Enhancing systematic reviews in orthodontics: a comparative examination of GPT-3.5 and GPT-4 for generating PICO-based queries with tailored prompts and configurations.

OBJECTIVES: The rapid advancement of Large Language Models (LLMs) has prompted an exploration of their efficacy in generating PICO-based (Patient, Intervention, Comparison, Outcome) queries, especially in the field of orthodontics. This study aimed to assess the usability of Large Language Models (LLMs), in aiding systematic review processes, with a specific focus on comparing the performance of ChatGPT 3.5 and ChatGPT 4 using a specialized prompt tailored for orthodontics. MATERIALS/METHODS: Five databases were perused to curate a sample of 77 systematic reviews and meta-analyses published between 2016 and 2021. Utilizing prompt engineering techniques, the LLMs were directed to formulate PICO questions, Boolean queries, and relevant keywords. The outputs were subsequently evaluated for accuracy and consistency by independent researchers using three-point and six-point Likert scales. Furthermore, the PICO records of 41 studies, which were compatible with the PROSPERO records, were compared with the responses provided by the models. RESULTS: ChatGPT 3.5 and 4 showcased a consistent ability to craft PICO-based queries. Statistically significant differences in accuracy were observed in specific categories, with GPT-4 often outperforming GPT-3.5. LIMITATIONS: The study's test set might not encapsulate the full range of LLM application scenarios. Emphasis on specific question types may also not reflect the complete capabilities of the models. CONCLUSIONS/IMPLICATIONS: Both ChatGPT 3.5 and 4 can be pivotal tools for generating PICO-driven queries in orthodontics when optimally configured. However, the precision required in medical research necessitates a judicious and critical evaluation of LLM-generated outputs, advocating for a circumspect integration into scientific investigations.

3D evaluation of cranial and dentofacial morphological differences between individuals with mouth breathing and nasal breathing.

INTRODUCTION: The present study aimed to identify the morphological differences in cranial and dentofacial structures between individuals with mouth-breathing and nasal-breathing. MATERIALS AND METHODS: The study included 120 individuals, 60 each in the nasal breathing (NB) and mouth breathing (MB) groups. 3D stereophotogrammetry, lateral cephalometric radiographs, and intraoral examination results were recorded by the researchers to determine the morphological differences between the MB group and the NB group. The study utilized cephalometric radiographs for 2D hard tissue measurements and 3D stereophotogrammetric records for linear and angular measurements. RESULTS: Statistically significant differences were found between the NB and MB groups' SNB angles (respectively, 79.3 ± 3.04, 76.6 ± 4.24, and p=0.002). Also, the NB group's SN-GoGn angle was lower than the MB group's (respectively, 31.5 ± 5.12, 36.0 ± 5.55, and p=0.002). Considering the Jarabak ratio, the NB group's Jarabak ratio was higher than the MB group (respectively,65.7 ± 4.16, 62.6 ± 4.10, and p=0.014). In 3D stereophotogrammetry measurements, increased Li-Me' was detected in the MB group than in NB group. CONCLUSION: Mouth breathing results in significant morphological differences that affect the development of both soft tissues and skeletal structures. Orthodontists utilize these characteristic features observed in mouth-breathing anomalies for early diagnosis and consider referring their patients for medical treatment of mouth breathing.

Clinical comparative study on the accuracy of palatal rugae in models obtained by different impression materials and intraoral scanning.

OBJECTIVE: Palatal rugae are frequently used in the evaluation of tooth movement after treatment in orthodontics and as a stable region in superimposition. It is important to note that the impression method and material used to record the rugae region affect the accuracy of the impression. The aim of this study is to compare the accuracy of palatal rugae, in three-dimensional (3D) by employing both conventional and digital impression methods. MATERIALS AND METHODS: In this study, 22 patients (12 females, 10 males) mean age of 13.5 ± 1.7 years old were selected with complete permanent dentition. Three different impressions were taken from the maxillae of the patients: conventional impression using silicone rubber impression material, conventional impression using alginate impression material, and optical impression using an intraoral scanner. The impressions' digital data were analyzed by the GOM Inspect (Version 2018, Braunschweig, Germany), a 3D analysis software. The Root Mean Square (RMS) values of the total ruga region were evaluated in this software. The data were statistically analyzed using the Jamovi program. The Kruskal-Wallis test and Mann-Whitney U test were performed due to the non-normal distribution of the data. RESULTS: There is no statistically significant difference between the comparison points of the right and left rugae's medial and lateral points and total rugae regions' RMS values. Although there was no statistically significant difference, the total RMS values of alginate and digital scan measurements showed closer results than the RMS values of silicone and digital scan measurements. CONCLUSION: The study found that there was no statistically significant difference in the total RMS values of the ruga region between traditional and digital impression methods. CLINICAL RELEVANCE: The treatment period in orthodontics is long. Different impression materials and methods can be used for diagnostic, mid-treatment, and final impressions. For superimpositions and treatment and post-treatment palatal ruga evaluations, traditional and digital impression methods are clinically acceptable and can be used as alternatives to each other.

