Table 3.

Classification of studies that evaluated changes during and after orthodontic tooth movement.

Outcome measure	Phase of orthodontic treatment
	Active	Retentive
Tissue changes	Gingival fibers (34–41)	Reitan & Murell in 1967 & 1996 (30, 31)
	Periodontal fibers (19, 42–51)
	Alveolar bone (42–51)
Biomarkers	Enzymes (MMPs, ALP, TRAP, LDH, AST, Cathepsin, beta glucuronidase) (11–17, 52–67, 75–77)	Markers of alveolar bone remodeling;
	Salivary proteins (29)	Animal studies (20, 21)
	Cytokines (2–8)	Human studies (33)
	Prostaglandins (9, 10)	Salivary proteins; Human studies (22, 32)
	ECM & Cell membrane receptors (68, 69); Neuropeptides (70, 71)