A total of 117 patients were identified, 103 (88 A total of 117 patients were identified, 103 (88.0%) of whom were females. The average age at the time of the scintigraphy was 46.7 years, with an age range of 19 to 74 years. A total of 32 age-matched controls were identified, 18 (56.3%) of whom were females. The average age of the controls at the time of the bone scan was 44.3 years, with ages ranging from 21 to 76 years. The results of the blood flow and blood pool phases of the bone scan were normal in all patients and control subjects. Overall, 76.1% of the IFP patients demonstrated a hot spot in at least one quadrant, compared to 25.0% for the controls (Table 2, Figures 1 - 3). This was a very significant difference (p <.0001) between IFP patients and controls. Hot spots were also seen in other parts of the head and neck region, primarily in the ethmoid, sphenoid and maxillary sinus areas and the cervical spine. The IFP patients demonstrated such extraoral hot spots 26.5% (31/117) of the time, compared to 18.8% (6/32) for the controls. This was not a significant difference (p = .3688) between the two groups. Approximately 63% (293/468) of the quadrants in the IFP cohort were associated with pain, either at the time of the original scan or at a later date (if more than 6 months from the original work-up, the new pain quadrant was accepted only if an additional 99m Tc scan was performed for the additional pain). In other words, these patients generally had more severe involvement than typical IFP patients, who usually have no more than one quadrant of pain; they were very ill individuals, usually with debilitating pain. The average duration of pain prior to scintigraphy was 5.4 years (range: 0.6 – 13.2 years). Of the 293 painful maxillofacial quadrants in the IFP patients, 79.2% contained at least one hot spot, compared to 12.6% for the nonpainful quadrants (Table 3). Pearson chi square analysis of the correlation between the quadrant of pain and a positive 99m Tc scan in that quadrant confirmed a very strong correlation (p<.0001). Likewise, the proportion of 99m Tc-positive painful quadrants in the IFP group was significantly different (p<.0001) from the proportion, 5.4%, in the pain-free quadrants of the controls. When the scintigraphic positivity of the 175 pain-free quadrants in the IFP patients was compared to the 148 pain-free quadrants in the controls there was no significant difference (p = .0688). Hence, the pain-free regions seemed similar to persons without any facial pain. A total of 117 patients were identified, 103 (88.0%) of whom were females. The average age at the time of the scintigraphy was 46.7 years, with an age range of 19 to 74 years. A total of 32 age-matched controls were identified, 18 (56.3%) of whom were females. The average age of the controls at the time of the bone scan was 44.3 years, with ages ranging from 21 to 76 years. The results of the blood flow and blood pool phases of the bone scan were normal in all patients and control subjects. Overall, 76.1% of the IFP patients demonstrated a hot spot in at least one quadrant, compared to 25.0% for the controls (Table 2, Figures 1 - 3). This was a very significant difference (p <.0001) between IFP patients and controls. Hot spots were also seen in other parts of the head and neck region, primarily in the ethmoid, sphenoid and maxillary sinus areas and the cervical spine. The IFP patients demonstrated such extraoral hot spots 26.5% (31/117) of the time, compared to 18.8% (6/32) for the controls. This was not a significant difference (p = .3688) between the two groups. Approximately 63% (293/468) of the quadrants in the IFP cohort were associated with pain, either at the time of the original scan or at a later date (if more than 6 months from the original work-up, the new pain quadrant was accepted only if an additional 99m Tc scan was performed for the additional pain). In other words, these patients generally had more severe involvement than typical IFP patients, who usually have no more than one quadrant of pain; they were very ill individuals, usually with debilitating pain. The average duration of pain prior to scintigraphy was 5.4 years (range: 0.6 – 13.2 years). Of the 293 painful maxillofacial quadrants in the IFP patients, 79.2% contained at least one hot spot, compared to 12.6% for the nonpainful quadrants (Table 3). Pearson chi square analysis of the correlation between the quadrant of pain and a positive 99m Tc scan in that quadrant confirmed a very strong correlation (p<.0001). Likewise, the proportion of 99m Tc-positive painful quadrants in the IFP group was significantly different (p<.0001) from the proportion, 5.4%, in the pain-free quadrants of the controls. When the scintigraphic positivity of the 175 pain-free quadrants in the IFP patients was compared to the 148 pain-free quadrants in the controls there was no significant difference (p = .0688). Hence, the pain-free regions seemed similar to persons without any facial pain.