Correction: The effect of sex and age on facial shape directional asymmetry in adults: A 3D landmarks-based method study.

[This corrects the article DOI: 10.1371/journal.pone.0288702.].

The effect of sex and age on facial shape directional asymmetry in adults: A 3D landmarks-based method study.

OBJECTIVES: Facial directional asymmetry research, including age-related changes, is crucial for the evaluation of treatment of craniofacial malformations/trauma in orthodontics, facial surgery and forensic sciences. The aim was to describe facial directional asymmetry (DA) in different age categories of adults using 3D methods. According to our hypothesis, facial shape DA (1) depends on sex; (2) differs among age groups; and (3) has wider variability in older age. MATERIAL AND METHODS: A cross-sectional sample of healthy Czech adults without craniofacial trauma or anomalies consisted of 300 3D facial models (151 females). The age-range in the study was between 20-80 years. The shape asymmetry of 28 3D landmarks was evaluated using geometric morphometrics and multivariate statistics. RESULTS: The manifestation of DA was similar in both sexes and in each age category; however, there were some statistical differences. In contrast to the ideal symmetrical face, the mean asymmetrical faces tended to create a slightly bent "C" shape of the midline. Therefore, the upper face was rotated slightly clockwise and the lower face counter-clockwise. The right eye was located slightly higher, with the nasal tip and mandibular region tilting to the left. Sex differences in facial DA were significant before the age of 40. DA was more significant in the youngest males than in the oldest, while the women's DA did not change. CONCLUSIONS: The DA patterns were similar in both sexes and in all age categories (a slightly bent C shape of the midline); however, some significant local differences between male age groups were found. A significantly more pronounced asymmetry compared to other age groups was found only in the youngest males from 20 to 40 years. Moreover, significant sexual dimorphism of DA rapidly decreased after middle age, likely caused by the same age-related changes of the face during aging.

Morphometric Assessment of Facial Morphology in Infants with Orofacial Clefts up to two Years of Age: A Three-Dimensional Cross-Sectional Study.

OBJECTIVE: To assess modelled facial development of infants with unilateral cleft lip (CL) and cleft lip and palate (UCLP) compared to controls up to two years of age. DESIGN AND PARTICIPANTS: A total of 209 facial images of children (CL: n = 37; UCLP: n = 39; controls: n = 137) were obtained in four age categories (T0 = 0.2-0.5; T1 = 0.6-1.0; T2 = 1.1-1.5; T3 = 1.6-2.0 years) and were evaluated using stereophotogrammetry and geometric morphometry. All patients underwent lip surgery before T0, patients with UCLP underwent palatoplasty (T0, T1 before palatoplasty; T2, T3 after palatoplasty). RESULTS: In patients with CL, the forehead was significantly retracted (p ≤ 0.001), while the supraorbital and ocular regions were prominent (p ≤ 0.001). The oronasal region appeared convex (p ≤ 0.001). The lower lip and chin were non-significantly protruded. In patients with UCLP, a significantly retracted forehead and prominent supraorbital region were apparent (p ≤ 0.001). A retrusive oronasal region (p ≤ 0.001) was observed in the middle face. The chin was anteriorly protruded (p ≤ 0.01). No progression of deviations was found with increasing age. After the first year, a slight improvement in the morphological features became apparent. The shape variability of the clefts and controls overlapped, suggesting a comparable modelled facial development. CONCLUSIONS: The facial morphology of individuals with cleft was comparable to the norm. Shape deviation was apparent in the oronasal region, forehead, and chin, which minimised with increasing age even in complete clefts.

Palatal surface development from 6 years of age to early adulthood: data modelling using 3D geometric morphometrics.

OBJECTIVES: The study followed the modelling of postnatal growth of a healthy palate of the Central European (Czech) population sample based on transverse data on sex and age from 6 to 19 years. MATERIALS AND METHODS: Digitised 3D models of 212 healthy palatal surfaces were evaluated using 3D geometric morphometrics and superimpositions. The individuals were grouped based on age (preschool, younger and older school age, younger and older adolescents, young adults) and sex (♂ n = 101, ♀ n = 111). RESULTS: Female palatal development was non-linear and was interrupted between the 10-12 years and then proceeded intensively until the age of 15 when it ceased. In contrast, male-modelled growth was consistent throughout the follow-up and continued linearly until at least 19 years of age. The palate did not widen further with increasing age, and primarily palatal vaulting and heightening were found. The characteristics and distribution of areas with extensive modelled growth changes were comparable in females and males, as confirmed by the location of principal components (PC1 and PC2) within modal space and growth trajectories. The extent of sexual dimorphism increased from 15 years of age due to pubertal spurt combined with earlier completion of palatal development in females. CONCLUSIONS: The study showed modelled healthy palatal development from 6 years of age to early adulthood, which might be utilised as reference standards for the Central European population sample. CLINICAL RELEVANCE: The comparison of normal reference subjects with patients with cranio-maxillo-facial dysmorphologies represents the first step in diagnosing and establishing effective therapy.

Three-dimensional analysis of modeled facial aging and sexual dimorphism from juvenile to elderly age.

