A quantitative research on clinical parameters of gingival contour for anterior teeth esthetic analysis and design

Digital analysis of periodontal phenotype in the maxillary anterior region

BACKGROUND

Accurate assessment of the periodontal phenotype is crucial for optimizing esthetic outcomes in dental practice. This study systematically evaluated key periodontal parameters in the maxillary anterior region and analyzed their interrelationships to enhance diagnostic precision and inform personalized treatment planning.

METHODS

Sixty-two periodontally healthy volunteers were included. Labial papilla height (PH), gingival zenith (GZ), the distance between the GZ of the lateral incisor and the gingival line (LID), height of contact surface (CS), crown width (CW), and crown length (CL) were measured using plaster models, intraoral photographs, and digital models obtained via intraoral scanning. Keratinized gingiva width (KGW) was assessed using a periodontal probe. Labial gingival thickness (GT) was measured at three locations-1 mm apical to the gingival margin, at the alveolar crest, and 2 mm apical to the crest-while labial alveolar bone thickness (BT) was evaluated at the alveolar crest and 2 mm apical to the crest, both using cone beam computed tomography (CBCT). Correlations among periodontal phenotype parameters were analyzed.

RESULTS

Parameters measured from intraoral scanned digital models showed no statistically significant differences compared to plaster models (NS, P>0.05). Varying degrees of correlation were identified among components of the periodontal phenotype, including GT, BT, KGW, PH, GZ, LID, and the ratios of CW to CL (CW/CL) and CS to CL (CS/CL).

CONCLUSIONS

Digital technology enables noninvasive, rapid, and precise assessment of periodontal phenotype, supporting risk assessment, and personalized treatment planning in aesthetic dentistry.

KEY POINTS

Digital methods yield precise periodontal phenotype analysis in aesthetic zones. Intraoral scanning and CBCT provide detailed periodontal phenotype parameters, revealing correlations with key esthetic factors like papilla height and gingival zenith. Correlation analysis between periodontal phenotype and key esthetic factors in the anterior maxilla enhances understanding of phenotype's impact on aesthetic outcomes and improves treatment planning.

PLAIN LANGUAGE SUMMARY

This study aimed to improve how dentists assess the surrounding tissues in the front upper teeth, which is essential for achieving natural-looking and aesthetically pleasing results in dental treatments. Researchers analyzed the gum, tooth, and bone characteristics of 62 healthy volunteers using traditional plaster models, intraoral photographs, and digital scans. They measured key parameters including gum thickness, bone thickness, and other relevant features. The study found that digital scans provided results as accurate as the traditional plaster models. Furthermore, the researchers identified connections between different gum and tooth characteristics, such as how the shape of teeth affects the appearance of the gums. These findings show that digital tools offer a quick, noninvasive, and precise way to assess these features, allowing dentists to plan more personalized treatments for improved aesthetic outcomes. Overall, this research supports the use of modern technology in dental care to enhance results and patient satisfaction.

Gingival zenith level, position, and symmetry: A systematic review and meta-analysis

STATEMENT OF PROBLEM

The gingival zenith (GZ) influences the line angle position in the emergence profile and the axial inclination of the crown. Irregularities in GZ symmetry and contour have a negative impact on dental esthetics. GZ location is not consistently distal to the crown's long axis; instead, it tends to be more distal in anterior teeth. The GZ levelling of the lateral incisor is often described as either level with or slightly above the zenith line connecting the central incisor and canine teeth, but there are also reports of GZ being aligned apically to the zenith line. Controversial reports persist regarding GZ positioning, magnitude, and location, potentially leading to inadequate positioning and levelling of the GZ in esthetic restorative therapy.

PURPOSE

The purpose of this systematic review and meta-analysis was to assess the scientific evidence related to GZ level, position, and symmetry in maxillary incisors and canines.

