Table 3. Summary of characteristics and outcome measurements of the studies included.

Study ID	Participants and settings	Outcomes and/or measurement method	Evaluation period	Main findings
Stefanovic et al., 202110	n = 77 (36 F, 41 M)	Psychosocial assessments.	1 y	Parental perception of altered emotional well-being of their children was the strongest predictor, increasing compliance odds by 3.4 times (95% CI, 1.2–9.4; p = .017).
	Mean age: 12 y	Discontinued treatment.		Patients with overjet > 8 mm were 3.1 times more compliant (95% CI, 1.0–9.4; p = .044).
	Age range: 11–13 y	Compliance.		Children’s self-assessed oral health and teeth appearance satisfaction were not valid predictors (p > 0.05).
	Treatment: removable functional appliances
	Location: University Dental Clinic, Rijeka, Croatia
Naseri et al., 202014	n = 50 (29 F, 21 M)	Personality traits.	3 mo	A correlation was found between self-efficacy, total score in the acceptance questionnaire (r = 0.486, p = 0.001), and level of liking of the orthodontic appliance (r = 0.530, p = 0.001).
	Mean age: 10.5 y	Severity of malocclusion.		There was no relationship between IOTN and the patient’s level of acceptance (p > 0.05).
	Age range: 10–12 y	Satisfaction.
	Treatment: removable orthodontics
	Location: private clinic, Shiraz, Iran
Sarul et al., 201917	n = 97 (51 F, 46 M)	Self-perception of smile attractiveness.	9 mo	DWT of participants with low self-perception of smile attractiveness: mean 9.64 +- 2.77 h.
	Age range = 9–12 y	Compliance (DWT measurements with TheraMon® software).		DWT of participants with low self-perception of smile attractiveness: mean 5.92 +- 2.28 h.
	Treatment: removable functional appliances			(p < 0.001)
	Location: Wroclaw Medical University, Wroclaw, Poland			There was a strong negative correlation between DWT and poor smile as regarded by patients (r = −0.77).
Lee et al., 201819	n = 298 (207 F, 91 M)	Satisfaction.	NR	Treatment satisfaction was positively related to motivation; the level of satisfaction with tooth alignment (92%), confident smile and self-image (71%) were higher than that with facial appearance (60%) and eating and chewing (59%) (p < 0.001).
	Age range: 21–67 y			Concerns with having to attend multiple regular visits and discomfort due to an inconvenient hospital system negatively influenced the level of satisfaction (p < 0.05).
	Treatment: NR
	Location: Yonsei University, Seoul, South Korea
Von Bremen et al., 201812	n = 114	Compliance (DWT measurements with TheraMon® software).	6 mo	An indirect association between BMI and appliance wear time, indicating that the higher the BMI, the less the patients wore their appliances (r = -0.267, p < 0.05).
	Mean age: 11 y
	Treatment: removable appliances
	Location: University of Giessen, Giessen, Germany
Sarul et al, 201718	n = 38 (19 F, 19 M)	Personality and parental traits.	9 mo	There was a strong negative correlation between DWT in children classified as having an emotional temperament, with a tendency to experience emotions intensely (r = -0.54, p < 0.01).
	Age range = 9 - 12 y	Compliance (DWT measurements with TheraMon® software).		The severity of the requirements imposed on the child (r = 0.591, p < 0.001), the child’s sense of self-efficacy (r = 0.511, p = 0.001) and conscientiousness (r = 0.721, p < 0.001) of the parents were positively correlated with the patient’s cooperation.
	Treatment: removable functional appliances
	Location: Wroclaw Medical University, Wroclaw, Poland
Von Bremen et al., 201611	n = 175 (88 F, 87 M)	Compliance	COT	There was a tendency for an increased BMI to appear as a risk factor for less cooperation (48% of normal weight patients and 20% of obese patients cooperated sufficiently), although this was not statistically significant (p = 0.16).
	Mean age: 12.9 y
	Treatment: multibracket fixed appliance
	Location: University of Giessen, Giessen, Germany
Feldmann, 201420	n = 110 (56 F, 54 M)	Motivation.	COT (mean = 25.3 mo)	There was a tendency toward significant correlations between prior treatment motivation and overall satisfaction with treatment (p < 0.01).
	Mean age: 16.9 y	Expectations.		The patient’s own decision to start treatment and the PAR index pre- and posttreatment did not correlate with treatment satisfaction (p > 0.05).
	Treatment: multibracket fixed appliance	Satisfaction.
	Location: Public Dental Service, Gvleborg County Council, Gävle, Sweden.	Severity of malocclusion.