A detailed understanding of craniofacial ontogenetic development is important in a variety of scientific disciplines dealing with facial reconstruction, forensic identification, ageing prediction, and monitoring of pathological growth, including the effect of therapy. The main goals of this study were (1) the construction of the facial aging model using local polynomial regression fitting separately for both sexes, (2) evaluation of the aging effect not only on facial form as a whole but also on dimensions important for clinical practice, and (3) monitoring of the development of shape facial sexual dimorphism. Our study was based on the form and shape analysis of three-dimensional facial surface models of 456 individuals aged 14-83 years. The facial models were obtained using a structured light-based optical scanner and divided (for some analyses) into four age categories (juveniles, young adults, middle adults, and elderly adults). The methodology was based on geometric and classic morphometrics including multivariate statistics. Aging in both sexes shared common traits such as more pronounced facial roundness reducing facial convexity, sagging soft tissue, smaller visible areas of the eyes, greater nose, and thinner lips. In contrast to female faces, male faces increase in size until almost 30 years of age. After the age of 70, male facial size not only stagnates, like in females, but actually decreases slightly. Sexual dimorphic traits tended to diminish in the frontal and orbitonasal areas and increase in the gonial area.

Palatal growth changes in newborns with unilateral and bilateral cleft lip and palate from birth until 12 months after early neonatal cheiloplasty using morphometric assessment.

OBJECTIVES: To compare palatal growth changes in infants with complete unilateral (UCLP) or bilateral (BCLP) cleft lip and palate during the first year of life. MATERIALS AND METHODS: Upper dental arches of 68 neonates with UCLP and BCLP were evaluated using 2D and 3D morphometry based on dental casts obtained in two age categories (T0 before early neonatal cheiloplasty-UCLP 4 ± 3 days, BCLP 6 ± 5 days; T1 before palatoplasty-UCLP 10 ± 2 months, BCLP 12 ± 3 months). RESULTS: Intensive palatal growth was manifested in both directions of the palate. Palatal growth in the anterior direction was not restricted, despite the intercanine (CC´) and anterior (LL´) widths being significantly narrowed in the BCLP group (CC´ p = 0.019, LL´ p = 0.009). The posterior dental arches were significantly enlarged (UCLP p ≤ 0.001; BCLP p ≤ 0.001). The negative effect of cleft severity on palatal length was not confirmed (p = 0.802). Variability of the palate was immense mainly in BCLP infants (T0); however, it decreased in both cleft types, confirming the formative effect of palatal growth leading to alveolar cleft closure (UCLP p ≤ 0.001; BCLP p = 0.006 on the right, 0.005 on the left). CONCLUSIONS: Both analyzed cleft groups (UCLP, BCLP) grew favorably during the first year of life, and the palatal growth was not limited in any direction. CLINICAL RELEVANCE: Geometric morphometry allowed a comprehensive analysis of the palate, which can contribute to the improvement of surgical methods.

Three-dimensional development of the palate in bilateral orofacial cleft newborns 1 year after early neonatal cheiloplasty: Classic and geometric morphometric evaluation.

OBJECTIVES: The aim of this study was to assess palatal growth in newborns with complete bilateral cleft lip and palate (cBCLP) and bilateral cleft lip and palate with tissue bridges (BCLP + B) 1 year after early neonatal cheiloplasty (ENC). MATERIAL AND METHODS: The methodology was based on classic and morphometric analysis of dental models of newborns with cBCLP or BCLP + B. These analyses included metric analysis, coherent point drift-dense correspondence analysis, superprojection methods, and multivariate statistics. Dental casts were observed in two age categories, which were compared with each other. The first cast was obtained from each patient before ENC (T0, 5 ± 5 days) and the second one prior to palatoplasty (T1, 12 ± 6 months). RESULTS: Fifty-two dental models obtained from 26 newborns with cBCLP and BCLP + B were evaluated. The results showed that over the 12-month period, alveolar clefts were narrowed in both cleft types due to anterior growth combined with the formative effect of suturing. This was confirmed by decreases in the dimensions of the right (T0 9.93 ± 2.80 mm, T1 6.64 ± 2.43 mm; p ≤ 0.003) and left (T0 10.71 ± 4.13 mm, T1 6.69 ± 4.29 mm; p ≤ 0.003) alveolar clefts in cBCLP patients. Similar reductions in alveolar cleft widths occurred on the left side (T0 11.69 ± 4.75 mm, T1 4.34 ± 2.97 mm; p ≤ 0.001) of BCLP + B patients, while on the right side, which was connected by a combined tissue bridge, there was non-significant narrowing of the alveolar cleft (T0 1.61 ± 1.34 mm, T1 1.04 ± 0.70 mm; p = 0.120). The ENC did not restrict posterior palatal growth, meaning that intertuberosity width was extended in cBCLP (T0 32.80 ± 3.15 mm, T1 35.86 ± 2.80 mm; p ≤ 0.001) and in BCLP + B neonates (T0 34.01 ± 2.15 mm, T1 36.21 ± 2.14 mm; p ≤ 0.004). Width and length measurements in the observed groups showed growth tendencies equivalent to those in noncleft or LOP patients. Palatal variability was greater in neonatal cBCLP, but was reduced during the monitored period, approximating that for BCLP + B. Regions with the most notable palatal growth were located primarily at the premaxilla and at the anterior and partially posterior ends of the maxillary segments. CONCLUSION: Early neonatal cheiloplasty had no negative effect on palatal growth in any direction. There was no reduction in the length or width of the palate during the first year of life, nor was there narrowing of the dentoalveolar arch. The formative effect of the operated lip on the anterior part of the palate was confirmed. This, in combination with the favorable growth, lead to closure of the alveolar cleft.