Retrieval of Green's function and generalized optical theorem for the scattering of complete dyadic fields.

Green's function retrieval has been widely used in different research fields due to the fact that the Green's function can be extracted by cross-correlating the records at two receivers. In this paper, the retrieval of the dyadic Green's function is studied by investigating the representation theorem. The generalized optical theorem for the dyadic fields is derived based on the elastic dynamic interferometric equation. By addressing the cross-correlation recorded at two receivers, the important role of the generalized optical theorem and energy equipartition in retrieving the exact Green's function is shown. The presented derivation also shows the Newton-Marchenko equation holdsif the condition of equipartition is not satisfied.

Simultaneous maxillomandibular distraction osteogenesis in severe progressive hemifacial atrophy with two distractors.

Progressive hemifacial atrophy is a rare disorder characterized by an acquired, idiopathic, self-limited, unilateral facial atrophy involving skin, subcutaneous tissue, fat, muscle, and bone. Symmetry and contour restoration are the main treatment challenges. Among many techniques, microvascular reconstruction has been introduced as the gold standard to correct the atrophic deformity. For some patients with severe manifestations, soft tissue reconstruction alone does not obtain the desired outcome. In this series, we used an effective method to restore the severe progressive hemifacial atrophy by simultaneous maxillomandibular distraction osteogenesis with 2 distractors. The results demonstrate an improvement in both the profile and the occlusion plane of the patients with corresponding satisfactory esthetic and functional outcomes. We conclude that the simultaneous maxillomandibular distraction osteogenesis with 2 distractors is an effective method for hemifacial atrophy and bone frame reconstruction, especially ones involved in the discrepancy of the occlusal plane.

The study of distraction osteogenesis with nitinol shape memory alloy spring controlled by infrared light.

OBJECTIVE: The objective of this study was to investigate the feasibility of distraction osteogenesis with a nitinol shape memory alloy spring controlled by infrared light. STUDY DESIGN: In each of 20 New Zealand white rabbits, a critical-size defect (15 x 10 mm) was made in the body of the mandible, and a 10 x 8-mm segmental osteotomy was performed just anterior to the defect to create a transporting disk. A heat-controlled distractor and a temperature detector were then inserted (experimental group). Nothing was attached to the other side of the mandible (control group). After a 2-day latency period, the distractor was activated by the infrared at a rate of once per day for 9 days. The contralateral side was treated with the same infrared light. Gross, radiographic, and histologic analyses and dual energy x-ray absorptiometry were performed at regular intervals. RESULTS: In the experimental group, the mandibular defect was reconstructed, whereas in the control group it was not. The histologic appearance of regenerated bone was similar to that observed with traditional distraction osteogenesis. CONCLUSION: Distraction osteogenesis using a nitinol spring controlled by infrared light is possible.

[Risk factors of fat necrosis in pectoralis major myocutaneous flaps].

OBJECTIVE: To explore the risk factors of fat necrosis in pectoralis major myocutaneous flaps. METHODS: From May 1998 to December 2005, 82 patients underwent reconstruction of oral and maxillofacial defects with pectoralis major myocutaneous flaps in our hospital. Postoperative fat necrosis of the flaps was occurred in 10 cases. Logistic regression analysis was used to investigate the risk factors. RESULTS: (1) Logistic univariate regression analysis indicated that there was a significant correlation between fat necrosis of pectoralis major myocutaneous flap and the following risk facoars: obesity, subcutaneous tissues dissection performed by electrotome, the design of skin island beyond the seventh costal cartilage and smoking. (2) Logistic multivariate regression analysis suggested that there was a significant correlation between fat necrosis of pectoralis major myocutaneous flap and obesity, subcutaneous tissues dissection performed by electrotome, the design of skin island beyond the seventh costal cartilage, whereas there was no significant correlation between fat necrosis of flap and smoking. CONCLUSIONS: Obesity, subcutaneous tissues dissection performed by electrotome and the design of skin island beyond the seventh costal cartilage were the risk factors of fat necrosis in pectoralis major myocutaneous flap.

[Correction of dento-maxillofacial deformities following cleft lip and palate repair with orthognathic surgery and orthodontics].

