title: An evaluation of buccal shield treatment. A clinical and cephalometric study.
abstract: OBJECTIVE
  To evaluate the short-term effects of the buccal shield modification of the lip-bumper design and on various mandibular dental arch parameters and to determine whether the changes in arch widths are due to the tipping or bodily movements of the teeth involved.
  
  
  METHODS
  This study included 45 consecutively treated patients (29 girls and 16 boys) from a private orthodontic practice. Student's and paired t-tests were used to test the null hypothesis of no change over time for the various measurements. Linear regression analyses were used to determine whether treatment time was a significant predictor of arch width expansion. Significance for all statistical tests was predetermined at P < or = .05.
  
  
  RESULTS
  Student's t-test results indicated the presence of a significant (P < .0001) increase in all the arch parameters measured. The greatest mean expansion was observed at the first (5.0 +/- 2.2 mm) and second (3.4 +/- 2.2 mm) premolar width measurements. The changes in arch width parameters were significantly (P < .0001) greater than the normal age-related changes in the corresponding parameters. There was no significant difference between arch width expansion of the occlusal vs gingival levels, indicating a bodily and not tipping movement. Only 30% of the lower incisors demonstrated an increase in their proclination beyond normal values.
  
  
  CONCLUSIONS
  When using the buccal shield appliance, the mandibular arch width parameters can be expanded in the mixed dentition with bodily movement of teeth. The expanded arch width dimensions are greater than what would be expected as a result of normal growth.
authors.affiliation: Department of Orthodontics, Harvard School of Dental Medicine, Boston, MA, USA. kambiz@drmoin.com
authors.forename: Kambiz
authors.initials: K
authors.lastname: Moin
authors.forename: Samir E
authors.initials: SE
authors.lastname: Bishara
mesh_terms: D000328:Adult; D002508:Cephalometry; D002648:Child; D003724:Dental Arch / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007180:Incisor / Q000503:physiopathology; D016014:Linear Models; D008046:Lip; D008334:Mandible / Q000033:anatomy & histology; D020247:Myofunctional Therapy / Q000295:instrumentation; D016382:Orthodontic Appliance Design; D017289:Orthodontic Appliances, Functional; D013997:Time Factors; D014087:Tooth Movement Techniques / Q000295:instrumentation*