Negative reviews are typically far and few between. When it does happen, don't panic. The best thing to do is provide a professional and approachable response to the review. There is no sense in arguing with someone online, even if they are in the wrong. You lose either way. Your goal here is to try and mitigate their anger towards you while also putting your best foot forward for other future patients reading your reviews. Sometimes if a review is fake or spam, you can flag it for Google to review. Then it will be Google's discretion if they should remove the review or not.