Inclusion Criteria:  swallowing difficulty group (SSD) who with symptomatic swallowing difficulties or with a history of swallowing difficulties, coughing or choking when eating or drinking or a sign of malnutrition control group (WSD) who without a history of swallowing difficulties, coughing or choking when eating or drinking or a sign of malnutrition  Exclusion Criteria:  People with chronic illnesses and tube feeding People with anterior bone deformity e.g. facial fracture, sino-nasal or anterior skill-based tumor/surgery