Association of facial sagittal and vertical characteristics with facial aesthetics in the Northern Finland Birth Cohort 1966

Occlusal characteristics in modern humans with tooth agenesis

Non-syndromic permanent tooth agenesis affects a significant proportion of the population, especially if third molars are considered. Although tooth agenesis has been linked to a smaller craniofacial size, reduced facial convexity and a shorter skeletal face, the occlusal characteristics of individuals with tooth agenesis remain largely unexplored. Therefore, this study investigated potential associations between tooth agenesis and metric occlusal traits in 806 individuals (491 with 4.1 missing teeth per subject, including third molars, and 315 without any tooth agenesis). Dentoskeletal morphology was defined through anatomical landmarks on pre-treatment cephalometric radiographs. Multivariate regression models, adjusted for sex and age, showed that tooth agenesis was significantly associated with a reduced overjet, an increased interincisal angle, and shorter upper and lower dental arch lengths, but not with overbite. Moreover, apart from reduced tooth length and dentoalveolar effects, as the number of missing teeth increased the upper front teeth were progressively retruded according to the craniofacial complex and to the face. Thus, tooth agenesis has a substantial influence on dental and occlusal characteristics, as well as on the sagittal position and inclination of anterior teeth. These findings emphasize the necessity for personalized, multidisciplinary approaches in individuals with multiple agenesis to successfully meet treatment goals.

Facial profile evaluation and prediction of skeletal class II patients during camouflage extraction treatment: a pilot study

BACKGROUND

The evaluation of the facial profile of skeletal Class II patients with camouflage treatment is of great importance for patients and orthodontists. The aim of this study is to explore the key factors in evaluating the facial profile esthetics and to predict the posttreatment facial profile esthetics of skeletal Class II extraction patients.

METHODS

124 skeletal Class II extraction patients were included. The pretreatment and posttreatment cephalograms were analyzed by a trained expert orthodontist. The facial profile esthetics of pretreatment and posttreatment lateral photographs were evaluated by 10 expert orthodontists using the visual analog scale (VAS). The correlation between subjective facial profile esthetics and objective cephalometric measurements was assessed. Three machine-learning methods were used to predict posttreatment facial profile esthetics.

RESULTS

The distances from lower and upper lip to the E plane and U1-APo showed the stronger correlation with profile esthetics. The changes in lower lip to the E plane and U1-APo during extraction exhibited the stronger correlation with changes in VAS score (r = - 0.551 and r = - 0.469). The random forest prediction model had the lowest mean absolute error and root mean square error, demonstrating a better prediction accuracy and fitting effect. In this model, pretreatment upper lip to E plane, pretreatment Pog-NB and the change of U1-GAll were the most important variables in predicting the posttreatment score of facial profile esthetics.

CONCLUSIONS

The maxillary incisor protrusion and lower lip protrusion are key objective indicators for evaluating and predicting facial profile esthetics of skeletal Class II extraction patients. An artificial intelligence prediction model could be a new method for predicting the posttreatment esthetics of facial profiles.

Total arch maxillary distalization using infrazygomatic crest miniscrews in the treatment of Class II malocclusion: a prospective study

OBJECTIVES

To evaluate treatment effects in Class II patients using infrazygomatic crest (IZC) miniscrews (MS).

MATERIALS AND METHODS

A prospective sample of 25 adolescents (14 females and 11 males; mean age: 13.6 ± 1.5 years) who underwent maxillary dentition distalization treatment with IZC MSs were recruited. Lateral cephalograms and digital models at the beginning of treatment (T1) and after Class II molar correction (T2) were obtained. To compare cephalometric and digital model changes, paired t-test and Wilcoxon test were used. A significance level of 5% was used.

RESULTS

All patients achieved Class II molar correction over a mean period of 7.7 ± 2.5 months. The IZC MS therapy provided 4 mm of distalization; there was 1.2 mm of intrusion of the first molar with 11.2° distal tipping. The maxillary incisors were retracted 4.7 mm and tipped lingually 13.4°. Overjet and overbite showed a reduction of 3.6 mm and 2.4 mm, respectively. The occlusal plane rotated clockwise 2.8°. The upper lip was retracted by 1 mm and the nasolabial angle increased 5.1°. There was an increase in the interpremolar and intermolar distances.

