"During Dental Procedures when you will be having multiple instruments in your patients mouth and the patient has to communicate with the dentist it becomes impossible to speak, this is where the Dental Hand Signs come in and are quite useful in communicating the patients concern without disturbing the working field. It is more useful in cases where Rubber Dam is used while restorations or in Root Canal Procedures."

Read more here 

https://www.juniordentist.com/use-dental-hand-signs-in-clinics-for-communication-during-procedures.html​

Dental Fear Central published a post focussed upon Dentisign and how it addresses dental fear and anxiety.

Being able to let your dentist (or hygienist) know that you need a break or you want them to stop is absolutely essential. This allows you to build trust and gives you control over the situation: - read more here 



https://www.dentalfearcentral.org/help/psychology/signalling/#h-dental-sign-language