{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T12:23:11Z","timestamp":1789129391237,"version":"build-2803163510"},"reference-count":34,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T00:00:00Z","timestamp":1789084800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Dent. J.","Dentistry Journal"],"abstract":"<jats:p>Background: This pilot clinical study aimed to evaluate the mandibular position at the maximum intercuspal position (MIP) obtained with a virtual interocclusal record using an intraoral scanner across different dental chair backrest inclinations, in order to establish a protocol for future larger studies. Methods: In this single-center pilot study, 10 fully dentate participants underwent maxillary and mandibular full-arch intraoral scans. Virtual interocclusal records at MIP were obtained with an intraoral scanner at three dental chair backrest inclinations (90, 120, and 180 degrees). Conventional vinyl polysiloxane interocclusal records were made at the same inclinations. All scans were printed into physical models and mounted using the conventional records. Digitized casts and intraoral scans were superimposed onto a single common reference, the virtually mounted 90-degree scan, using metrology software. Because all deviations were expressed relative to that reference, the virtual 90-degree condition is zero by construction and was excluded as a data level from inferential models. Separate linear mixed-effects models were fitted for each translation and rotation axis, with participant as a random intercept and recording method, inclination, and their interaction as fixed effects; p values were Holm-adjusted across the six axes. Equivalence was explored with two one-sided tests against margins of \u00b10.5 mm and \u00b11.0 degrees; because these margins were specified post hoc, the equivalence analysis is exploratory. Results: Chair inclination did not detectably affect either recording method: no inclination main effect or method \u00d7 inclination interaction survived multiplicity correction, and virtual records at 120 and 180 degrees differed by no more than 0.05 mm and 0.08 degrees. Recording method did differ. Conventional records were displaced relative to virtual records by 0.27 mm along the Y axis (95% CI 0.19 to 0.34; Holm-adjusted p &lt; 0.001), in the same direction in 9 of 10 participants. The corresponding X-axis offset was 0.23 mm (95% CI 0.06 to 0.40) and did not survive multiplicity correction in the primary analysis (Holm-adjusted p = 0.060). The exploratory equivalence criterion was met, that is, the 90% confidence interval fell entirely within the post hoc equivalence margin, for 11 of 18 method \u00d7 inclination comparisons, rising to 16 of 18 in the sensitivity analysis. Conclusions: In this pilot sample, no statistically detectable effect of dental chair backrest inclination between 90 and 180 degrees on the recorded mandibular position at MIP was observed for either recording method in healthy, fully dentate individuals; virtual and conventional records met the exploratory post hoc equivalence criterion in most rotational axes but showed a small, systematic translational offset of approximately 0.23 to 0.31 mm, most clearly along the Y axis. These preliminary findings require confirmation in a larger, prospectively powered and randomized equivalence trial with a prospectively defined equivalence margin.<\/jats:p>","DOI":"10.3390\/dj14090590","type":"journal-article","created":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T10:51:37Z","timestamp":1789123897000},"page":"590","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Effect of Dental Chair Backrest Inclination on Mandibular Position Obtained with a Virtual Interocclusal Record at the Maximum Intercuspal Position: A Pilot Clinical Study"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6991-0756","authenticated-orcid":false,"given":"Kawther","family":"Ali","sequence":"first","affiliation":[{"name":"Department of Restorative Sciences, College of Dentistry, Kuwait University, Sabah Al Salem University City, P.O. Box 5969, Safat 13060, Shadadiya, Kuwait"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1160-3248","authenticated-orcid":false,"given":"Sasiya","family":"Bhumpattarachai","sequence":"additional","affiliation":[{"name":"School of Dentistry, Loma Linda University, Loma Linda, CA 92350, USA"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"}]},{"given":"Roberto","family":"Savignano","sequence":"additional","affiliation":[{"name":"School of Dentistry, Loma Linda University, Loma Linda, CA 92350, USA"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"software","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"}]},{"given":"Mason","family":"Possinger","sequence":"additional","affiliation":[{"name":"Materials Science and Engineering Department, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"software","vocabulary":"credit"}]},{"given":"Joseph","family":"Kan","sequence":"additional","affiliation":[{"name":"School of Dentistry, Loma Linda University, Loma Linda, CA 92350, USA"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Academy of prosthodontics (2017). The Glossary of Prosthodontic Terms: Ninth Edition. J. Prosthet. Dent., 117, e1\u2013e105.","DOI":"10.1016\/j.prosdent.2016.12.001"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"419","DOI":"10.1016\/0022-3913(81)90104-9","article-title":"Intercuspal contacts of the natural dentition in centric occlusion","volume":"45","author":"Ehrlich","year":"1981","journal-title":"J. Prosthet. Dent."