Subjective and Objective Evaluation of the Symmetry of Maxillary Incisors among Residents of Southwest Poland

Bilateral Symmetry in the Aesthetic Area Achieved by Digital Smile Design on 3D Virtual Patient and Conventional Diagnostic Wax-Up-A Comparative Study

Background: Digital diagnostic waxing is a contemporary alternative to the conventional wax-up method. This study aims to evaluate the impact of both techniques on the perceived frontal symmetry in aesthetic treatment planning. Dental symmetry significantly influences smile perception and, consequently, the acceptance of treatment outcomes, highlighting its clinical importance in restorative dentistry. Materials and Methods: A total of 100 teeth were measured, with 50 (n = 50) waxed up using traditional modeling techniques and 50 using a face-guided digital approach. The study involved ten patients requiring fixed restorations in the aesthetic zone. Both digital and conventional wax-ups were performed for each participant. Gypsum models with wax-ups were digitized and superimposed onto the digital diagnostic design using 3Shape Dental Designer Studio software, Version 2023 (3Shape, Copenhagen, Denmark). Screenshots of the frontal view were captured, and the width of each morphologically altered tooth was measured using ImageJ software Version 1.54 (National Institutes of Health, Bethesda, MD, USA). Results: The results indicated no statistically significant difference in symmetry between the right and left sides achieved by the two diagnostic approaches (t-value = -1.89, p-value = 0.07). The perceived symmetry of morphologically modified frontal teeth, as achieved by digital and conventional waxing, was found to be comparable. Conclusions: Digital diagnostic planning is validated as a reliable alternative to the conventional wax-up method, offering comparable accuracy in achieving dental symmetry while potentially enhancing efficiency and precision in the aesthetic treatment planning process. This result underscores the potential of digital technologies to streamline clinical workflows and improve patient outcomes. Clinically, achieving symmetry in the aesthetic zone is crucial for patient satisfaction and acceptance of restorative procedures, emphasizing the need for continued integration of digital tools in dental practice.

Two- and three-dimensional symmetry of maxillary incisors: A clinical study

OBJECTIVE

To assess the 2D and 3D natural symmetry of the maxillary incisors.

MATERIALS AND METHODS

Maxillary alginate impressions were taken of 59 young adult volunteers. Gender, orthodontic treatment history, and dominant hand were collected. For 2D analysis, a digital caliper was used for measurements on maxillary casts. For 3D analysis, the casts were scanned using a lab scanner, and the labial surface symmetry of contralateral incisors was evaluated. Mann-Whitney tests and Student's t-test were performed, α = 0.05.

RESULTS

Results indicated a lack of identical lengths among contralateral central or lateral incisors, with minimal occurrences of identical width measurements. 68% of central incisors and 73% of lateral incisors showed differences in length exceeding 0.2 mm. Central incisors showed more similarities than lateral incisors in width, with 61% central incisors and 47% lateral incisors having differences under 0.2 mm. The differences between highly asymmetrical contralateral teeth are situated at the transitional lines. The influence of sexual dimorphism, orthodontic factors, and the dominant hand on incisors' symmetry was not statistically significant.

CONCLUSIONS

2D and 3D symmetry of the natural maxillary incisors are rare. 3D symmetry remains consistent across orthodontic treatment status, gender, and dominant hand, suggesting its independence from such parameters.

CLINICAL SIGNIFICANCE

To achieve a natural and aesthetic smile rehabilitation, the symmetry of the maxillary incisors must be well understood. In our study, 2D and 3D symmetry of the maxillary incisors occurred rarely, but central incisors showed more similarities than lateral incisors in width, with differences under 0.2 mm. On the other hand, differences between highly asymmetrical contralateral teeth are situated at the transitional lines. These conclusions should be included in further computer-assisted three-dimensional smile designs.

Cross-Sectional Study on Self-Perception of Dento-Facial Asymmetry

Background and Objectives: Facial symmetry is a key component of facial beauty and attractiveness. However, perfect symmetry is rare, and slight asymmetries, also known as natural asymmetries, are common and contribute to the uniqueness of each face. The perception of facial asymmetry varies among individuals and can be influenced by several factors. This study aimed to investigate the self-perception of dento-facial asymmetry among a sample of Romanian individuals, focusing on their awareness, the extent to which it bothers them, and their desire for correction. Materials and Methods: A cross-sectional analytical study was conducted with 283 participants from Romania between January and February 2024. Participants completed a questionnaire designed to assess their self-perception of facial asymmetry and socio-demographic characteristics. The questionnaire included 10 questions on self-perception of facial asymmetry and 8 questions on socio-demographic data. Statistical analysis was performed using SPSS 26.0, and the Pearson Chi-square test was used for comparative analysis. Results: The sample was predominantly female (75.3%) with an average age of 32.24 years. Most participants were from urban areas (80.6%) and had university degrees (58.7%). About 28.7% of participants observed facial asymmetry, with dental asymmetry being the most frequently reported, followed by asymmetries in the eyebrows and eyelids. The right side of the face was more commonly perceived as asymmetric. Although 24.4% of participants were bothered by their asymmetry, 39.2% expressed a desire to correct it. Conclusions: One-third of participants identified dento-facial asymmetry, with the dental level being the most reported. A significant portion of participants expressed a desire to correct their asymmetries, highlighting the importance of understanding self-perception in the context of facial aesthetics. This study underscores the subjective nature of facial asymmetry perception and the varying thresholds for what is considered bothersome or in need of correction.

