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Abstract

Aims

To evaluate and compare the perception of rotational discrepancies of the permanent maxillary right central incisor among dental professionals and laypersons using standardized three-dimensional (3D) digital models.

Material and Methods

Participants assessed digital images of a 3D dental model via an online questionnaire. The model featured induced rotational discrepancies of tooth 11 at ±2.5°, ±5°, ±10°, and 0°. Participants were asked to indicate whether they detected a rotation. Accuracy rates were calculated, and chi-square tests were used to compare group differences (α = 0.05).

Results

A total of 205 participants were included: 67 laypersons, 51 prosthodontists, 50 orthodontists, and 37 general dentists. Significant differences were found across groups in the detection of simulated rotations. Dental professionals showed higher accuracy in identifying rotational discrepancies, particularly at smaller angles. Orthodontists achieved the highest detection rates, accurately identifying rotations as small as ±2.5°, while laypersons typically failed to perceive discrepancies below ±10°. Statistically significant differences (p < .05) were observed between orthodontists and laypersons at most rotation levels. General dentists and prosthodontists also outperformed laypersons, although with less consistency at lower degrees of rotation.

Conclusion

Dental specialists, especially orthodontists, are significantly more accurate in identifying minor rotational discrepancies of anterior teeth. In contrast, laypersons are generally only able to perceive larger deviations (≥10°). These findings underscore the critical role of professional expertise in the diagnostic and esthetic evaluation processes during orthodontic and restorative treatment planning.

Keywords

Perception orthodontics esthetics rotation questionnaires

Introduction

Understanding patient expectations and motivations for seeking orthodontic treatment is essential for achieving satisfactory outcomes from both professional¹ and patient perspectives.^{2, 3} Arnett and Worley⁴ identified three primary reasons why patients pursue orthodontic care: facial enhancement, relief from headaches and neck pain, and correction of dental irregularities. Hence, addressing the patient’s chief complaint should be the major consideration during treatment planning.⁵

Andrews⁶ established that ideal occlusion is defined by six keys, including proper angulation, inclination, and absence of tooth rotation. Specifically, tooth rotations are not present in normal occlusion.^{7, 8} Disruption of any of these keys may lead to functional⁹ or facial esthetic compromise.¹

Esthetics also play a central role in orthodontic demand, as a harmonious smile significantly impacts social interactions.^{10, 11} Previous studies^{12, 13} have shown that patients often prioritize esthetic improvements over functional outcomes, and that perceptions of dental appearance vary depending on cultural and individual beauty standards.^{14, 15}

Perception is a subjective construct influenced by individual experience and expertise.¹⁶ Research comparing dental professionals’ and laypersons’ perceptions has shown varying degrees of agreement, with specialists demonstrating greater sensitivity to minimum dental deviations.¹⁷ However, the layperson’s perspective remains vital for patient satisfaction and successful case acceptance.^{2, 5, 18}

Despite the extensive literature comparing the perception of smile-related deviations among professionals and laypersons,² perceptual thresholds for rotational discrepancies of anterior teeth remain poorly documented. Most available studies focus on crowding, midline deviation, gingival display, or general smile esthetics, while the specific ability to detect subtle rotational changes, particularly using standardized 3D digital models, has not been thoroughly explored. Considering that the maxillary central incisors play a key role in smile harmony and serve as reference points in orthodontic diagnosis, investigating perceptual sensitivity to their rotations fills an important gap in esthetic and diagnostic research.

Although it is expected that dental specialists demonstrate greater sensitivity to minor dental discrepancies, the perception of laypersons remains clinically relevant. Patients are the primary recipients of orthodontic and restorative treatments, and their ability, or inability, to perceive dental rotations may influence treatment acceptance, satisfaction, and adherence. Identifying perceptual thresholds among laypersons allows clinicians to distinguish between discrepancies that are clinically significant but visually imperceptible to patients and those that are both clinically and esthetically relevant from the patient’s perspective. Therefore, assessing laypersons’ perception is essential for improving patient education, expectation management, and shared decision-making. By understanding how non-professionals perceive rotational discrepancies, clinicians can better tailor communication strategies and educational tools, particularly when recommending orthodontic intervention for deviations that patients may not initially recognize.

If dental rotations are not recognized and addressed in a timely manner, they may lead to functional and esthetic consequences, including altered proximal contacts, occlusal interferences, periodontal compromise, and long-term instability.^9–12 Even minor rotational discrepancies can affect smile harmony and occlusal relationships, reinforcing the importance of early identification and accurate diagnostic assessment.^{1, 4}

This study aims to assess and compare the perception of dental professionals and laypersons regarding rotational discrepancies of the permanent maxillary right central incisor, in order to better understand perceptual differences relevant to diagnosis, patient communication, and treatment planning.

