Gali, you need more medical opinions, perhaps from docs at the closest
academic medical facility.

Here's what a Medline search turns up:

Ann Emerg Med. 1987 Oct;16(10):1174-6.     Related Articles, Links
    Click here to read
    An unusual cause of headache: a dentigerous cyst in the maxillary
sinus.

    Freedland ES, Henneman PL.

    Department of Emergency Medicine, Harbor-UCLA Medical Center, Torrance.

    We report the case of a patient with a dentigerous cyst in the
maxillary sinus presenting as two months of intermittent, unilateral,
pressure-like headaches. The diagnosis was suspected after an upright
Waters' projection radiogram and confirmed histologically after surgical
removal. The patient was symptom free one year later.

    Publication Types:

        * Case Reports

    PMID: 3662168 [PubMed - indexed for MEDLINE]

Susan

Was the onset sudden or did it get gradually worse over time?

And is head pain the only symptom you are experiencing?

I would be surprised if a cyst in your RIGHT maxillary sinus would cause
such severe pain on the LEFT side of your head.

Either you have more extensive sinusitis that is affecting the LEFT side
of your head too (including spread to the inner ear)--or the pain has
another cause.

What tests did your neurologist perform?

I had numerous polyps in my first surgery.  When it is so bad you get choked
because you cannot eat and breath at the same time, it is time to go to a
doctor.  I was only 21 the first time.  35 the next time.  43 the next time.
But the last time no polyps, just old infection that just sat there.  I am
having problems again but not anywhere near that.  Polyps constrict your
breathing.  And if you sneeze too hard, like I did one time, a large one may
show it's face. I had a cyst the next operation.  You really need to get it
removed.  You are only asleep for a short time and it is worth it, believe
me.  To be able to breath?  Wonderful!!

I wish you luck.

Vicki