The Collaborative International Dictionary of English v.0.48:

Toothache \Tooth"ache`\, n. (Med.)
   Pain in a tooth or in the teeth; odontalgia.
   [1913 Webster]

   Toothache grass (Bot.), a kind of grass (Ctenium
      Americanum) having a very pungent taste.

   Toothache tree. (Bot.)
   (a) The prickly ash.
   (b) A shrub of the genus Aralia (Aralia spinosa).
       [1913 Webster]

WordNet (r) 3.0 (2006):

toothache
    n 1: an ache localized in or around a tooth [syn: toothache,
         odontalgia]

Moby Thesaurus II by Grady Ward, 1.0:

26 Moby Thesaurus words for "toothache":
   ache, aching, angina, backache, bellyache, cephalalgia, colic,
   collywobbles, earache, fret, gnawing, gripe, gripes, gut-ache,
   headache, heartburn, hemicrania, megrim, migraine, odontalgia,
   otalgia, pyrosis, sick headache, splitting headache, stomachache,
   throbbing pain