CONCLUSIONS

Total arch distalization of the maxillary dentition using IZC MS was effective in the treatment of Class II malocclusions.

Balance and thickness of soft tissue of the lower third of the face in different vertical patterns of growth

Introduction/Objective. Variations in thickness of soft tissues can influence the position of facial structures as well as facial aesthetics. The objective of the study was to determine whether the frequency of soft tissues imbalance depends on the vertical growth pattern of the face. Methods. The present study consisted of 90 pretreatment lateral cephalograms of adult Serbian Caucasian orthodontic patients (30 male and 60 female), between 18?27 years of age, average 23.6 years. Only the patients with the skeletal class I, based on the values of A-Nasion-point B angle and Wits appraisal, were chosen for the study. All patients were divided into three groups of 30 patients, those with hyperdivergent, hypodivergent and normal vertical growth patterns based on the values of Frankfort mandibular plane angle. Soft tissue of each patient was evaluated following the method given by Merrifield. Results. The obtained results showed that soft tissues of the chin and upper lip were thickest in hypodivergent and thinnest in patients with hyperdivergent growth type. The largest number of patients with soft tissue imbalance was observed in the normal and hyperdivergent vertical growth pattern groups, eight out of 30 patients. The number of patients with imbalance greater than 3 mm was largest in the group with hyperdivergent growth pattern. Conclusion. The pathological skeletal pattern of growth combined with the common occurrence of soft tissue imbalance makes orthodontic treatment in hyperdivergent group of patients more difficult in comparison to patients with normal or hypodivergent growth pattern.

Impact of facial profile on young adults' oral health-related quality-of-life item levels: A hierarchical analysis

Objective:

To assess the impact of facial profile on young adults’ oral health-related quality of life (OHRQoL) item levels.

Methods:

A cross-sectional study was carried out with a population-based sample of 205 young adults, with a mean age of 23.1 years. The individuals answered questions about OHRQoL (OHIP-14) and self-esteem (Global Negative Self-Evaluation). The Dental Health Component (DHC) of the Index of Orthodontic Treatment Need (IOTN) was used to evaluate normative orthodontic treatment needs and define dental malocclusion clinically. Facial profile was analyzed using photographs and dichotomized into two levels: normal (straight) and altered facial profile (convex or concave). A calibrated researcher performed the clinical examination. Association between the independent variables and the outcome (OHRQoL) was established by hierarchical multiple linear regression analysis for each item level. Considering the variable of interest (facial profile), the psychological incapacity domain was the most affected item.

Results:

Individuals with changed facial profile had 2.47 (1.04-5.85) times higher chances of reporting impacts on psychological incapacity than those with a normal profile (p> 0.05). The association was modulated by dental malocclusion and self-esteem.

Conclusions:

The convex and concave facial profile showed a negative impact on the psychological aspects of young adults’ quality of life.

Facial profile study using 3-dimensional photographs to assess esthetic preferences of Hong Kong Chinese orthognathic patients and laypersons

INTRODUCTION

This study was conducted to investigate and compare esthetic perceptions of different facial profiles among Hong Kong Chinese laypersons and patients scheduled for orthognathic treatment.

METHODS

Two sets of 3-dimensional facial photographs (1 male and 1 female) each comprised 7 images that showed different dentoskeletal relations (ie, Class I, bimaxillary protrusion, bimaxillary retrusion, maxillary protrusion, maxillary retrusion, mandibular protrusion, and mandibular retrusion). The sets of photographs were shown to 101 laypersons (age, 28.87 ± 6.22 years) and 60 patients seeking orthognathic treatment (age, 27.12 ± 6.07 years). They rated their esthetic perceptions of the photographs on the basis of a 100 mm visual analog scale (VAS) from 0 (very unattractive) to 100 (very attractive).

