#15 & #25 — When We Don’t Have the Magic Triangle

Margarida Carido
Jan 20
1 min read

As Dr. Chen once said,

“Number 5 usually sits under what we call the magic triangle: a small island of bone just behind the apical portion of the premolar.”

But what if, right behind the apical portion of the upper second premolar, instead of a nice little island of bone… there’s only sinus cortical bone? ........No island. No triangle.............. No magic.

What would you do?

A delayed approach would probably be the safest and most reasonable option.

But then reality steps in.

The patient lives abroad. They are terrified of dentists. And, of course, they want everything done yesterday.

Suddenly, immediate placement becomes very attractive.

So, with no magic triangle to rely on, how do we survive? Where does this leave us?

It leaves us working with what we still have: the walls of the extraction socket—and a bit of creativity with implant macrogeometry.

Think of the new TikTok trend: doorframe climbing. The narrower the doorway, and the longer your arms and legs, the easier it is to stay suspended without falling.

Now apply that logic to teeth 15 and 25.

Use Lateral bone engagement for increased primary stability

The root is thick in the bucco-palatal dimension but relatively thin mesiodistally. That anatomical reality gives us an opportunity. We select an implant diameter that respects the mesio-distal limits and compensate with length and aggressive macrogeometry, allowing the implant to “climb” and mechanically engage the mesial, palatal, and distal bony walls of the socket.