A cephalometric investigation of horizontal lip position in adult Nigerians

Ricketts' E-line profile preferences among Nigerian orthodontists, orthodontic trainees, and a young undergraduate students' population

Aim

This study compared the perceptions of orthodontists, orthodontic trainees, and young university undergraduate students in Nigeria regarding facial profile attractiveness and the need for orthodontic treatment.

Materials and Methods

We used a photo-editing software to alter the lips on Ricketts' esthetic line (E-line) in a lateral silhouette to produce five silhouette profiles with 2 mm incremental changes in the upper and lower lips from the 'normal' position on the E-line (-4 mm/-2 mm to + 4 mm/+6 mm). Two hundred and thirty-two participants (consisting of six groups) ranked the five profiles on a 5-point Likert scale (least attractive, 1 to most attractive, 5). Participants also assessed whether orthodontic treatment was needed to improve facial esthetics. Data were analysed in SPSS 20. Intra-rater reliability was assessed using Cohen's Kappa. We tested the null hypothesis (P ≤ 0.05) that ranked preferences between groups using the Kruskal-Wallis test. Mann-Whitney U test was also used to assess pairwise comparisons between the groups.

Results

Intra-rater reliability for facial profiles and treatment needs were moderately acceptable (perceptions ≥67.7%; treatment needs ≥67.0%). Perceptions between orthodontists and orthodontic trainees were not significantly different. However, orthodontists/trainees tended to rank the 'normal' Ricketts' E-line profile as most attractive, while students preferred more protrusive lips. Participants' age rather than sex significantly influenced esthetic preferences. About one-half of all participants (46.6%) ranked the 'normal' Ricketts' E-line as unacceptable; hence required orthodontic treatment to improve their facial attractiveness.

Conclusion

Clinical/professional judgment and age significantly influenced participants' perceptions of facial attractiveness. Most participants preferred slightly protrusive lips.

Age- and Sex-Related Changes in Labial Dimensions of Sudanese Youngs of Arab Descent: A Three-Dimensional Cross-Sectional Study

Proper evaluation of facial features during growth and development requires the knowledge of anthropometric reference values validated for ethnicity, sex and age. In order to provide information concerning the normal sex-related size of the lips during childhood and young adulthood in Sudanese people of Arab descent, the three-dimensional coordinates of nine labial soft tissue landmarks were obtained by a laser scanner in 332 male and 386 female healthy Northern Sudanese subjects aged 3-30 years. Six labial linear distances, the vermilion height to mouth width ratio, vermilion areas and lip volumes were calculated and averaged for age and sex. Comparisons were performed by factorial analysis of variance (p < 0.01). All labial dimensions significantly increased with age. Significant effects of sex were found for four measurements only, with very small effect size; nonetheless, lips and their parts grew faster in females than in males at almost all ages. Philtrum width was the first linear distance that attained adult values. The vermilion height to mouth width ratio was nearly constant across the age groups. Data collected in this study contribute to information about ethnic-specific lip morphology during growth and development. As orolabial features change over time with their own pattern, the relevant age-related trends should be properly considered for clinical treatment planning.

Evaluation of Lip Position in Esthetically Pleasing Profiles Using Different Reference Lines: A Photographic Study

The aim of this article is to assess the lip position using five different reference lines in individuals with a pleasing profile.

A cross-sectional study was conducted with a sample size of 200 subjects chosen from the local North Indian population. Non-growing subjects, between the age group of 18 years and 25 years with a pleasing facial profile were screened for the study via a questionnaire-based method to confirm their North Indian ancestry (history of past two generations from North India). All subjects included in the study gave their due consent to be a part of the study.

The following conclusions were derived: Norms for the horizontal lip position were derived for the North Indian population. Upper lip position in relation to S1 (Steiner’s) line and Ricketts’ E line showed females having protrusive lips, while S2 (Sushner’s) line showed protrusive upper lip in males. S1 (Steiner’s) line, showing protrusive lower lip in females. The norms derived in this study showed statistically significant difference with retrusive upper and lower lips when compared to normative values of Ricketts’ E plane and retrusive lower lip when compared to normative values of Sushner’s line. Sushner’s S2 line showed the maximum stability and consistency; hence, it is the line of choice to judge the sagittal lip positions in profile analysis.

