title: Three-dimensional analysis of tooth movement after intrusion of a supraerupted molar using a mini-implant with partial-fixed orthodontic appliances.
abstract: OBJECTIVE
  To evaluate three-dimensional (3D) positional changes of an intruded tooth, a neighboring tooth, and a tooth connected to a mini-implant following intrusion of a single supraerupted molar, using a mini-implant with partial-fixed orthodontic appliances.
  
  
  METHODS
  The study consisted of 14 adult patients (two males and 12 females, mean age 41.9 years) with a supraerupted molar due to loss of an antagonist. Intrusion was performed using a mini-implant with a partial strap-up. The mean treatment time was 11.9 months, and the mean retention time was 23.3 months. To quantify the positional changes of the teeth, 3D models using a laser-based, dental scanning system and 3D software at pretreatment, posttreatment, and retention were oriented in a coordinate system and superimposed using nonmoved teeth as references. The changes on the x-, y-, and z-axes were measured at the tip of each cusp in the involved teeth.
  
  
  RESULTS
  A supraerupted molar was intruded by a mean amount of 1.35 ± 0.48 mm and was well maintained during the retention period. The overall change in the neighboring tooth was insignificant, although it showed opposite movement compared to the intruded tooth during the intrusion. The tooth connected to a mini-implant exhibited a secure anchorage.
  
  
  CONCLUSIONS
  3D analysis showed the detailed positional changes of each tooth, and the involved molars were well maintained after intrusion.
authors.affiliation: Department of Orthodontics, School of Dentistry & Dental Research Institute, Seoul National University, Seoul, Korea.
authors.forename: Shin-Jae
authors.initials: SJ
authors.lastname: Lee
authors.forename: Sook-Yun
authors.initials: SY
authors.lastname: Jang
authors.forename: Youn-Sic
authors.initials: YS
authors.lastname: Chun
authors.forename: Won Hee
authors.initials: WH
authors.lastname: Lim
mesh_terms: D000328:Adult; D002508:Cephalometry; D015921:Dental Implants; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008437:Maxilla; D008875:Middle Aged; D008963:Molar / Q000473:pathology*; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D016382:Orthodontic Appliance Design; D009967:Orthodontic Appliances; D009968:Orthodontic Appliances, Removable; D014087:Tooth Movement Techniques / Q000295:instrumentation*; D055815:Young Adult
chemical_list: D015921:Dental Implants