OBJECTIVE: To restore good occlusion and face profile, the orthognathic operation and orthodontics were used to correct the dento-maxillofacial deformities following the repair of cleft lip and palate. METHODS: 21 patients (7 males and 14 females, mean age of 20.6 years) were included in this study. Their dento-maxillofacial deformities following the repair of cleft lip and palate have been corrected in our hospital since 1996. Of them, 17 patients received pre- and postoperative orthodontic treatments. 21 cases underwent the following surgical procedures: Le Fort I osteotomy in 7 cases, multisegmental Le Fort I osteotomy in 5 cases, Le Fort I osteotomy and bilateral sagittal split ramus osteotomy (BSSRO) in 4 cases, Le Fort I osteotomy and mandibular body osteotomy in 2 cases, BSSRO and genioplasty in 2 cases, BSSRO in 1 case. Rigid internal fixation was used in all patients. After multisegmental Le Fort I osteotomy, the rigid fixed palatine splint was used for 6 approximately 8 weeks. RESULTS: Osteotomy segments healed well in all cases without severe complications. 14 patients were followed-up for an average of 25.6 months. There was no evident relapse. 12 patients who received pre- and postoperative orthodontic treatments had satisfactory occlusion and face profile. CONCLUSIONS: Orthognathic operation combined with orthodontics can be used satisfactorily to correct the dento-maxillofacial deformities following cleft lip and palate repair.

[Maxilla reconstruction with the free iliac osteomuscular flap and simultaneous osseointegrated implant embeding].

OBJECTIVE: To evaluate the clinical outcome of reconstruction of maxillary defects with vascularized iliac crest flap and simultaneous osseointegrated implant embedding. METHODS: During September to October 2003, two patients with maxillary defects from tumor resection underwent microsurgical reconstruction. The free iliac osteomuscular flap transferring and simultaneous osseointegrated implant embedding were performed to repair the defects. Three months after the reconstructive surgery, an abutment operation was preformed and denture was applied in both cases. RESULTS: The flaps survived well. Postoperative follow-up for 8 to 9 months showed that the patients obtained good zygomaxillary appearance, normal occlusion, and satisfactory pronunciation, without oronasal fistula or other serious complications. CONCLUSIONS: The free iliac crest osteomuscular flap with simultaneous osseointegrated implant embedding is an ideal, effective and cosmetically acceptable method for maxilla reconstruction.

[Expression of p15 and p16 proteins in tongue squamous cell carcinoma and their significances].

BACKGROUND & OBJECTIVE: Abnormal expression of p15 and p16 were commonly found in many kinds of primary tumors, but the possible correlation between p15 and p16 abnormalities and tongue neoplasms is still unknown. This study was designed to investigate the expression of p15 and p16 proteins and their possible correlation with clinicopathology and prognosis of tongue squamous cell carcinoma (TSCC). METHODS: The expression of p15 and p16 were detected by immunohistochemistry (ultra-sensitive SP method) and the results were analyzed quantitatively by imagine cytometry in 45 cases of TSCC and 10 cases of normal tongue tissues, thereafter, the results were analyzed with clinicopathological parameters and survival time. RESULTS: Both p15 and p16 proteins were expressed in squamous epithelia of the normal tongue tissues. The negative expression rates of p15 and p16 protein in TSCC were 46.7%(21/45) and 66.7%(30/45), respectively. 80%(12/15) of the p16 positive cases accompanied with p15 positive staining. However, 85.7%(18/21) of the cases with p15 deletion exhibited p16 negative expression. Most of the cases with both p15 and p16 co-deletion were found in stage III and IV (16/18). The expression rates of p15 and/or p16 in stage I, II were significantly higher than those in stage III, IV (P< 0.05), while p15 and/or p16 expression rates in node-positive groups were much lower than those in node-negative groups (P< 0.01). p15 deletion, or both p15 and p16 co-deletion group, also had a decreased 3-year survival rate (P< 0.05). CONCLUSION: The expression of p15 and p16 protein are closely associated with clinical stages and cervical lymph node metastasis of TSCC. p15 deletion, or both p15 and p16 co-deletion in TSCC can also predict a poor prognosis. p15 and p16 expression can be used as parameters for evaluating clinical stages and metastatic potential as well as prognosis of TSCC.