Mode-independent thermo-optic switch based on the total-internal-reflection effect.

A broadband mode-independent thermo-optic (TO) switch using the total-internal-reflection (TIR) effect is proposed and experimentally demonstrated on a polymer waveguide platform. By optimizing geometric parameters of the TIR switch, a mode-independent TO switching function with a large bandwidth and extinction ratio can be realized for E11, E12, and E21 modes. The measurement results show an extinction ratio larger than 18.1 dB with a driving power of 160 mW for each mode over the wavelength range of 1500-1620 nm. The designed structure can also be cascaded to form a 1 × N switch network for mode-division multiplexing (MDM) systems, which greatly improves the network flexibility.

Endoscopy-Assisted Transoral Versus Endoscopy-Assisted Transcervical Minimal Incision Plus Mandibular Osteotomy Approach in Resection of Large Parapharyngeal Space Tumors.

BACKGROUND: Resection of the parapharyngeal space is often challenging. This study aims to evaluate the outcome of the endoscopy-assisted transoral approach for resection of the parapharyngeal space tumors compared with the endoscopy-assisted transcervical approach. METHODS: Twenty-three consecutive patients (15 males, 8 females) who underwent resection of large parapharyngeal space tumors via endoscopy-assisted transoral (ETO) approach or endoscopy-assisted transcervical minimal incision plus osteotomy of the vertical ramus outside the mandibular foramen (ETC + MO) approach were analyzed retrospectively. RESULTS: The tumors in ETO group are benign; there are 2 patients with adenoid cystic carcinoma and 1 patient with recurrent pleomorphic adenoma in ETC + MO group. All of the tumors were removed completely and without rupture. No major complications developed in any patient. Temporary facial paresis occurred in 1 patient in the ETC + MO group, which resolved spontaneously within 8 weeks. The cosmetic effects of all patients in ETO groups and 10 patients in ETC + MO groups were excellent. Patients were followed up for 7 to 26 months, no recurrence was encountered. CONCLUSION: ETO and ETC + MO approach in resection of large parapharyngeal space tumors are feasible and safe technique that achieve excellent aesthetic and functional results. Endoscopy-assisted transoral approach can shorten hospitalized time and avoid the risk of marginal mandibular nerve injury and ETC + MO approach may be used in malignant or recurrent parapharyngeal space tumors.

Role of Negative-Pressure Wound Therapy in the Management of Submandibular Fistula After Reconstruction for Osteoradionecrosis.

PURPOSE: Although negative-pressure wound therapy (NPWT) for complicated wounds has been extensively studied, it is rarely used in cases involving a submandibular fistula due to radiation-induced osteoradionecrosis of the mandible. This study aimed to investigate the efficacy of NPWT for submandibular fistulas after reconstruction for osteoradionecrosis. PATIENTS AND METHODS: Nine patients with submandibular fistulas after reconstruction for osteoradionecrosis treated with NPWT between 2011 and 2014 were included in the study. The wound healing was documented. RESULTS: The NPWT device was removed postoperatively between days 7 and 12 (mean duration, 9.6 days). The wound bed was filled with healthy granulation tissue, and successful healing by second intention was observed in all patients within 2 weeks. No complications were observed. The follow-up ranged from 4 to 27 months (mean, 18 months); the fistulas exhibited excellent healing, and no recurrence or infection was observed. CONCLUSIONS: NPWT is a safe, effective technique for managing submandibular fistulas after reconstruction for osteoradionecrosis.

Novel Local Full-Thickness Skin Grafts for Closure of Free Fibular Osteocutaneous Flap Donor Sites.