Assessment of the biointeractivity of a novel vital pulp therapy agent derived from eggshell biowaste: An in vitro study.

This study aimed to assess the calcium (Ca2+) and hydroxyl (OH-) ion-releasing ability, namely the biointeractivity of eggshell-derived hydroxyapatite (ESDHA) in comparison with mineral trioxide aggregate (MTA) and calcium hydroxide (CH). ESDHA, MTA and CH samples (n = 10; 8 × 1.6 mm) were immersed in 10 mL of deionised water (37°C, pH 6.8). Ca2+ and OH- ion releases were detected in 1, 7 and 21 days. Scanning electron microscopy and Fourier transform infrared spectroscopy analyses were also conducted. IBM SPSS 20.0 was used for statistical analyses. The cumulative Ca2+ ions (56.22 ± 11.28 ppm) were detected as most significant in ESDHA (day 21; p < 0.05). The OH- ion values of the ESDHA group were statistically higher than MTA and CH (days 1 and 7; p < 0.05). ESDHA and CH showed a similar pattern with sharp peaks in Ca2+, oxygen and carbon elements. ESDHA being a sustainable material with a high ion-releasing ability may be a preferable alternative to the commercial vital pulp therapy agents.

A comparative analysis of AI-based chatbots: Assessing data quality in orthognathic surgery related patient information.

INTRODUCTION: The aim of the current study is to evaluate the quality, reliability, readability, and similarity of data provided by different AI-based chatbots in the field of orthognathic surgery. MATERIALS AND METHODS: Guidelines on orthognathic surgery were reviewed, and a list of questions for patients to ask chatbots was produced by two reasearchers. The questions were categorized into 'General Information and Procedure' and 'Results and Recovery', with 30 questions in each category. Five different scoring criteria were used to evaluate the chatbot responses to 60 questions: Ensuring Quality Information for Patients (EQIP) tool, Reliability Scoring System (adapted from DISCERN), Global Quality Scale (GQS), Simple Measure of Gobbledygook (SMOG) and Similarity Index. RESULTS: The highest mean values were observed in OpenEvidence for EQIP tool, SMOG, and Similarity Index, while for Reliability and GQS assessment criteria, MediSearch showed the highest values. When evaluated in terms of reliability and quality, all three AI-based chatbots demonstrated high reliability and good quality; however, they required at least a college-level education for readability based on the SMOG index. Additionally, upon assessment of similarity, ChatGPT-4 displayed high originality, while OpenEvidence exhibited a high degree of similarity. CONCLUSION: AI-based chatbots with a variety of features have usually provided answers with high quality, reliability, and difficult readability to questions. Although the medical information in the field of orthognathic surgery provided through chatbots is of higher quality, it is recommended that individuals consult their healthcare professionals on this issue.

The Quality of CLP-Related Information for Patients Provided by ChatGPT.

OBJECTIVE: To assess the quality, reliability, readability, and similarity of the data that a recently created NLP-based artificial intelligence model ChatGPT 4 provides to users in Cleft Lip and Palate (CLP)-related information. DESIGN: In the evaluation of the responses provided by the OpenAI ChatGPT to the CLP-related 50 questions, several tools were utilized, including the Ensuring Quality Information for Patients (EQIP) tool, Reliability Scoring System (Adapted from DISCERN), Flesh Reading Ease Formula (FRES) and Flesch-Kinkaid Reading Grade Level (FKRGL) formulas, Global Quality Scale (GQS), and Similarity Index with plagiarism-detection tool. Jamovi (The Jamovi Project, 2022, version 2.3; Sydney, Australia) software was used for all statistical analyses. RESULTS: Based on the reliability and GQS values, ChatGPT demonstrated high reliability and good quality attributable to CLP. Furthermore, according to the FRES results, ChatGPT's readability is difficult, and the similarity index values of this software exhibit an acceptable level of similarity ratio. There is no significant difference in EQIP, Reliability Score System, FRES, FKGRL, GQS, and Similarity Index values among the two categories. CONCLUSION: OpenAI ChatGPT provides a highly reliable, high-quality, but challenging to read, and acceptable similarity rate in providing information related to CLP. Ensuring that information obtained through these models is verified and assessed by a qualified medical expert is crucial.

