Facial Asymmetry Phenotypes in Adult Patients With Bilateral Cleft Lip and Palate and Skeletal Class III Malocclusion Using Principal Component Analysis and Cluster Analysis

Mihee Hong; Su-Ji Yoon; Il-Hyung Yang; Jin-Young Choi; Jong-Ho Lee; Myung-Jin Kim; Jee Hyeok Chung; Sukwha Kim; Seung-Hak Baek

doi:10.1111/ocr.70003

Facial Asymmetry Phenotypes in Adult Patients With Bilateral Cleft Lip and Palate and Skeletal Class III Malocclusion Using Principal Component Analysis and Cluster Analysis

Orthod Craniofac Res. 2025 Jul 1. doi: 10.1111/ocr.70003. Online ahead of print.

Authors

Mihee Hong¹, Su-Ji Yoon², Il-Hyung Yang³, Jin-Young Choi⁴, Jong-Ho Lee⁴, Myung-Jin Kim⁵, Jee Hyeok Chung⁶, Sukwha Kim⁷, Seung-Hak Baek³

Affiliations

¹ Department of Orthodontics, School of Dentistry, Kyungpook National University, Daegu, Korea.
² Department of Orthodontics, Seoul National University Dental Hospital, Seoul, Korea.
³ Department of Orthodontics, School of Dentistry, Dental Research Institute, Seoul National University, Seoul, Korea.
⁴ Department of Oral and Maxillofacial Surgery, School of Dentistry, Seoul National University, Seoul, South Korea.
⁵ Angle Dental Clinic, Seoul, South Korea.
⁶ Department of Plastic and Reconstructive Surgery, Seoul National University Children's Hospital, Seoul, Korea.
⁷ Department of Plastic Surgery, CHA Bundang Medical Center, CHA University, Seongnam, Korea.

PMID: 40590440
DOI: 10.1111/ocr.70003

Abstract

Objective: To classify and characterise facial asymmetry (FA) phenotypes in adult patients with bilateral cleft lip and palate (BCLP) and skeletal Class III (C-III) malocclusion.

Materials and methods: The samples consisted of 72 adult BCLP patients (56 males, 16 females; mean age, 21.0 years), who were candidates for orthognathic surgery (OGS) or had undergone OGS for the correction of C-III malocclusion. Because BCLP patients have two cleft sides, the vertically longer defect (VLD) side was used for the reference side. Twenty-three cephalometric parameters were measured in posteroanterior cephalograms taken at least 1month before OGS. Principal component analysis was performed to obtain seven representative parameters [ANS-deviation (mm), U1-deviation (mm), L1-deviation (mm), Me-deviation (mm), MaxAntOP-cant (°), MaxPostOP-cant (°), ManBorder-cant (°)]. K-means cluster analysis was conducted using these representative parameters. Differences in cephalometric parameters among the clusters were statistically analysed.

Results: FA phenotypes were classified based on the deviation direction towards the VLD or less VLD side and the upward or downward cant in the VLD side. The classifications were: (1) Symmetry type (20.8%); (2) MxMn-VLD-dev & MxMn-no-cant type (22.2%); (3) MxMn-less-VLD-dev & Mnbase-VLD-down-cant type (9.7%); (4) Mn-less-VLD-dev & MxMn-VLD-down-cant type (20.8%); (5) MxMn-no-dev & MxMn-VLD-up-cant type (19.4%), and (6) MxMn-VLD-dev & MxMn-VLD-up-cant type (6.9%). The possible etiologies of FA phenotypes included ANS deviation, movement of the maxillary incisor by pre-operative orthodontic treatment, and adaptive growth or compensatory growth of the maxilla and/or mandible.

Conclusion: This FA phenotype classification could serve as a guideline for diagnosis and OGS planning for BCLP patients.

Keywords: BCLP; class III malocclusion; cluster analysis; facial asymmetry.