The right logo tells both customers and potential customers a lot about the practice instantly, without much conscious thought on their part. Just as the five-year-old knows that sign means delicious food is near, you want your medical logo design to symbolize what your practice is about.
In the American English, bracket usually refers specifically to the square or box type. In British English, bracket normally refers to the round type, which is called a parenthesis mark in American usage. Parentheses are the curved brackets ( ).
In addition to referring to the class of all types of brackets, the unqualified word bracket is most commonly used to refer to a specific type of bracket: in modern American usage this is usually the square bracket and in modern British usage this is usually the round bracket.