Combining Orthodontic and Restorative Care with Novel Workflows

This report describes multidisciplinary care combining orthodontics and restorative dentistry for a patient with Class II occlusion and stained mandibular and maxillary resin composite veneers. The orthodontic treatment improved severe overjet and malocclusion prior to restorative care. Occlusal assessment was provided with a novel digital device (PlaneSystem, Zirkonzahn) that is integrated with digital workflows for the evaluation of the occlusal plane and condylar path inclination. Diagnostic digital impressions and digital wax-up for intraoral mock-ups led to the patient's treatment acceptance. Minimally invasive tooth preparation, final digital impressions, and bonding under dental dam isolation fulfilled the patient's esthetic and functional demands with all-ceramic restorations.

Upper Midline Correction Using the Mesial-Distalslider

AIM

The purpose of the present study is the three-dimensional (3D) analysis of molar and incisor movements that occur during the correction of the upper midline deviation by using the Mesial-Distalslider appliance.

MATERIALS AND METHODS

A total of 20 consecutive patients (12 women and 8 men; mean age 19.6 ± 11.1 years) were selected from the Orthodontic Department of Heinrich-Heine University of Düsseldorf. To correct the upper midline deviation (>2 mm), the patients were treated with asymmetric mechanics (mesialization on one side and distalization on the contralateral side) with the aid of Mesial-Distalslider. Dental casts were taken for each patient before (T0) and after the treatment (T1). The casts were 3D digitized and the models were superimposed on the palatal anterior region. Three-dimensional molar movements and sagittal incisor movements (proclination and retroclination) were assessed for T0 and T1.

RESULTS

At the end of the treatment, the total movements of the molars resulted in 4.5 ± 2.2 mm (antero-posterior direction), -0.4 ± 2.4 mm (transverse direction) and 0.3 ± 0.9 mm (vertical direction) on the mesialization side, and -2.4 ± 1.7 mm (antero-posterior direction), -0.5 ± 1.5 mm (transverse direction) and 0.2 ± 1.4 mm (vertical direction) on the distalization side. Incisor displacement was 0.9 mm ± 1.7 (mesialization side) and 0.6 mm ± 0.7 (distalization side).

CONCLUSION

The Mesial-Distalslider appliance could be considered a valuable tool in orthodontic treatment for upper midline correction. Within the limits of a retrospective study, asymmetric molar movements appeared possible without clinically relevant anchorage loss.

Correlation Between Maxillary Anterior Teeth and Common Facial Measurements

Background

The symmetry between maxillary anterior teeth and the face holds significant importance. This study assessed and analyzed the relationship between facial parameters and anterior teeth in the maxillary arch of male and female subjects. Specifically, individual width and combined width (CW) measurements of the maxillary anterior teeth were investigated.

Methods

This study involved a total of 150 dentate Yemeni subjects (74 men and 76 women), whose ages ranged from 18 years old to 30 years old. A maxillary cast was created, and two digital photographs of the face of each subject were taken and analyzed. Digital calipers and AutoCAD were used to gather measurement data of the dental parameters (intercanthal distance [ICD], interpupillary distance [IPD], interalar width [IAW], intercommissural width [ICW], and bizygomatic width [BZW]) and facial parameters (profile distance).

Results

Significant correlations were found for the following: IPD and width of six maxillary anterior teeth of each of the study subjects; ICD and their central incisors; and BZW and their canine width measurements. In contrast, IAW and ICW were not correlated with all tooth measurements. Linear regression findings showed that the CW measurement of the four incisors was significantly correlated with all facial parameter measurements, excluding the ICW and IAW in females and the IAW, ICW, and profile distance in males.

Conclusion

The IPD and ICD of males and females may be used to determine their CW measurements. The BZW and IPD of males can be used to take precise anthropological measurements of the width of the central canines and incisors. Meanwhile, the IPD distance of females can be used to assess the central and lateral incisor widths.