In this context, web-based surveys have become a valuable tool for collecting data from diverse respondent groups, enabling the analysis of perception differences across populations. Therefore, this study aims to assess the perception of dental professionals and laypeople regarding rotational discrepancies of the permanent maxillary right central incisor (tooth 11), using standardized 3D digital models in an online survey format. The null hypothesis of this study is that there is no significant difference between dental professionals and laypersons in their ability to perceive rotational discrepancies of the permanent maxillary right central incisor in 3D digital models.

Materials and Methods

This observational, cross-sectional study was conducted using an online questionnaire targeting dental professionals (orthodontists, prosthodontists, and general dentists) as well as individuals without formal dental training (laypersons). The methodology followed the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology)¹⁹ and CHERRIES (Checklist for Reporting Results of Internet E-Surveys) guidelines²⁰ to ensure transparency and rigor.

The sample size was estimated based on previous perception studies that compared detection thresholds among professional groups.¹³ Using an expected intergroup difference of at least 20% in accuracy and a chi-square test framework, a minimum of 180 participants was required to achieve 80% power at a 5% significance level.

Participants were recruited via email invitations sent through academic and professional mailing lists associated with the School of Dentistry at the Rio de Janeiro State University (UERJ), using a convenience sampling strategy. Participants were recruited using a non-probabilistic convenience sampling technique, based on voluntary participation from academic and professional mailing lists associated with a single dental school. This sampling strategy was selected to allow controlled comparison of perceptual thresholds under standardized digital conditions rather than to estimate population prevalence. Although the sample included a range of professional and non-professional respondents, it may not be fully representative of the broader population of dental professionals or laypersons.

The study received ethical approval from the Research Ethics Committee of the Pedro Ernesto University Hospital (CEP/HUPE) at Rio de Janeiro State University (UERJ) (approval number 6.760.243; CAAE: 78786824.0.0000.5259), complying with national regulations (National Health Confederation Resolutions 196/96 and 466/2012) and the Declaration of Helsinki. Informed consent was obtained through the online platform prior to participation. The consent form outlined the study objectives, estimated duration (approximately 10 min), data confidentiality, anonymity, and participants’ right to withdraw at any time without penalty. Participation was entirely voluntary.

The survey invitation included a brief explanation of the study and a direct link to the Google Forms questionnaire (https://www.google.com/forms/about/), along with instructions for participation. The questionnaire (Supplemental file#1) was pre-tested internally to ensure clarity and technical compatibility across devices. Responses were collected anonymously and securely stored on a password-protected server accessible only to the research team. No personally identifiable data were collected, and all information was encrypted in accordance with institutional data protection policies.

To create the clinical cases used in the questionnaire, a digital model (STL file available online as supplementary material) with near-ideal occlusion was selected from the postgraduate orthodontic program database at Rio de Janeiro State University (UERJ).. The model was manipulated using ArchForm software (version 2.1, Medical Equipment Manufacturing, USA). Rotational movements were applied to the upper right central incisor (tooth 11) in both mesio-distal (+2.5°, +5°, +10°, and 0°) and disto-mesial (−2.5°, −5°, and −10°) directions, resulting in eight distinct images within rotational discrepancies. Participants assessed standardized static two-dimensional (2D) images rendered from a three-dimensional (3D) digital dental model via an online questionnaire.

Participants were instructed to examine each image and indicate whether they perceived any rotation in the marked tooth, which was highlighted with a red arrow. Because the survey was administered online, viewing conditions such as screen size, resolution, brightness, and viewing distance could not be standardized. Participants were instructed to view the images on their preferred devices, reflecting real-world digital consultation scenarios but introducing potential variability in visual perception. While individual responses were not forced, participants were required to complete all items before submitting the form, ensuring full data completeness. Adaptive questioning was implemented to improve user experience. For example, questions about postgraduate training were only shown to specialists based on their responses. Participants were able to review and revise their answers prior to submission using the platform’s “Back” button.

To minimize order bias, the sequence of images was randomized for each participant through the survey platform. This approach reduced the risk of learning or pattern-recognition effects that could occur if images of increasing magnitude were shown in a fixed order. Randomization enhances methodological rigor and is recommended in perception studies where repeated exposures may influence responses.

To maintain data integrity, browser cookies and IP address monitoring were used to detect and prevent duplicate entries. When duplicates were identified, only the first valid submission was retained for analysis. The view rate was calculated as the ratio of unique visitors who accessed the survey page to the number of email invitations sent. Participation rate was defined as the proportion of visitors who began the survey, and the completion rate, recorded as 100%, reflected the number of participants who completed all sections of the questionnaire relative to those who started it.