YouTube™ as a source of parents' information for craniosynostosis.

OBJECTIVE: This study aimed to evaluate the content, reliability and quality levels of YouTube™ videos regarding craniosynostosis for parents' information. METHODS: A keyword search for 'craniosynostosis' was conducted on YouTube, and the uniform resource locators of the first 160 videos were initially recorded and evaluated. Ninety-four videos that met the inclusion criteria were analysed. Each video received a score ranging from 0 to 9 points, classifying them as low-content (0-3), moderate-content (4-6) and high-content (7-9). The reliability scores adapted from DISCERN and Global Quality Scale (GQS) scores were recorded. RESULTS: The median content score for the videos was 4. According to the content scores, 34% of included videos (n = 32) were classified as low-content, 60.6% (n = 57) as moderate-content, and 5.3% (n = 5) as high-content. The median reliability score for the videos was 3, and the median GQS score was 3. The reliability and quality levels of videos classified as high-content and moderate-content were significantly superior to low-content videos (P < .05). Laypersons were identified as the most frequent source of information in the videos. However, most of the videos lacked information about syndromic/non-syndromic forms and specific complications. The importance of early referral/timing of surgery and minimally invasive surgical treatment techniques was mentioned in all high-content videos. CONCLUSION: The results of the present study suggest that YouTube™ in its current format, is not a fully trustable source for parents seeking information on craniosynostosis. Craniofacial units must increase the content, quality and reliability level of videos on craniosynostosis.

The effect of layer thickness on the accuracy of the different in-house clear aligner attachments.

OBJECTIVE: The accuracy of the attachments, one of the key components of clear aligner therapy, is important for obtaining more precise tooth movement. The aim of this study was to evaluate the accuracy of the ovoid, hemi-ellipsoid, and vertical rectangular attachments produced by the digital light-processing(DLP) 3-dimensional printing technologies with 25 µm, 75 µm, and 125 µm layer thickness. MATERIALS AND METHODS: The ovoid, hemi-ellipsoid, and vertical rectangular attachments were positioned onto the convex surface of the central incisor by the software. The printing process was carried out by a DLP printer using a commercially printed resin with 25 µm, 75 µm, and 125 µm layer thickness (n = 30, for each group). All test models' digital data was exported into the reverse engineering software for the superimposition. After selecting the 5 comparison points for the ovoid and vertical rectangular attachments, and 6 comparison points for the hemi-ellipsoid attachment, the Root Mean Square (RMS) was evaluated for each group. RESULTS: There is a statistically significant difference between the 25 µm and 125 µm layer thickness of total RMS values in the ovoid, hemi-ellipsoid, and vertical rectangular attachment groups (p = 0.001, p = 0.03, and p = 0.00 respectively). The printing time with the 25 µm layer thickness was 4 times longer than with the 125 µm layer thickness. CONCLUSIONS: This study revealed that the accuracy of the attachments used for in-house clear aligner therapy is affected by the layer thickness of the 3D printer. CLINICAL RELEVANCE: The layer thickness of the 3D printer is a crucial factor in determining attachment accuracy, but its clinical significance is minimal. Clinicians should make informed decisions about the appropriate layer thickness, taking into account their workflow preferences, time constraints, and other practical considerations specific to their clinical practice.

The effect of aging on the mechanical properties of 3-dimensional printed biocompatible resin materials used in dental applications: An in vitro study.

