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Updated: Aug 6, 2026
Measuring Maxillary Posterior Tooth Movement: A Model Assessment using Palatal and Dental Superimposition
Published on: February 23, 2024
Skeletal Class II malocclusion is associated with a more distant maxillary first molar-sinus adjacency: a
Wenjing Peng1, Na Tang2,3, Hao Liu2,3
1Department of Orthodontics, Xuzhou Stomatological Hospital, Affiliated Stomatological Hospital of Xuzhou Medical University, No.130 Huaihai West Road, Quanshan District, Xuzhou, Jiangsu Province, China. 209062968@qq.com.
Introduction:
The relationship between maxillary posterior tooth roots and the maxillary sinus floor is a key risk factor in orthodontic treatment. This study systematically evaluated this relationship for the maxillary second premolar, first molar, and second molar in adults with different growing patterns.
Methods:
This retrospective cross-sectional study analyzed CBCT data from 502 adults (20-45 years). Patients were grouped by sagittal pattern (ANB angle: Class I, II, III) and vertical skeletal pattern (MP-SN angle: hyperdivergent, normodivergent, hypodivergent). A modified classification (scores 1-5) assessed the vertical relationship between each tooth apex and the sinus floor. The effects of age, sex, and skeletal pattern on scores were analyzed.
Results:
After adjusting for age and sex, the vertical pattern showed no significant association with root-sinus scores (P > 0.05). Sagittally, Class II patients had significantly lower first molar scores than Class I patients (P = 0.032), indicating roots positioned farther from the sinus floor. Age was significantly negatively correlated with scores (P < 0.001), and females had lower scores than males (P < 0.001). While scores among tooth positions were correlated at the population level, high individual heterogeneity was observed, with 43.4% of patients showing irregular fluctuations.
Conclusions:
Vertical skeletal pattern is not significantly associated with the maxillary posterior root-sinus relationship in adults. Skeletal Class II patients exhibit a more distant maxillary first molar apex-to-sinus adjacency, indicating a static anatomical association. Increasing age is associated with more distant root-to-sinus adjacencies.