Statistical analysis was performed using IBM Statistical Package for the Social Sciences (SPSS) Statistics software (version 29.0; IBM Corp., Armonk, NY, USA). Descriptive statistics were used to summarize the frequency and percentage of correct responses for each rotation angle. Intergroup comparisons between professional categories (orthodontists, prosthodontists, general dentists, and laypersons) were conducted using the chi-square test, with the level of significance set at p < .05. Chi-square tests were selected because the primary outcome was categorical (perception of rotation: yes/no), and the objective was to compare accuracy rates across independent professional groups at predefined rotation magnitudes. Each rotation angle was analyzed as a distinct perceptual condition rather than as repeated measurements of the same outcome.

Results

The final sample of 205 respondents exceeded the sample size, increasing the robustness and representativeness of subgroup comparisons. A total of 205 responses were collected, including 67 laypersons, 51 prosthodontists, 50 orthodontists, and 37 general dentists. Data collection took place between April 15th and May 30th, 2024, allowing sufficient time for participant recruitment and response acquisition across the target groups. Overall, female participants represented the majority across all categories (76.1%), while male participants accounted for 23.9%. The layperson group (n = 67) was used as the baseline for comparative analysis with the professional groups (Table 1).

Table 1.

Sample Characterization.

	General Dentists	Prosthodontists	Orthodontists	Laypersons	Total
Male	7 (18.9%)	12 (23.5%)	13 (26%)	17 (25.3%)	49 (23.9%)
Female	30 (81%)	39 (76.4%)	37 (74%)	50 (74.6%)	156 (76.1%)
Total	37	51	50	67	205

Participants additionally provided information on how many years had passed since they completed their postgraduate training in prosthodontics/restorative dentistry and orthodontics. When stratified by years of postgraduate training, specialists with more than 10 years of experience tended to demonstrate higher accuracy, particularly at 0° and ±5°. Although not powered for detailed subgroup analysis, this pattern suggests that clinical exposure and diagnostic repetition may strengthen perceptual acuity for minor discrepancies. Among prosthodontists, 39% had less than 2 years of previous training, 31% between 2 and 10 years, and 29% more than 10 years. Among orthodontists, most had over 10 years of training (56%), followed by 28% with 2–10 years, and 16% with less than 2 years (Table 2).

Table 2.

Completed Postgraduate Training of Specialists.

	Prosthodontists (n = 51)	Orthodontists (n = 50)
Less than 2 years	20 (39%)	8 (16%)
Between 2 and 10 years	16 (31%)	14 (28%)
More than 10 years	15 (29%)	28 (56%)

Based on the responses, it was possible to assess participants’ accuracy in detecting simulated dental rotations discrepancies. Accuracy rates were analyzed for each magnitude of movement (Table 3, Figure 1). The highest accuracy was observed at the extremes of rotation (−10° and +10°), with laypersons achieving 74% and 88% accuracy, respectively, and general dentists 92% and 97%. Prosthodontists and orthodontists showed near-unanimous accuracy for these magnitudes, with prosthodontists reaching 98%–100% and orthodontists 100% for both.

Table 3.

Percentage of Agreement Level of the Research Participants (n = 205) Regarding Mesio-distal Rotation Movements (Positive Values and 0°) and Disto-mesial Rotation Movements (Negative Values) According to the Simulated Tolerance Levels for Tooth 11 in Each Group.

	General Dentists (n = 37)	Prosthodontists (n = 51)	Orthodontists (n = 50)	Laypersons (n = 67)
Rotation	Correct Answer (%)
−10°	34 (92)	50 (98)	50 (100)	49 (74)
−5°	21 (57)	34 (67)	42 (84)	41 (62)
−2.5°	10 (27)	8 (16)	9 (18)	22 (33)
0	32 (86)	45 (88)	46 (92)	53 (80)
+2.5°	12 (32)	22 (43)	32 (64)	20 (30)
+5°	25 (68)	46 (90)	48 (96)	19 (29)
+10°	36 (97)	51 (100)	50 (100)	58 (88)

Figure 1.

Notes: Positive values and 0° represent mesio-distal rotations, while negative values represent disto-mesial rotations. Data are presented according to the magnitude of simulated rotational movement (0°, ±2.5°, ±5°, and ±10°).

Orthodontists also demonstrated high accuracy for +5° (96%) and the control image at 0° (92%). Notably, only orthodontists showed a statistically distinct perception of no movement (0°). For negative rotations, orthodontists maintained high accuracy at −5° (84%), but performance dropped to 18% for −2.5°, indicating reduced perception sensitivity at this smaller deviation.