INTRODUCTION: The mechanical properties of biocompatible printable resin materials in an intraoral environment is still being investigated. This study aimed to assess the effect of the aging process on the mechanical properties of resin samples produced by stereolithography appearance (SLA) and digital light processing (DLP) 3-dimensional printer systems. METHODS: The cylindrical sample (4.00 × 20.00 mm) was designed by software, and the data were transformed into digital format. A DLP printer (n = 40) and an SLA printer (n = 40) carried out the printing process. The aging procedure was applied to 20 samples from each group using a thermocycling device. After the aging procedure, the samples were placed in the universal testing device for the 3-point bending test. RESULTS: This study showed that the aging procedure decreased maximum load, bending stress, and Young's modulus values and increased maximum deflection values of the DLP group (P <0.01). However, no statistical difference was detected in the parameters compared with the SLA group except for the maximum deflection values. Furthermore, statistically significant differences were found between maximum deflection and Young's module values of SLA and DLP control and study groups (P <0.05). CONCLUSIONS: This in vitro study revealed that the biocompatible printable resin materials produced by DLP and SLA printers had the mechanical strength to resist the values resembling the physiological occlusal forces even after the aging procedure and could produce intraoral appliances.

Are Social Media Platforms Appropriate Sources of Information for Patients Regarding the Topic of Facial Trauma?

BACKGROUND: Internet technologies have made a wide variety of information available to the public. Social media platforms (SMPs) can also be used as a source of information for patients seeking health care information. However, the quality of health information on SMPs is not clear and standardized. PURPOSE: To evaluate the content, reliability, and quality levels of videos reporting on facial trauma on a SMP (YouTube [Google LLC, San Bruno, California]) regarding patients' information. STUDY DESIGN, SETTING, SAMPLE: This was a cross-sectional study, and the sample is composed of videos found on a SMP based on searching the keyword "facial trauma." English-language videos with acceptable audiovisual quality and content related to facial trauma were included in the study. PREDICTOR VARIABLE: The descriptive features such as number of views, number of likes, number of comments, video duration, date of uploading, and the demographic features such as source and uploader were recorded. MAIN OUTCOME VARIABLES: The primary outcome variable was content level. Secondary outcome variables were reliability and quality levels measured by DISCERN and Global Quality Scale. COVARIATES: The name and uniform resource locator of the videos were recorded as additional data. ANALYSES: The Mann-Whitney U test was used to compare low-content and high-content videos with a significance level of P < .05. The Kappa test was used to assess the inter-rater reliability. RESULTS: The sample was composed of 50 videos that met study's inclusion. The mean total content score for the videos was 2.87 (range: 0 to 7), with 64% of all videos (n = 32) classified as low-content. The reliability and quality levels of videos classified as high-content were significantly superior (P < .001). In addition, the video duration was significantly higher in the high-content videos (P = .045). High-content videos were uploaded by health care professionals with a ratio of 39%, and the sources of these videos were predominantly oral and maxillofacial surgeons; however, low-content videos were mostly uploaded by clinics (75%), with the sources of these videos predominantly laypersons. CONCLUSION AND RELEVANCE: Given the generally low content, reliability, and quality of online videos regarding facial trauma, clinicians should be cautious in recommending or referring patients to SMPs.

Comparing the physical and mechanical properties of different biocompatible three-dimensional resin materials in possible use of dental appliances: An in vitro study.

OBJECTIVE: This study aimed to assess the colour stability, water sorption, microhardness and water contact angle of two different 3D printing systems (SLA and DLP) in a possible use of producing paediatric and orthodontic dental appliances. MATERIALS AND METHODS: SLA and DLP printer systems produced a total of 160 disk samples with a diameter of 15.00 mm and a height of 2.00 mm. Colour changes of 64 samples were assessed in distilled water, coffee, coke and cherry juice and Vicker's microhardness tests were also conducted. Solubility and water sorption were held following the water contact angle assessment. Statistical analyses were performed using the SPSS software. Mann-Whitney-U test, Friedman test and Bonferroni post hoc Multiple Comparison Test were performed. RESULTS: In DLP and SLA groups, coffee had a statistically significant colouring effect regarding the assessment periods (P = .001, 20.09 ± 2.96, 22.09 ± 3.51, respectively), and the discolouration effect of coffee was higher in the SLA group at all endpoints (P < .05). At the same time, DLP was more affected by coke solution in T0-T1 and T0-T7 (P < .05). The values of water sorption showed statistically significant differences in the group of DLP compared to the SLA (P = .01, 121.11 ± 10.54, 92.78 ± 8.70, respectively). No statistical significance was detected between the solubility values and water contact angle of SLA and DLP groups. The SLA printer's microhardness values revealed statistically significantly higher values than the DLP group (P = .001) and a decrease was detected following the immersion period in the microhardness values of the SLA group (P = .022). CONCLUSION: The compared groups exposed to staining solutions revealed colour changes above the clinically acceptable values at all periods (ΔE00 = 2.25).

