Management of the condyle following the resection of tumours of the mandible.

The aim of this study was to assess the management of the condyle during the restoration of mandibular defects following tumour resection. A total of 41 patients who underwent simultaneous tumour resection and reconstruction with vascularized iliac myocutaneous flaps for mandibular defects, from September 2010 to October 2014, were included. These patients were divided into three groups: group 1, condyle preserved; group 2, condyle sacrificed; group 3, condyle frozen. Patients were followed up at 1, 3, 6, and 12 months for the evaluation of appearance, occlusion, and speech. The TMJ disability index (DI) and craniomandibular index (CMI) differed significantly according to the method of management, as well as the position and morphology of the reconstructed condyle (P<0.01); however, no statistically significant difference in mandible movement was observed between the groups. The DI and CMI values were significantly lower in group 1 patients compared to group 2 and group 3 patients. The results showed that TMJ function in group 1 patients was superior to that in group 2 and group 3 patients, and that function in group 3 patients was better than that in group 2 patients. In conclusion, the condyle should be preserved when benign mandibular lesions are situated near the condyle, as preservation has a positive effect on TMJ function and mandible movement.

Use of couplers for vascular anastomoses in 601 free flaps for reconstruction of defects of the head and neck: technique and two-year retrospective clinical study.

We describe our experience with the use of 854 couplers for venous or arterial anastomoses, or both, in 601 free flaps for reconstruction of defects of the head and neck. We reviewed 601 patients who had had free flaps (with the microvascular anastomoses being made with couplers in 519) between July 2013 and December 2015. Personal details, and clinical data including the site of the defect, the tumour excised, the types of flaps, the size of the couplers, the method of anastomosis (venous or arterial) in which the coupler was used, and postoperative complications were recorded. There were 417 men (69%) and 184 women (31%), mean (range) age 53 (13-91) years. Four types of flaps were used: anterolateral thigh flap (n=232), radial forearm flap (n=223), fibula free flap (n=78), and iliac crest flap (n=68). The sizes of couplers ranged from 1-4mm, most being 2mm (n=158), followed by 1.5mm (n=122). The recipient vessels used included a single vein (n=348), two veins (n=406), and both vein and artery (n=100). The overall success rate was 99%, and eight patients required resuture, which was successful in each case. This retrospective study shows that a coupler is easy to use, and is a reliable and time-saving technique for microvascular anastomosis. However, the disadvantage is the cost of the instrument, which in less developed countries will limit its use.

Reconstruction of the tongue and mouth floor with the myofascial vastus lateralis free flap after cancer ablation.

The current study was undertaken to evaluate a novel approach to tongue and mouth floor reconstruction using the myofascial vastus lateralis free flap (MVLF). The surgical techniques, benefits, complication rate, and the aesthetic and functional results are described. A series of six patients underwent functional tongue reconstruction between July 2013 and November 2014. The myofascial vastus lateralis flap was obtained as follows: the vastus lateralis muscle was exposed, the neurovascular pedicle was identified, and the myofascial flap was raised. Postoperatively, the neotongue appeared plump and was able to maintain palatal contact. Moreover, no obvious decrease in flap volume was observed during the follow-up period. Most patients experienced good tongue mobility. Further use of the MVLF should confirm whether the mucous membrane on the surface of the flap becomes part of the tongue mucosa in the true sense, whether and how well the patients will recover their sense of taste, and the degree to which quality of life is improved after nerve anastomosis. So far, it appears to be a suitable approach to tongue and mouth floor reconstruction.

Individual design of the anterolateral thigh flap for functional reconstruction after hemiglossectomy: experience with 238 patients.