At +2.5°, only orthodontists (64%) retained a higher percentage of agreement compared to laypersons (30%), prosthodontists (43%), and general dentists (32%). General dentists were better at identifying rotations of 10° and 5° in both directions, with accuracy above 50%, still considered −2.5° (27%) and +2.5° (32%).

Laypersons showed reduced sensitivity for minor changes, particularly at ±2.5°, but maintained accuracy above 50% for more pronounced rotations: 74% for −10°, 62% for −5°, 80% for 0°, and 88% for +10°. Prosthodontists had the lowest accuracy for −2.5° (16%) across all groups but performed comparably to orthodontists for the larger rotations (+10°, +5°, −10°, −5°, and 0°), maintaining accuracy above 50%.

Statistical comparisons using the chi-square test (p < .05) revealed significant differences between groups (Table 4). General dentists differed significantly from laypersons only at −5° (p = .05) and +5° (p = .00). Orthodontists showed significantly greater accuracy than laypersons at all degrees except +2.5° (p = .50). Prosthodontists also showed higher accuracy than laypersons in most comparisons, except for −5°, +2.5°, and 0°, where differences were not statistically significant.

Table 4.

Intergroup Comparisons of Accuracy in Detecting Simulated Rotational Discrepancies of the Maxillary Right Central Incisor (Tooth 11) Between Professional Groups (Orthodontists, Prosthodontists, and General Dentists) and Laypersons at Each Rotation Magnitude.

	General Dentists	Prosthodontists	Orthodontists
Laypersons	−10° (p = .24)−5° (p = .05)−2.5° (p = .33)0° (p = .25)+2.5° (p = .50)+5° (p = .00)+10° (p = .01)	−10° (p = .00)−5° (p = .38)−2.5° (p = .02)0° (p = .21)+2.5° (p = .11)+5° (p = .00)+10° (p = .00)	−10° (p = .00)−5° (p = .01)−2.5° (p = .05)0° (p = .04)+2.5° (p = .50)+5° (p = .00)+10° (p = .01)

Notes: p values were obtained using chi-square tests, with statistical significance set at p < .05. *Significant statistical difference (p < .05).

Discussion

The increasing use of 3D digital models in diagnosis, treatment planning, and patient communication warrants investigation into whether these tools affect perceptual accuracy. Digital environments allow precise manipulation of specific tooth movements, making them ideal for assessing rotation-detection thresholds across different observer groups. However, little is known about how professionals and laypersons interpret rotational discrepancies when viewing digitally simulated images, emphasizing the need for studies evaluating perception within modern digital workflows.

This study aimed to evaluate the perception of rotational discrepancies in digital dental models among different groups: laypersons, general dentists, prosthodontists, and orthodontists. The identification and interpretation of such movements^21–23 are critical for improving orthodontic diagnosis⁴ and treatment outcomes.⁵ The results revealed significant variation in perceptual accuracy between groups, as well as correlations with the duration of specialty training.

Rotational discrepancies of maxillary incisors are not only esthetically relevant but also biomechanically significant.^{22, 23} Even minor rotations may influence proximal contacts, occlusal pathways, and long-term stability. The fact that laypersons were unable to perceive movements below 10° underscores the need for clinicians to educate patients about discrepancies that may be clinically important yet visually imperceptible. This becomes especially relevant in clear aligner therapy, where rotational control, particularly of rounded teeth, remains one of the most challenging movements to predict and achieve.

More than 60% of dental specialists in this study were able to identify rotational discrepancies of the upper right central incisor from as little as 5°, in both mesio-distal and disto-mesial directions. In contrast, general dentists and laypersons demonstrated lower sensitivity at smaller magnitudes. These findings emphasize the importance of specialization^{15, 24} and experience²³ in the detection of minor dental movements and serve as a foundation for interdisciplinary communication and clinical decision-making.

At the smallest rotation magnitude (±2.5°), orthodontists demonstrated higher sensitivity than other groups; however, perception at this level was inconsistent and asymmetric. While detection at +2.5° reached 64%, accuracy at −2.5° dropped markedly to 18%, indicating that rotations of this magnitude cannot be considered reliably perceived, even by specialists. These findings suggest that ±2.5° represents a perceptual threshold region rather than a consistently detectable deviation. The asymmetric perception observed between mesio-distal and disto-mesial rotations at minimal magnitudes may be attributed to visual orientation effects, shading, and contour perception in static digital images. Directional bias has been previously described in esthetic perception studies,^15–17 in which observer sensitivity varies according to tooth orientation, light reflection, and visual framing. Therefore, the reduced detection of −2.5° rotations should not be interpreted as inferior diagnostic ability, but rather as a limitation of perceptual resolution at minimal angular deviations under static viewing conditions.