Evaluation of the accuracy of fully automatic cephalometric analysis software with artificial intelligence algorithm.

OBJECTIVE: The aim of this study is to evaluate whether fully automatic cephalometric analysis software with artificial intelligence algorithms is as accurate as non-automated cephalometric analysis software for clinical diagnosis and research. MATERIALS AND METHODS: This is a retrospective archive study using lateral cephalometric radiographs taken from individuals aged 12-20 years. Cephalometric measurement data were obtained from these lateral cephalometric radiographs by manual landmark marking with non-automated computer software (Dolphin 11.8). Again, the same radiographs were made using fully automatic digital cephalometric analysis software OrthoDx™ (AI-Powered Orthodontic Imaging System, Phimentum) and WebCeph (Assemblecircle, Seoul, Korea) with artificial intelligence algorithm, without manual intervention of the researcher and fully automatic markings and measurements were made by the software. RESULTS: According to the consistency test, a statistically significant good level of consistency was found between Dolphin and OrthoDx™ measurements and Dolphin and WebCeph measurements in angular measurements (ICC > 0.75, P < .01, ICC > 0.75, P < 0, respectively. 01). A weak level of consistency was found in linear measurement and soft tissue parameters in both software (ICC < 0.50, P < .05, ICC < 0.50, P < .05), and the difference between measurements was statistically found to be different from "0." CONCLUSION: The results obtained from fully automatic cephalometric analysis software with artificial intelligence algorithms are similar to the results of non-automated cephalometric analysis software, although there are differences in some parameters. To minimize the margin of error in artificial intelligence-based fully automatic cephalometric software, the manual intervention of the observer is needed.

YouTube™ for information on paediatric oral health instructions.

INTRODUCTION: Parents and caregivers of paediatric patients usually tend to search for health information on social networks and other online platforms. At this point, the quality and reliability of these sources play an essential part in maintaining the oral health of paediatric patients. AIM: The recent study aimed to analyse the reliability, quality and content of YouTube™ videos on paediatric oral health instructions; assess the efficacy of these videos; and help health providers lead the parents accessing accurate information on the subject mentioned. DESIGN: The searching term was detected as 'children oral health' (Google Trends Application). The first 150 videos were taken into the study. Six excluding criteria were used, and 40 videos have lasted for the further examinations. Content headings were determined according to the AAPD guidelines on paediatric oral health. The content analysis scores, reliability scores and Global Quality Score were calculated for each of these 40 videos. SPSS 26 statistical software was used in the statistical analysis process of the data; p < 0.05 was considered statistically significant. RESULTS: The recent study results showed that according to content analyses, the videos were classified as 'poor' content with the mean values 4.07 (±1.32). The mean reliability score 2.96 (±0.69) has shown that the reliability of the videos was moderate. Mean Global Quality Score values were 2.95 (±0.73), which means the subjects were moderate quality. The mean reliability of the rich content videos (3.39 ± 0.59) and the Global Quality Score of them (3.43 ± 0.62) were statistically higher compared to the average values of the poor content videos (respectively; 2.73 ± 0.64; 2.69 ± 0.66) (p < 0.05) The average number of likes, dislikes, length, interaction index and viewing rate of rich content videos were higher than the same features of poor content videos (p < 0.05). The videos with rich content were determined in the first 50 videos listed for analyses, and the distribution of the included videos on the list was equally. CONCLUSION: The present study concluded that the YouTube™ videos providing oral health instructions for paediatric patients and their parents had poor content, medium quality and reliability. Although all the listed content headings were not mentioned in the videos, the content of them still may be useful and educational for individuals. However, dental hygiene practitioners and dentists should be aware of the need in this area and put more effort into improving the YouTube™ videos on children's oral health in a more detailed way regarding content headings, quality and reliability.

Is YouTubeTM an adequate source of oral hygiene education for orthodontic patients?

