Table 1.

General characteristics of the included case reports

Authors (year of publication)	Orthodontic appliances	Patient’s sex	Patient’s age (years)
Nazif et al. (1983) 2 cases[23]	Expansion keys	–	–
Hinkle (1987)[9]	Modified lower spring retainer	Male	14
Lee et al. (1992)[16]	Piece of archwire	Male	15
Milton et al. (2000) 3 cases[17]	Bracket on LR6 (46)	Female	14
	Segment of wire	Female	13
	Segment of wire	Male	15
Dibiase et al. (2000)[10]	Simple removable appliance	Female	9
Abdel-Kader et al. (2002)[11]	Transpalatal arch	Female	12
Al-Wahadni et al. (2006)[26]	Molar Band	Female	16
Allwork et al. (2007)[12]	Quadhelix	Male	13
Obinata et al. (2011) 2 cases[18]	Orthodontic wire	Male	62
	Orthodontic lingual arch ST lock	Female	8
Monini et al. (2011)[21]	Expansion key	Male	9
Rohida and Bhad (2011)[13]	Twin-block appliance fragment	Male	12
Tripathi et al. (2011)[22]	Key	Male	17
Hoseini et al. (2013)[20]	Orthodontic wire	Male	29
Naragond et al. (2013)[27]	Molar Band	Male	16
Verma et al. (2014)[14]	Wire of pendulum appliance	Female	15
Puryer et al. (2016)[15]	Archwire fragment	Female	15
Jauhar et al. (2016)[19]	Section of orthodontic archwire	Male	15
Pantuzo et al. (2017)[24]	RPE activation key	Male	13
Mahto et al. (2019)[25]	Molar band (16)	Male	15

Articles appear in chronological order; RPE=Rapid palatal expansion