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Objective: To assess longitudinal variation in patterns of retromolar space growth, with regard to sex and cervical vertebrae maturation., Design: We utilized serial lateral cephalograms from three craniofacial growth studies (Denver, Iowa, Oregon), measuring retromolar space and cervical vertebrae maturation in 99 subjects (56% male) from 8 to 18 years of age for each subject. Repeated measures ANOVA and a linear mixed effects model were used to assess retromolar space growth through time., Results: Our analyses revealed an average increase in retromolar space of 8.73 mm from 8 to 18 years. While t-tests failed to find differences in retromolar space growth between males and females at the measured age points, repeated measures ANOVA and linear mixed effects models revealed modest differences in growth trends between sexes, with females having more growth earlier but a younger age of deceleration of growth (between 12 and 14 years of age)., Conclusions: Our results confirm large increases in retromolar space through growth, reaching an average of 1.38 mm/year around puberty. Importantly, we add to the conversation regarding sex differences, showing differences in timing of growth. This highlights the importance of using longitudinal data and analytical approaches to address questions of this nature., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Objective: We hypothesize that childhood obesity influences both facial and mandibular size and form in children and adolescents., Design: Pre-treatment records of patients (n = 181; 86 males, 95 females) from the Department of Orthodontics at the University of Illinois at Chicago representing six different ancestry groups (Asian, African-American, Caucasian Non-Hispanic, Hispanic, Multiracial, Unknown) were reviewed retrospectively. Body mass index (BMI) scores and categories were calculated using the Center for Disease Control and Prevention (CDC) guidelines. Twenty-two landmarks were collected on lateral cephalometric radiographs. The landmark dataset was analyzed as a whole (facial shape) and a subset of landmarks was also used to study mandibular shape in isolation., Results: Evidence of allometry (size related shape differences) was detected. Principal Component Analyses (PCA) were performed on the allometric regression residuals. Overall facial shape did not correlate with BMI. A series of one-way ANOVA tests on PC1-6 on a mandible-only subset of the landmarks using BMI category (normal, overweight, obese) showed PC5 and PC6 were significant (p = 0.003; p = 0.027). Centroid size was positively correlated with BMI when controlling for age (facial: p = 0.011, r = 0.196; mandibular: p < 0.001, r = 0.256)., Conclusions: Our results mostly did not support a relationship between high BMI and facial shape. However, we found larger facial skeletal sizes in high BMI children, providing tentative evidence that childhood obesity may lead to accelerated timing of facial growth., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Objectives: A thorough understanding of influence of maxillary growth on patterns of mandibular rotation during development is important with regard to the treatment of skeletal discrepancies. In the present study, we examined whether experimentally altered maxillary position has a significant influence on patterns of mandibular rotation in a pig model., Design: Maxillary growth was altered in a sample of n=10 domestic pigs via surgical fixation of the circummaxillary sutures. We compared the experimental group to control and surgical sham samples and assessed the effects of altered maxillary growth on mandibular form using geometric morphometric techniques. We tested for significant differences in mandibular shape between our samples and examined axes of morphological variation. Additionally, we examined whether altered mandibular shape resulting from altered maxillary position was predictably associated with morphological changes to the condylar region., Results: There was a statistically significant difference in mandibular shape between the experimental and control/sham groups. As a result of vertical displacement of the snout, mandibles in the experimental sample resulted in greater anterior rotation when compared to the control/sham pigs. Variation in rotation was correlated with morphological changes in the condyle including the shape of the articular surface and condylar orientation indicative of greater anterior mandibular rotation., Conclusions: Vertical displacement of the maxilla had a significant effect on mandibular shape by encouraging anterior mandibular rotation. This result has important implications for understanding the effects of altered mandibular posture on condylar remodeling the treatment of skeletal discrepancies such as the correction of hyperdivegent mandibular growth., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

To investigate the influence of menstrual cycle phase and the presence of severe premenstrual symptoms on cardiac autonomic control during sleep, we performed heart rate variability (HRV) analysis during stable non-rapid eye movement (NREM) and REM sleep in 12 women with severe premenstrual syndrome and 14 controls in the mid-follicular, mid-luteal, and late-luteal phases of the menstrual cycle. Heart rate was higher, along with lower high frequency (HF) power, reflecting reduced vagal activity, and a higher ratio of low frequency (LF) to high frequency power, reflecting a shift to sympathetic dominance, in REM sleep compared with NREM sleep in both groups of women. Both groups of women had higher heart rate during NREM and REM sleep in the luteal phase recordings compared with the mid-follicular phase. HF power in REM sleep was lowest in the mid-luteal phase, when progesterone was highest, in both groups of women. The mid-luteal phase reduction in HF power was also evident in NREM sleep in control women but not in women with PMS, suggesting some impact of premenstrual syndrome on autonomic responses to the hormone environment of the mid-luteal phase. In addition, mid-luteal phase progesterone levels correlated positively with HF power and negatively with LF/HF ratio in control women in NREM sleep and with the LF/HF ratio during REM sleep in both groups of women. Our findings suggest the involvement of female reproductive steroids in cardiac autonomic control during sleep in women with and without premenstrual syndrome., (Copyright © 2013 Elsevier Ltd. All rights reserved.)