MATERIAL AND METHODS

This study adhered to the population, variable, outcome (PVO) criteria and the preferred reporting items for systematic reviews and meta-analysis (PRISMA) checklist. Cross-sectional studies involving healthy adults with complete dentition of the maxillary anterior sextant were subjected to prevalence analysis and quantitative measurement to assess the gingival zenith level and position. Data were extracted, and methodological quality was appraised using the Joanna Briggs Institute critical appraisal checklist for analytical cross-sectional studies. Certainty of evidence was evaluated through the grading of recommendations, assessment, development, and evaluation (GRADE) system.

RESULTS

The GZs were distally positioned, coinciding with the tooth axis or mesially positioned in, respectively, 96%, 3%, and 1% on central incisors; 84%, 14%, and 1% on lateral incisors; and 43%, 44%, and 5% on canines. GZ distal positioning was greater in central incisors, followed by lateral incisors and canines. In lateral incisors, the GZ was levelled coronally in 82% of the population. Contralateral symmetry was observed for GZ levelling and positioning. The certainty of the evidence was very low for all comparisons.

CONCLUSIONS

The frequency and magnitude of the distal position of the GZ increased the more anterior the tooth. Axially, the GZ was frequently levelled coronally to the zenith line. The contralateral positioning and levelling of the GZ was symmetrical.

Perceptions in Digital Smile Design: Assessing Laypeople and Dental Professionals' Preferences Using an Artificial-Intelligence-Based Application

Digital Smile Design (DSD) is used in many fields of dentistry. This prospective observational study assessed laypeople's and dental professionals' perceptions of a DSD application. SmileCloud, an online DSD platform, was used to create two different designs for three patients; after that, the participants, in a 30-question online illustrated survey, were asked about the most attractive design and other features of the smile. Dentists' and laypeople's perceptions about specific DSD features were assessed. The Kolmogorov-Smirnov normality test was used. Descriptive and crosstab analyses compared the respondents' opinions for each statement. Chi-square tests were used to determine the relationship between the questions and any association with age, gender, and profession. The test results were rated as significant at a p-value < 0.05. A total of 520 participants (dental professionals, students, dental technicians, and laypeople) were enrolled. The statistically significant features were self-esteem related to appearance (p = 0.05), facial and smile symmetry (p = 0.42, p < 0.0001), tooth color (p = 0.012), and symmetry of gums (p < 0.001). For each patient, the design with dominant round upper incisors and perfect symmetry was preferred (p < 0.001). Digital pre-visualization benefits diagnosis and enriches treatment planning. The dentist-dental technician-patient team should be involved in the decision-making process of pre-visualization.

Compatibility of digital and analog methods in assessment of gingival zeniths

OBJECTIVE

The compatibility of digital and analog methods assessing the positions of gingival zenith (GZ) points has not been evaluated before. Therefore, the aim of this study was to investigate the accuracy of a digital scanner and a three-dimensional (3D) measuring tool in specifying positions of GZs by comparing it to the conventional method, an analog plaster cast and a caliper.

MATERIALS AND METHODS

Both analog and digital impressions were obtained from 32 individuals. Following measurements were conducted in the anterior maxillary region from canine to canine on both the plaster casts and 3D images: (1) The distance from GZ to the corresponding vertical midline in each tooth (GZVM), (2) The distance from GZ of lateral incisor to the corresponding tangent that connects GZs of central incisor and canine (GZLI).

RESULTS

The intraclass correlation coefficients (ICC) of GZVM in each tooth varied between 0.366 and 0.755, demonstrating moderate to good compatibility between the two methods. The ICC of analog and digital GZLI for the right and left lateral incisors was 0.788 and 0.395, respectively.

CONCLUSION

The digital and analog methods used in this study are compatible in determining the positions of GZs. Therefore, within the limitations of the present study, the choice of method can be based on the available equipment, time, comfort, and personal preference of the researcher.

CLINICAL SIGNIFICANCE

Both digital and analog methods have the capability of determining the positions of GZs in compatible way.