PURPOSE: The fibular flap donor site after skin paddle harvest is usually covered with abdominal full-thickness skin grafts. However, this kind of skin graft creates an inevitable third operative area and additional esthetic damage. The aim of this report was to present a novel approach to manage fibular donor site defects using a full-thickness skin graft from the adjacent area and avoid further esthetic damage in a third area. MATERIALS AND METHODS: Seventeen patients underwent mandibular and maxillary defect reconstruction using free fibular osteocutaneous flaps and the fibular donor-site defects were covered with full-thickness skin grafts from the adjacent area. The skin harvesting sites were closed primarily. RESULTS: The skin donor sites were closed without dehiscence in all cases. Fifteen full-thickness skin grafts survived completely, whereas 2 grafts were partial failures. There were no complete skin graft losses. All fibular osteocutaneous flaps were viable, and the recipient sites had no complications. CONCLUSIONS: This study shows that adjacent full-thickness skin grafts provide a straightforward and reliable technique for closure of the free fibular osteocutaneous flap donor site. The primary advantage of this technique is the avoidance of a third surgical site, an additional surgical scar, and subsequent additional esthetic impairment.

Minimally invasive selective neck dissection: a prospective study of endoscopically assisted dissection via a small submandibular approach in cT(1-2_N(0) oral squamous cell carcinoma.

BACKGROUND: Selective neck dissection (SND) in clinical N0 (cN0) cases of oral squamous cell carcinoma (SCC) has been performed by surgeons using a retroauricular or modified facelift approach with robotic or endoscopic assistance. However, these procedures provide cosmetic satisfaction at the cost of possible maximal invasiveness. In this prospective study, we introduced and evaluated the feasibility as well as surgical invasiveness and cosmetic outcome of endoscopically-assisted SND via a small submandibular approach. METHODS: Forty-four patients with cT1-2N0 oral SCC (OSCC) were randomly divided into two groups of endoscopically-assisted SND and conventional SND. Perioperative and postoperative outcomes of patients were evaluated, including the length of the incision, operating time for neck dissection, estimated blood loss during the operation, amount and duration of drainage, total hospitalization period, total number of lymph nodes retrieved, satisfaction scores based on the cosmetic results, perioperative local complications, shoulder syndrome, and follow-up information. RESULTS: The mean operation time in the endoscopically-assisted group (126.04 ± 12.67 min) was longer than that in the conventional group (75.67 ± 16.67 min). However, the mean length of the incision was 4.33 ± 0.76 cm in the endoscopically-assisted SND group, and the amount and duration of drainage, total hospital stay, postoperative shoulder pain score, and cosmetic outcomes were superior in the endoscopically-assisted SND group. Additionally, the retrieved lymph nodes and complications were comparable. CONCLUSIONS: Endoscopically-assisted SND via a small submandibular approach had a longer operation time than the conventional approach. However, endoscopically-assisted SND was feasible and reliable while providing minimal invasiveness and satisfactory appearance.

Use of extended vertical lower trapezius island myocutaneous flaps to cover exposed reconstructive plates.

PURPOSE: Plate exposure is the most common complication after reconstruction of oncologic resection using a titanium plate. The outcomes of covering exposed reconstructive plates with extended vertical lower trapezius island myocutaneous flaps (TIMFs) were evaluated. PATIENTS AND METHODS: Twelve instances of exposure of reconstructive plates occurred in patients after segmental mandibulectomy to treat cancer of the oral cavity and oropharynx. The plates were covered with extended vertical lower TIMFs. The site of the primary tumor was the gingiva or mandible in 5 cases, the buccal mucosa in 3, the floor of the mouth in 2, and the base of the tongue in 2. The types of bone defect were hemimandibular in 1 case, central in 2, and lateral in 9. Intraoral, extraoral, and intra- and extraoral exposures occurred in 1, 7, and 4 instances, respectively. Intraorally and extraorally exposed plates were re-covered with skin paddles measuring 6 × 7 to 6 × 23 cm (average, 6.0 × 13.5 cm). Four folded extended vertical lower TIMFs were constructed to cover plates exhibiting intra- and extraoral exposure. RESULTS: All flaps survived. Patients were followed for 12 to 36 months (median duration, 22.8 months). One patient (8.3%) exhibited external plate exposure at 20 months. Nine patients (75.0%) were alive with no evidence of disease at 12 to 36 months, and 2 (16.7%) were alive with disease at 20 to 28 months. One patient (8.3%) died of local recurrence at 23 months. CONCLUSIONS: The use of extended vertical lower TIMFs to cover intraorally, extraorally, or intra- and extraorally exposed plates is reliable.

