We have always gotten very friendly responses from doctors, dentists, orthodontists when we schedule appointments. I tell them that we homeschool and are happy to fit an appointment in during the day. Every office has been happy about this, during the school year they like filling up the morning schedule. I remember when I was a teen, my orthodontist would schedule one visit during school and the next after school. Everyone had to take turns. But for homeschoolers it's easier to work around appointments.
I'm not saying that we like to take days off for checkups, and we also don't schedule appointments on busy school days when we have big stuff planned. I write appointments on our school planner so when I'm getting it ready for the next week I know when to schedule less work. Depending on the appointment, we may just skip a couple of simple things like grammar or spelling. If it's going to be a longer visit, we may skip math or math and language arts for the day.
Sometimes kids bring school work along. My youngest usually finishes quickly, but she has brought a story or practice page to read to me while an older sibling is getting their braces checked. An older child has brought a math assignment to finish if they needed. I am lucky to have two kids who are old enough to tend their younger siblings, so sometimes kids stay home while only one goes to their appointment.
Once we decided to go to an event that was about an hour and a half away from home. We had a little amount of school to do that day, and it could all be completed in the car. The kids thought that was fun, and though it's not something we'll do often, it worked out well for an occasional occurrence!