Assessment of the nasolabial angle in young Brazilian black subjects with normal occlusion

Evaluation of the Influence of Nasolabial Angle, Upper Sulcus Depth, and Nasal Tip Protrusion in the Perception of Facial Attractiveness

Objective

To evaluate the influence of variations in the upper sulcus depth, nasal tip protrusion, and nasolabial angle on the esthetic perception of profiles.

Design

A web-based survey study and was conducted in the Department of Orthodontics and Dentofacial Orthopaedics. This survey was conducted for a period of 10 months and included orthodontists practicing in India.

Methods

This study included lateral cephalograms of the most esthetic profiles from a set of 30 profiles that were within Holdaways norms; the most esthetic profile was determined by a panel of two orthodontists and two general dentists. The most esthetic profile photograph will be transferred to a computer in Corel software. The outline of the profile will remain the same, with the inner aspect converted into a dark area (black); now, the profile is completely converted into facial silhouettes. This black facial silhouette is presented to avoid any distractions and bias. There will be a total of 27 silhouettes by various combinations of increased, decreased, and normal values for nasolabial angle, upper sulcus depth, and nasal tip protrusions.

Results

Both the orthodontist and layman chose the most favored profile as a normal profile having a normal nasal tip, normal nasolabial angle, and normal upper sulcus depth, whereas among dentists, 50% chose the most favored profile in which the nasolabial angle was normal but the nasal tip and upper labial sulcus were decreased. When it comes to the least favored profiles, opinions varied between orthodontists, dentists, and laymen.

Conclusion

The perception of facial esthetics has always been and still is varied between the layman, the dentist, and the orthodontists. Profiles with normal to sharp noses with normal and increased nasolabial angles were considered more attractive than the others. Profiles with fuller upper labial sulci were considered least attractive with other parameters changing.

Nasal Morphology and Its Correlation to Craniofacial Morphology in Lateral Cephalometric Analysis

Nose shape, size, and inclination influence facial appearance, but few studies concern the relationship between the nasal profile and craniofacial structures. The objective of this study was to analyze association of nasal cephalometric variables with skeletal structures, age, and sex. Cephalometric and nasal analysis was performed in 386 Polish orthodontic patients (aged 9-25 years). Student t-test and Mann-Whitney test were used to compare quantitative variables and Pearson's or Spearman's correlation coefficients-to find correlations. Soft tissue facial convexity angle correlates to Holdaway ratio, ANB (A-Nasion-B), and Wits appraisal. Nasal dorsum axis, nose length, nose depth (1) and nose depth (2), nose hump, lower dorsum convexity, and columella convexity increase with age. Nasal base angle, nasolabial angle, nasomental angle, soft tissue facial convexity and nasal bone angle decrease with age. Nasal base angle and nasomental angle are smaller in females. Thus, a relationship exists between nasal morphology and sagittal jaw configuration. Nasal parameters significantly change with age. Sexual dimorphism characterizes nasal bone angle and nasomental angle.

Methods of Analysis of the Nasal Profile: A Systematic Review with Meta-analysis

The nose is the most prominent structure of the face, influencing facial appearance and profile. Orthodontists have an awareness of facial structures, including nasal morphology, when diagnosing and treatment planning. Maxillofacial surgeons influence facial profile by bimaxillary surgery, improving facial aesthetics and harmony. The aim of this review was to summarize the available methods of analysing nasal morphology and profile, and to assess their complexity. A literature search was conducted in PubMed, Scopus, Web of Science, and Embase using the following search terms: "nasal profile analysis", "nasolabial angle", and "nasal profile cephalometric" in order to select studies providing knowledge on correlations between occlusion and nasal development, differences between skeletal classes, ethnic variability, and differences between the sexes. Studies concerning genetic disorders were excluded. Finally, 17 full-text papers were analysed, which pertained to nasolabial angle, or facial profile including the nose. Data concerning methods, ethnic group, reference landmarks used, and measurements made were extracted and placed in tables. Numerous methods of nasal profile analysis can be found in the literature. These methods describe various numbers of parameters, which have influence on facial aesthetic. Nasal parameters are correlated to skeletal class and nasolabial angle, positions of upper incisors, and maxillary inclination.

[Does gender make a difference in orthodontics? A literature review]

OBJECTIVES

The objective of this literature review is to investigate whether the gender of patients and practitioners makes any difference to orthodontic treatment.

MATERIALS AND METHODS

Sixty-nine articles were selected, the vast majority of which studied patient gender.

RESULTS

Young females are the category of patients which most often apply for orthodontic treatment, probably because of their higher aesthetic demands, despite their objective needs being no greater. Aesthetic, skeletal and dental analyses reveal an obvious dimorphism with larger dimensions in males, especially for the nose, cheekbones, mouth and mandibular canines. Nevertheless, cephalometric angular values do not vary significantly between male and female individuals. Growth is quantitatively greater in males. It also occurs later, as does eruption and maturation of their teeth. Response to the different orthodontic / orthopedic therapies would appear not to differ according to the sex of the patient.

DISCUSSION

These results, however, need to be qualified according to the country concerned, the patients' life style and mind frames, as these can modify or influence the studied parameters.