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"386","DOI":"10.1016\/S0022-3913(83)80099-7","article-title":"Daily variations in occlusal contacts","volume":"50","author":"Berry","year":"1983","journal-title":"J. Prosthet. Dent."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"473","DOI":"10.1111\/j.1365-2842.1983.tb01470.x","article-title":"A clinical study of the distribution of occlusal tooth contacts in the intercuspal position at light and hard pressure in adults","volume":"10","author":"Riise","year":"1983","journal-title":"J. Oral Rehabil."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"602","DOI":"10.1067\/mod.2002.122829","article-title":"Masticatory performance and areas of occlusal contact and near contact in subjects with normal occlusion and malocclusion","volume":"121","author":"Owens","year":"2002","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1016\/j.prosdent.2015.01.009","article-title":"Comparison of a conventional and virtual occlusal record","volume":"114","author":"Solaberrieta","year":"2015","journal-title":"J. Prosthet. Dent."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1280","DOI":"10.14219\/jada.archive.2001.0373","article-title":"An evaluation of occlusal contact marking indicators: A descriptive quantitative method","volume":"132","author":"Millstein","year":"2001","journal-title":"J. Am. Dent. Assoc."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"522","DOI":"10.1067\/mpr.2002.129064","article-title":"In vivo and in vitro evaluation of occlusal indicator sensitivity","volume":"88","year":"2002","journal-title":"J. Prosthet. Dent."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"7173824","DOI":"10.1155\/2016\/7173824","article-title":"Intraoral digital impressions for virtual occlusal records: Section quantity and dimensions","volume":"2016","author":"Solaberrieta","year":"2016","journal-title":"BioMed Res. Int."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"528","DOI":"10.1016\/j.jdent.2007.02.004","article-title":"Accuracy of contacts calculated from 3D images of occlusal surfaces","volume":"35","author":"DeLong","year":"2007","journal-title":"J. Dent."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1111\/joor.12374","article-title":"Simulation of dental collisions and occlusal dynamics in the virtual environment","volume":"43","author":"Stavness","year":"2016","journal-title":"J. Oral Rehabil."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"573","DOI":"10.2341\/17-272-C","article-title":"Accuracy of buccal scan procedures for the registration of habitual intercuspation","volume":"43","author":"Zimmermann","year":"2018","journal-title":"Oper. Dent."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"309","DOI":"10.2341\/12-233-L","article-title":"Dimensional accuracy of optical bite registration in single and multiple unit restorations","volume":"38","author":"Iwaki","year":"2013","journal-title":"Oper. Dent."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"594","DOI":"10.1111\/jopr.12439","article-title":"Comparison of maximum intercuspal contacts of articulated casts and virtual casts requiring posterior fixed partial dentures","volume":"26","author":"Arslan","year":"2017","journal-title":"J. Prosthodont."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1016\/j.prosdent.2015.06.013","article-title":"Determining the requirements, section quantity, and dimension of the virtual occlusal record","volume":"115","author":"Solaberrieta","year":"2016","journal-title":"J. Prosthet. Dent."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"904","DOI":"10.1016\/j.prosdent.2018.01.024","article-title":"The accuracy of virtual interocclusal registration during intraoral scanning","volume":"120","author":"Edher","year":"2018","journal-title":"J. Prosthet. Dent."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"693","DOI":"10.1016\/j.prosdent.2015.05.013","article-title":"Influence of dental chair backrest inclination on the registration of the mandibular position","volume":"114","author":"Coelho","year":"2015","journal-title":"J. Prosthet. Dent."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"190","DOI":"10.1016\/S0022-3913(05)80161-1","article-title":"Clinical study of location and reproducibility of three mandibular positions in relation to body posture and muscle function","volume":"73","author":"Tripodakis","year":"1995","journal-title":"J. Prosthet. Dent."