The Impact of the COVID-19 Pandemic on Orthodontic Adult Patients’ Characteristics and Decision on Orthodontic Appliance

Figures & data

Table 1 Baseline demographics of Orthodontic Patients Stratified by Year of First Visit as Before or During the COVID-19 Pandemic (n = 311)

Variable	All patients (n = 311)		Patients before the COVID-19 pandemic (n = 167)		Patients after the COVID-19 pandemic (n = 144)		P value
	Mean	SD	Mean	SD	Mean	SD
Age (year)	28.7	8.2	28.3	8.0	29.1	8.4	0.392^†
Height (cm)	163.2	7.4	163.0	7.5	163.4	7.2	0.571^†
Weight (kg)	57.4	10.6	57.3	11.2	57.4	9.9	0.966^†
Body mass index (kg/m2)	21.5 ± 3.3		21.5 ± 3.4		21.5 ± 3.3		0.854^†
Female sex, n (%)	239 (76.8)		127 (76.0)		112 (77.8)		0.788^†
Student, n (%)	95 (30.6)		60 (35.9)		35 (24.5)		0.036*^‡
Hospital employee, n (%)	62 (19.9)		27 (16.2)		35 (24.3)		0.088^‡
Diabetes mellitus, n (%)	3 (1)		1 (0.6)		2 (1.4)		0.597^‡
Hypertension, n (%)	2 (0.6)		1 (0.6)		1 (0.7)		1.000^‡
Smoking habits, n (%)	3 (1)		0 (0)		3 (2.1)		0.098^‡
Alcohol consumption, n (%)	1 (0.3)		1 (0.6)		0 (0)		1.000^‡
Betel nut chewing, n (%)	0 (0)		0 (0)		0 (0)		1.000^‡
Bruxism, n (%)	11 (3.5)		6 (3.6)		5 (3.5)		1.000^‡

Note: *P < 0.05, ^†Independent t tests, ^‡Chi-square tests.

Abbreviation: SD, standard deviation.

Table 2 Orthodontic Bracket Type Chosen by the Patients Stratified by Year of First Visit as Before or During the COVID-19 Pandemic (n = 311)

Variable	All patients (n = 311)	Patients before the COVID-19 pandemic (n = 167)	Patients after the COVID-19 pandemic (n = 144)	P value
No treatment, n (%)	38 (12.2)	21 (12.6)	17 (11.8)	0.022*^‡
Metal brackets, n (%)	158 (50.8)	97 (58.1)	61 (42.4)
Ceramic brackets, n (%)	47 (15.1)	19 (11.4)	28 (19.4)
Invisalign, n (%)	68 (21.9)	30 (18.0)	38 (26.4)

Note: *P < 0.05, ^‡Chi-square tests.

Table 3 Decayed, Missing, and Filled Teeth (DMFT) Index of the Orthodontic Patients Stratified by Year of First Visit as Before or During the COVID-19 Pandemic (n = 311)

Variable	All patients (n = 311)		Patients before the COVID-19 pandemic (n = 167)		Patients after the COVID-19 pandemic (n = 144)		P value
	Mean	SD	Mean	SD	Mean	SD
Decayed	1.2	1.6	1.2	1.7	1.2	1.6	0.933^†
Missing	0.7	1.7	0.8	1.8	0.7	1.5	0.782^†
Filled	6.3	4.9	5.9	4.8	6.8	4.9	0.072^†
DMFT index	8.2	6.2	7.8	6.1	8.7	6.2	0.171^†

Note: ^†Independent t tests.

Abbreviation: SD, standard deviation.

Table 4 Sagittal Skeletal Relationship of the Orthodontic Patients Stratified by Year of First Visit as Before or During the COVID-19 Pandemic (n = 311)

Variable	All patients (n = 311)	Patients before the COVID-19 pandemic (n = 167)	Patients after the COVID-19 pandemic (n = 144)	P value
Class I, n (%)	109 (35.3)	55 (33.1)	54 (37.8)	0.265^‡
Class II, n (%)	150 (48.5)	79 (47.6)	71 (49.7)
Class III, n (%)	50 (16.2)	32 (19.3)	18 (12.6)

Note: ^‡Chi-square tests.

Table 5 Dental Malocclusion Type of the Orthodontic Patients Stratified by Year of First Visit as Before or During the COVID-19 Pandemic (n = 311)

Variable	All patients (n = 311)	Patients before the COVID-19 pandemic (n = 167)	Patients after the COVID-19 pandemic (n = 144)	P value
Angle’s Class I, n (%)	133 (42.8)	63 (37.7)	70 (48.6)	0.044*^‡
Angle’s Class II, n (%)	92 (29.6)	59 (35.3)	33 (22.9)
Angle’s Class III, n (%)	86 (27.7)	45 (26.9)	41 (28.5)

Note: *P < 0.05, ^‡Chi-square tests.

Table 6 Index of Complexity Outcome and Need (ICON) of the Orthodontic Patients Stratified by Year of First Visit as Before or During the COVID-19 Pandemic (n = 311)

Variable	All patients (n = 311)		Patients before the COVID-19 pandemic (n = 167)		Patients after the COVID-19 pandemic (n = 144)		P value
	Mean	SD	Mean	SD	Mean	SD
Aesthetic	5.9	1.2	6.0	1.1	5.9	1.3	0.562^†
Upper arch crowding	1.8	1.6	1.9	1.5	1.8	1.6	0.390^†
Crossbite	0.5	0.5	0.6	0.5	0.4	0.5	< 0.001***^†
Incisor open bite	0.6	0.4	0.1	0.3	0.1	0.5	0.664^†
Incisor overbite	0.5	0.8	0.5	0.8	0.6	0.8	0.587^†
Buccal segment anteroposterior	1.9	1.5	2.4	1.4	1.3	1.3	< 0.001***^†
ICON	61.3	15.1	63.9	14.0	58.3	15.3	0.001**^†

Note:**P < 0.01, *** P < 0.001, ^†Independent t tests.

Abbreviation: SD, standard deviation.

Table 7 Degree of Treatment Difficulty Stratified by Year of First Visit as Before or During the COVID-19 Pandemic (n = 311)

Variable	All patients (n = 311)		Patients before the COVID-19 pandemic (n = 167)		Patients after the COVID-19 pandemic (n = 144)		P value
	Mean	SD	Mean	SD	Mean	SD
Skeletal score	2.1	1.6	2.3	1.0	2.0	1.1	0.007*^†
Dental score	1.8	1.0	1.8	1.0	1.9	1.0	0.601^†
Facial score	0.9	0.8	1.0	0.8	0.7	0.7	0.001**^†
Model score	2.3	1.4	2.4	1.3	2.3	1.4	0.626^†
Total score	7.2	2.6	7.4	2.6	6.8	2.6	0.049*^†

Note:*P < 0.05, **P < 0.01, ^†Independent t tests.

Abbreviation: SD, standard deviation,