Biomedical subjects

Lai Gui

Publications and source records attributed to Lai Gui.

At least 19 recordsLinked to original sources

PubMed2006

The sagittal curving osteotomy: a modified technique for advancement genioplasty.

PURPOSE: The purpose of the present study was to develop a new type of osteotomy for advancement genioplasty to decrease the incidence of neurosensory disturbance of the chin. PATIENTS AND METHOD: Forty-six patients who suffered from a slight or moderate degree of microgenia received a sagittal curving osteotomy for advancement genioplasty. Patients were followed for 1-6 months to assess the neurosensory function of the chin region by evaluating light-touch perception. The control group, 57 patients, who suffered from the same degree of microgenia, received a horizontal sliding osteotomy. They were operated on by the same surgical group and were followed for 1-33 months. RESULTS: All of the test and control patients were satisfied with the aesthetic results of the surgery. In the test group, 47 sides (51.87%) of 92 total left and right sides of chins had a transient neurosensory deficiency but none had permanent neurosensory deficiency. In the control group, 98 sides (86.84%) of 114 total chin sides had a transient neurosensory deficiency and five sides (4.43%) of 114 total chin sides had permanent neurosensory deficiency. When applied to patients who suffer from a mild or moderate degree of microgenia and have normal bite function, the sagittal curving osteotomy is a simple, safe and effective technique for advancement genioplasty. This technique can distinctively decrease the incidence of neurosensory disturbance of the chin.

Adult↗

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

[Temporal three-point relief-tension suspension technique for facial rhytidectomy].

OBJECTIVE: To evaluate a facial rhytidectomy technique to reduce the complications of temporal alopecia and incisional scar hyperplasia. METHODS: The 82 aged patients were divided into 2 groups in random way: group A in 46 with the use of the three-point relief-tension suspension technique and group B in 36 as control. In group A, the two point of every relief-tension suture was located respectively in the subcutis of the hairline and fascia under the incision. The parallel three sutures formed a mechanical plane to make the relief suture more strong and permanent. The temporal alopecia and incisional scar was observed with the follow-ups after the operation. RESULTS: With the 82 cases of facial rhytidoplasty, the complications of the temporal alopecia and incisional scars in group A were much less than in group B. CONCLUSIONS: This technique could decrease the complications such as temporal alopecia and incisional scars, and get a good and long term effect of temporal lifting simultaneously.

Adult↗

PubMed2006

[The application of three-dimensional skull model in the treatment of craniofacial malformation].

OBJECTIVE: This study was to construct a geometric skull model with 3-dimension scanning and rapid-prototyping (RP) technology and also to evaluate the significance and further application of surgery simulation in the treatment of complex craniomaxillofacial malformation. METHODS: Twelve patients with complex craniomaxillofacial malformation were involved. The data obtained with CT scanning were transferred to a personal computer for surface rendering 3-dimension reconstruction. A geometric model was manufactured by selective laser sintering using rapid-prototyping device. Surgery simulation was performed both on the model and in the computer. Accordingly, a custom implant and an implant template, when needed, were constructed with the computer-aided design (CAD) and prefabricated with computer-aided manufacture (CAM) process. RESULTS: Surgery simulation made the operation shorter, the complications lower and the outcome better. CONCLUSIONS: Skull model provides great convenience in the treatment of cranio-maxillofacial malformation.

Adult↗

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↗

PubMed2006

[The influences on mandibular development after removing the outer cortex of mandibular body in childhood minitype pigs].

OBJECTIVE: To study the influences on mandibular development after removing the outer cortex of mandibular body in childhood minitype pig. METHODS: Six childhood minitype pigs were selected as the experimental animals. The outer cortex of mandibular body measured as 3.0 cm x 1.5 cm was removed in one side, and the other side remained intact as the control. The changes of mandibular modality and occlusion relationship as well as the histological and biomechanical changes were studied 24 weeks after operation. RESULTS: There was no obvious difference compared with the control side in the height of the mandibular ramus and the length of the mandibular body, However, lateral deviation occlusion was found in some animals. The body thickness was thinner than that of the control side, there were no obvious biomechanical and histological differences between the two sides. CONCLUSIONS: There was less influence on the growth of mandibular bone after removing one side of the outer cortex of the mandibular body in childhood minitype pig. But further study should be done for the cause of the lateral deviation of the mandible in part of the animals.

Animals↗

PubMed2006

[Application of CTA and CAD\CAM techniques in mandible reconstruction with free fibula flap].

OBJECTIVE: To explore the application of computed tomographic angiography (CTA) and computer aided design\manufacture (CAD\CAM) techniques in mandible reconstruction with free fibula flap. METHODS: 7 cases of complex mandible defect were reconstructed with free fibula flap. Patients' lower extremity vasculature was evaluated by preoperative CTA examination; mandible tumor resection and reconstruction were simulated by CAD technique, the surgical template was manufactured with CAM technique preoperatively; and fibula flap was shaped according to surgical template during mandible reconstruction operation. RESULTS: Preoperative CTA examination performed without complication, the desired anatomy was adequately demonstrated in all patients. All of flaps survived, patients' facial contour are symmetry approximately. CONCLUSIONS: CTA and CAD\CAM techniques have important value for complex mandible reconstruction in selection of donor site, planning of operation and shaping of fibula flap.

Adolescent↗

PubMed2006

[Appraisal of augmentation rhinoplasty with 3-dimension CT investigation].

