I went to my dentist after having a bad taste in my mouth for some
time, and after she x-rayed my teeth, she noticed that my tooth was
loose, and on the film there was a dark spot where infection had eaten
into my bone.  She was convinced my tooth had cracked (it already had a
root canal with a crown on it) but after a visit to the endodontist, he
determined the tooth wasn't perforated and had cracked horizontally
along the crown and chipped off some tooth.  I was advised to either
extract the tooth, or do a root canal retreat and then get a crown
lengthening.  I've done both and had the lengthening two days ago.
When the periodontist was doing the lengthening he saw the hole in my
bone filled with milky puss and cleaned it out before sowing up my gum.
He said my prognosis was decent and to come back in 3 weeks.

My main problem is for the past few weeks, after the inital root canal
retreat, i've had a headache pretty continuously.  All my dentists are
saying it's unrelated, but the headache is only on one side (yup, the
root canal side) and it comes every few hours in painful spurts every
minute or so.  could it be related?  i already had had antibiotics for
the infection in the jaw bone, but the periodontist found more puss.
any input would be greatly appreciated.

Thanks.