Investigation of the esthetic perception of different canine parameters

OBJECTIVES

The aim of this study is to analyze the esthetic perception of selected canine features, namely crown length, shade, inclination, and angle of incisal edge tip.

MATERIALS AND METHODS

The anterior maxillary teeth of a Central European woman were photographed and digitally modified in order to investigate esthetic perceptions of the above four categories. Three groups of examiners with different levels of experience in the field of dentistry (laypersons/inexperienced dental students, advanced dental students, dentists) evaluated the photographs twice with the help of visual analogue scales.

RESULTS

The best-evaluated canines have approximately the same length as the central incisor, have the same shade as the other anterior teeth, are best embedded in a lighter overall tooth shade, are neutral to slightly palatal inclined, and have a right angled to rounded incisal edge (≥ 90°). The canines evaluated as least esthetic, however, are longer than the central incisors, darker, inclined labially, and have a tapered incisal edge. No significant differences could be found between the evaluations of the groups with regard to the four feature categories.

CONCLUSIONS

Laypersons, advanced dental students, and dentists generally evaluate according to the same esthetic standards. Gender does not have a significant influence on evaluation. Clear definitions of esthetically favored shades, incisal edge shapes, inclination, and lengths of the canines can be given.

CLINICAL RELEVANCE

Since the esthetics of the smile line play a critical role for patients, dentists, dental technicians, and their supplying industry, knowledge of the esthetically preferred morphology of canines is essential.

CLINICAL SIGNIFICANCE

The aim of this study is to give clear definitions of esthetically favored shades, incisal edge shapes, and lengths of the canines, as the esthetics of the smile line play a critical role for patients, dentists, dental technicians, and their supplying industry (e.g., denture tooth manufacturers). Precise knowledge of esthetic preferences is important in clinical practice for both dentists and dental technicians, for example, in order to adequately advise patients regarding esthetic corrections. Also, in the case of missing teeth, this knowledge is essential for optimal and satisfactory restorations. Thus, this study can contribute to the satisfaction of general practitioners and patients.

Correlation between clinical parameters of crown and gingival morphology of anterior teeth and periodontal biotypes

Background

In this study, we conducted a quantitative analysis of the clinical parameters of crown and gingival morphology (CGM) of the maxillary anterior teeth (MAT). We also analyzed the correlation of these parameters with periodontal biotype (PB), with a view to providing objective standards for PB diagnosis.

Methods

The three-dimensional (3D) maxillary digital models of 56 individuals were obtained using an intra-oral scanner. The following parameters were measured with the SpaceClaim software: gingival angle (GA), papilla width (PW), papilla height (PH), crown length (CL), crown width (CW), crown width/crown length ratio (CW/CL), bucco-lingual width of the crown (BLW), contact surface width (CSW), and contact surface height/crown length ratio (CS/CL). The PB were determined based on the transparency of the periodontal probe through the gingival sulcus. Independent factors influencing PB were analyzed by logistic regression, and the optimal cutoff values for the independent influencing factors were analyzed using receiver operating characteristic curves (ROC curves).

Results

There was no significant difference in the parameters of CGM of the MAT at the left and right sides. The thick biotype accounted for 69.6%, and the parameters of GA, PW, PH, CW, CW/CL and CS/CL were significantly correlated with PB (P ≤ 0.2). GA (odds ratio (OR) = 1.206) and PW (OR = 5.048) were identified as independent predictive factors of PB, with areas under the ROC curve (AUC) of 0.807 and 0.881, respectively, and optimal cutoff values of 95.95° and 10.01 mm, respectively.

Conclusion

The CGMs of the MAT at the left and right side are symmetrical. The thin biotype accounts for a small proportion, and GA and PW are independent influencing factors of PB. GA of 95.95° and PW of 10.01 mm are the optimal cutoff values for categorization of individuals as thick biotype. This indicates that when the GA and PW of the right maxillary central incisor are G ≥ 95.95° and ≥ 10.01 mm, respectively, there is a higher probability that these individuals will be categorized as thick biotype.