Even in the tightest pocket FAK it pays to insert a birthday candle or tiny stub of a candle.

The wax can be stuffed into the hole left by a missing filling or wrapped around the tooth stub of a broken tooth or where a crown has been lost. To be used this way you have to be careful about which candle you select. The modern plastic candles with a rubbery or stiff consistency don't work well. Beeswax based candles and others that will soften in the mouth sufficiently that they can be worked like putty with the fingers is what you want.

They also make a good fire starter, fuel for light and heat, solid-form lubricant and sealer. Warmed and thumbed into a leak in a rain fly or raincoat it can help keep you dry and eliminate the annoyance.

Its roll as stopgap in field expedient dentistry is another plus.

Actually, at the orthodontist they give away dental wax in little cases, so I may pick one up and add it to the kit! Just check your local orthodontist and they should have some!

It looks like this

really small and thin and keeps it from getting smooshed

Probably wouldn't be a good idea to use one of those trick can't blow 'em out candles...