastic instrument made of steel wire, spring, and plastic syringe; continuous distraction of the inverted nipples; and sustaining 3 to 6 months. From August 2002 to December 2003, 14 patients (26 nipples) were treated. 12 patients had bilateral inverted nipples. Patient age at operation ranged from 14 to 40 years (mean age, 24 years). All nipples were congenital, and they had no previous operation. Six nipples were grade I, 9 nipples were grade II, and 11 nipples were grade III according to the classification of inverted nipple by Han and Hong. The mean follow-up period was 7.3 months (range, 3-12 months). Follow-up examinations revealed no evidence of recurrence of inversion. There was no complication associated with surgery, such as infection, hematoma, permanent sensory disturbance, or nipple necrosis. All patients were satisfied with their results. The authors conclude that their procedure is reliable, a simple, safe, and effective method for correction inverted nipple. But a long-term follow-up is needed. This technique can be applied to any type of inverted nipple as a primary surgical procedure.

Adult↗

PubMed2005

[Distraction osteogenesis in patients with syndromic midface retrusion--a primary experience].

OBJECTIVE: To study the feasibility of midface distraction for correction of severe syndromic Four consecutive patients with severe syndromic midface retrusion underwent midface retrusion. METHODS: distraction osteogenesis. The patients(three girls and one boy) aged from 4 to 12 years. Two were with Crouzon syndrome, one with Apert and one with Marfan syndrome. One was treated with Le Fort III external distraction, two with Le Fort III internal distraction, and the other with monobloc internal distraction. The distraction devices were activated on the fourth postoperative day at 1 mm per day. RESULTS: All patients completed the distraction as activated on the fourth postoperative day at 1 mm per day. Results was planned. Successful advancement of 8 to 20 mm was obtained at the occlusal level in all patients as measured by cephalograms. The facial appearance was significantly improved,especially in the orbits and the upper part of the nose. Follow-up from 4 months to one year demonstrated that the face was symmetrical. All patients obtained This study shows that although midface distraction osteogenesis needs to be satisfactory results. CONCLUSIONS: This study shows that although midface distraction osteogenesis needs to be improved to increase its controllability, it has obvious advantages over the traditional way of bone graft and rigid fixation. Midface distraction avoids bone grafts and alleviates the restriction of the soft tissue to midfacial bone advancement. Midface distraction osteogenesis is an effective and practical way to correct severe syndromic midfacial hypoplasia.

Australia↗

PubMed2005

[Mandibular distraction osteogenesis in the treatment of obstructive sleep apnea syndrome in children with micrognathia].

OBJECTIVE: To evaluate the treatment of obstructive sleep apnea syndrome (OSAS) in children with congenital micrognathia using mandibular distraction osteogenesis and to discuss the advantages and disadvantages of this approach. METHODS: 6 patients (4 males, 2 females) had undergone mandibular distraction osteogenesis, 12 distraction devices were placed through extraoral incision for bilateral distraction. The mean age of treatment was 1 year and 9 months (range 4 months to 9 years). Every patient had been evaluated pre and postoperatively with cephalometry. The period of consolidation was 4 - 11 weeks. The period of follow-up was from 2 to 10 months. RESULTS: The average distraction distance was 19.2 mm (range 15 to 25 mm). The osteotomy and distraction processes were smooth in all the cases, the osteogenesis was good, without infection and other complications. The posterior airway space was increased from averaged 4.5 mm preoperatively to 10. 1mm after surgery. Five children had normal respiration and sleep restored with naso-pharyngeal airway removal or tracheostomy decannulation. One patient is to receive a planned second stage of distraction with a horizontal vector. The results were stable without relapse during a follow-up period of 2 to 10 months. CONCLUSIONS: Application of mandibular distraction osteogenesis is an important component and effective in the treatment of OSAS and permits mandibular advancement in the younger child. As more experience is gained with distraction osteogenesis in the treatment of children with OSAS, the role of distraction will become better defined.

Child↗

PubMed2005

[Complications of scalp coronal incision: analysis, prevention, and treatment].

OBJECTIVE: The aim of this study was to analyze the complications of coronal incision and investigate the methods of prevention. METHODS: The retrospective analysis was based on 149 cases, who have had operations since 1997 for congenital craniofacial malformation, second deformation of craniomaxillofacial trauma, maxillofacial tumor or cosmetic purposes. RESULTS: Of them, there were injury of unilateral frontal branch of the facial nerve in 3 cases, subcutaneous hematoma in 9 cases, alopecia in 12 cases, incision scar in 14 cases, obvious strip scar in 2 cases, pains, numbness and paraesthesia in 23 cases, ptosis of facial soft tissue in 8 cases and infection in 4 cases. CONCLUSIONS: The coronal incision has the merits of distinct exposure, hidden incision scar, but its complications can not be neglected. During the operation, care should be taken to anatomical layers, protecting the blood vessel and nerve bundle in order to reduce complications.

Adolescent↗

PubMed2005

[Surgical management of craniomaxillofacial fibrous dysplasia].

OBJECTIVE: To explore the method to obtain good aesthetic and functional results in surgical management of craniomaxillofacial fibrous dysplasia and correct the grotesque deformity. METHODS: According to the type of the lesions, different excision and reconstruction methods were used. RESULTS: 19 cases (4 monostotic cases and 15 polyostotic cases) were surgically treated. The period of follow-up range from 9 months to 5 years, all patients obtained satisfactory aesthetic and functional results. No relapse happened during follow up. CONCLUSIONS: Based on modern craniomaxillofacial techniques and computer aided design, extensive radical excision and craniomaxillofacial skeleton reconstruction could be safely accomplished, and the better results were obtained, both aestheticly and functionally.

