Esthetic impact of malocclusions in the anterior segment on children in the mixed dentition


To assess the esthetic subjective effect of malocclusions in the anterior segment on children in the mixed dentition.


A cross-sectional study was carried out with a population-based sample of 787 children aged 8-10 years in the late mixed dentition (n = 787). Orthodontic Aesthetic Subjective Impact Score determined the esthetic subjective effect. For assessing the malocclusions in the anterior segment (anterior crowding, anterior spacing, diastema, anterior open bite, and anterior maxillary overjet), the following Dental Aesthetic Index criteria were used. Sex, family income, and education level were used as control variables. The variables were analyzed using a simple logistic regression model, estimating crude odds ratios. The variables with P <0.20 in the simple analyses were tested in multiple regression models, estimating adjusted odds ratios with the respective 95% confidence intervals.


Increased overjet was 1.54 (95% CI: 1.08-2.17) times more likely to cause greater esthetic concern ( P <0.05), especially in girls ( P <0.05).


Increased overjet negatively affected children’s esthetic self-perception in the mixed dentition.


  • We assessed the esthetic effect of anterior segment malocclusion in the mixed dentition.

  • Orthodontic Aesthetic Subjective Impact Score was used to assess the esthetic effect.

  • Increased overjet negatively affected esthetic self-perception in the mixed dentition.

  • No impact was found for anterior crowding or spacing, diastema, or anterior open bite.

Mixed dentition is characterized by a wide range of occlusal variations that do not necessarily define a malocclusion. In addition, children at this stage develop self-perceptions related to esthetics, , , self-esteem, and social acceptance, , using criteria similar to adults. Therefore, it is essential to understand how occlusal changes, typical at this stage, affect the individual. The psychological benefits of orthodontic treatment generally prevail over the impact on oral function and health, which justifies the highlight in the mixed dentition. , ,

Most studies assessing the impact of malocclusion on oral health–related quality of life (OHRQOL) were performed in the primary or permanent dentition. Studies in the mixed dentition , present limitations, especially regarding the occlusal indexes used, which, when applied fully, do not consider the individualities and transient changes inherent in this stage.

OHRQOL may differ between countries and individuals because a self-perceived measure can depend on the context of the child. , In addition, the literature highlights the absence of studies assessing the impact of malocclusion on psychological well-being and self-esteem of children in the mixed dentition. Malocclusions can negatively affect children’s and adolescents’ OHRQOL, especially if the malocclusions were present in the esthetic zone.

Occlusal characteristics, such as increased overjet, deep overbite, dental crowding, and spacing, are usually associated with dissatisfaction with dental appearance. , , In the same context, the physiological occlusal changes inherent to the mixed dentition should be verified more carefully. Some malocclusions in the anterior segment are particularly visible in interpersonal interactions, limiting awareness of malocclusion to the smile.

Therefore, we tested the hypothesis that malocclusions present in the esthetic zone affect children’s esthetic self-perception in this stage. This study aimed to assess the perceived esthetic impact of anterior occlusal conditions on children in the mixed dentition.

Material and methods

A cross-sectional observational study was conducted with children aged between 8 and 10 years with late mixed dentition. A 2-phase sampling method was used to ensure the representativeness of the sample. Initially, a list of schools was obtained from the Secretary of Education. Then, the schools were selected from each city district by a stratified sampling procedure, proportional to children’s age. The schools were randomly selected by drawing from each district in the first phase, and children were randomly selected from each school in the second phase. The minimum sample of 650 patients was calculated on the basis of a 5% significance level, 95% confidence interval (CI), a test power of 80%, and effect size of 1.5. An additional 20% of children were added to compensate for possible dropouts, for a final estimated sample size of 780 children. The Human Research Ethics Committee approved the study (no. 74393317.7.0000.5385), and it was performed according to the STROBE (STrengthening the Reporting of OBservational studies in Epidemiology) statement.

The mixed dentition was determined having as reference dental age, proposed by Van der Linden (1983), and based exclusively on the teeth present in the buccal cavity. According to this referential, the mixed dentition presents 2 important exchange periods of deciduous by permanent teeth: early (first transitional period) and late (second transitional period) mixed dentition. In this study, all children were in late mixed dentition. Current orthodontic treatment, deciduous dentition, early mixed dentition, and complete permanent dentition, in addition to systemic diseases such as cerebral palsy or Down syndrome, were exclusion criteria.

The Orthodontic Aesthetic Subjective Impact Score (OASIS) determined the esthetic impact of malocclusion. The first part of the instrument contains 5 items, each with 3 response choices. The responses are quantified and scored in ascending order according to the Likert scale. The second part includes the Aesthetic Component of the Index of Orthodontic Treatment Need (AC-IOTN). The AC-IOTN assesses psychosocial needs with a dental attractiveness scale illustrated by 10 colored photographs with a descending and continuous level of attractiveness. Image 1 represents the most attractive dental arrangement, and image 10 is the least attractive. The children completed the assessments, identifying the level of esthetic compromise in the scale images they considered similar to their own smile. The final OASIS result was obtained by adding together the responses to the instrument with the value of the image selected in the AC-IOTN for a single score. The esthetic effect was considered the outcome variable and was dichotomized by the median of responses. Lower values indicate a lower esthetic concern, and higher values indicate a higher esthetic concern. ,

The independent variables were classified into clinical (components of the Dental Aesthetic Index [DAI]), social (family income and parental level of education), and demographic characteristics (sex and race). Family income (≤R$ 2,000.00 or >R$ 2,000.00) and parental level of education (up to eighth grade completed or > eighth grade completed) were categorized on the basis of the response medians.