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1116","DOI":"10.1111\/jerd.70082","article-title":"Effect of head posture on the accuracy of occlusal contacts at maximum intercuspation using intraoral scanners and digital occlusal analysis: A comparative clinical study","volume":"38","author":"Ntovas","year":"2026","journal-title":"J. Esthet. Restor. Dent."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"289","DOI":"10.4103\/jips.jips_94_26","article-title":"Effect of patient position on digitally recorded interocclusal distance in prepared teeth: A computer-aided design and manufacturing-based evaluation","volume":"26","author":"Nikhil","year":"2026","journal-title":"J. Indian Prosthodont. Soc."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"563.e1","DOI":"10.1016\/j.prosdent.2025.09.041","article-title":"Discrepancies of maximal intercuspal position recorded by using four intraoral scanners at different dental chair positions: A clinical study","volume":"135","author":"Barmak","year":"2026","journal-title":"J. Prosthet. Dent."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"546","DOI":"10.1016\/j.prosdent.2022.09.005","article-title":"Accuracy of intraoral scanners for static virtual articulation: A systematic review and meta-analysis of multiple outcomes","volume":"132","author":"Morsy","year":"2024","journal-title":"J. Prosthet. Dent."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Kuroda, S., Yotsuya, M., Sato, T., Hisanaga, R., Nomoto, S., and Sekine, H. (2023). The effect of scanning pathways on trueness and precision in full-arch optical impression. BMC Oral Health, 23.","DOI":"10.1186\/s12903-023-03101-z"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1177\/1948550617697177","article-title":"Equivalence tests: A practical primer for t tests, correlations, and meta-analyses","volume":"8","author":"Lakens","year":"2017","journal-title":"Soc. Psychol. Personal. Sci."},{"key":"ref_25","first-page":"259","article-title":"Equivalence testing for psychological research: A tutorial","volume":"1","author":"Lakens","year":"2018","journal-title":"Adv. Methods Pract. Psychol. Sci."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"667","DOI":"10.1016\/j.prosdent.2019.11.014","article-title":"Clinical accuracy and reproducibility of virtual interocclusal records","volume":"124","author":"Abdulateef","year":"2020","journal-title":"J. Prosthet. Dent."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1016\/j.ajodo.2005.04.042","article-title":"Assessing the American Board of Orthodontics objective grading system: Digital vs plaster dental casts","volume":"131","author":"Okunami","year":"2007","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"307","DOI":"10.1016\/S0140-6736(86)90837-8","article-title":"Statistical methods for assessing agreement between two methods of clinical measurement","volume":"1","author":"Bland","year":"1986","journal-title":"Lancet"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1016\/j.jcm.2016.02.012","article-title":"A guideline of selecting and reporting intraclass correlation coefficients for reliability research","volume":"15","author":"Koo","year":"2016","journal-title":"J. Chiropr. Med."},{"key":"ref_30","first-page":"365","article-title":"Evaluation of vertical accuracy of interocclusal records","volume":"16","author":"Vergos","year":"2003","journal-title":"Int. J. Prosthodont."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1691","DOI":"10.1016\/j.identj.2025.03.005","article-title":"Virtual articulator software: Accuracy, usability, and clinical applicability: A systematic review","volume":"75","author":"Saini","year":"2025","journal-title":"Int. Dent. J."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"622","DOI":"10.1067\/mpr.2002.129379","article-title":"Comparing maximum intercuspal contacts of virtual dental patients and mounted dental casts","volume":"88","author":"DeLong","year":"2002","journal-title":"J. Prosthet. Dent."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"104138","DOI":"10.1016\/j.jdent.2022.104138","article-title":"Influence of ambient light conditions on the accuracy and scanning time of seven intraoral scanners in complete-arch implant scans","volume":"121","author":"Cascos","year":"2022","journal-title":"J. Dent."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"e17150","DOI":"10.2196\/17150","article-title":"Influence of scanner precision and analysis software in quantifying three-dimensional intraoral changes: Two-factor factorial experimental design","volume":"22","author":"Toole","year":"2020","journal-title":"J. Med. Internet Res."}],"container-title":["Dentistry Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2304-6767\/14\/9\/590\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T11:17:33Z","timestamp":1789125453000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2304-6767\/14\/9\/590"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,11]]},"references-count":34,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["dj14090590"],"URL":"https:\/\/doi.org\/10.3390\/dj14090590","relation":{},"ISSN":["2304-6767"],"issn-type":[{"value":"2304-6767","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,11]]}}}