The Esthetic Evaluation Of The Positional Relationship Between Lip Bead Midpoint And Dentition Center Line

Objective: To figure out the differences in the aesthetic evaluation between the position of dentition center line and malposition of the lip bead among different groups of people with the tool of Q-sort assessment.Methods: Adobe Photoshop CS6 was used to make up photos of both male and female models,in which the lip bead center or lip bead center together with the teeth were deviated.Specifically,the deviation was an increment of 1mm and 3 mm on each.There are in total 13 photos of male and 13 photos of female which were made up in this way.Then,a total of 160 dentists(78 males and 82 females),165 orthodontics(82 males and83 females),and 163 freshmen(78 males and 85 females)were asked to evaluate lip position in these photos with Q-sort assessment.The related data obtained was then analyzed by SPSS23.0,carrying out statistical one-way ANOVA,comparison of pairs and t-test analysis.If P <0.05,then the result is supposed to have statistical significance.Results: 1.Most of the stomatologists can identify the deviation when it is less than 2mm,but when the lip bead center deviation is more than 1 mm,there is no statistical significance of the choice between the dentition center line being consistent with lip bead center,and the dentition center line being consistent with the face midline.When the deviation of lip bead center is 2 mm and above,there is statistical significance upon the priority of choice of the upper end of the maxillary dentition center line being consistent with the face midline.2.Most orthodontic patients and high school graduates cannot figure out the deviation when it is less than 2 mm,and there is no significant statistical difference in the choice of midline position of the dentition center line when the deviation of lip bead center is less than or equal to 2 mm.When the lip bead center deviation is 3mm,there is statistical significance in the fact that the orthodontic patients and students give priority to the dentition center line being consistent with the face midline.3.Doctors from aesthetics-related departments(orthodontics,rehabilitation,planting),compared with doctors from other departments,have higher consistency in the aesthetic evaluation.They also have more stringent requirements and a high sensitivity towards deviation.When the lip bead center is deviated,there is statistical significance in their priority of choosing dentition center line being consistent with the face midline.4.There is significant difference in the evaluation of various photos of female models from evaluators of different genders.Also,female evaluators have a better ability in indentifying those photos than male evaluators when the degree of deviation is 1 mm.5.Among most of the photos which have the same degree of deviation,those which are deviated to the right have a lower average score than those which are deviated to the left.They are therefore thought to be more attractive.Conclusion:1.Non-professionals have a lower sensitivity towards the lip bead center deviation which is less or equal to 2 mm.The orthodontist should provide the appropriate aesthetic orientation about the position of the center line of the dentition center line in orthodontic process.They should also have substantive communication especially with young women before operation.2.When the lip bead center deviation reached 3 mm,the public is more able to accept the treatment programs that dentition center line being consistent with the face midline,rather than the lip position.3.When rectifying of the teeth,the irregular relationship between the dentition center line,the lip bead center and the face midline should be controlled within 2 mm.