Development of a compact coaxial cusped periodic permanent magnet focusing system.

To achieve the application of a periodic permanent magnet in high power microwave, a compact coaxial cusped periodic permanent magnet (CPPM) focusing system is constructed. The system consists of permanent magnets with different magnetization directions and soft magnets. Taking the required magnetic field performance and the effect of demagnetization into account, NdFeB and FeCoV are selected as the permanent and soft magnet materials. After the system is constructed, the magnetic field is measured. The results show that the guiding magnetic field strength and period of the CPPM are about 0.29 T and 26 mm, respectively, and the magnetic field distribution of measurement shows good agreement with the simulation results. However, there are some differences between the measurement and simulation results, and the differences are compared and analyzed here.

Removal of benign tumor in the lower pole of the parotid gland through concealed incision in the retroauricular sulcus / 口腔疾病防治

Objective @#To assess the safety and feasibility of incision in the retroauricular sulcus for removal of benign tumors in the lower pole of the parotid gland and to provide some ideas for aesthetic consideration of parotidectomy.@*Methods@# In total, 18 cases with benign tumors of the lower pole regions of the parotid gland were included in this study, including 9 pleomorphic adenomas, 2 myoepitheliomas, 5 Warthin tumors, 1 basal cell adenoma and 1 oncocytoma. Three months after the operation, facial paralysis and salivary fistula were assessed. A visual analog scale was used to score the cosmetic satisfaction of the surgical incision. Tumor recurrence was followed up 6 ~ 12 months after operation.@*Results@# In 18 patients with benign tumors the lower pole regions of the parotid gland, the tumor diameter ranges from 1.0 to 3.1 cm, with an average value of 2.5 cm. All patients experienced successful complete removal of the parotid mass with the minimally invasive retroauricular approach, and all wounds healed in one stage after operation. No serious complications, such as permanent facial paralysis and tumor recurrence, occurred 3 months after the operation. The patients were satisfied with the appearance of the surgical incision (aesthetic score 9.3 ± 0.4), achieving the expected aesthetic effect. @*Conclusion@#This approach is feasible and safe for most small benign parotid tumors located in the lower pole region of the parotid gland and in the posterior region of the jaw. The scar is located in the retroauricular sulcus, which significantly meets the aesthetic needs of the concealed incision for patients.

[Carcinoma ex pleomorphic adenoma occurring in the sublingual gland: a case report].

Carcinoma ex pleomorphic adenoma occurring in the sublingual gland is extremely rare. In this report, a case of adenoid cystic carcinoma ex pleomorphic adenoma of the sublingual gland was presented.

[Ectopic recurrence of ameloblastoma in the bucca region of the mandible: a case report].

The postoperative recurrence of ameloblastoma is common. However, ectopic recurrence in clinical operations is rare. A case of ectopic recurrence of ameloblastoma in the bucca region of the mandible after 15 years is presented in this paper. The causes of the ectopic recurrence were analyzed based on relevant literature.

[Platysma myocutaneous flaps in reconstruction of oral defect caused by tumor resection].

OBJECTIVE: To study the method and feasibility of platysma myocutaneous flap in reconstruction of oral defects. METHODS: From March 2003 to June 2004, 15 patients with defects of tongue, floor of mouth, bucca, lateral pharynx and soft palate were treated with platysma myocutaneous flaps. There were 12 males and 3 females with an age range of 41-77 years. Defect was caused by resection of bucca (11 cases), tongue (1 case), floor of mouth (2 cases)and lateral pharyngeal and soft palate (1 case) squamous cell carcinoma. All patients were given primary cancer dissection and radical neck dissection. The defect sizes were from 3.0 cmX 3.5 cm to 7.0 cm X 4.0 cm. The sizes of the platysma myocutaneous flap were from 7.0 cm x 3.5 cm to 12.0 cm x 4.0 cm. RESULTS: All the patients were followed up for 6-12 months. In 15 patients, the flap survived, and the color and appearance of the flaps were normal. Mouth-opening was not limited. Eight patients had cutaneous fistula after 10-15 days of operation and were cured by secondary operation. No complication of ankyloglossia and tumor relapse occurred. The operation results were satisfactory. CONCLUSION: Platysma myocutaneous flap has generous blood supply, it is useful in reconstruction of oral tissue defects.