Extracapsular dissection of pleomorphic adenoma of the parotid gland through minimal preauricular and retroauricular incisions in children.

We evaluate treatment outcomes in children with benign parotid neoplasms who underwent extracapsular dissection of the tumor using minimal incisions. Nine pediatric patients (4 boys and 5 girls) with pleomorphic adenoma of the parotid gland were treated with extracapsular dissection via preauricular and retroauricular incisions. The mean age of the patients at the time of surgery was 9.4 years. The size of the tumors ranged from 1.5 × 1.4 to 3.5 × 3.0 cm. Seven tumors were located in the superficial lobe of the parotid gland and 2 were located in the deep lobe. All histologically confirmed cases of malignancy were excluded. All 9 operations were performed successfully. No patient exhibited any permanent postoperative complication. Neither hematomas of the parotid region nor salivary fistula occurred. One patient had slight transient postoperative facial paresis. The scars were almost invisible. All patients had excellent cosmetics and complete function of the facial nerve. The patients were followed up for 5.1 to 7.0 years. Tumor recurrence developed in 1 patient who subsequently underwent curative parotidectomy. Extracapsular dissection through preauricular and retroauricular incisions is a feasible technique, providing excellent cosmetic outcome in the treatment of benign parotid neoplasms in children.

Maxillary functional reconstruction using a reverse facial artery-submental artery mandibular osteomuscular flap with dental implants.

PURPOSE: This clinical study assessed the reverse facial artery-submental artery mandibular osteomuscular flap with titanium dental implants for the functional reconstruction of maxillary defects. PATIENTS AND METHODS: Class 2a defects in 5 patients were repaired with a reverse facial artery-submental artery mandibular osteomuscular flap with titanium dental implants (n = 21). All patients received a fixed partial denture after a 3- to 6-month healing period. RESULTS: All lesions were widely excised in an area extending to the maxilla. Of the implants, 20 (95.2%) were loaded and 1 was lost before loading. Reconstruction with a fixed partial denture was successful in all patients. The patients were followed up for 12 to 20 months (mean, 15.8 months), and no recurrence was observed. CONCLUSION: The reverse facial artery-submental artery mandibular osteomuscular flap with titanium dental implants is safe, quick, and simple to elevate and is reliable for the functional reconstruction of maxillary defects.

Optical Waveguide Sensors for Measuring Human Temperature and Humidity with Gel Polymer Electrolytes.

In this work, multimodal responsive optical waveguide sensors using a stable cross-linking gel polymer electrolyte are successfully designed and fabricated by bottom metal-printing technology. Temperature and humidity sensing characterization based on the polymer electrolyte is simulated and analyzed. The multimodal responsive properties of the photonic chip are defined based on the analysis of ion relaxation dynamics: optical phase variable to monitor temperature and optical attenuation variable to detect humidity. In the supervising temperature (36.0-38.0 °C) and relative humidity (45-65%) range, the temperature and humidity sensitivities of the device are measured as 0.5π rad/°C and 1.14 dB/% RH, respectively. The fast-response time for both temperature and humidity of the multifunctional sensor can be obtained as 4.21 ms and 1.32 s, respectively. These findings provide a feasible scheme for the design and application of temperature and humidity sensors in potential medical treatment. From gel polymer electrolytes to multimode monitoring applications, the application exploration of high stability and ultrafast response multimode waveguide sensors is gradually being carried out. This study has great significance for the comprehensive monitoring of sophisticated human physical signs by multimodal responsive waveguide sensors.

Polymer Optical Waveguide Grating-Based Biosensor to Detect Effective Drug Concentrations of Ginkgolide A for Inhibition of PMVEC Apoptosis.

