In this area, it seems that the smaller MD practices are becoming less common, particularly in primary care. Primary care appears to be more likely to be findable in large multispecialty practices (with shared centralized billing and insurance handling) and concierge practices (some of which do not handle insurance paperwork, so patients need to deal with that on their own).
Small dental practices still seem to be common. But the newer ones seem to advertise a lot of cosmetic dentistry.