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 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.