Articles Vol. 67 No. 6 25/06/2026

ASSOCIATION BETWEEN CLINICAL AND RADIOGRAPHIC CHARACTERISTICS OF MANDIBULAR THIRD MOLARS AND DISTAL CARIES IN ADJACENT SECOND MOLARS

Pham Phuoc Danh1,2,3,4, Hong Quoc Khanh1,3, Lam Nhut Tan2,4, Tran Duy Quan5,6, Be Nguyen Kim Tu7,8, Hong Do Gia Khang1,3, Le Ngoc Thanh Truc2,4, Nguyen Thien Phuoc9,10
1 Ho Chi Minh city Odonto-Maxillo-Facial Hospital
2 Can Tho University of Medicine and Pharmacy
3 Bệnh viện Răng Hàm Mặt thành phố Hồ Chí Minh
4 Trường Đại học Y Dược Cần Thơ
5 Nguyen Tat Thanh University
6 Trường Đại học Nguyễn Tất Thành
7 Ishii Saigon General Hospital
8 Phòng khám Đa khoa Ishii Sài Gòn
9 University of Health Sciences, Vietnam National University Ho Chi Minh city
10 Trường Đại học Khoa học Sức khỏe, Đại học Quốc gia thành phố Hồ Chí Minh
DOI: 10.52163/yhc.v67i6.5515
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Keywords
Distal caries, mandibular second molar, third molar, panoramic radiograph.
Abstract

Objectives: To investigate the association between clinical and radiographic characteristics of mandibular third molars and the prevalence of distal caries in the adjacent second molars.

Subjects and methods: A cross-sectional study was conducted on 475 patients aged 18 and older at the Department of Oral Surgery, Ho Chi Minh city Odonto-Maxillo-Facial Hospital from July 2025 to December 2025. General information was collected via patient history interviews. Distal caries status and third molar characteristics were recorded through clinical examinations combined with digital panoramic radiograph analysis. Logistic regression analysis was employed with a significance level of p < 0.05.

Results: The prevalence of distal caries in mandibular second molars was 49.5% among participants and 33.6% among total teeth examined. Logistic regression revealed that patients aged 25 and older and males had significantly higher risks, with odds ratios (OR) of 2.82 and 2.17, respectively (p < 0.001). Regarding third molar characteristics, partial eruption increased the risk of adjacent caries by 3.88 times compared to the clinically unerupted group. Mesioangular impaction was identified as the strongest risk factor (adjusted OR = 4.37; p < 0.001), followed by horizontal impaction (adjusted OR = 2.74; p = 0.002), both compared to vertical impaction.

Conclusion: The prevalence of distal caries in mandibular second molars is high and closely associated with the eruption status and angulation of adjacent third molars, as well as demographic factors such as age and gender.

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