The DAI is a numerical index that indicates the occlusal characteristic selected according to the likelihood of causing psychosocial incapacity and includes parameters related to clinical and esthetic aspects. In general, the DAI index is assessed as the sum of the scores of each characteristic evaluated added to a constant value. This sum identifies patients’ orthodontic treatment needs to be determined by the severity of the malocclusion. In our study, for analysis, the index was not calculated mathematically, but its components that evaluate the anterior segment of the occlusion were used separately to verify which of them were related to the self-perception of dental appearance. The following clinical conditions were assessed in the anterior segment of the occlusion: anterior crowding, anterior spacing, midline diastema, anterior maxillary overjet, and anterior open bite.

The crowding in anterior segments, including the 4 permanent incisors, was observed in the maxillary and mandibular arches. Crowding was considered when the space between right and left canines was insufficient to accommodate the 4 incisors in alignment. Crowding in the anterior segment was classified as follows: 0 = no crowding in maxillary and mandibular segments, 1 = crowding in 1 segment (maxillary or mandibular), 2 = crowding in 2 segments (maxillary and mandibular). For data analysis, it was dichotomized as 0 = absence of crowding and 1 and 2 = presence of crowding.

Anterior spacing was considered when the space between the right and left canines was larger than required for the normal alignment of incisors. Spacing in the anterior segment was classified as follows: 0 = no spacing; 1 = spacing in 1 segment (maxillary or mandibular); 2 = spacing in 2 segments (maxillary and mandibular). For data analysis, it was dichotomized as 0 = absence of anterior spacing and 1 and 2 = presence of anterior spacing.

Diastema in the midline between permanent maxillary central incisors was registered in millimeters from the height of the line of adjacent teeth or in the point of greater convexity of the proximal surface. The values considered were ≤1 mm = absence of diastema and >1 = presence of diastema.

Anterior open bite was assessed in millimeters with the periodontal probe, from the middle of the incisal margin of the teeth involved. The values considered were 0 mm = normal overbite and ≥1 mm = presence of anterior open bite.

Anterior maxillary overjet was measured in millimeters as the distance between the buccal incisal margin of the most protruded maxillary incisor and the buccal surface of the correspondent mandibular incisor, with the periodontal probe placed in contact with the buccal surface of the mandibular incisor, parallel to the occlusal plane and perpendicular to the archline. The values considered were ≥3 mm = normal overjet, ≤0 mm = decreased anterior maxillary overjet, and >4 mm = increased anterior maxillary overjet.

One trained and calibrated examiner (J.B.) performed the clinical examinations in the school in a naturally lit environment and used wooden spatulas and gauze as aids. Before the examiner started the experimental phase, a 16-hour training was performed, including 4 hours of theoretical classes and 12 hours of practical classes. Another 4 hours were dedicated to the calibration process to obtain an estimate of the diagnostic extension. The intraexaminer kappa coefficient was higher than 0.92 for the assessment of the DAI.

Statistical analysis

Simple logistic regression models were constructed, estimating crude odds ratios (ORs) with the respective 95% CIs. All variables in the individual analyses with P ≤0.20 were tested with multiple logistic regression simultaneously, but only those with P ≤0.05 remained in the final model. Adjusted ORs were estimated with the respective 95% CIs. The analyses were performed in the R Program (R Foundation for Statistical Computing, Vienna, Austria) at a 5% significance level.


The final sample was composed of 787 girls (50.3%) and boys (49.7%) aged 8 to 10 years (mean: 9.1 years). Most of them were white (60.7%), with low family income (74%) and low maternal (41.6%) and paternal level of education (47%). Among the anterior occlusal conditions, 45.1% presented anterior crowding, 56.5% presented anterior spacing, 50.8% presented midline diastema, 29.0% presented anterior maxillary overjet, and 8.4% presented anterior open bite. In addition, 44.9% of the boys and 35% of the girls showed high esthetic concern by OASIS ( Table I ).

Table I
Frequency distribution of esthetic impact in the anterior segment: Social and demographic characteristics
Variable Category n (%) Lower esthetic concern Higher esthetic concern
Frequency (%) Frequency (%)
Sex Male 391 (49.7) 254 (65.0) 137 (35.0)
Female 396 (50.3) 218 (55.1) 178 (44.9)
Race White 478 (60.7) 289 (60.5) 189 (39.5)
Nonwhite 309 (39.3) 183 (59.2) 126 (40.8)
Family income Low income 582 (74.0) 344 (59.1) 23 (40.9)
High income 205 (26.0) 128 (62.4) 77 (37.6)
Father’s education Low schooling 370 (47.0) 213 (57.6) 157 (42.4)
High schooling 417 (53.0) 259 (62.1) 158 (37.9)
Mother’s education Low schooling 327 (41.6) 184 (56.3) 143 (43.7)
High schooling 460 (58.4) 288 (62.6) 172 (37.4)
Anterior crowding Absence 432 (54.9) 261 (60.4) 171 (39.6)
Presence 355 (45.1) 211 (59.4) 144 (40.6)
Anterior spacing Absence 342 (43.5) 217 (63.5) 125 (36.5)
Presence 445 (56.5) 255 (57.3) 190 (42.7)
Midline diastema Absence 387 (49.2) 246 (63.6) 141 (36.4)
Presence 400 (50.8) 226 (56.5) 174 (43.5)
Anterior maxillary overjet Decreased 228 (29.0) 129 (56.6) 99 (43.4)
Normal 331 (42.1) 217 (65.6) 114 (34.4)
Increased 228 (29.0) 126 (55.3) 102 (44.7)
Anterior open bite Absence 721 (91.6) 435 (60.3) 286 (39.7)
Presence 66 (8.4) 37 (56.1) 29 (43.9)
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Jan 30, 2021 | Posted by in Orthodontics | Comments Off on Esthetic impact of malocclusions in the anterior segment on children in the mixed dentition
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