Specialist training appears to enhance sensitivity to minimum dental discrepancies that may go unnoticed by non-specialists. This increased perceptual ability underscores the relevance of professional expertise in determining whether slight rotations, though potentially imperceptible to patients, should be addressed orthodontically or considered functionally and esthetically acceptable.²⁵ Previous studies^{24, 26} support these findings, showing that orthodontists can detect discrepancies at thresholds as low as 1.0 mm, compared to 3.0 mm for laypeople, again reinforcing the diagnostic advantage of specialization. These results also highlight the need for closer collaboration between orthodontists, prosthodontists, and general dentists. If minor rotations are overlooked during restorative or rehabilitative planning, undesired gingival margins, midline canting, or functional disharmonies may persist or worsen. Incorporating shared diagnostic protocols and interdisciplinary consultations could mitigate these risks and improve treatment outcomes, particularly in patients undergoing combined orthodontic-restorative care. Although this study did not assess treatment recommendations or clinical decision-making, the observed differences in perceptual sensitivity may have implications for diagnostic awareness and communication among dental professionals. These findings should be interpreted as perceptual tendencies rather than direct predictors of clinical behavior or treatment choice.

Accurate patient education is also essential, particularly in identifying movements like dental rotation that may compromise occlusal balance.^{9, 27, 28} The loss of proximal contact, for instance, can initiate rotation and lead to functional problems, such as occlusal trauma or masticatory inefficiency.^{6, 7} When patients are informed about these effects, possibly through 3D digital model visualization, they may be more likely to recognize minor relapses and seek timely retreatment, preventing more complex issues.¹⁵ The limited ability of laypersons to detect minor rotational discrepancies reinforces the importance of patient education. Clinicians should not assume that the absence of patient concern reflects the absence of clinically relevant irregularities.

Similarly, prosthodontists and general dentists can apply these insights to inform patients about the esthetic and functional risks associated with undetected rotations, potentially enhancing the longevity of restorative treatments.²⁹ Evidence also shows that most laypeople prefer orthodontic alignment over restorative approaches when correcting rotated teeth, reflecting dissatisfaction with dental rotation and supporting the need for accurate diagnosis.¹

The role of general dentists in orthodontic treatment is expanding. Studies suggest that 20%–50% of orthodontic cases are managed by general dentist practitioners,³⁰ yet tooth rotation remains one of the most unpredictable movements, particularly when treated with aligners. Nearly half of orthodontists report limited success in correcting rotations with aligners, especially in posterior teeth. In our study, general dentists and laypersons demonstrated notably lower accuracy in detecting small rotations such as ±2.5° in anterior teeth, suggesting that these discrepancies may be missed during treatment or not prioritized in planning.

The decision to focus on the maxillary right central incisor was based on its critical role in smile esthetics and on previous evidence demonstrating higher reliability for rotational assessment of this tooth compared with posterior teeth. Vermeulen et al.²⁸ reported measurement errors ranging from 1.18° to 5.05° for maxillary central incisors, whereas posterior teeth exhibited lower reproducibility. This approach enabled methodological standardization but inevitably narrowed the scope of the investigation.

By quantifying perception thresholds for dental rotation across different professional backgrounds, this study fills a gap in the literature concerning esthetic zone diagnostics. Orthodontists achieved the highest accuracy, frequently recommending alignment based on rotational discrepancies observed in manipulated images. This may be attributed to greater clinical experience: 56% of orthodontists in the study had over 10 years of training, compared to only 39% of prosthodontists with less than 2 years. These results reaffirm the value of clinical experience and specialization in dental diagnostics. If rehabilitative specialists such as prosthodontists fail to identify minimum rotations, restorative treatments may be inappropriately indicated. In turn, patients should be informed about the qualifications of their providers, and inter-specialty communication should be prioritized to avoid over- or under-treatment.

Little’s Irregularity Index is a quantitative method used to assess anterior dental alignment by summing the linear displacements between adjacent anatomic contact points of the anterior teeth.⁸ Originally described for mandibular incisors, the index has been widely applied in orthodontic research to estimate the severity of anterior irregularity and to establish perceptual and diagnostic thresholds for dental misalignment.^{21, 22, 25} Higher index values indicate greater degrees of crowding or irregularity. In perception studies, Little’s Irregularity Index has been used as a reference to correlate objective measurements of dental misalignment with subjective esthetic perception among professionals and laypersons.^{12, 23} Ma et al.²³ also found that orthodontists were more perceptive in detecting anterior crowding. Their study showed that orthodontists and general dentists identified central incisor misalignment at a Little’s Irregularity Index²² of 1.5 mm, while laypersons required at least 2.0 mm to perceive the change. For lateral incisors, orthodontists identified crowding at 3.0 mm, dentists at 4.0 mm, and laypersons failed to detect the discrepancy altogether, reinforcing that increased orthodontic experience improves diagnostic sensitivity to minimum discrepancies.

