Abstract: Objective: To quantitatively evaluate the size of proximal contact strength (PCS) in patients with neat teeth in natural dentition. Methods: Forty-three college students (22 males and 21 females) with natural dentition from Nanjing University were recruited during November 2021 to March 2022. A total of 10 sites (the proximal surfaces of upper and lower central incisors, bilateral canines and first premolars, and second premolars and first molars) were selected respectively. The PCS of above 10 sites were measured by digital display push-pull meter, and the mean and standard deviation of each measured site were calculated. Then, the differences between maxilla and mandible, anterior and posterior, left and right, and male and female were analyzed. Results: (1) The average PCS between anterior, middle, and posterior segments of maxilla and mandible were 11/21: (0.86±0.52) N; 31/41: (1.13±0.60) N; U3/U4: (1.86±0.79) N; L3/L4: (2.44±1.06) N; U5/U6: (2.44±0.98) N; L5/L6: (2.93±1.16) N; (2) The PCS between anterior, middle, and posterior segments of the mandible were larger than those between the same sites in the maxilla. (3) The PCS in anterior, middle, and posterior segments increased gradually. (4) There was no statistical difference in PCS between the homonymic sites in the middle and posterior segments; (5) There was no gender difference between anterior, middle, and posterior segments. Conclusion: This study can provide reference for orthodontic or prosthodontic treatment to reconstruct appropriate proximal contact.

Key words: natural dentition, neat teeth, proximal contact strength, quantitative research