Background & Aims

Headache attributed to temporomandibular disorders (HA2TMD) is a secondary headache which can be classified using two systems: Diagnostic Criteria for Temporomandibular Disorders (DC/TMD),1 and International Classification of Headache Disorders-3rd edition (ICHD3).2 Diagnostic Criterion B addresses the primary disorder which, within the DC/TMD, requires examiner ascertainment of a painful primary TMD (which is fully operationalized, reliable, and represents a valid disorder1), and which, within the ICHD3, requires only evidence of pathology (which is not operationalized and does not require a formal primary disorder). Criterion C addresses clinical evidence of causation, and the two diagnostic systems implement this somewhat differently. We investigated impact of the two HA2TMD classification systems on comorbid characteristics. Primary headache alone was included as the reference group to gauge overall pattern of results.

Methods

Data were from participants with headache from OPPERA-2, a community-based, cross-sectional sample of US adults (n=499 aged 19-70 years; 73% female; 67% white). Participants were classified into 1 of 3 groups; primary only, classified using ICHD3 (tension-type) or ID-migraine (migraine-type), or HA2TMD, classified according to 2 diagnostic systems: DC/TMD, using more restrictive criteria requiring diagnoses of myalgia or arthralgia, or ICHD3, using less restrictive criteria of hyperalgesia in any masticatory structure. Comorbid characteristics, previously described,3 included 11 TMD-specific variables, 10 variables contrasting masticatory and non-masticatory regions, 17 psychological and health domain variables, and number of other overlapping pain conditions. Descriptive statistics were computed, by headache type, and differences were tested using 1-way ANOVA and post-hoc tests at alpha=0.05. Cohen’s D effect size was computed for significant differences.

Results

The sample consisted of primary headache only and without a TMD, 55%; ICHD3-HA2TMD, 21%; and DC-HA2TMD, 25%. Only 60% of those with ICHD3-HA2TMD had co-occurring painful TMD. Of the 39 characteristics, the between-group differences were significant for 33 comparing ICHD3-HA2TMD to primary headache, for 34 comparing DC-HA2TMD to primary headache, and for 25 comparing the two HA2TMD groups. The magnitudes of the characteristics were least severe for primary headache alone, mid-range for ICHD3-HA2TMD, and most severe for DC-HA2TMD. Effect sizes of significant characteristics comparing ICHD3-HA2TMD to primary headache ranged 0.2-2.0, those comparing DC-HA2TMD to primary headache ranged 0.4-2.8, and those comparing DC-HA2TMD to ICHD3-HA2TMD ranged 0.2-0.8, indicating HA2TMD classified by DC/TMD is a more severe secondary headache than that classified by ICHD3, noting that the latter is clearly distinct from primary headache alone.

Conclusions

We report elsewhere that DC-HA2TMD and ICHD3-HA2TMD have very similar headache characteristics (duration, pain intensity, and pain-related disability) and differ only with DC-HA2TMD as more frequent,4 suggesting that the two classification systems may equally identify a secondary headache. In comparison to ICHD3-HA2TMD, DC-HA2TMD is associated with greater severity in two-thirds of the examined comorbid characteristics, suggesting either greater risk for or greater impact from the more restrictive form of secondary headache. The increased frequency of DC-HA2TMD may be a critical clue regarding progression from a perhaps more intermediate form of secondary headache (ICHD3-DC2TMD). Both classification methods appear to be important for secondary disease staging but the differences in Criterion B, requirement of formal primary disorder or not, point to very different pathways for treatments for complex patterns of headache co-occurring with a possible painful TMD.

References

1. Schiffman E, Ohrbach R. Executive summary of the Diagnostic Criteria for Temporomandibular Disorders for clinical and research applications. Journal of the American Dental Association. 2016;147:438-445.
2.Headache Classification Committee of the International Headache Society (IHS). The International Classification of Headache Disorders, 3rd edition. Cephalalgia. 2018;38:1-211.
3.Sharma S, Slade GD, Fillingim RB, Ohrbach R. A rose by another name? Characteristics that distinguish headache secondary to temporomandibular disorder from headache that is comorbid with temporomandibular disorder. Pain. 2023;164:820-830.
4.Gill M, Sharma S, Slade G, Ohrbach R. Headache attributed to TMD: Impact of different diagnostic criteria on headache characteristics. American Acadeny of Orofacial Pain. Scottsdale, AZ2024.

Presenting Author

Richard Ohrbach

Poster Authors

Richard Ohrbach

PhD

University at Buffalo

Lead Author

Manavjot Kaur Gill

BDS

University of Buffalo

Lead Author

Gary D Slade

BDS PhD

University of North Carolina-Chapel Hill

Lead Author

Sonia Sharma

BDS PhD

University of Michigan

Lead Author

Topics

  • Specific Pain Conditions/Pain in Specific Populations: Orofacial Pain