Thyroidectomy is a standard procedure for benign and malignant pathologies of the thyroid gland. Each year, some 100 total thyroidectomies are performed in Kowloon East Cluster, Hospital Authority, Hong Kong. Total thyroidectomy is associated with voice dysfunction and temporary hypocalcaemia in up to 80% and 50%, respectively. Previous study from our institute showed a 3% rate of permanent vocal cord palsy and 16% of permanent hypoparathyroidism requiring calcium and/or vitamin D supplements. The use of dexamethasone has been studied in the past in total thyroidectomy patients and has been shown to be safe and effective in improving post-operative nausea and vomiting. No complications or drug related side effects were associated with a single dose of steroid. Recent studies have also shown that Dexamethasone is effective in improving voice outcome and hypocalcaemia in thyroidectomy patients. The investigators aim to study the effect of Dexamethasone in post-operative voice outcome and hypocalcaemia. Objective assessment of the vocal cords during phonation will be performed pre-operative and post-operatively. Serum Calcium level will be monitored.