This study has limitations that should be considered when interpreting the findings. The sample was obtained through convenience sampling from a single academic institution, which may limit the generalizability of the results to broader populations. Additionally, female participants represented a higher proportion of respondents across all groups, reflecting participation patterns commonly reported in web-based surveys and current demographic trends in dentistry. Although laypersons’ demographic characteristics were not collected to preserve anonymity and reduce survey burden, this precluded subgroup analyzes based on age or gender. Furthermore, the general dentist group constituted the smallest subgroup; while statistical assumptions for chi-square analysis were met and the overall sample size exceeded the calculated power, comparisons involving smaller subgroups should be interpreted with caution. Consequently, the present findings should be regarded as exploratory and hypothesis-generating, providing a foundation for future studies with probabilistic sampling strategies and more balanced demographic representation.

The statistical approach adopted in this study reflects its exploratory and comparative design. Although multiple group comparisons were performed across different rotation magnitudes, each angle was treated as an independent perceptual condition with distinct clinical meaning. More complex analytical models, such as multivariable regression or effect size estimation, were not employed because the study was not powered for causal inference or confounder adjustment. In particular, experience-based subgroup analyzes were underpowered and are therefore presented descriptively to illustrate trends rather than to support inferential conclusions. Future studies with larger and more balanced samples may benefit from multivariable modeling and effect size estimation to further refine these findings.

The use of static 3D-rendered images may not accurately replicate dynamic clinical evaluation, in which lighting, head position, and emotional expression influence perception. Additionally, variations in screen size and device resolution among respondents could have affected detection accuracy. Future studies employing eye-tracking methods, standardized display conditions, or augmented reality models could provide more ecologically valid assessments. Future research should also explore perceptual thresholds for posterior rotations, investigate cultural influences on dental esthetics, and examine whether emerging technologies, such as 3D immersive environments or AI-driven visualization, can improve patient understanding of rotational discrepancies. The rotational movements were digitally applied using ArchForm software, which enables precise angular adjustments. However, no formal measurement error analysis or reliability testing was conducted for the stimulus generation process, which should be considered a methodological limitation of the study. Longitudinal studies assessing whether higher perceptual sensitivity correlates with better treatment outcomes may also be valuable.

The degree intervals selected (0°, ±2.5°, ±5°, and ±10°) were informed by Larson et al.,¹³ who proposed 2° as the clinical threshold for rotation detection, in accordance with the American Board of Orthodontics (ABO) guidelines. This study stands out for its prospective design and use of precisely manipulated digital models to simulate a range of rotational discrepancies, enabling real-time perception analysis. These findings contribute to orthodontic education and clinical training and suggest that future research should continue exploring perception thresholds and their impact on long-term treatment outcomes.

Conclusion

Dental professionals demonstrated greater perceptual sensitivity to rotational discrepancies than laypersons, particularly at moderate to larger magnitudes (≥5°). At minimal deviations (±2.5°), perception was inconsistent and asymmetric, even among specialists, suggesting that these angles approach the lower limit of reliable visual detection in static digital models.

Specialist dental professionals, orthodontists and prosthodontists demonstrated greater accuracy in identifying minor rotational discrepancies in anterior teeth compared to laypersons and general dental practitioners, highlighting the importance of professional expertise in diagnosis and esthetic evaluation during orthodontic and restorative treatment planning.

Footnotes

Acknowledgments

The present study was developed as part of the first author’s orthodontic specialization monograph, fulfilling the requirements for obtaining the title of specialist in Orthodontics. The authors would like to express their sincere gratitude to all individuals who participated in this research, especially the respondents who generously contributed their time and efforts by completing the questionnaires.