Anderson et al., 20095	n = 147	Personality and parental traits	COT	Patients more focused on the post-treatment esthetics (r = 0.337, p = 0.004) and functioning (r = 0.231, p = 0.053;) outcomes and more energized by thinking about their posttreatment possible selves were more satisfied with the treatment.
	Mean age: 11.6 y			Parents were also more satisfied with the treatment when they believed that their children were energized by thinking about their posttreatment possible selves (r = 0.326, p = 0.007).
	Treatment: NR
	Location: University of Michigan, USA
Amado et al., 20089	n = 70 (46 F, 24 M)	Personality traits.	At least 4 mo	The patient’s personality traits of extroversion/introversion, self-control and harshness do not predict cooperation during the orthodontic treatment (p < 0.05).
	Mean age: 13.4 y	Compliance.
	Age range: 12–15 y
	Treatment: NR
	Location: CES University, Medellin, Colombia
Mandall et al., 20083	n = 144 (79 F, 65 M)	Discontinued treatment.	COT (mean = 16.6 mo)	The IOTN score and the aesthetic impact of malocclusion variables showed no association with completion of orthodontic treatment (logistic regression analysis; p> 0.05).
	Mean age: 13.7 y	Severity of malocclusion.
	Age range: 10 – 19 y
	Treatment: fixed or removable appliances
	Location: University Dental Hospital of Manchester, Bolton Royal Hospital, St Anne’s Orthodontic Practice, and Hope Hospital, Salford, UK
Al-Omiri et al., 200615	n = 50 (30 F, 20 M)	Personality traits.	COT (mean, 19 mo)	Patients with high neuroticism scores were associated with lower levels of satisfaction with the dentition (r2 = -0.367, p < .01). Other personality traits (extroversion, openness, agreeableness, conscientiousness) demonstrated no relationship with satisfaction (P > 0.05).
	Mean age: 20.7 y	Satisfaction.		The IOTN had no relationship with the patient’s satisfaction (p > 0.05).
	Age range: 13–28 y	Severity of malocclusion.
	Treatment: multibracket fixed appliance
	Location: Jordan University of Science and Technology, Irbid, Jordan
Barker et al., 200516	n = 294	Personality traits.	NR	Individuals with lower scores of social closeness were twice as likely to be dissatisfied with their orthodontic result (OR: 2.07, p = 0.02).
	Age range: 15 - 26 y	Satisfaction.		The DAI had no relationship with the patient’s satisfaction (p > 0.05).
	Treatment: any type of orthodontic appliance	Severity of malocclusion.
	Location: Queen Mary Hospital, Dunedin, New Zealand.
Bartsch et al., 19931	n = 77 (37 F, 40 M)	Compliance (DWT measurements with TheraMon® software).	3.9 mo	Both internal motivation and parental involvement were beneficial for compliance (r = 0.41, p < 0.001; r = 0.50, p < 0.001).
	Mean age: 10.2 y	Psychosocial assessments.		Compliant patients are more often exposed to positive social models (r = 0.57, p <0.001).
	Age range: 9–15 y	Motivation.		Compliant patients report a high need for academic achievement (r = 0.36, p < 0.01).
	Treatment: removable functional appliances
	Location: Würzburg university, Würzburg, Germany
Egolf et al., 199022	n = 100	Personality traits.	at least 3 mo under treatment	Four factors were found to correlate weakly, but significantly,
	Mean age: 15.3 y	Compliance.		with compliance: internal/external motivation for treatment (r = 0.241, p = 0.017), health awareness (r = -0.289, p = 0.004), stoic/sensitive personality (r = -0.374, p < 0.001), and self-confidence (r = 0.252, p = 0.012).
	Treatment: headgear and intraoral elastics	Motivation.		The importance of straight teeth, oral beauty, and the social importance of beauty were not correlated with compliance (p > 0.05).
	Location: University of Illinois College of Dentistry, Chicago, USA
Woolass et al., 198821	n = 219	Personality traits.	3 y	The best cooperation group reported an increased self-concept of behavior (MD = 9.01, p <0.01), reported being able to hide their emotions (MD = 1.73, p < 0.001), and were more popular (MD = 0.68, P < 0.01), more sociable (MD = 0.60, P < 0.01) and more confident (MD = 0.49, p < 0.02).
	Age range = 11–12 y	Psychosocial assessments.		Patients with antisocial behavior were associated with poor compliance (MD = 0.71, p < 0.05).
	Treatment: NR	Compliance.
	Location: Cardiff, UK

BMI: body mass index; COT: Completed orthodontic treatment; DAI: dental aesthetic index; DWT: daily wear time; EAS-C: emotionality activity sociability-children; F: female; h: hours; IOTN: index of orthodontic treatment need; M: male; mo: months; NR: not reported; PAR: peer assessment rating; y: years.