{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,15]],"date-time":"2026-01-15T03:47:55Z","timestamp":1768448875383,"version":"3.49.0"},"reference-count":52,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2025,5,30]],"date-time":"2025-05-30T00:00:00Z","timestamp":1748563200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"FCT\u2014Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia under the project","award":["UIDB\/00006\/2025"],"award-info":[{"award-number":["UIDB\/00006\/2025"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background\/Objectives: Temporomandibular disorder (TMDs) patients often present limited mouth opening (LMO). A key diagnostic cutoff is a mouth opening threshold &gt;40 mm. However, this universal cutoff may not accurately reflect gender anatomical variations. This study investigates gender-specific differences in maximum mouth opening (MMO) to propose revised diagnostic criteria for LMO. Methods: A five-year prospective study was conducted from 1 August 2019 to 1 May 2024 in a Portuguese TMDs department. The patients\u2019 gender, MMO, and LMO complaints with clinical validation were recorded. Statistical analyses, including Generalized Additive Models (GAMs) and Generalized Linear Models (GLMs), assessed the relationship between MMO and LMO, with gender-stratified comparisons. Results: In this study 1045 patients were included. The median (accompanied by the interquartile range [25th percentile\u201375th percentile]) MMO was lower in females (40 mm [34\u201345]) than in males (44 mm [40\u201348]). Patients presenting LMO complaints exhibited significantly reduced MMO values compared to those without LMO complaints (p &lt; 0.001). Gender-specific thresholds emerged: for females, LMO was observed when MMO was \u226435 mm, while in males, LMO symptoms appeared when MMO was \u226438 mm. A \u201cgray zone\u201d of diagnostic uncertainty was identified between 36 and 37 mm for females and 38 and 42 mm for males. Conclusions: In this study we observed the gold standard cutoff for diagnosing MMO in female should be &lt;35mm and for male &lt;38mm. These findings suggest that a single LMO threshold does not account for gender-related anatomical differences, potentially leading to underdiagnosis in females and misclassification in males. Revising diagnostic criteria to incorporate gender-specific thresholds could enhance accuracy, improve early diagnosis, and promote personalized treatment strategies for TMDs patients. Further research incorporating additional variables such as age, dental occlusion, craniofacial structure, and body mass index is recommended to refine these diagnostic guidelines.<\/jats:p>","DOI":"10.3390\/jcm14113865","type":"journal-article","created":{"date-parts":[[2025,5,30]],"date-time":"2025-05-30T09:22:41Z","timestamp":1748596961000},"page":"3865","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Gender Differences in Mouth Opening on Temporomandibular Disorder Patients\u2014Implications for Diagnosis"],"prefix":"10.3390","volume":"14","author":[{"given":"David Faustino","family":"\u00c2ngelo","sequence":"first","affiliation":[{"name":"Instituto Portugu\u00eas da Face, 1500-493 Lisboa, Portugal"},{"name":"Centre for Rapid and Sustainable Product Development, Polytechnic Institute of Leiria, 2430-028 Marinha Grande, Portugal"},{"name":"Faculty of Medicine of Lisboa University, 1649-028 Lisboa, Portugal"},{"name":"Servi\u00e7o de Estomatologia Hospital Egas Moniz\u2014Centro Hospitalar de Lisboa Ocidental, 1349-019 Lisboa, Portugal"},{"name":"Clinica Universit\u00e1ria de Estomatologia, Centro Hospitalar Universit\u00e1rio Lisboa Norte (CHUNL), 1349-019 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5750-2875","authenticated-orcid":false,"given":"Henrique Jos\u00e9","family":"Cardoso","sequence":"additional","affiliation":[{"name":"Instituto Portugu\u00eas da Face, 1500-493 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3137-0891","authenticated-orcid":false,"given":"Ricardo S\u00e3o","family":"Jo\u00e3o","sequence":"additional","affiliation":[{"name":"Department of Computer Science and Quantitative Methods, School of Management and Technology, Polytechnic Institute of Santar\u00e9m, 2001-904 Santar\u00e9m, Portugal"},{"name":"CEAUL\u2014Centro de Estat\u00edstica e Aplica\u00e7\u00f5es, Faculdade de Ci\u00eancias, Universidade de Lisboa, 1749-016 Lisboa, Portugal"},{"name":"Center for Global Studies (CEG-UAb), Aberta University, 1250-100 Lisboa, Portugal"},{"name":"Nursing Research, Innovation and Development Center of Lisbon (CIDNUR), 1600-190 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1551-6531","authenticated-orcid":false,"given":"Carlos","family":"Br\u00e1s-Geraldes","sequence":"additional","affiliation":[{"name":"CEAUL\u2014Centro de Estat\u00edstica e Aplica\u00e7\u00f5es, Faculdade de Ci\u00eancias, Universidade de Lisboa, 1749-016 Lisboa, Portugal"},{"name":"Instituto Superior de Engenharia de Lisboa (ISEL), Instituto Polit\u00e9cnico de Lisboa, 1959-007 Lisboa, Portugal"}]},{"given":"David","family":"Sanz","sequence":"additional","affiliation":[{"name":"Instituto Portugu\u00eas da Face, 1500-493 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1293-2107","authenticated-orcid":false,"given":"Francesco","family":"Maffia","sequence":"additional","affiliation":[{"name":"Instituto Portugu\u00eas da Face, 1500-493 Lisboa, Portugal"},{"name":"Maxillofacial Surgery Unit, Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples \u201cFederico II\u201d, Via Sergio Pansini 5, 80131 N\u00e1poles, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1095-8090","authenticated-orcid":false,"given":"Francisco","family":"Salvado","sequence":"additional","affiliation":[{"name":"Faculty of Medicine of Lisboa University, 1649-028 Lisboa, Portugal"},{"name":"Clinica Universit\u00e1ria de Estomatologia, Centro Hospitalar Universit\u00e1rio Lisboa Norte (CHUNL), 1349-019 Lisboa, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,5,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"819","DOI":"10.1111\/joor.12681","article-title":"Association between chewing dysfunctions and temporomandibular disorders: A systematic review","volume":"45","author":"Ferreira","year":"2018","journal-title":"J. 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