OBJECTIVE: To appraise results of augmentation rhinoplasty with combination of CT and clinical examination. METHODS: 10 female patients (average 29 years old) of augmentation rhinoplasty with longer than 3 months, period of recovery were selected. All of them received cranial CT examination and aesthetic evaluation. RESULT: Although 60% of patients were pleased with their augmentation rhinoplasty, 90% of them existed problems in varied extent, if evaluated by CT-investigation and physical examination. CONCLUSION: modification in prosthesis had a direct effect on postoperative aesthetic effects. In order to improve outcomes and to lower complications, individual prosthesis were required.

Adult↗

PubMed2005

[Skeleton reconstruction of oblique facial clefts using mandibular outer table].

OBJECTIVE: This paper presents a new method of skeleton reconstruction for oblique facial clefts using autogenous bone of the mandibular outer table. METHODS: In the operation, the mandibular outer table was harvested through the intraoral approach. Assisted with internal rigid fixation technique, the mandibular outer table was used to reconstruct the naso-orbital framework as inlay or onlay bone graft. RESULTS: From 1993 to 2001, seven cases of oblique facial clefts were repaired with mandibular outer table bone graft. Postoperative follow-up for 6 months to 3 years demonstrated that the grafted bone healed well with the adjacent bones. No obvious bone resorption was observed. The facial appearance was improved greatly. CONCLUSIONS: The mandibular outer table, with similar bone density to the calvarium, is easy to harvest without donor site scar. The method is quite ideal for skeleton reconstruction of oblique facial clefts.

Adolescent↗

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

[Fabrication of 3-dimensional skull model with rapid prototyping technique and its primary application in repairing one case of cranio-maxillo-facial trauma].

OBJECTIVE: To investigate the methods of establishing 3-dimensional skull model using electron beam CT (EBCT) data rapid prototyping technique, and to discuss its application in repairing cranio-maxillo-facial trauma. METHODS: The data were obtained by EBCT continuous volumetric scanning with 1.0 mm slice at thickness. The data were transferred to work-station for 3-dimensional surface reconstruction by computer-aided design software and the images were saved as STL file. The data can be used to control a laser rapid-prototyping device (AFS-320QZ) to construct geometric model. The material for the model construction is a kind of laser-sensitive resin power, which will become a mass when scanned by laser beam. The design and simulation of operation can be done on the model. The image data were transferred to the device slice by slice. Thus a geometric model is constructed according to the image data by repeating this process. Preoperative analysis, surgery simulation and implant of bone defect could be done on this computer-aided manufactured 3D model. One case of cranio-maxillo-facial bone defect resulting from trauma was reconstructed with this method. The EBCT scanning showed that the defect area was 4 cm x 6 cm. The nose was flat and deviated to left. RESULTS: The 3-dimensional skull was reconstructed with EBCT data and rapid prototyping technique. The model can display the structure of 3-dimensional anatomy and their relationship. The prefabricated implant by 3-dimensional model was well-matched with defect. The deformities of flat and deviated nose were corrected. The clinical result was satisfactory after a follow-up of 17 months. CONCLUSION: The 3-dimensional model of skull can replicate the prototype of disease and play an important role in the diagnosis and simulation of operation for repairing cranio-maxillo-facial trauma.

Adult↗

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↗

PubMed2005

[Scanning electron microscopic study of titanium-hydroxyapatite, the functionally graded-material implanted in rabbits].

OBJECTIVE: The purpose of this study was to observe the tissue tolerance of Ti-HA functionally graded-material (FGM) and the form of the material-bone interface. METHODS: The sintered Ti -HA FGM, pure HA and pure Ti were respectively implanted into the parietal bone of rabbits. The specimens were observed by SEM at 2, 4, 8 postoperative weeks. RESULTS: In the early stage, the new bone surrounding the Ti -HA FGM formed earlier with larger amount and better maturity than the pure Ti. The condition was similar to the pure HA. Two months after the operation, direct bonding of material-bone interface was formed between the Ti -HA FGM and the new bone as an integral body. However, there was a little space left between the new bone and the pure Ti. CONCLUSIONS: The Ti -HA FGM has good tissue tolerance. Its early integration with bone is similar to pure HA and better than pure Ti.

Animals↗

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

[Compositive treatment of square face].

OBJECTIVE: To investigate the treatment of square face with compositive methods. METHODS A total of 71 patients with square-shape face were treated. According to the different face skeleton and desire of patient, mandible angle curved-osteotomy and mentoplasty were used as main methods and zygomatoplasty, buccal fat pad resecting and other aesthetic methods as assistant methods to recontour the whole face skeleton. RESULTS: The face skeleton of all patients was improved with satisfaction. The following-up period was 6 months to 2 years. In this patients group, massive haemorrhage was occurred during operation in one patient, mental nerve of of one side was injured in two patients, the lip mucosa was wounded in five patients. CONCLUSION: Mandible angle curve-osteotomy and mentoplasty combined with other assistant aesthetic operations were ideal methods to recontour square face. The result was satisfactory.

Adolescent↗

PubMed2004

[Individual prefabricated titanium implant for the reconstruction of the skull bone defect].

OBJECTIVE: This paper presents a new method of individual prefabricated titanium implant for the reconstruction of the skull bone defect. METHOD: A computer-based 3D model of the cranial bone defect is created from helical CT-data and serves as the basis for the computer aided design and manufacturing (CAD/CAM) of the individual prefabricated titanium implant for the cranial bone defect reconstruction. RESULT: Since 2001, a total of nine patients suffering from the cranial bone defect have been operated on by this method with satisfied result. The fallow-up is 3 to 12 months. CONCLUSION: These individual prefabricated titanium implants have won a high precision, a good biomechanics and a excellent biocompatibility. It is a quite ideal and very simple method with much less complication for the surgical treatment of the cranial bone defect.

Adolescent↗