A Digital Approach to Extracting Horizontally Impacted Mandibular Third Molars: The Cross-Sectioning Method

Kejiong Wu; Yuan Xie; Fangming Dong; Qin Huang; Rongxin Sun; Haiping Yang; Fudong Zhu; Huiming Wang; Chao Liu

doi:10.1111/eje.70005

A Digital Approach to Extracting Horizontally Impacted Mandibular Third Molars: The Cross-Sectioning Method

Eur J Dent Educ. 2025 Jul 8. doi: 10.1111/eje.70005. Online ahead of print.

Authors

Kejiong Wu¹, Yuan Xie¹, Fangming Dong¹, Qin Huang¹, Rongxin Sun¹, Haiping Yang¹, Fudong Zhu¹, Huiming Wang¹, Chao Liu¹

Affiliation

¹ Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, China.

PMID: 40625210
DOI: 10.1111/eje.70005

Abstract

Introduction: Surgical extraction of horizontally impacted mandibular third molars, particularly those requiring osteotomy, is highly sensitive to the surgeons' experience and poses challenges for residents to master. This study introduces the Cross-sectioning method developed through digital measurement and resistance analysis to minimise bone removal during extraction.

Materials and methods: A comparative study of 400 patients (200 per group) undergoing either Cross-sectioning or Traditional method was conducted. Cone beam computed tomography (CBCT)-based digital measurements validated an odontosection depth of 9 mm through the distomarginal ridge at a 75° angle to the occlusal plane for the Cross-sectioning protocol. The Cross-sectioning protocol involved dividing the tooth into four segments (distolingual, mesiolingual, mesiobuccal, distobuccal) for sequential removal, whereas the Traditional method involved bifurcation with root extraction before crown.

Results: The Cross-sectioning group demonstrated significantly shorter operation times, reduced postoperative pain, and swelling compared to the traditional group (p < 0.01). Subgroup analysis (Pell and Gregory classification) revealed superior outcomes for Cross-sectioning: in Horizontal-IIA cases, shorter operation time (p < 0.01) and reduced swelling (p < 0.05); in Horizontal-IIB cases, superior outcomes in operation time and complications (p < 0.01); in Horizontal-IIC cases, shorter operation time (p < 0.05).

Discussion: The Cross-sectioning method effectively reduces bone and adjacent tooth resistance, offering a structured approach for resident training to enhance procedural efficiency and minimise complications.

Conclusion: The Cross-sectioning method represents a precise, clinically advantageous technique for impacted third molar extraction, emphasising targeted odontosection depth and improved postoperative outcomes.

Keywords: cone‐beam computed tomography; horizontal impaction; mandibular third molars; minimally invasive surgical procedure; oral surgery; tooth extraction.

Abstract

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