Meaning: This sentence describes the male person experiencing severe pain in his teeth.
Choice of Words: "His" is a possessive pronoun that refers to the male person mentioned earlier. "Teeth" is the plural form of "tooth", which are hard, white structures in the mouth used for biting and chewing. "Ached" is the past tense of the verb "ache", which means to feel pain. "Badly" means to a severe or unpleasant degree.