Study Number of patients Type of thyroid dysfunction Effects of thyroid dysfunction impact
on the periodontium 		Main characteristics of
the periodontium
Mykolaivna [7] 100 Hypothyroidism Hypothyroidism associated with negative dynamics of calcium-phosphorus in oral fluid: increased phosphorus and decrease of calcium content of inflammatory-dystrophic process in the periodontium The development of chronic inflammatory process in periodontium
Lexomboon et al. [8] 6151
(1415 male; 4736 female) 		pHTP (primary after PTX) Primary pHTP patients were more likely to have risk of tooth extractions and periodontal interventions during the first two years after PTX and pHTP Characteristic periodontal bone remodeling parameters: decreasing lamina dura, increasing periodontal ligament width but not periodontal inflammatory parameters, such as bleeding on probing and furcation involvement and periodontal status
Zheng et al. [14] 2943
(1484 male; 1459 female) 		Hyperthyroidism Hyperthyroidism associated with lower oral microbiome diversity. Patients microbiome diversity metrics improved after treatment and restoration of thyroid function, suggesting that the decrease in the microbiome diversity may be closely related to the progression of the disease Increased progression of periodontal disease
Kadhom et al. [16] 90
(all female) 		Hyperthyroidism Hyperthyroid patients have increased PPD, CAL, IL6, which show a positive association with periodontal disease progression Increased PPD, CAL and IL6
Song et al. [19] 5468
(2866 male;
2602 female) 		Hyperthyroidism Hyperthyroidism when is low TSH levels (< 1.76 mlU/L) were rather associated with a higher prevalence of periodontitis CPI code ≥ 3, indicating that at least one site had a > 3.5 mm pocket in the index tooth 11, 16, 17, 26, 27, 31, 36, 37, 46, and/or 47 of 1423 periodontitis patients
Han et al. [20] 2352 Hyperthyroidism Hyperthyroidism patients with low serum TSH levels are more likely to have periodontitis The development of chronic inflammatory process in periodontium

pHTP = hyperparathyroidism; PPD = periodontal pocket depth; PTX = parathyroidectomy; CAL = clinical attachment loss; TSH = thyroid-stimulating hormone; CPI = clinical attachment loss.