Abstract: Objective: To obtain the 3D dental model data by high precision laser scanning technique, and observe the variation of crown thickness, and its relationship to skeletal structure. Methods: 60 Mongolian teenagers orthodontic patients were selected from Affiliated Hospital of Inner Mongolia Medical University between December 2015 to July 2019. The thickness of anterior teeth was measured,and the difference analysis of the measurements of the examinations was conducted, and the correlation of the thickness of upper anteriors with skeletal craniofacial pattern was evaluated. Results: The thickness of upper anterior teeth displayed the biggest difference 3mm to the occlusal surface,and the smallest variation 1mm to the occlusal surface. The thickness of maxillary lateral incisor displayed the biggest difference.The thickness of maxillary canine at 3mm to the occlusal surface was significant different to those of central incisor and lateral incisor(P=0.00). And the thickness at 2mm to the occlusal surface of maxillary lateral incisor was significant different to those of central incisor and canine(P=0.00). The thicknesses of male at U1T3, U2T3, U3T2, and U3T3 were statistically bigger than those of female. There was a moderate positive correlation between upper anterior teeth thickness of U3T3 and ∠SNA, between U2T3 and ∠SNB, between U1T3, U2T3, U3T2, U3T3 and ∠ANB, and negative correlation between U2T2, U2T3 and ∠MR-Copd. Conclusion: The thickness of maxillary anterior teeth varies greatly. When facing orthodontic treatment for Mongolian teenagers with different relationship between the jaws, the influence of anterior crown thickness on anterior torque, overjet, overbite, and establishment of occlusal relationship should be taken into account, therefore, the correctional quantity should be different.

Key words: anterior upper teeth, dental crowns thickness, teenager, digital models, skeletal relations