RESULTS

The dentoskeletal Class I facial profile was ranked as the most attractive profile. Female orthognathic judges selected the retrusive maxilla while male orthognathic judges and male and female laypersons ranked the mandibular protrusion profile as the least attractive profile for both females and males. A bimaxillary protrusive female profile was viewed as more attractive by the orthognathic male (P = 0.006) and female (P = 0.006) judges, compared with female layperson judges. After adjustment for age, no statistically significant interaction between sex and judges (P >0.10) for all VAS scores were detected. For the female bimaxillary protrusive profile, orthognathic patient judges assigned a mean VAS score of 9.174 points higher than layperson judges (95% confidence interval, 3.11-15.24; P = 0.003).

CONCLUSION

Dentoskeletal Class I facial profile was generally considered the most attractive profile in both sexes; male and female orthognathic patients preferred a bimaxillary protrusive female profile. A concave facial profile was perceived as least attractive in both sexes.

Personalized Orthodontics: From the Sagittal Position of Lower Incisors to the Facial Profile Esthetics

Background: One of the goals of orthodontic treatment is to obtain maximum facial harmony. The sagittal position of the lower incisors plays a significant role in the planning of orthodontic treatment. The aim of the study was to evaluate the relationship between the sagittal position of lower incisors and facial profile esthetics with reference to the skeletal vertical dimension. Methods: There were 200 patients included in the study. Patients were allocated into three groups, depending on the vertical growth pattern: normal-angle, low-angle, and high-angle cases. Tweed–Merrifield cephalometric analysis was used to assess the sagittal and vertical position of the mandible, as well as to assess the sagittal position of the lower incisors. Results: Z-angle and Frankfort mandibular incisor plane angle (FMIA) decreased significantly (p < 0.001) with the increase of the skeletal vertical dimension. Incisor mandibular plane angle (IMPA) was significantly higher (p < 0.001) in low-angle patients compared to the high-angle ones. Z-angle appeared to be the most accurate parameter (area under curve, AUC = 0.957) describing patients with a convex profile. The cutoff value of Z-angle 68.0° was characterized by the sensitivity of 94.1% and the specificity of 84.3%. Conclusions: The sagittal position of the lower incisors significantly affects the facial profile convexity. The Z-angle is the parameter which most accurately describes the patients with a convex profile.

Esthetic evaluation of profile photographs showing various sagittal and vertical patterns

INTRODUCTION

The purpose of this study was to determine the esthetic preferences of people at different levels of society and also to determine whether this preference is affected by sex, age, education level, social status, geographic region, and individual profile factors.

METHODS

Facial profile photographs of 1 man and 1 woman, each having a profile designated as ideal (the ideal profile), were digitized. The sagittal and vertical dimensions of these photographs were modified, and 9 variations of each profile picture were obtained using different combinations of alterations. The photographs were scored by 373 participants. For the analysis, Mann-Whitney U and Kruskal Wallis-H tests were used in the comparison of the scores.

RESULTS

The ideal profile was the most preferred in both sexes, whereas the least preferred was a severe Class III malocclusion with a reduced vertical dimension of 8 mm. In general, esthetics decreased as it moved away from the ideal profile in a sagittal or vertical direction.

CONCLUSIONS

Some factors from among those sampled (sex, age, education, social status, geographic region, and personal profile) affected esthetic preference, whereas others did not.

Different approaches to the treatment of skeletal Class II malocclusion during growth: Bionator versus extraoral appliance

INTRODUCTION

Class II malocclusion, which has a significant incidence in the population, may compromise facial esthetics and the smile, as well as the masticatory and respiratory functions. Often associated with skeletal abnormalities, it severely affects and compromises quality of life. An accurate diagnosis is fundamental to prepare a treatment plan to correct dental and skeletal anomalies.

OBJECTIVES

This study discusses treatment alternatives to the correction of Class II division 1 and 2 malocclusion in growing patients, using a Bionator and an extraoral appliance.