Children and adolescents with speech sound disorders are more likely to have orofacial dysfunction and malocclusion

Abstract

Background: Children with speech sound disorders (SSD) form a heterogeneous group that differs in terms of underlying cause and severity of speech difficulties. Orofacial dysfunction and malocclusions have been reported in children with SSD. However, the association is not fully explored.

Objectives: Our aims were to describe differences in orofacial function and malocclusion between a group of children and adolescents with compared to without SSD and to explore associations between those parameters among the group with SSD.

Methods: A total of 105 participants were included, 61 children with SSD (6.0-16.7 years, mean age 8.5 ± 2.8, 14 girls and 47 boys) and 44 children with typical speech development (TSD) (6.0-12.2 years, mean age 8.8 ± 1.6, 19 girls and 25 boys). Assessments of orofacial function included an orofacial screening test and assessment of bite force, jaw stability, chewing efficiency, and intraoral sensory-motor function. Possible malocclusions were also assessed.

Result: Children with SSD had both poorer orofacial function and a greater prevalence of malocclusion than children with TSD. Furthermore, children with SSD and poorer orofacial function had a greater risk of malocclusion.

Conclusion: Our result suggests that children with SSD are more prone to having poorer orofacial function and malocclusion than children with TSD. This illustrates the importance of assessing coexisting orofacial characteristics in children with SSD, especially since orofacial dysfunction may be linked to an increased risk of malocclusion. This result highlights the need for a multiprofessional approach.

Keywords: Nordic Orofacial Test-Screening; bite force; chewing efficiency; intraoral sensory-motor function.

Figure 1

Boxplots describing orofacial function (Biteforce (a), Jaw stability (b), Chewing efficiency (c), Sensory function (d)) among the children with SSD (gray) and children with TSD (white). Boxplots illustrate quantiles with the thick black line illustrating the median, the upper and lower limit of the box illustrate the 25th and the 75th percentile, and the lower and upper whisker plots indicate the minimum and maximum values, except “extreme values,” which are marked as separate circles. If the boxes and whiskers are roughly symmetrical around the median, the sample is roughly normally distributed on that variable, as is mostly the case for the SSD participants. SD Hue, the standard deviation of the variance of Hue; SSD, speech sound disorders; TSD, typical speech development.

Figure 2

Illustration of the logistic regressions between malocclusion and NOT‐S (a), bite force (b), jaw stability (c), and chewing efficiency (d) in children with SSD. In each panel, the logistic regression function has been back‐transformed to the probability scale (y‐axis). The solid black curve illustrates the output of the logistic regression model describing the probability of a malocclusion (y‐axis) for a particular predictor value (x‐axis). The light red area illustrates the 95% CI around the regression function. We also want to communicate the empirical data, that is, the empirical proportion of malocclusion for different children along with the predictor variable (x‐axis). As the predictors are continuous variables, we have to simplify the communication and bin the participants into different groups along the x‐axis (e.g., 100–150 N). Each bin is illustrated by a circle in the figures. The circles' position on the x‐axis is the group's binned predictor value and its position on the y‐axis is the actual proportion of participants in that group that had a malocclusion. The size of the circle is proportional to how many participants were included in that group. Note that the logistic regression model was built upon the continuous data of the predictor variables, the binning is only for illustrative purposes in this figure. Our aim is to communicate that the regression function aligns with the empirical data. CI, confidence interval; NOT‐S, Nordic Orofacial Test‐Screening; SSD, speech sound disorders.

Figure 3

A “heat map” listing the relative risk of having the malocclusion listed in the column based on having a positive answer on the NOT‐S domains listed in the rows. The number is the relative risk. The color scale is based on the lower limit of a 95% CI around the relative risk; in this way, the coloring indicates the confidence of the relationship is strong, rather than the strength of the relationship. See the main text for more information. CI, confidence interval; NOT‐S, Nordic Orofacial Test‐Screening.