Meaning: This sentence describes someone cleaning their hard, white structures in the mouth used for biting and chewing with a brush two times each period of 24 hours.
Choice of Words: The word "brushed" is the past tense of the verb "brush," which means to clean with a brush. "My" is a possessive adjective that means belonging to me. "Teeth" is the plural noun for the hard, white structures in the mouth used for biting and chewing. "Twice" means two times. "A" is an indefinite article that means one. "Day" is a period of 24 hours.