# Table 4 Hierarchical Poisson regression for impact on OHRQoL of family and independent variables

Variable Impact on family’s OHRQoL Bivariate Multivariate
Present n (%) Absent n (%) Unadjusted Adjusted
PR* PR †
p-value p-value
(95% CI) (95% CI)
Sex
Female 106 (26.0) 301 (74.0)   1.00 - -
Male 115 (26.4) 321 (73.6) 0.913 1.013 (0.807-1.270) - -
Age
3 years 66 (24.0) 209 (76.0)   1.00 - -
4 years 85 (25.4) 249 (74.6) 0.681 1.060 (0.802-1.402) - -
5 years 70 (29.9) 164 (70.1) 0.133 1.246 (0.935-1.662) - -
1 st level
Type of preschool
Public 131 (28.7) 325 (71.3) 0.074 1.235 (0.980-1.557) - -
Private 90 (23.3) 297 (76.7)   1.00 - -
Mother’s schooling
≤ 8 years of study 117 (30.2) 271 (69.8) 0.019 1.311 (1.045-1.644) - -
> 8 years of study 104 (23.0) 348(77.0)   1.00 - -
Monthly household income
≤ 1 minimum salary 132 (29.9) 310 (70.1) 0.023 1.318 (1.039-1.673) - -
> 1 minimum salary 82 (22.7) 280 (77.3)   1.00 - -
Parent’s/guardian’s age
≤ 30 years 120 (28.4) 302 (71.6) 0.080 1.232 (0.975-1.557) - -
> 30 years 93 (23.1) 310 (76.9)   1.00 - -
Number of residents in home
< 6 176 (25.2) 523 (74.8)   1.00 - -
≥ 6 43 (33.3) 86 (66.7) 0.046 1.324 (1.005-1.744) - -
Birth order
Only child 55 (20.9) 208 (79.1)   1.00 - -
Oldest child 39 (31.7) 84 (68.3) 0.020 1.516 (1.068-2.152) - -
Middle child 27 (26.0) 77 (74.0) 0.290 1.241 (0.832-1.853) - -
Youngest child 98 (28.1) 251 (71.9) 0.046 1.343 (1.006-1.792) - -
2 nd level
Perception of general health
Good 157 (23.1) 523 (76.9)   1.00 - -
Poor 61 (38.4) 98 (61.6) <0.001 1.662 (1.307-2.113) - -
Perception of oral health
Good 88 (15.7) 472 (84.3)   1.00   1.00
Poor 133 (47.2) 149 (52.8) <0.001 3.001 (2.389-3.770) <0.001 2.116 (1.624-2.757)
3 rd level
Dental caries
Absent 35 (12.4) 248 (87.6)   1.00 - -
Present 186 (33.2) 374 (66.8) <0.001 2.686 (1.928-3.742) - -
Cavitated lesions
Absent/white spots 55 (12.5) 386 (87.5)   1.00   1.00
Cavitated anterior teeth 14 (24.1) 44 (75.9) 0.013 1.935 (1.152-3.252) 0.079 1.586 (0.949-2.651)
Cavitated posterior teeth 73 (39.7) 111 (60.3) <0.001 3.181 (2.345-4.315) <0.001 2.380 (1.679-3.372)
Cavitated anterior and posterior teeth 79 (49.4) 81 (50.6) <0.001 3.959 (2.954-5.306) <0.001 2.809 (2.009-3.926)
TDI
Absent 143 (25.9) 410 (74.1)   1.00 - -
Present 74 (25.9) 212 (74.1) 0.996 1.001 (0.786-1.274) - -
Type of TDI
Discolouration 32 (33.0) 65 (67.0) 0.080 1.322 (0.968-1.805) 0.054 1.326 (0.995-1.766)
Avulsion and/or luxation 4 (36.4) 7 (63.6) 0.352 1.457 (0.660-3.217) 0.006 2.448 (1.288-4.653)
Enamel + dentine fracture 9 (21.4) 33 (78.6) 0.614 0.858 (0.474-1.554) 0.877 1.048 (0.582-1.885)
Enamel fracture and without trauma 172 (25.0) 517 (75.0)   1.00   1.00
Malocclusion
Absent 81 (27.6) 212 (72.4) 0.386 1.110 (0.877-1.405) - -
Present 136 (24.9) 410 (75.1)   1.00 - -
Anterior crossbite
Absent 207 (25.5) 606 (74.5)   1.00 - -
Present 9 (39.1) 14 (60.9) 0.107 1.537 (0.911-2.593) - -
Anterior open bite
Absent 166 (25.7) 481 (74.3) 0.950 1.009 (0.759-1.341) - -
Present 45 (25.4) 132 (74.6)   1.00 - -
Posterior crossbite
Absent 548 (74.9) 184 (25.1)   1.00 - -
Unilateral 27 (29.0) 66 (71.0) 0.408 1.155 (0.821-1.625) - -
Bilateral 5 (55.6) 4 (44.4) 0.009 2.210 (1.216-4.017) - -
Increased overbite
Absent 185 (27.8) 481 (72.2) 0.006 1.688 (1.164-2.449) - -
Present 26(16.5) 132(83.5)   1.00 - -
Increased overjet
Absent 128 (27.2) 342 (72.8) 0.298 1.133 (0.896-1.432) - -
Present 88 (24.0) 278 (76.0)   1.00 - -
1. *Unadjusted Poisson regression for independent variables and impact on family’s quality of life.
2. **Variables incorporated in multivariate model (p < 0.20): sex, age, type of preschool, mother’s schooling, monthly household income, parent’s/guardian’s age, number of residents in home, child’s birth order, parent’s/caregiver’s perception of child’s general health, parent’s/caregiver’s perception of child’s oral health, dental caries, untreated dental caries, traumatic dental injury, type of traumatic dental injury, malocclusion, anterior crossbite, posterior crossbite and increased overbite.
3. ***For dental caries, the cut-off point was code ≥ 2; for cavitated lesions, absent/white spots (codes ≤ 2) and cavitated tooth (codes ≥ 3) were considered.
4. †Hierarchical Poisson regression: Level 1 adjusted for child’s characteristics and socio-demographic variables; Level 2 adjusted for child’s characteristics, socio-demographic variables and parent’s/caregiver’s perception of child’s health; Level 3 adjusted for child’s characteristics, socio-demographic variables, parent’s/caregiver’s perception of child’s health and oral health problems (dental caries, traumatic dental injuries and malocclusion).