Effect of smile esthetics on the quality of life in a Han Chinese population

OBJECTIVE

This study aimed to explore the influence of smile esthetics on the quality of life in a Han Chinese population.

METHODS

A total of 110 Han Chinese volunteers (52 males and 58 females, mean age 26.7 years) were recruited, and frontal images of their smiles were collected. A photoediting program was used to evaluate the following components of smile esthetics: the buccal corridor ratios, the angle between the interpupillary and commissural lines, the number of visible teeth, and width-to-length ratios of the maxillary central incisors. Oral health-related quality of life (OHRQoL) in these volunteers was evaluated using the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) and Oral Health Impact Profile-14 (OHIP-14). Statistical analyses were performed by using Pearson's correlations and multiple linear regression (α = 0.05).

RESULTS

Compared to males, females scored higher on psychological impact (p = 0.017). Moreover, the number of visible teeth had a significant effect on social impact, psychological impact and esthetic concern (all p < 0.05). However, the buccal corridor ratios, the angle between the interpupillary and commissural lines, and the width-to-length ratios of the maxillary central incisor did not correlate with the OHRQoL (all p > 0.05).

CONCLUSIONS

The number of visible teeth significantly influenced the quality of life in a Han Chinese population. Smile esthetics had a significantly greater psychological impact on females than males.

CLINICAL SIGNIFICANCE

This study highlights the effects of smile esthetics on the quality of life in a Han Chinese population. Female patients may raise more esthetic concerns in clinical practice.

A simple method for quick evaluation of the anterior tooth ratio: an observational study

Background

An ideal relationship of anterior teeth is closely related to postoperative function, stability, and aesthetics. Therefore, it is necessary to estimate the proportion of anterior teeth when communicating with patients about possible treatment plans and outcomes. This study aimed to establish a simple method for assessing the proportion of anterior teeth and to identify the standard ratio value to provide references for clinical work.

Methods

Five hundred fourteen patients were divided into derivation, standard, and validation datasets. We first deduced our novel simplified anterior tooth ratio (SATR) by finding the key teeth with the derivation datasets, then established standard values by measuring the standard models, and finally validated the diagnostic performance of SATR. Independent sample t-test was used to select key teeth. Pearson’s correlation analysis and linear regression analysis was used to test and verify the correlation between SATR and the anterior Bolton ratio. Chi-square test and diagnostic test were used to verify the diagnostic results using SATR. P values of < 0.05 were considered statistically significant.

Results

Patients with an abnormal anterior Bolton ratio were more likely to have variations in the maxillary and mandibular lateral incisors. Therefore, the ratio of maxillary and mandibular lateral incisors was chosen as a simple way to assess the anterior tooth ratio and was defined as SATR (simplified anterior tooth ratio). A positive correlation was observed between SATR and anterior Bolton ratio (r = 0.702, p < 0.001), with the linear regression equation as follows: y = 0.503 + 0.328x, x = SATR, y = anterior Bolton ratio. The standard value of SATR was established (85.69% ± 3.57%) and proven reliable in clinical practice.

Conclusions

The ratio of maxillary and mandibular lateral incisors can be used to estimate the anterior tooth ratio, which showed high reliability and efficiency.

Oral-Health-Related Quality of Life and Anxiety in Orthodontic Patients with Conventional Brackets

The aim of this study was to evaluate the oral-health-related quality of life (OHRQoL) and anxiety levels of adult patients undergoing orthodontic treatment with fixed multibracket appliances.

MATERIALS AND METHODS

The study was carried out at the Dental Clinic of the University of Salamanca in 2021. It included 120 adult patients between 19 and 45 years of age undergoing orthodontic treatment with conventional metal brackets. The data collection instruments chosen were the state-trait anxiety inventory (STAI) to assess anxiety levels and the OHIP-14 questionnaire to measure the OHRQoL. Anxiety levels and OHRQoL were analyzed one month after starting treatment.

RESULTS

The mean age was 31.7 years ± 6.5 years; 68 patients were women (56.7%) and 52 were men (43.3%). Psychological disability was the dimension of the OHIP-14 questionnaire that was found to have the greatest impact (3.20 ± 1.08) on patients, as compared to the dimension of disability, which had the lowest impact on the oral-health quality of life (0.37 ± 0.56). The mean total score of the OHIP-14 questionnaire was 11.93 (±2.19). There was no statistically significant influence from either sex or age on the anxiety and oral-health quality of life of the participants; however, there was a significant relationship between the dimensions of physical disability and anxiety traits.

CONCLUSIONS

The physical disability dimension of the OHIP-14 questionnaire increased the anxiety level of adult patients treated with conventional brackets. The impact of orthodontic treatment on adult patients may negatively influence their levels of anxiety.