The effects of playing wind musical instruments on the occlusal characteristics in a Northern Nigerian Population

Introduction

Dentists are often questioned on whether playing a wind musical instrument can adversely affect dental occlusion. This study compared the occlusal characteristics in wind instrument players (WIPs) and non-WIPs.

Materials and Methods

This was a cross-sectional comparative study comprising a group of fifty males aged 18-45 years that had been playing wind instruments for a minimum of 2 years, whereas the control group were non-WIPs in the same environment. All the participants had full complement of dentition. The occlusal characteristics of overjet, overbite, anterior open bite and Little's irregularity were assessed for both groups. Excellent intra-examiner reliability was observed (Cronbach's alpha - 0.997). The Statistical Package for Social Sciences (SPSS Inc., Chicago, IL, USA) version 17 was used for data analysis, and statistical significance level was set at P < 0.05.

Results

The number of years of playing wind musical instrument ranged from 2 to 25 years. The mean overjet was 3.46 ± 1.49 mm and 3.18 ± 1.27 mm in the WIP and non-WIP groups, respectively (P > 0.05). The maxillary anterior segment showed statistically significantly higher Little's Irregularity Index score in the WIP group (3.18 ± 3.73 mm) than that in the non-WIP group (1.87 ± 2.21 mm) (P < 0.05). The maxillary Little's Irregularity Index score in trumpet and trombone players (3.55 ± 3.93 mm) was significantly higher than that in saxophone and clarinet players (1.69 ± 2.39 mm). Both the maxillary and mandibular anterior-segment alignments were neither influenced by the number of years nor the frequency of play.

Conclusions

Playing wind musical instruments significantly affects the maxillary anterior-segment alignment.

Age-related and sex-related changes in the normal soft tissue profile of native Northern Sudanese subjects: a cross-sectional study

Information about age-related and sex-related normative measurements of the nasolabial region in native Northern Sudanese subjects is scanty. We have therefore used a hand-held laser scanner to measure nasolabial angles and distances, and collected the 3-dimensional coordinates of seven landmarks on the facial soft tissues from 654 healthy native Northern Sudanese subjects (327 male and 327 female, aged 4-30 years). From these we calculated five angles and two linear distances and took the mean (SD) for age and sex, and compared them using factorial analysis of variance. All measurements analysed were significantly modified by age in both sexes (p < 0.01) except for the distance from the lower lip to Ricketts' E-line. Sex had a significant effect on the mentolabial and maxillary prominence angles and both distances (p < 0.005). Nasal convexity and the interlabial angle became more obtuse with growth, while the nasolabial and mentolabial angles reduced progressively with female subjects having significantly more obtuse mentolabial angles (p < 0.001). The maxillary prominence angle progressively decreased during childhood, and increased after adolescence, with larger values in male subjects. The upper and lower lip distances from Ricketts' E-line were also significantly larger in male subjects (p < 0.003), but the difference reduced with age. Overall, there were several differences when we compared our data with published data for African and white subjects, which points to the need for ethnic-specific data. Measurements collected in the current study could be used for the quantitative description of facial morphology in native Northern Sudanese children, adolescents, and young adults.

A Quantitative Analysis of Lip Aesthetics: The Influence of Gender and Aging

INTRODUCTION

The quantitative analysis of sexual dimorphism of facial structures may valuably support reconstructive and feminization surgery, thanks to the estimation of metrical thresholds useful for distinguishing male and female traits. This study aims at verifying the metrical characteristics of female and male lips, to provide indications for aesthetic surgery.

METHODS

Thirty healthy Caucasian volunteers (20 men and 20 women) were divided into two groups according to age: 21-34 years and 45-65 years. Arches and the cutaneous (external) and mucosal (internal) labial surfaces were reproduced by stone models, and digitised using a computerised electromechanical instrument. Area, volume and thickness were measured separately for the upper and lower lips, and compared between sexes and ages by Student's t test, and multinomial logistic regression.

