external root resorption
Conditions
Interventions
Angle class I group:Nil
Angle class II group:Nil
Angle class III group:Nil
Sponsors
Department of Orthodontics, School of Stomatology, the Fourth Military Medical University
Eligibility
Sex/Gender
All
Age
18 Years to 50 Years
Inclusion criteria
Inclusion criteria: 1) The CBCT data before and after treatment which can be used for clinical diagnosis. 2) Agree to participate in this experiment and sign the informed consent form. 3) Over 18 years old, the development of root of 13-23 teeth and 33-43 teeth were completed. 4) No history of orthodontic treatment.
Exclusion criteria
Exclusion criteria: 1) the history of abrasion or trauma of anterior teeth, the history of restoration or root canal treatment of anterior teeth, the history of missing teeth, impacted teeth or supernumerary teeth, the history of periodontitis or maxillofacial surgery involving anterior teeth, 2) patients with systemic diseases who are unable to cooperate with the examination, 3) people who plan to get pregnant in the near future, 4) pregnant and lactating women, 5) personnel exposed to radiation at work, 6) according to the patient's medical history, it is estimated that the annual radiation dose has exceeded the annual equivalent dose limit.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Crown-root ratio;Morphological characteristics; | — |
Countries
China
Contacts
Public ContactJin Zuolin
Department of Orthodontics, School of Stomatology, the Fourth Military Medical University
Outcome results
None listed