Probably this, from Magen Avraham 11:18:
כ' בשל"ה ומט"מ שאל יחתוך בסכין אלא ינשכם בשיניו ע"ש:
Shaloh and Mateh Moshe say that you shouldn't cut [the tzitzis strings] with a knife, but bite them with your teeth; see there.
I heard in a shiur that wearing Tzitzit helps reduce toothaches and teeth pains
This is brought in a Hirhurim blogpost on Tzitzit:
It is said that being careful in the observance of the mitzva of Tzitzit is a segula for preventing tooth aches. [Kaf Hachaim 11:17].
The Kaf Hachaim (Sofer), brings it here. He, in turn, is quoting the Kaf Hachaim (Palaggi) ...
There could be another explanation. Rambam in Hilchos Beis Habdhira says that the Altar was not a building, but one of the tools, used in the Temple (just like the Menorah or the table).
As such it is exempt from the railings because it is not a building to start with, like building a giant chair.