Grading the intensity of nondental orofacial pain: identification of cutoff points for mild, moderate, and severe pain

Figures & data

Table 1 Demographic and clinical data of the patients

	Total	TMD	CIFP	TN	P
Sex, n (%)					χ^2
Female	186 (76%)	90 (80.4%)	63 (74.1%)	33 (70.2%)	0.333
Male	59 (24%)	22 (19.6%)	22 (25.9%)	15 (29.8%)
Total	245	112	85	48
					Mann–Whitney U
Age, years, median (range)	47 (12–84)	36.5 (12–77)	50 (23–84)	64 (20–81)	<0.001*
Duration of pain, months, median (range)	27 (6–468)	24 (6–180)	36 (6–360)	64 (6–468)	<0.001*
Referred by, n (%)					χ^2
GDP	71 (41%)	37 (52.1%)	27 (37.5%)	7 (23.3%)	0.051
GMP	43 (24.9%)	18 (25.4%)	15 (20.8%)	10 (33.3%)
Specialist	59 (34.1%)	16 (22.5%)	30 (41.7%)	13 (43.3%)
					Mann–Whitney U
Number of specialists visited before the referral, median (range)	2 (0–7)	1 (0–6)	2 (0–7)	2 (0–5)	<0.001*
Depression, n (%)					χ^2
None	60 (52.2%)	41 (67.2%)	15 (57.7%)	19 (67.9%)	0.140
Borderline/mild depression	25 (21.7%)	12 (19.7%)	3 (11.5%)	7 (25%)
Severe depression	30 (26.1%)	8 (13.1%)	8 (30.8%)	2 (7.1%)
Anxiety, n (%)					χ^2
None	75 (65.2%)	27 (44.3%)	16 (61.5%)	17 (60.7%)	0.493
Borderline/mild anxiety	22 (19.1%)	16 (26.2%)	4 (15.4%)	5 (17.9%)
Severe anxiety	18 (15.7%)	18 (29.5%)	6 (23.1%)	6 (21.4%)
Pain intensity, mean ± SD					Analysis of variance
Average	4.9±2.9	4.3±2.7	5.7±2.8	5.2.±3.2	0.004*
Worst	5.7±3.2	5.2±3.2	6.2±3	6±3.4	0.081
Least	3.5±3.1	3±2.9	4.2±3.1	3.8±3.6	0.025
Current	4.1±3.2	3.7±3.1	4.7±3.1	4±3.5	0.097
Pain-related interference, mean ± SD	3.7±2.9	3.3±2.8	4.3±3	3.8±3	0.055
Pain-related disability, n (%)					χ^2
Grade 1	64 (28.1%)	38 (36.9%)	16 (21.3%)	10 (20%)	0.206
Grade 2	62 (27.2%)	28 (27.2%)	22 (29.3%)	12 (24%)
Grade 3	35 (15.4%)	14 (13.6%)	14 (18.7%)	7 (14%)
Grade 4	67 (29.3%)	23 (22.3%)	23 (30.7%)	21 (42%)

Notes:

* P<0.01. Specialist – health care professional with dental or medical specialization; number of specialists visited before the referral, number of medical and/or dental specialists that patient saw before he/she was referred to the Facial Pain Unit; pain intensity (average, worst, least, right now), intensity subscales of the Brief Pain Inventory; pain-related interference, overall interference calculated from the interference subscales of the Brief Pain Inventory; pain-related disability determined by the Chronic Graded Pain Scale.

Abbreviations: TMD, temporomandibular disorder; CIFP, chronic idiopathic facial pain; TN, trigeminal neuralgia; SD, standard deviation; GDP, general dental practitioner; GMP, general medical practitioner.

Table 2 Combination of cutoff points with associated Wilks’ lambda statistics

	35	36	37	38	46	47	48	57	58
	Mild 1–3, moderate >3–5, severe >5–10	Mild 1–3, moderate >3–6, severe >6–10	Mild 1–3, moderate >3–7, severe >7–10	Mild 1–3, moderate >3–8, severe >8–10	Mild 1–4, moderate >4–6, severe >6–10	Mild 1–4, moderate >4–7, severe >7–10	Mild 1–4, moderate >4–8, severe >8–10	Mild 1–5, moderate >5–7, severe >7–10	Mild 1–5, moderate >5–8, severe >8–10
All patients	19.064	19.336	21.327	17.982	20.452	23.064	20.502	18.999	17.163
TMD	9.195	10.919	12.073	9.579	11.502	12.999	10.941	9.823	8.254
CIFP	6.097	5.557	5.667	5.113	5.985	6.276	6.004	5.678	5.781
TN	4.375	4.077	5.475	5.523	4.306	5.899	6.129	5.244	5.511

Notes: Numbers in bold represent different cutoff point combinations of mild, moderate, and severe pain. The scheme with the most significant intergroup difference, expressed by the smallest P-value determined from Wilks’ lambda, indicates the maximum difference between the groups providing optimal cutoffs between mild, moderate, and severe pain (shaded cells).

Abbreviations: TMD, temporomandibular disorder; CIFP, chronic idiopathic facial pain; TN, trigeminal neuralgia.

Figure 1 Pain-related interference in the three pain-intensity groups.

Abbreviations: TMD, temporomandibular disorder; CIFP, chronic idiopathic facial pain; TN, trigeminal neuralgia; SD, standard deviation.

Figure 2 Pain-related disability in the three pain-intensity groups (grades 1–4, pain-related disability determined by the Chronic Graded Pain Scale).

Abbreviations: TMD, temporomandibular disorder; CIFP, chronic idiopathic facial pain; TN, trigeminal neuralgia.

Figure 3 Anxiety and depression in the three pain-intensity groups.

Abbreviations: TMD, temporomandibular disorder; CIFP, chronic idiopathic facial pain; TN, trigeminal neuralgia.