Patients with dentofacial disharmonies (DFDs) seek orthodontic care and orthognathic surgery to address issues with mastication, esthetics, and speech. Speech distortions are seen 18 times more frequently in Class III DFD patients than the general population, with unclear causality. We hypothesize there are significant differences in spectral properties of stop (/t/ or /k/), fricative (/s/ or /ʃ/), and affricate (/tʃ/) consonants and that severity of Class III disharmony correlates with the degree of speech abnormality. To understand how jaw disharmonies influence speech, orthodontic records and audio recordings were collected from Class III surgical candidates and reference subjects (n = 102 Class III, 62 controls). A speech pathologist evaluated subjects and recordings were quantitatively analysed by Spectral Moment Analysis for frequency distortions. A majority of Class III subjects exhibit speech distortions. A significant increase in the centroid frequency (M1) and spectral spread (M2) was seen in several consonants of Class III subjects compared to controls. Using regression analysis, correlations between Class III skeletal severity (assessed by cephalometric measures) and spectral distortion were found for /t/ and /k/ phones. Class III DFD patients have a higher prevalence of articulation errors and significant spectral distortions in consonants relative to controls. This is the first demonstration that severity of malocclusion is quantitatively correlated with the degree of speech distortion for consonants, suggesting causation. These findings offer insight into the complex relationship between craniofacial structures and speech distortions.

The prevalence of childhood and adolescent obesity is increasing worldwide. Reports suggest that elevated body mass index (BMI) is associated with larger craniofacial dimensions and advanced dental and skeletal development. Such an association is important for timing orthodontic treatment relative to pubertal growth and dental eruption. To evaluate associations between BMI, craniofacial morphology, dental age, and cervical vertebrae maturation staging (CVMS), 400 participants were consecutively selected (8–15 years, n = 200 overweight and obese BMI >85%, 200 normal weight) from the University of North Carolina database. Records were analysed for cephalometric measures, Demirjian index values, and CVMS. Bivariate statistics and linear regression analysis evaluated whether CVMS, dental age, and cephalometric dimensions varied with BMI. Overweight/obese children and adolescents had a proportionally larger bimaxillary prognathic skeletal pattern compared to those of normal weight. These cephalometric measurements [articulare–gnathion (Ar–Gn), condylion–anterior nasal spine (Co–ANS), sella–gonion (S–Go), nasion–menton (N–Me), anterior nasal spine–menton (ANS–Me), sella-nasion-A point (SNA), sella-nasion-B point (SNB), and sella-nasion-pogonion (SNPg)] were significantly different [statistically (P < 0.05) and clinically (>2 mm or >2 degrees)] between the two study groups, with a linear relationship between BMI percentile and craniofacial dimension. The overweight/obese BMI group had a mean dental age 1.4 years advanced relative to the normal weight group (P < 0.05), with an advancement of nearly one CVM stage between the ages of 12 and 14 (P < 0.05). The study is retrospective. Obese/overweight children and adolescents have proportionally larger antero-posterior and vertical dimensions and are more likely to experience advanced dental and skeletal maturation. Obese/overweight subjects may enter their growth spurt at a younger age and have earlier eruption of teeth, affecting treatment timing. BMI percentile should be a consideration for orthodontic treatment in growing patients.

Introduction: Articulation problems are seen in 80% to 90% of dentofacial deformity (DFD) subjects compared with 5% of the general population, impacting communication and quality of life, but the causal link is unclear. We hypothesize there are both qualitative (perceptual) and quantitative (spectral) differences in properties of stop (/t/ or /k/), fricative (/s/ or /ʃ/), and affricate (/tʃ/) consonant sounds and that severity of anterior open bite (AOB) jaw disharmonies correlates with degree of speech abnormality. Methods: To test our hypotheses, surgical orthodontic records and audio recordings were collected from DFD patients (n = 39 AOB, 62 controls). A speech pathologist evaluated subjects, and recordings were analyzed using spectral moment analysis (SMA) to measure sound frequency distortions. Results: Perceptually, there is a higher prevalence of auditory and visual speech distortions in AOB DFD patients when compared to controls. Quantitatively, a significant ( P < .01) increase in the centroid frequency (M1) was seen in the /k/, /t/, /tʃ/, and /s/ sounds of AOB subjects compared to the controls. Using linear regression, correlations between AOB skeletal severity and spectral distortion were found for /k/ and /t/ sounds. Conclusions: A higher prevalence of qualitative distortions and significant quantitative spectral distortions in consonant sounds were seen in AOB patients compared to controls. Additionally, severity of skeletal AOB is correlated with degree of distortion for consonant sounds. These findings provide insight into how the surgical and/or orthodontic treatment of AOB may impact speech.

Prevalence of adolescent obesity has markedly increased from 5.2% in 1974 to 19.7% in 2021. Understanding the impacts of obesity is important to orthodontists, as growth acceleration and greater pre-pubertal facial dimensions are seen in children with elevated body mass index (BMI). To identify whether adolescent obesity shifts the timing and rate of craniofacial growth resulting in larger post-treatment dimensions, we evaluated cephalometric outcomes in overweight/obese (BMI > 85%, n = 168) and normal weight (n = 158) adolescents (N = 326 total). Cephalometric measurements were obtained from pre- and post-treatment records to measure growth rates and final dimensions and were statistically evaluated with repeated measures analysis of variance and linear regression models. Overweight and obese adolescents began and finished treatment with significantly larger, bimaxillary prognathic craniofacial dimensions, with elevated mandibular length [articulare-gnathion (Ar-Gn)], maxillary length [condylion-anterior nasal spine (Co-ANS), posterior nasal spine-ANS (PNS-ANS)], and anterior lower face height (ANS-Me), suggesting overweight children grow more overall. However, there was no difference between weight cohorts in the amount of cephalometric change during treatment, and regression analyses demonstrated no correlation between change in growth during treatment and BMI. BMI percentile was a significant linear predictor (P < 0.05) for cephalometric post-treatment outcomes, including Ar-Gn, Co-ANS, ANS-Me, upper face height percentage (UFH:total FH, inverse relationship), lower face height percentage (LFH:total FH), sella-nasion-A-point (SNA), and SN-B-point (SNB). The study is retrospective. Growth begins earlier in overweight and obese adolescents and continues at a rate similar to normal-weight children during orthodontic treatment, resulting in larger final skeletal dimensions. Orthodontics could begin earlier in overweight patients to time care with growth, and clinicians can anticipate that overweight/obese patients will finish treatment with proportionally larger, bimaxillary-prognathic craniofacial dimensions.