RESULTS

All lip measurements were larger in males than in females; upper lip thickness best divided males from females, adopting a 9.5-mm threshold (percentage of correct diagnosis: 85 %). Young subjects always showed higher measurements than old subjects; lower lip thickness provided the highest percentage of correct age diagnosis (85 %, adopting a 13.8-mm threshold).

CONCLUSION

This study provides novel thresholds that may contribute to the assessment of adequate reconstruction of lips in aesthetic surgery.

LEVEL OF EVIDENCE III

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Sagittal lip positions in different skeletal malocclusions: a cephalometric analysis

BACKGROUND

The objectives of this paper are to (1) study use of soft tissue analyses advocated by Steiner, Ricketts, Burstone, Sushner and Holdway to develop soft tissue cephalometric norms as baseline data for sagittal lip position in Northeast Chinese adult population, (2) compare the sagittal lip positions in different skeletal malocclusions and (3) compare the sagittal lip positions in Northeast Chinese adults with other reported populations.

METHODS

Lateral cephalometric radiographs of subjects were taken in natural head position. Radiographs were manually traced and five reference lines - Sushner, Steiner, Burstone, Holdway and Ricketts, were used. The linear distance between the tip of the lips and the five reference lines were measured. Statistical analysis was done using the Statistical Package for Social Sciences (SPSS) 21. Descriptive analysis was done for each variable for each subject. Coefficient of variation between lip positions as assessed by reference lines was determined. Post hoc Tukey's test was used for comparison of the mean cephalometric values of three skeletal malocclusions. The level of significance for the analysis was set at p < 0.05.

RESULTS

The findings showed significant difference in the sagittal lip positions in different skeletal malocclusions. There was variation in consistent reference line in each skeletal malocclusion. The S2 line was the most consistent reference line in skeletal class I and class II group. The B line was the most consistent line in skeletal class III. In skeletal class II group, upper lips were the most protrusive and lower lips were retrusive than in skeletal class I and class III groups. In case of skeletal class III group, upper lips were retrusive and lower lips were more protrusive than in skeletal class I and class II groups.

CONCLUSIONS

The sagittal lip positions were found to be associated with the skeletal malocclusion pattern. Northeast Chinese population has protrusive upper and lower lip in comparison to Caucasians. Each skeletal malocclusion group showed different preferable reference lines for analysis of sagittal lip position.

Mandibular asymmetry: a three-dimensional quantification of bilateral condyles

INTRODUCTION

The shape and volume of the condyle is considered to play an important role in the pathogenesis of the mandibular deviation. Curvature analysis is informative for objectively assess whether the shape of the condyles matches that of the glenoid fossa. In this study, a three-dimensional (3-D) quantification of bilateral asymmetrical condyles was firstly conducted to identify the specific role of 3-D condylar configuration for mandibular asymmetry.

METHODS

55 adult patients, 26 males (26 ± 5 yrs) and 29 females (26 ± 5 yrs), diagnosed with mandibular asymmetry were included. The examination of deviation of chin point, deviation of dental midlines, inclination of occlusal plane, and depth of the mandibular occlusal plane were conducted. After the clinical investigation, computed tomography images from the patients were used to reconstruct the 3-D mandibular models. Then the condylar volume, surface size, surface curvature and bone mineral density were evaluated independently for each patient on non-deviated and deviated sides of temporomandibular joint.

RESULTS

Both the condylar surface size and volume were significantly larger on deviated side (surface size: 1666.14 ± 318.3 mm2, volume: 1981.5 ± 418.3 mm3). The anterior slope of the condyle was flatter (0.12 ± 0.06) and the posterior slope (0.39 ± 0.08) was prominently convex on the deviated side. The corresponding bone mineral density values were 523.01 ±118.1 HU and 549.07 ±120. 6 HU on anterior and posterior slopes.

CONCLUSIONS

The incongruence presented on the deviated side resulted in a reduction in contact areas and, thus, an increase in contact stresses and changes of bone density. All aforementioned results suggest that the difference existing between deviated and non-deviated condyles correlates with facial asymmetrical development. In mandibular asymmetry patients, the 3-D morphology of condyle on deviated side differ from the non-deviated side, which indicates the association between asymmetrical jaw function and joint remodeling.