Nasolabial angle at rest and upon smiling

PURPOSE

The objectives of this study were 1) to determine the mean and SD of the nasolabial angle (NLA) and the linear measure pronasale (Prn)-A' at rest and upon smiling and 2) to determine the difference between smile and rest in participants with normal occlusion and facial harmony.

MATERIALS AND METHODS

The sample consisted of 40 white Brazilian participants (20 of each gender) aged 20 to 30 years and with normal occlusion, a pleasant profile, and facial harmony. The measures NLA and Prn-A' were analyzed in profile photographs at rest and during smile, with a millimeter ruler in front of the profile during use of the Dolphin software. The statistical analysis included dependent t tests to compare the rest and smiling variables.

RESULTS

The mean of the NLA at rest was 104.93°; it was 110.67° during smile; and the difference between them was statistically significant, with a mean of 5.74°. The mean of the linear variable Prn-A' at rest was 23.25 mm, whereas during smile it was 24.04 mm, and the difference between them was statistically significant, with a mean of 0.79 mm.

CONCLUSIONS

The variability in the NLA and Prn-A' at rest and upon smiling was found to be significant in a normal sample, and it should be considered as a diagnostic tool in the treatment planning for sagittal dentoskeletal deformities.

The ideal nasolabial angle in rhinoplasty: a preference analysis of the general population

BACKGROUND

In aesthetic rhinoplasty, the described ideal nasolabial angle ranges from 90 to 120 degrees, with variable anthropologic differences. The authors sought to verify the most aesthetic nasolabial angle as specifically perceived by a random prospective sample of the general population and determine whether age, sex, race, and education were independent associated predictors.

METHODS

The authors prospectively recruited 98 random volunteers from the general population. They were asked to rank three different nasolabial angles for the female nose (100, 105, and 110 degrees) and the male nose (90, 100, and 105 degrees) as "most," "moderately," and "least aesthetic." Demographic data were used to determine correlations between aesthetic preferences. Pearson chi-square test and t test were used to determine statistical significance

RESULTS

The most aesthetic female nasolabial angle was 104.9±4.0 degrees. The most aesthetic male nasolabial angle was 97.0±6.3 degrees. Male subjects, younger volunteers, Native Americans, and African Americans preferred more acute male nasolabial angles (90 degrees). Female subjects, volunteers older than 50 years, college graduates, those with a previous rhinoplasty, and Caucasian and Asian subjects preferred more obtuse male nasolabial angles.

CONCLUSIONS

In the authors' sample of the general population, the ideal and most aesthetic nasolabial angle ranged from 100.9 to 108.9 degrees in the female nose and 90.7 to 103.3 degrees in the male nose. Age, sex, race, education, and having undergone a previous rhinoplasty were predictors of differences in the ideal male nasolabial angle but did not change preference of the female nasolabial angle.

Craniofacial characteristics of Caucasian and Afro-Caucasian Brazilian subjects with normal occlusion

Objective

The objective of this study was to compare the skeletal, dental and soft tissue characteristics of Caucasian and Afro-Caucasian Brazilian subjects with normal occlusion and to evaluate sexual dimorphism within the groups.

Material and Methods

The sample comprised lateral cephalograms of untreated normal occlusion subjects, divided into 2 groups. Group 1 included 40 Caucasian subjects (20 of each sex), with a mean age of 13.02 years; group 2 included 40 Afro-Caucasian subjects (20 of each sex), with a mean age of 13.02 years. Groups 1 and 2 and males and females within each group were compared with t tests.

Results

Afro-Caucasian subjects presented greater maxillary protrusion, smaller upper anterior face height and lower posterior face height, larger upper posterior face height, greater maxillary and mandibular dentoalveolar protrusion as well as soft tissue protrusion than Caucasian subjects. The Afro-Caucasian female subjects had less mandibular protrusion and smaller total posterior facial height and upper posterior facial height than males.

Conclusions

Brazilian Afro-Caucasian subjects have greater dentoalveolar and soft tissue protrusion than Brazilian Caucasian subjects, with slight sexual dimorphism in some variables.

Nasal morphology as an indicator of vertical maxillary skeletal pattern

OBJECTIVE

To investigate the relationship between nasal morphology and vertical maxillary skeletal pattern.

DESIGN

A retrospective study.

SETTING

Department of Orthodontics and Dentofacial Orthopaedics, Armed Forces Medical College, Pune, India.

SUBJECTS AND METHODS

The sample included the lateral cephalometric radiographs of 190 Indian adults (103 women, 87 men), aged 18 to 27 years with no previous history of trauma, surgical intervention, congenital disease or orthodontic treatment. Seven skeletal parameters of vertical facial growth and six nasal parameters were measured.

RESULTS

There was a significant correlation between vertical maxillary skeletal and soft tissue nasal parameters. Nasal length significantly correlated with upper anterior facial height (r=0.850, P<0.001) and inclination of palatal plane (r=0.433, P<0.001). Upward nasal tip inclination showed a significant negative correlation with inclination of the palatal plane (r=-0.462, P<0.001).

CONCLUSION

The clinical significance of this study is that the nasolabial angle in itself may not reflect a midface vertical discrepancy, however its upper component, i.e. the degree of upturn of the nose with decreased nasal length in an adult subject may indicate an underlying change in inclination of the palatal plane. This might be of value during orthodontic diagnosis and treatment planning.