The aim of this study was to evaluate tongue function in patients with oral cancer treated surgically and reconstructed with anterolateral thigh free flaps (ALTFs). Patients (N=238) underwent primary reconstruction after hemiglossectomy between September 2012 and October 2014. Patients were divided into two groups according to the flap design: 'individual design' (ABC flap) and 'common design'. Patients were followed postoperatively and assessed after 6 months for the following functional outcomes: speech, deglutition, tongue mobility, and donor site morbidity. Intelligibility and deglutition were each scored by an independent investigator. Data were analyzed using SPSS version 16.0 software. No differences in mean speech intelligibility scores were observed between the two groups (good: P=0.908; acceptable: P=0.881). However, the ABC flap offered recovery advantages for swallowing capacity compared to the common design flap (MTF classification good: P=0.028; acceptable: P=0.001). The individualized ABC flap not only provides volume but also preserves mobility, speech intelligibility, and swallowing capacity. ALTFs require further improvement for the individualized functional reconstruction of the tongue after hemiglossectomy, but this work lays the foundation for these improvements.

Clinical experience with 80 microvascular couplers in 64 free osteomyocutaneous flap transfers for mandibular reconstruction.

Microvascular couplers have been introduced as an alternative method for anastomosis in mandibular reconstruction. This study included 64 patients who had undergone free flap reconstruction for mandibular defects and had been scheduled for follow-up at 1, 3, 6, and 12 months. After completion of the tumour resection and harvesting of the osteomyocutaneous flap, appropriate preparation of both ends of the vessels was performed for microsurgery. Single-vein anastomoses were performed in 35 patients and double-vein anastomoses in 29 patients. Except for 75 couplers used for venous anastomosis only, both arterial and venous anastomoses were performed using the coupler in seven flaps. No flap failures occurred in these cases, resulting in an overall flap success rate of 100%. As expected, anastomoses were completed successfully using the coupler in 78 out of 80 attempted cases (97.5%). Additional large and randomized studies are needed to compare the outcomes of coupler anastomoses to those of traditional sutured anastomoses, and to define to what extent this would present cost-savings per procedure.

A 10-year retrospective study of free anterolateral thigh flap application in 872 head and neck tumour cases.

The aim of this study was to report the clinical features, reliability, and various applications of free anterolateral thigh (ALT) flaps and to provide a 10-year retrospective review of the application of this flap in head and neck tumour patients. A retrospective study was performed of 872 patients who underwent immediate reconstruction of head and neck tumour-induced defects with ALT flaps between April 2005 and April 2014. The study sample consisted of 609 males and 263 females aged 18-79 years. The shapes and sizes of the flaps were designed individually to meet various demands of reconstruction in the head and neck region. The overall rate of successful reconstruction was 97.4%. The reasons for 57 cases of flap compromise were analyzed. The time to detection of flap crisis was often within the first 8h after surgery (64.9%). One- and two-vein anastomosis strategies in microsurgery were compared, and significant differences were observed in terms of the time to detection of flap compromise and the rate of successful flap salvage. In conclusion, the free ALT flap provides unique features for the reconstruction of oral and facial defects in a reliable and versatile approach. The ALT flap is a favourable and versatile 'workhorse' flap for head and neck reconstruction.

In vitro effects of nitric oxide synthase inhibitor L-NAME on oral squamous cell carcinoma: a preliminary study.

It has been reported that increased nitric oxide synthase (NOS) expression and nitric oxide (NO) production may play an important role in cancer biology. The aim of this study was to determine the roles of NO in tumour cellular proliferation and DNA or RNA synthesis, and to investigate the therapeutic potential of NOS inhibitors in oral cancer. After exposure to different concentrations of the NOS inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME), the growth of TSCCa cells, established from a patient with squamous cell carcinoma of the tongue, was evaluated using MTT and crystal violet assay. DNA or RNA synthesis, inducible/endothelial NOS (iNOS/eNOS) mRNA expression and NO production were then examined to determine the possible mechanisms of inhibitory effects of L-NAME on TSCCa cells. L-NAME had an inhibitory effect on TSCCa cell growth in both a concentration- and time-dependent manner. Acridine orange staining revealed that DNA and/or RNA synthesis of TSCCa cells was reduced after treatment with L-NAME. An in situ hybridisation (ISH) study showed clearly that L-NAME down-regulated eNOS and iNOS mRNA expression and this was followed by a decrease in NO production. It is postulated that the NOS/NO pathway may be implicated in cellular proliferation and DNA or RNA synthesis of cancer cells, apart from promoting tumour angiogenesis. Further studies have provided with new insight into the mechanisms by which NOS/NO takes part in oral carcinogenesis, and possible therapeutic interventions based on the NOS/NO pathway for tumour progression control.

