Happy brand name created for any product or service that brings u a "smile" to one's face.
MissionSmile has 12 characters and three syllables. Established brands using three syllable names include Grammarly, Microsoft and Sainsbury's.
Missionsmile.com is a dot com domain. Dot com domains are the most desirable top-level-domain in the world, famously used by websites like twitter.com. Owning a dot com says that you own the word "MissionSmile" online.