Authors’ Contribution

D.Z.B.: Conceptualization, data curation, investigation, methodology, software, formal analysis, validation, visualization, writing—original draft, writing—review and editing. L.S.C.B.: Data curation, investigation, methodology, software, formal analysis, validation, visualization, writing—original draft, writing—review and editing. C.Z.T.V.: Data curation, investigation, methodology, formal analysis, visualization, writing—original draft, writing—review and editing. D.S.A.: Conceptualization, data curation, investigation, methodology, software, formal analysis, project administration, validation, visualization, writing—original draft, writing—review and editing. C.P.M.C.: Conceptualization, data curation, investigation, methodology, software, formal analysis, project administration, validation, visualization, writing—original draft, writing—review and editing. F.A.R.C.: Conceptualization, data curation, investigation, methodology, software, formal analysis, project administration, validation, visualization, writing—original draft, writing—review and editing. All authors made substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work; drafting the work or revising it critically for important intellectual content; final approval of the version to be published; and agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Declaration of Conflicting Interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Ethical Approval Institutional Statement

Experimental study approved by the Research Ethics Committee of Pedro Ernesto University Hospital (CEP/HUPE) at UERJ, approval number 6.760.243 (CAAE: 78786824.0.0000.5259).

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Supplementary Material

Supplementary material for this article is available online.

ORCID iDs

Dafne Zalctregier Bank

Luísa Schubach da Costa Barreto

Camila Zager Tinoco Viana

David Silveira Alencar

Caroline Pelagio Maués Casagrande

Felipe de Assis Ribeiro Carvalho

References

Peng

, Zhang

, Zheng

, . Predicting changes of incisor and facial profile following orthodontic treatment: a machine learning approach. Head Face Med 2025; 21: 22. DOI: 10.1186/s13005-025-00499-5

Harshini

, Rajesh

RNG

, Kondody

, . Perception of smile attractiveness based on upper dental midline shift and gingival display among dental professionals and general population: a cross-sectional study. J Esthet Restor Dent 2025; 17(12): e99173. DOI: 10.7759/cureus.99173

Johal

, Damanhuri

, and Colonio-Salazar

Adult orthodontics, motivations for treatment, choice, and impact of appliances: a qualitative study. Am J Orthod Dentofacial Orthop 2024; 166: 36–49. DOI: 10.1016/j.ajodo.2024.02.009

Arnett

and Worley

CM.

The treatment motivation survey: defining patient motivation for treatment. Am J Orthod Dentofacial Orthop 1999; 115: 233–238. DOI: 10.1016/S0889-5406(99)70323-9

Bos

, Hoogstraten

, and Prahl-Andersen

Expectations of treatment and satisfaction with dentofacial appearance in orthodontic patients. Am J Orthod Dentofacial Orthop 2003; 123: 127–132. DOI: 10.1067/mod.2003.84

Andrews

LF.

The six keys to normal occlusion. Am J Orthod 1972; 62: 296–309. DOI: 10.1016/S0002-9416(72)90268-0

Pasukdee

, Cheng

, and Chen

DS.

Smile preferences of orthodontists, general dentists, patients, and the general public in three-quarter and lateral views. Am J Orthod Dentofacial Orthop 2021; 159: e311–e320. DOI: 10.1016/j.ajodo.2020.09.012

Sinclair

and Little

RM.

Maturation of untreated normal occlusions. Am J Orthod 1983; 83: 114–123. DOI: 10.1016/S0002-9416(83)90296-8

Desai

, Weir

, and Meade

MJ.

Estimation of centers of rotation of the maxillary incisors during nonextraction space closure using the Invisalign appliance. Am J Orthod Dentofacial Orthop 2025; 168: 88–98. DOI: 10.1016/j.ajodo.2025.02.012

10.

Badran

Perception of smile attractiveness by laypeople—influence of profession and treatment experience. Br J Med Med Res 2014; 4: 3777–3786. DOI: 10.9734/BJMMR/2014/5545

11.

Chawla

, Deshmukh

, and Bhosale

An assessment of orthodontists’ perception about efficiency of various tooth movements carried out using clear aligner therapy. J Indian Orthod Soc 2023; 58: 65–74. DOI: 10.1177/03015742231202303

12.

Alqahtani

, Preston

, and Guan

Perception of dental professionals and lay persons to altered mandibular incisors crowding. J World Fed Orthod 2012; 1: e61–e67. DOI: 10.1016/j.ejwf.2012.06.002

13.

Larson

, Vaubel

, and Grünheid

Effectiveness of computer-assisted orthodontic treatment technology to achieve predicted outcomes. Angle Orthod 2012; 83: 557–562. DOI: 10.2319/080612-635.1

14.

Cavalcanti

, Valentim

, Guerra

SMG

, . Aesthetic perception of gingival smiles. Rev Odontol UNESP 2018; 47: 45–50. DOI: 10.1590/1807-2577.08017

15.

Parrini

, Rossini

, Castroflorio

, . Laypeople’s perceptions of frontal smile esthetics: a systematic review. Am J Orthod Dentofacial Orthop 2016; 150: 740–750. DOI: 10.1016/j.ajodo.2016.06.022

16.

