AG	Aligners group
API	Approximative plaque index
BoP	Bleeding of probing
CCM	Conventional ceramic brackets
ELB	Elastomeric-ligated brackets
FG	Fixed group
FMBS	Full mouth bleeding score
FMPS	Full mouth plaque score
GI	Gingival index
MPI	Modified plaque index
PBE	Periodontal basic examination
PBI	Papillary bleeding index
PD	Probing depth
PI	Plaque index
REC	Gingival recession
SBI	Sulcus bleeding index
SLB	Self-ligated brackets
Tn	Time measure in months