At my insistence, my dentist made me an old-fashioned a spider or Nesbitt
bridge.  Perfect low-tech solution for what I wanted.  His work in fitting
it was great.

After I took possession of the bridge  noted that 1 of the arms of one of
the clasps had no "shoulder."  That is, the point where the arm joins the
body of the bridge is very thin whereas the others [and all 4 on others I've
seen] are thick and robust.   This one measures only .65 mm thick and 1.5 mm
wide.

The arm thicknes towards the tip and basically  looks unsupported.
Visually, the arm almost disappears and seems to "float."

I'd guess any shock would break it.   And, indeed, that's what happened
almost immediately.

The bridge still "clicks" into place even without the 4th arm.  No problems
eating [my dentist told me not to], sleeping, etc.

I dont want to make a needless/silly fuss or impose on my dentist.  2
questions:

Did the lab do a poor job in grinding/casting the shoulder down to .65 mm?
Should I complain to the lab?

Is there any reason why I need to have this replaced [bad force
distribution?] since it still seems to fit perfectely without the 4th arm?

Thank you.