Medeiros

, Pecho

, Pérez

, . Influence of background color on color perception in dentistry. J Dent 2021; 108: 103640. DOI: 10.1016/j.jdent.2021.103640

17.

Kokich

, Kokich

, and Kiyak

AH.

Perceptions of dental professionals and laypersons to altered dental esthetics: asymmetric and symmetric situations. Am J Orthod Dentofacial Orthop 2006; 130: 141–151. DOI: 10.1016/j.ajodo.2006.04.017

18.

Klages

, Claus

, Wehrbein

, . Development of a questionnaire for assessment of the psychosocial impact of dental aesthetics in young adults. Eur J Orthod 2005; 28: 103–111. DOI: 10.1093/ejo/cji083

19.

von Elm

, Altman

, Egger

, . The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement. Ann Intern Med 2007; 147: 573–577. DOI: 10.7326/0003-4819-147-8-200710160-00010

20.

Eynon

, Schulz

, Frisch

, . Improving the quality of web surveys: the checklist for reporting results of internet e-surveys (CHERRIES). J Med Internet Res 2004; 6: e34. DOI: 10.2196/jmir.6.3.e34

21.

Burns

, Dowling

, Garvey

, . The reliability of Little’s Irregularity Index for the upper dental arch using three-dimensional digital models. J Dent 2014; 42: 1320–1326. DOI: 10.1016/j.jdent.2014.07.012

22.

Little

RM.

The irregularity index: a quantitative score of mandibular anterior alignment. Am J Orthod Dentofacial Orthop 1975; 68: 554–563. DOI: 10.1016/0002-9416(75)90086-X

23.

, Preston

, Asai

, . Perceptions of dental professionals and laypeople to altered maxillary incisor crowding. Am J Orthod Dentofacial Orthop 2014; 146: 579–586. DOI: 10.1016/j.ajodo.2014.07.018

24.

Kokich

, Kiyak

, and Shapiro

PA.

Comparing the perception of dentists and lay people to altered dental esthetics. J Esthet Restor Dent 1999; 11: 311–324. DOI: 10.1111/j.1708-8240.1999.tb00414.x

25.

Macauley

, Garvey

, Dowling

, . Using Little’s Irregularity Index in orthodontics: outdated and inaccurate. J Dent 2012; 40: 1127–1133. DOI: 10.1016/j.jdent.2012.09.010

26.

, Choi

, Chung

, . Comparing esthetic smile perceptions among laypersons with and without orthodontic treatment experience and dentists. Korean J Orthod 2014; 44: 294–302. DOI: 10.4041/kjod.2014.44.6.294

27.

Arrubla-Escobar

, Barbosa-Liz

, Zapata-Noreña

, . Smile aesthetics assessment in patients undergoing the finishing phase of orthodontic treatment: an observational cross-sectional study. Cureus 2023; 15: e45644. DOI: 10.7759/cureus.45644

28.

Vermeulen

FMJ

, Aartman

IHA

, Kuitert

, . The reliability of assessing rotation of teeth on photographed study casts. Angle Orthod 2012; 82: 1033–1039. DOI: 10.2319/112811-733.1

29.

Arunachalam

, Nathwani

, Nejati

, . Assessing dentists’ awareness of the orthodontic–restorative interface. J Dent 2024; 141: 104811. DOI: 10.1016/j.jdent.2023.104811

30.

Marques

, Junior

, Pereira

, . Quality of orthodontic treatment performed by orthodontists and general dentists. Angle Orthod 2011; 82: 102–106. DOI: 10.2319/061311-389.1

Perception of Dental Rotation Discrepancies Among Dental Professionals and Laypersons: A Cross-sectional Observational Study

Abstract

Aims

Material and Methods

Results

Conclusion

Keywords

Introduction

Materials and Methods

Results

Sample Characterization.

Completed Postgraduate Training of Specialists.

Percentage of Agreement Level of the Research Participants (n = 205) Regarding Mesio-distal Rotation Movements (Positive Values and 0°) and Disto-mesial Rotation Movements (Negative Values) According to the Simulated Tolerance Levels for Tooth 11 in Each Group.

Intergroup Comparisons of Accuracy in Detecting Simulated Rotational Discrepancies of the Maxillary Right Central Incisor (Tooth 11) Between Professional Groups (Orthodontists, Prosthodontists, and General Dentists) and Laypersons at Each Rotation Magnitude.

Discussion

Conclusion

Footnotes

Acknowledgments

Authors’ Contribution

Declaration of Conflicting Interests

Ethical Approval Institutional Statement

Funding

Supplementary Material

ORCID iDs

References