Study Of Changes In Facial Soft Tissue And Mandibular Morphology After The Extraction Of Mandibular Third Molar

Objective: To study the changes in soft tissue on the frontal view and morphological changes of mandibular after the extraction of mandibular third molar.Materials and methods: A sample of twenty adult patients who had undergone the extraction of bilateral mandibular third molar at the Stomatological Hospital of Lanzhou University from November 2017 to April 2018 were selected for the study.CBCT was taken before extraction(T0),6 months(T1)and 12 months(T2)after extraction.Import image DICOM files into Invivo5 software for measurement analysis.Comparisons between pre and post treatment values of different variables were done by paired sample t test.Result: Compared with pre extraction,variations including bizygomatic breadth(Zy-Zy’),bigonial breadth(SGo-SGo’),mouth breadth(Ch-Ch’),lower facial height(Sn-Pg),cheek breadth(BCh),mandibular index(MI),Zy/SGo,Ch/SGo,mandibular breadth(Go-Go’),anterior mandibular ramus breadth(Mr-Mr’),mandibular ramus breadth(Mrm-Mrm’),thickness of soft tissue(SGo-Go)at 6months and 12 months after extraction were within the matching error of the system.Facial soft tissue and mandibular hard tissue did not have statistically significant effects.Conclusion: In this study,the extraction of the mandibular third molar has no significant effect on the soft and hard tissues of the face.