INTRODUCTION: The present study aims to assess the quality, reliability and content of the information provided by the YouTubeTM videos on oral hygiene during orthodontic treatment, to reveal the efficacy of the videos for patients and to help dentists who use this platform as a source to guide their patients accurately. METHOD: In the beginning, it was found that the most common search term on oral hygiene during orthodontic treatment in Google Trends was 'how to clean braces'. A total of 150 videos containing keywords were reviewed, and 56 videos were assessed within the scope of the study. Videos were analysed for reliability score, content analysis and GQS criteria. RESULTS: According to the results, the mean video length was statistically significantly greater in rich-content videos than in poor-content videos (p = 0.024). In addition, the reliability score of rich-content videos was statistically significantly higher than that of poor-content videos (p = 0.026). Likewise, the GQS of rich-content videos was statistically significantly higher than that of poor-content videos (p < 0.001). However, the number of views, the number of likes, the number of dislikes, the number of comments, the number of days since upload, the interaction index and the view rate did not statistically significantly differ by content categories (p > 0.05). CONCLUSION: The present study concluded that the YouTubeTM videos providing oral hygiene education for patients receiving or scheduled for orthodontic treatment had poor content and overall medium quality. The instantaneous data collection was one of the study's limitations.

Effects of Different Remineralisation Agents and Adhesives Around Orthodontic Brackets: Is There a Relationship Between Remineralisation and Shear Bond Strength?

PURPOSE: The aim of this in-vitro study was to evaluate the effects of different remineralisation agents and adhesives on the remineralisation of white spot lesions (WSL) using quantitative light-induced fluorescence (QLF) and the shear bond strength (SBS) of brackets. MATERIALS AND METHODS: One hundred fifty premolars were bonded with Transbond XT and resin-modified glass-ionomer cement (RMGIC). WSL were created using a demineralization solution and an APF gel, Tooth Mousse (TM) and Duraphat were applied for remineralisation. WSL were evaluated using QLF and SBS of brackets and tested using an Instron testing machine. Paired-samples t-test, independent-samples t-test and one-way ANOVA were used for comparisons of the ∆F, area and SBS. Post-hoc tests were performed using Tukey's test. RESULTS: In the Transbond group, all remineralisation agents provided remineralisation, with Duraphat producing greater improvement. In terms of lesion area, the positive control and APF gel group values were close to each other, and a statistically significant improvement was observed in the TM and Duraphat groups' areas. In the RMGIC group, with TM application, the ΔF value was statistically significantly higher; area differences between the APF and TM groups were not statistically significant. The Transbond group showed greater SBS than did RMGIC, and in the Transbond group, Duraphat had the highest SBS value. CONCLUSIONS: In bonding with Transbond, the Duraphat group demonstrated greater improvement than other remineralisation agents. In the RMGIC group, the best remineralisation was obtained by TM. The Transbond XT and Duraphat combination provided the highest SBS values.

Effects of Different Head Positioning Methods on Facial Soft Tissue Analysis Using Stereophotogrammetry.

PURPOSE: The purpose of this study was to compare the sagittal tilt of the head in different head positioning techniques using an inclinometer and facial stereophotogrammetric measurements. MATERIALS AND METHODS: The study was carried out in 45 participants (26 female, 19 male). Participants' head positioning was obtained with dynamic walking, Frankfort horizontal plane (FHP'), self-balance plus mirror, and subjective photographic positioning methods. All pitch values were recorded by an inclinometer and stereophotogrammetric images were obtained. Facial analysis included distances of the glabella (G'), pronasale (Pn), soft tissue A point (A'), upper lip (Ls), lower lip (Li), soft tissue B point (B)', and soft tissue pogonion (Pog') to the true vertical line (TVL) and face height and lip length measurements. RESULTS: Participants' head positions were observed to be more forward in the FHP' head positioning technique compared with other methods, whereas a more backward head position was recorded with subjective head positioning, and the difference was significant (P < .001). There were no relevant differences in pitch values between the self-balance plus mirror and dynamic walking methods. G'-TVL (P < .000), Pn-TVL (P < .029), A'-TVL (P < .039), Ls-TVL (P < .001), Li-TVL (P < .037), B'-TVL (P < .003), and Pog'-TVL (P < .000) in the profile view and face height, lower face height, and lower lip length values in the frontal view (P < .001) differed significantly by head positioning method. CONCLUSIONS: The dynamic walking and self-balance plus mirror head positioning methods offered similar and advisable natural head position results, whereas FHP' head positioning was questionable for an accurate determination of natural head position. Facial soft tissue measurements, such as face height, lower face height, lower lip length, and projection of structures such as the G', Pn, lips, and chin, varied based on head positioning method.