In this work, we successfully developed a fluorinated cross-linked polymer Bragg waveguide grating-based optical biosensor to detect effective drug concentrations of ginkgolide A for the inhibition of pulmonary microvascular endothelial cell (PMVEC) apoptosis. Fluorinated photosensitive polymer SU-8 (FSU-8) as the sensing core layer and polymethyl methacrylate (PMMA) as the sensing window cladding were synthesized. The effective drug concentration range (5-10 µg/mL) of ginkgolide A for inhibition of PMVEC apoptosis was analyzed and obtained by pharmacological studies. The structure of the device was optimized to be designed and fabricated by direct UV writing technology. The properties of the biosensor were simulated with various refractive indices of different drug concentrations. The actual sensitivity of the biosensor was measured as 1606.2 nm/RIU. The resolution and detection limit were characterized as 0.05 nm and 3 × 10-5 RIU, respectively. The technique is suitable for safe and accurate detection of effective organic drug dosages of Chinese herbal ingredients.

Extended supraclavicular fasciocutaneous island flap based on the transverse cervical artery for head and neck reconstruction after cancer ablation.

PURPOSE: This clinical study assessed a pedicled supraclavicular fasciocutaneous island flap (SFIF) based on the transverse cervical artery that was extended to include shoulder skin for reconstructing the head and neck. PATIENTS AND METHODS: Pedicled SFIFs extended to include the shoulder skin based on the cutaneous feeder vessels and perforator vessels in the deep fascia of the transverse cervical artery were designed for 24 patients with defects of the head and neck after cancer ablation. Preoperative 3-dimensional computed tomographic angiography was performed in all patients. The patients consisted of 15 men and 9 women ranging in age from 24 to 73 years. RESULTS: The primary lesions included squamous cell carcinoma of the tongue, buccal mucosa, floor of the mouth, oropharynx, palate, and lower gingiva. Three-dimensional computed tomographic angiography showed that the transverse cervical artery arose from the thyrocervical trunk in 13 cases and from the subclavian artery in 11 cases. The diameter of the artery ranged from 0.15 to 0.24 cm. The size of flaps ranged from 4 × 8 cm to 6 × 12 cm, and the mean length of the vascular pedicle was approximately 18.5 cm. Of the flaps, 23 survived completely, for a success rate of 95.8%. Three patients underwent radiotherapy, and the follow-up period ranged from 3 to 12 months. One patient died of local tumor recurrence, and cervical recurrences developed in 3 patients. CONCLUSION: An SFIF extended to include the shoulder skin based on the cutaneous feeder vessels and perforator vessels in the deep fascia of the transverse cervical artery is a useful, viable option for defects of the head and neck after cancer ablation.

Reverse facial-submental artery island flap for the reconstruction of maxillary defects after cancer ablation.

This study assessed the reliability of the reverse facial-submental artery island flap for reconstructing maxillary defects. Twelve patients with cancer underwent surgical resection and sequential maxillary reconstruction using a reverse facial-submental artery island flap. There were 9 men and 3 women. The patients ranged in age from 42 to 73 years. Palate squamous cell carcinoma was present in 7 cases; and maxillary gingival squamous cell carcinoma, in 5 cases. The remaining defects were classified as class 1 in one case, class 2a in 8 cases, and class 3b in 3 cases. The sizes of the skin paddle varied from a minimum of 4 x 12 cm to a maximum of 5 x 12 cm. No flaps failed. There were no donor-site problems. The patients were followed up for 16 to 30 months; one case of tumor local recurrence was observed. The reverse facial-submental artery island flap is safe, quick, and simple to elevate. The flap can be used reliably for reconstructing maxillary defects.

Pediatric mandibular reconstruction after benign tumor ablation using a vascularized fibular flap.