VEGF is up-regulated by hypoxic stimulation and related to tumour angiogenesis and severity of disease in oral squamous cell carcinoma: in vitro and in vivo studies.

The present study was aimed to speculate whether the up-regulation of VEGF in oral squamous cell carcinoma (OSCC) is associated with oxygen levels, tumor angiogenesis and severity of disease. Under different oxygen levels, VEGF protein production in two oral cancer cell lines was quantitatively documented by using ELISA kit. Correlations between expression of VEGF, microvessel density, and various clinico-pathologic factors were studied in forty patients with OSCC. VEGF production was continuously elevated in supernatants from both cell lines in respond to the drop of oxygen levels. When oxygen level decreased to 1%, there was a 2.1-fold and nearly a 2.9-fold elevation of VEGF production in TSCCa and GNM cell line, respectively. On hypoxia VEGF production also presented a time-dependent up-regulation in both oral cancer cell lines. VEGF positivity was correlated with regional lymph nodal involvement and clinical stage. Microvessel density was significantly higher in VEGF-positive tumors than in VEGF-negative tumors. The presence of hypoxia in oral cancers is partly responsible for the up-regulation of VEGF. The elevation of VEGF expression in OSCC tissues correlates with the increased microvessel density and severity of the disease.

Potential role of disc repositioning in preventing postsurgical recurrence of traumatogenic temporomandibular joint ankylosis: a retrospective review of 17 consecutive cases.

The potential role of disc repositioning in preventing postsurgical recurrence of traumatogenic temporomandibular joint (TMJ) ankylosis was investigated. Seventeen cases of traumatogenic TMJ ankylosis underwent disc repositioning during arthroplasty. During surgery, the dislocated disc was carefully dissected outside the ankylotic TMJ and repositioned over the top of the condylar stump, and then sutured to the soft tissue of the zygomatic root. In the 22 ankylotic TMJs of the 17 patients, dislocated discs were found in front of the ankylotic TMJ, behind the ankylotic TMJ or between the ramus and fossa. At the last follow-up (longer than 1 year) examination, interincisal opening distances ranged from 24 to 43 mm (mean 32.86 mm). No recurrence and TMJ symptoms were found during the period of follow-up. Disc repositioning in the treatment of traumatogenic TMJ ankylosis proves to be a feasible and effective method of preventing recurrence of this condition.

Circulating levels of vascular endothelial growth factor in patients with oral squamous cell carcinoma.

Angiogenesis is a crucial step in tumour growth, progression, and metastasis. Recently, many angiogenic factors have been identified. Vascular endothelial growth factor (VEGF) is thought to be one such angiogenic factor and is also thought to be a selective mitogen for vascular endothelial cells. The present study was designed to determine the circulating levels of VEGF in human oral squamous cell carcinoma (OSCC) and to investigate its correlation with the clinicopathologic features and prognosis. The study consisted of 10 healthy volunteers and 31 patients with OSCC. A quantitative sandwich enzyme immunoassay technique was used to measure the concentrations of VEGF in the sera. The data obtained from the experiment were analysed with independent-samples t-test. The mean concentrations of serum VEGF were 148.80 +/- 64.17 pg x ml(-1) (range, 59-231 pg x ml(-1)) in normal controls and 567.97 +/- 338.17 pg x ml(-1) (range, 136-1,892 pg x ml(-1)) in OSCC group. Statistical analysis showed that the mean VEGF level in sera of OSCC patients was significantly higher than that in healthy controls (P<0.001). The serum VEGF levels of OSCC patients correlated with condition of nodal metastasis (P<0.05) and clinical stage (P<0.05) but not with sex (P>0.05) and degree of differentiation (P>0.05). Our study showed that OSCC was associated with significantly elevated serum VEGF concentration. Higher level of serum VEGF also correlated with lymph node metastasis and clinical stage of OSCC. Determination of serum VEGF concentration may be helpful to distinguish OSCC patients from the normal individuals.