Table 4.

Studies addressing the relationship between estrogen hormone levels and TMD.

Reference	Year	Study Design and Subjects	Conclusion
Targeting Temporo-mandibular Disorder Pain Treatment to Hormonal Fluctuations: A Randomized Clinical Trial [20]	2011	Randomized clinical trial 147 female participants	Long-term benefits of self-applied therapeutic interventions for TMD pain by patients at the recommendation of the dental hygienist have been observed.
A cross-sectional study of the relationship between serum sexual hormone levels and internal derangement of temporomandibular joint [21]	2013	Cross-sectional 47 patients with ADDwR 95 patients without TMD	Low levels of serum progesterone could be associated with internal derangements of the temporomandibular joint. No difference was found for estrogen serum levels.
Hormonal Fluctuations Intensify Temporo-mandibular Disorder Pain Without Impairing Masticatory Function [22]	2015	Case–control 1 group (n = 25) evaluated for menstrual cycle and 1 group (n = 25) evaluated for OC (oral contraceptives) intake	The level of temporomandibular joint pain in women is influenced by hormonal fluctuations (lower pain level in ovulatory phase). The menstrual cycle does not interfere with masticatory function.
Estrogen-Induced Monocytic Response Correlates with Temporo-mandibular Disorder Pain: A Case Control Study [23]	2017	Case–control Blood samples taken from 18 patients (9 with TMD, and 9 controls)	Women with TMD had a systemic hyperinflammatory phenotype, as seen by increased monocytic cytokine release following an inflammatory insult, amplified by estrogen. Monocytes from participants who reported more pain on the VAS scale produced higher levels of IL6 than those from people who indicated lesser pain sensitivity.
Do sex hormone imbalances contribute to idiopathic condylar resorption? [24]	2021	Case–control 94 patients with ICR (idiopathic condylar resorption) 324 patients with DD (disc displacement)	There is no contribution of low estrogen levels in ICR in females, but higher testosterone and estrogen levels in men is related to ICR.
Influence of the menstrual cycle on the pressure pain threshold of masticatory muscles in patients with masticatory myofascial pain [25]	2008	Case–control 36 patients divided into 4 groups: 7 with TMD and no OC intake, 8 with TMD and OC intake, 13 healthy with no OC intake, 8 healthy with OC intake	The menstrual cycle phases do not have a significant impact on the masticatory muscle tenderness, but reported pain is slightly increased during the menstrual phase. The use of oral contraceptives is associated with an increased pain threshold to pressure.