In this case, we've got one tooth missing and a few crowns on front teeth. Initially we planned a single implant to replace the missing tooth. CBCT showed there is extensive bone resorption around the missing tooth, which needs bone grafting before putting a dental implant.
Before we started bone grafting, two front crowns chipped and they have been fixed a few time and didn't last long. The patient wanted to have new ones instead of repairing them repeatedly. Because the situation changed, we got more treatment options for the missing tooth. Finally we decided to have a cantilever bridge instead of bone graft and implant.
A cantilever bridge is a fixed bridge that attaches to adjacent teeth on one end only, whereas a conventional bridge attaches from teeth on both sides. Because only one tooth provides support for the artificial tooth, a cantilever bridge is limited to areas of the mouth that do not receive much stress during chewing. Like this case, the much bigger central incisor supports a smaller lateral incisor, which does not take too much chewing force. Without connecting the other central incisor, it's much easier to floss and maintain oral hygiene around the area.