Odynophagia is
Pain during swallowing
Difficulty in swallowing
Bad odour from mouth
Psychiatric disease
Dysphagia is difficulty in swallowing. The term odynophagia is used when swallowing causes pain. The latter is more marked in ulcerative and inflammatory lesions of food passages - oral cavity, oropharynx and oesophagus. (Ref: Textbook of diseases of ENT, PL Dhingra, 7th edition, pg no. 393)
Oral cavity & Oesophagus