This study evaluated the aesthetic and functional outcomes of vascularized fibular flaps used for pediatric mandibular reconstruction. Six pediatric patients ranging in age from 12 to 15 years underwent mandibular reconstruction using a vascularized fibula flap with a skin paddle, after benign tumor ablation. All of the flap transfers were successful, and there were no complications. Panorex radiographs showed good bone union in all patients. The flap conferred adequate support for dental rehabilitation. The mean follow-up was 24.2 months. The aesthetic and functional outcomes were normal. No patient had recurrence. A vascularized fibular flap is a very reliable method for reconstructing the pediatric mandible after benign tumor ablation.

Computer-assisted resection and reconstruction of bilateral osteoradionecrosis of the mandible using 2 separate flaps prepared from a single fibula.

OBJECTIVES: Osteoradionecrosis of the mandible is a late radiation-induced complication, which is a major concern in survivors of head and neck cancer. STUDY DESIGN: In this study, we present a case of a patient with nasopharyngeal carcinoma who developed extensive bilateral osteoradionecrosis of the ascending ramus of the mandible. After preoperative virtual surgical planning, the obtained data were used to fabricate patient-specific cutting templates. The bilateral mandibular defects were reconstructed using 2 separate flaps prepared from a single fibula. RESULTS: Both defects were successfully reconstructed, and satisfactory aesthetic and functional results were achieved. CONCLUSIONS: Bilateral mandibular osteoradionecrosis can be managed with virtual surgical planning, and the defects can be reconstructed using 2 separate flaps prepared from a single fibula.

Treatment of the recanalization of maxillary and mandibular arteriovenous malformations in children.

OBJECTIVE: This study reviewed our experience in treating the recanalization of maxillary and mandibular arteriovenous malformations in children. STUDY DESIGN: Four patients with maxillary or mandibular arteriovenous malformations (AVMs) were included in this study. All the patients had undergone multidisciplinary treatment of AVM at least 26 months before our review, including superselective intra-arterial embolization combined with bone wax packing. Computed tomographic angiography and digital subtraction angiography were performed to confirm the presence of recanalization. Superselective intra-arterial embolization combined with bone wax packing and tooth extractions were performed in the patients with recanalization. RESULTS: After confirmation of the recanalization of AVM by digital subtraction angiography, the patients were treated with superselective intra-arterial embolization combined with bone wax packing and tooth extractions (if necessary). All the patients were followed up for 5 to 14 months, with an average of 9.5 months. The outcome for all patients was good, and no patient complained of pulsatile sensation or hemorrhage after treatment. CONCLUSIONS: In the treatment for recanalization of maxillary and mandibular AVMs, reapplication of the superselective intra-arterial embolization, combined with bone wax packing, remains necessary.

Endoscopically-assisted operations in the treatment of odontogenic peripheral osteomyelitis of the posterior mandible.

The aim of this study was to evaluate the possibility of using an endoscope in the treatment of five patients with odontogenic peripheral osteomyelitis of the posterior mandible diagnosed between March 2012 and September 2014. After imaging and general preoperative examination, the patients had endoscopically-assisted curettage and sequestrectomy. The data collected included the duration of the operation, complications, and patients' degree of satisfaction. The mean duration of the operation through an intraoral incision, was 46 (range 40-60) minutes. Patients were followed up at 1 week, 3 months, and 6 months, with no signs of recurrence. One patient reported postoperative swelling in the mandibular angle but this settled. The incision was minimal and left no postoperative scar on the face. All the patients recovered free of complications and were satisfied with the results of the operation. Because of the minimally-invasive intraoral incision, endoscopically-assisted treatment of odontogenic peripheral osteomyelitis of the posterior mandible can maintain external facial integrity without surgical scars.

Reconstruction of full-thickness cheek defects with a folded extended supraclavicular fasciocutaneous island flap following ablation of advanced oral cancer.