Adolescent↗

PubMed2004

[Treatment of the asymmetric prominent mandibular angle].

OBJECTIVE: To investigate the causes and treatment of the asymmetric prominent mandibular angle. METHODS: From 1996 to 2001, mandibular angle osteotomy, mandibular outer cortex osteotomy, mandible, genioplasty and buccal pad excision were selected to treat 70 patients. RESULTS: All the patients had satisfactory results with complications of bleeding, infection and labial scar in three patients. CONCLUSION: Asymmetric prominent mandibular angle should be treated according to the characteristics of the deformity. Mandibular angle osteotomy, osteotomy of outer cortex of the mandible, genioplasty and bucal pad excision can provide satisfactory result.

Adolescent↗

PubMed2004

[Chin augmentation with bone transplantation from the mandible].

OBJECTIVE: To explore a new method for mentoplasty. METHODS: The bilateral prominent mandibular angle or outer lamina was resected through the intraoral approach. The resected bone fragments were shaped and rigid fixed to the chin with miniplates and screws. RESULTS: A total of 30 patients (28 females, 2 males) accepted chin augmentation with this method. The mandibular angle bone was used in 20 cases and the mandibular outer lamina was used in 10 cases. The operative results were satisfactory, and the patient's facial contour was improved substantially. CONCLUSION: No rejection reaction was found after this procedure. Chin augmentation with autogenous mandibular bone is an ideal method for genioplasty.

Adult↗

PubMed2004

[The correction of fronto-orbital deformity in infant craniosynostosis--a one year experience].

OBJECTIVE: To evaluate the correction of fronto-orbital deformation in infant craniosynostosis and to discuss the timing of treatment and surgical technique. METHODS: Eleven consecutive patients with craniosynostoses underwent bilateral fronto-orbital osteotomies and advancement via coronal approaches. There were two females and 9 males with an age range from 6 to 9 months. Among the patients, six had trigonocephaly secondary to metopic synostosis, two had non-syndromic plagiocephaly secondary to unilateral coronal synostosis, one had turricephaly secondary to multi-sutural synostosis and two patients had brachycephaly due to syndromic synostosis (Apert syndrome and Saethre-Chotzen syndrome). RESULTS: The shape of forehead, bilateral orbit and bilateral temples in all patients markedly improved with 2-11 months follow-up. There were not obvious complications except that the unilateral parietal bossing happened to the child with turricephaly postoperatively. CONCLUSIONS: Satisfactory results show that fronto-orbital advancement is safe and effective way to correct frontal and orbital retrusion secondary to craniosynostosis.

Craniosynostoses↗

PubMed2004

[Surgical treatment of orbital and periorbital fibrous dysplasia].

OBJECTIVE: To explore the surgical approaches to obtain good aesthetic and functional results in the management of orbital and periorbital fibrous dysplasia and related deformities. METHODS: Ten cases of orbital and periorbital fibrous dysplasia were treated surgically. The location, extension and shape of the lesions were identified based on X-ray examination and two and three dimensions CT examinations preoperatively. According to the type of the lesion, different approaches were used to excise the lesion and to reconstruct the orbit. The lesions were radically or partially excised through bicoronal, intraoral and subciliary approach; the orbit was reconstructed with autogenous outer or inner table of calvarium, outer table of mandible, Medpor and prefabricated individual titanic implants. RESULTS: In 10 cases treated surgically, radical excision was employed in 4 cases and partial excision in 6 cases. Autogenous inner table of calvarium was used in 2 cases, Medpor in 2 cases, outer table of mandible in 1 case, and titanic meshwork and prefabricated individual titanic implants in 4 cases to reconstruct the orbit. After the treatment, all patients obtained satisfactory aesthetic and functional results. CONCLUSIONS: Carefully planed surgical approaches with methods for preventing the complications can be used for the treatment of orbital and periorbital fibrous dysplasia and obtaining satisfactory aesthetic and functional results.

Adolescent↗

PubMed2003

[Intro-extro cranial approach treat serious post fronto-orbital fracture deformities].

OBJECTIVE: To explore the method of treating serious secondary fronto-orbital fracture deformities through intro-extra cranial approach. METHODS: The fronto-orbital fracture was divided into two types according to whether there were any large scale fronto-orbital bone defects: type I: Large scale fronto-orbital bone defect; type II: Concave fronto-orbital fracture deformity without large scale bone defect. Both types were treated through intro-extra cranial approach to expose the fracture site. For type I deformity, the bone defects were repaired and reconstructed with outer table of cranial bone and artificial bone. For type II, the deformity was repaired by osteotomy, bone reposition and internal rigid fixation. RESULTS: 18 cases were treated from June 1998 to October 2000, include type I, 12 cases, and type II, 6 cases. All the patients recovered well and the post-operative appearance were greatly improved. CONCLUSIONS: Intro-extra cranial approach can expose the fractured site better than the simple extrocranio approach, and make the operation more easily done. Combined with the technique of cranio maxillo facial surgery, the treatment can be more complete and the results can be more satisfactory.

Fracture Fixation, Internal↗

PubMed2003

[Analysis of the complications following correction of mandibular angle prominence].

OBJECTIVE: To investigate the causes and the prophylactic measures for the complications following correction of mandibular angle prominence. METHODS: From 1996 to 2001, a total of 203 patients with mandibular angle prominence underwent mandibular angle osteotomy. RESULTS: Of them, 9 patients had postoperative complications, which included bleeding, hematoma, infection, mental nerve injury, labia scar, asymmetry, and steep mandibular angle. CONCLUSION: The correction of mandibular angle prominence should be designed and performed precisely. Care must be taken to avoid severe complications like condyle fracture.

Cicatrix↗