Original Research

Year : 2026 | Volume : 17 | Issue : 2 | Page : 1-16

Assessment of Mandibular Molar Inclination and Buccal Bone Thickness in Different Facial Patterns of Class II Division 1 Malocclusion using the WALA Ridge: A CBCT Based Cross-Sectional Study

Poongodhai S 1, Thirunavukkarasu Ramanathan 2, Sola Rajan 3, Tamizhmani 4, Harini Abilasha K 3

1-Postgraduate Resident, 2-Professor and Head, 3-Senior Lecturer, 4-Reader, Department of Orthodontics & Dentofacial Orthopaedics, Karpaga Vinayaga Institute Of Dental Sciences, Madhuranthagam, Kanchipuram, TamilNadu, India-603308.

Address for Correspondence:

Dr. Thirunavukkarasu Ramanathan, MDS

Professor and Head, Department of Orthodontics and Dentofacial Orthopedics

Karpaga Vinayaga Institute Of Dental Sciences,

TamilNadu, India- 603308.

Email.id: tringortho.tr@gmail.com

ABSTRACT

Background: Orthodontic treatment planning in the mandibular posteriors requires careful consideration of alveolar bone limits to ensure biologically safe tooth movement and long term stability. The WALA ridge, described as the most prominent contour of the buccal alveolar mucosa at the level of the mucogingival junction, has been proposed as a stable landmark, closely associated with the basal bone of the mandible.

Aim: To assess and compare mandibular molar inclination and buccal bone thickness in patients with Class II Division 1 malocclusion across different facial patterns using the WALA ridge as a reference landmark on CBCT scans.

Materials & Methods: This was a cross-sectional observational study conducted retrospectively on pre-treatment CBCT scans from Class II Division 1 malocclusion patients (n=66, age 18-35 yrs), obtained from patient records at the Department of Orthodontics from January to December 2025. Ethical approval (IEC: KIDS/IEC/2026/I/015) and informed consent from study subjects (obtained at CBCT imaging) were secured. Subjects were grouped into euryprosopic (≤80.9), mesoprosopic (81.0-85.4), and leptoprosopic (≥85.5) facial patterns by facial index (Martin & Saller 1957). Molar inclination was measured as the angle between the tooth long axis and a vertical reference line parallel to midsagittal plane. Buccal bone thickness at various mandibular tooth sites (from canine to molar region) on both sides was measured in relation to WALA ridge level on axial sections using Carestream software. Data were analyzed in SPSS software. P<0.05 was considered statistically significant.

Results: Molar inclination differed significantly among facial patterns (P<0.0001). Euryprosopic subjects showed greater buccal crown tipping (14.18 ± 2.32° for 36; 13.05 ± 1.96° for 46) than leptoprosopic subjects (9.31 ± 1.08° for 36; 9.32 ± 1.36° for 46). BBT showed a significant anterior-to-posterior increase (P<0.05) across sites, with 0.00 mm at canine/first premolar regions in all groups. Euryprosopic subjects showed greatest posterior thickness, first molar distal (1.78 ± 0.42 mm), second molar distal (6.20 ± 1.43 mm), vs. leptoprosopic (first molar distal: 0.56 ± 0.48 mm).

Conclusion: Facial pattern influences mandibular molar inclination and buccal bone thickness at the WALA ridge level, supporting individualized transverse planning to reduce periodontal risk.

Keywords: WALA ridge; facial pattern; BBT ( buccal bone thickness); molar inclination; CBCT; Class II Division I.

CONFLICT OF INTEREST AND FUNDING

Nil

How to cite this article: Poongodhai S, Thirunavukkarasu Ramanathan, Sola Rajan, Tamizhmani, Harini Abilasha K. Assessment of Mandibular Molar Inclination and Buccal Bone Thickness in Different Facial Patterns of Class II Division I Malocclusion using the WALA Ridge: A CBCT Based Cross-Sectional Study.

Int J Orthod Rehabil 2026; 17 (2): 1-16.

Doi: 10.56501/Intjorthodrehabil.172.ijor0079