PURPOSE: The aim of the present clinical study was to evaluate the feasibility of a folded extended supraclavicular fasciocutaneous island flap (SFIF) for full-thickness cheek defect reconstruction following ablative oral cancer surgery. PATIENTS AND METHODS: The nine patients with advanced squamous cell carcinoma of the buccal mucosa were six men and three women, with a mean age of 60.8 years. All patients were treated with surgery including ipsilateral radical neck dissection. A folded extended SFIF with a skin paddle ranging between 6 × (6 + 5) cm and 7 × (10 + 9) cm were used to reconstruct the full-thickness cheek defects. RESULTS: One minor flap failure and one wound dehiscence in donor site occurred, but all flaps survived, and there was no major complication in any patient. All patients were able to receive all of their nutrition orally and had normal speech. The patients were followed-up for 9-28 months; six patients were living with no evidence of disease, two was living with disease, and one died of local recurrence. CONCLUSION: The folded extended SFIF to reconstruct full-thickness cheek defects is reliable and an excellent alternative to other options for patients who have full-thickness defect of the cheek.

Intraoral lining with the fibular osteomyofascial flap without a skin paddle during maxillary and mandibular reconstruction.

BACKGROUND: To achieve an ideal intraoral lining, we harvest the fibular osteomyofascial flap to avoid the common embarrassment caused by the fibular osteomyocutaneous flap, and we report on our experience with this technique in this article. METHODS: Twenty-eight patients underwent reconstruction of the maxilla and mandible using an osteomyofascial free fibula flap after oncologic ablation. Data, including the size of the fascial flaps, the number of debulking operations, the complications at both the donor and recipient sites, and the dental rehabilitation, were collected. RESULTS: All fascial flaps survived and were remucosalized, except one with partial necrosis. None of the patients in the osteomyofascial group required an additional debulking operation, and 82% of the patients (23 of 28) had conventional dentures and showed good chewing function and cosmetic results. CONCLUSION: The fibular osteomyofascial flap yielded a more anatomic solution for oral mucosal defects, obviating the need for additional debulking and potentially reducing donor-site wound problems. © 2015 Wiley Periodicals, Inc. Head Neck 38: E832-E836, 2016.

Synchronous reconstruction of bilateral osteoradionecrosis of the mandible using a single fibular osteocutaneous flap in patients with nasopharyngeal carcinoma.

BACKGROUND: The reconstruction of bilateral osteoradionecrosis (ORN) of mandibular defects using a single free bone flap is rarely performed because extensively radiated neck tissue with severe fibrosis is usually unsuitable for vascularized reconstruction. METHODS: Thirty-one patients with nasopharyngeal carcinoma (NPC) underwent bilateral reconstruction of advanced ORN in the mandible using a single fibular osteocutaneous flap. Clinical factors associated with the operation were assessed, including classification of mandible defects, types of recipient vessels, perioperative complications, and postoperative outcomes. RESULTS: All of the fibular osteocutaneous flaps survived completely, with the exception of 1 inner skin paddle that presented partial necrosis in a reconstruction of through-and-through defects. All patients experienced an improvement in cosmetic results 6 months after the reconstruction, whereas 23 patients experienced improved mouth opening compared to the preoperative condition. CONCLUSION: Advanced bilateral ORN in patients with NPC could be synchronously reconstructed with a single fibular osteocutaneous flap. © 2015 Wiley Periodicals, Inc. Head Neck 38: E-E, 2016.

Endoscopy-assisted transoral resection of large benign parapharyngeal space tumors.

We have evaluated the outcomes of endoscopically-assisted resection of large benign tumours of the parapharyngeal space by an intraoral approach. Six patients with primary benign tumours were treated in this way. The lesions were pleomorphic adenomas, Warthin's tumour, and schwannoma. The sizes of the tumours varied from 4×4 cm to 7×7 cm. All tumours were removed completely without rupture and without damage to the facial nerve. No patient developed any permanent postoperative complications such as damage to the facial nerve, salivary fistula, or limited mouth opening. The cosmetic effects were excellent. The patients were followed up for 8 to 21 months without recurrence. Endoscopically-assisted transoral resection of large benign tumours of the parapharyngeal space is a simple and safe technique that achieves excellent aesthetic and functional results.