Hearing threshold levels among steel industry workers in Samut Prakan, Thailand.

BACKGROUND: Industrial noise is generally considered from the perspective of environmental health and safety, with requirements for reduced occupational noise exposure, strict standards for hearing protection, and public health awareness campaigns. MATERIALS AND METHODS: This cross-sectional study aimed to identify the hearing threshold levels (HTLs) among steel industry workers exposed to hazardous noises in Samut Prakan Province, Thailand, and investigate the associations between hearing loss and age and length of employment in the industry. Audiometric data for 93 participants were collected at the Samut Prakan Provincial Hospital. Qualified technicians performed audiometric screening using an audiometer in a quiet environment. Tests were conducted after participants had completely rested for ≥14 hours after the last exposure to workplace noise. RESULTS: The results showed that all participants had been employed in a work zone with a noise hazard for >1 year. Participants' age ranged from 19 to 59 years and their work experience from 1 to 39 years. Average mean hearing thresholds in the right ear at 4, 6, and 8 kHz were 31.34, 29.62, and 25.64 dB, respectively. Mean hearing thresholds in the left ear at 4, 6, and 8 kHz were 40.15, 32.20, and 25.48 dB, respectively. Hearing loss related to work experience was greater than that attributable to age and work station. Duration of noise exposure ranged from 1 to 39 years, and more than half of the participants (60.2%) were exposed to hazardous noises from 6 to 25 years. CONCLUSION: These findings show that participants' age and experience were significantly associated with hearing loss at all levels. HTLs among industrial workers should be regularly assessed. At the health policy level, these workers need to start being protected when they begin working.

Intensity-modulated radiation therapy in head-and-neck cancer, first report in Thailand.

OBJECTIVE: This is the first report in Thailand to evaluate the efficacy of using intensity-modulated radiotherapy (IMRT) in the primary treatment of head-and-neck cancer. MATERIAL AND METHOD: From July 2005 to March 2006, eighteen patients with head and neck cancer were treated with IMRT, fourteen of which were nasopharyngeal cancer. The median age at diagnosis was 52 years (range 23-58 years). The treatment plan composed of two sequential plans for PTV-low risk (50Gy in 25 fractions) and PTV-high risk (20Gy in 10 fractions). Chemotherapy was given to 13 patients with locoregionally advanced disease (stage T3/T4 and N2/3) using cisplatin (n = 3) or carboplatin (n = 10) every 3 weeks during the course of radiation therapy. RESULTS: The median overall treatment time was 49 days (range, 43-57 days), and 77.8 percent of the patients completed 35 fractions within 50 days. The clinical complete response and partial response rates at 3 months after complete radiation were 71.4% and 28.6%, respectively. However at the median follow-up of 5.6 months, the complete response rate increased to 89%. Treatment break during RT range from 3 to 7 days, was observed in three patients. All of them received concurrent chemoradiation. No distant metastasis was noted. CONCLUSION: The authors' experience of using concurrent chemotherapy with IMRT for a cohort of patients with head and neck carcinoma showed a very high rate response rate at early follow-up. Long-term clinical outcome is expected.

Carcinoma of the external auditory canal.

Carcinoma of the external auditory canal is one of the most inaccessible areas of the body. It is a rare malignant neoplasm with an aggressive nature and an overall poor prognosis. In a ten year period, 16 patients were treated in King Chulalongkorn Memorial Hospital. From TNM staging proposed by the University of Pittsburgh, the authors found T1 = 1, T2 = 6, T3 = 5, T4 = 4 cases. In 14 patients who were operated on (radical mastoidectomy in 8, lateral temporal bone resection in 5, sleeve resection in 1), 7 had cured (50%), 7 were recurrence. 6 cases of recurrence developed in patients with radical mastoidectomy, 1 case with lateral temporal bone resection. The overall cure rate in stage I-II = 85.71% (6/7) but only 11.11% (1/9) in the advanced stages (III-IV). The present data suggest that in early cancer (stage I-II) the lateral temporal bone resection with postoperative radiation is better than radical mastoidectomy with postoperative radiation.

The pectoralis major myocutaneous flap: applications and complications in head and neck reconstruction.

Ninety-six pectoralis major myocutaneous flaps were used in the head and neck reconstruction of 93 patients who underwent extirpation of cancer. The utilization of the pectoralis major myocutaneous flap included 50 tongue replacements, 19 hypopharynx and pharyngoesophageal closure, 11 oral mucosal closure and external skin replacement, 7 soft tissue coverage of the reconstruction plate, 3 soft tissue protection of the great vessels at the neck and 6 correction of the wound breakdown from failure of the other flap reconstruction. The major complication, which included total flap loss, partial skin paddle loss, orocutaneous fistula, dehiscence and plate exposure, was 17.7%. The overall complication rate was 54.2% and most of them were healed by conservative management. The pectoralis major myocutaneous flap is feasible and reliable for immediate reconstruction of various defects in the head and neck area. The pectoralis major myocutaneous flap should be the suitable flap for the advanced-staged cancer patient with a limited life expectancy.

Large middle meatal antrostomy vs undisturbed maxillary ostium in the endoscopic sinus surgery of nasal polyposis.

BACKGROUND: There is controversy of creating the drainage lumen in endoscopic sinus surgery for diffuse nasal polyposis. OBJECTIVE: To compare the patency rate of drainage lumen between large middle meatal antrostomy and undisturbed maxillary ostium in endoscopic sinus surgery for nasal polyposis. SETTING: Department of Otolaryngology, King Chulalongkorn Memorial Hospital. DESIGN: Randomized double-blind control trial. SUBJECT: Patients diagnosed at the King Chulalongorn hospital who had chronic maxillary sinusitis developed by nasal polyposis. METHOD: Sixty patients who had similar degree of bilateral nasal polyps and chronic maxillary sinusitis were enrolled. The sides of which each surgical technique would be applied were randomized by simple randomization. The patients did not know which treatment technique was applied to which side of the nose. The evaluator evaluated the objective endoscopic examination from the recorded videotape of each side separately at the third month till one year after surgery without notifying the patients. RESULTS: The patency rate of a large middle meatal antrostomy was 71.7 per cent-85 per cent compared to 61.7 per cent-65 per cent of the undisturbed maxillary ostium. There was a statistically significant difference only in early phase evaluation between the two surgical techniques (p-value = 0.002). Thirty-six of 60 cases (60%) had good results with adequate drainage lumens, no infection and no recurrent polyps at the final evaluation. Early and small nasal polyps (grade I polyp) was the main correlation factor to the success of endoscopic sinus surgery for nasal polyposis (p-value = 0.017). The occlusion of the drainage system after surgery was mainly from recurrent polyps. CONCLUSION: The large middle antrostomy group had a better statistically significant patency rate than undisturbed maxillary ostium only in the early phase after surgery. Recurrent polyp was the main cause of stenosis. Early surgical intervention of the small nasal polyposis had a better result compared to large diffuse nasal polyps.