Download OP06 VERTICAL AND HORIZONTAL ALVEOLAR BONE CHANGES

OP06 VERTICAL AND HORIZONTAL ALVEOLAR BONE CHANGES AROUND MANDIBULAR INCISORS AFTER
ORTHODONTICTOOTHMOVEMENT
ShivaSenathirajah,SachinAgarwal,PaulSchneider,DentalSchool,UniversityofMelbourne,Australia
AIM:Toevaluateverticalandhorizontalalveolarbonechangesafterorthodontictoothmovementinorderto
assessifthealveolarenvelopelimitsorthodontictoothmovement.
MATERIALS AND METHOD: Pre- and post-treatment cone beam computed tomography images of 41 adult
patients were used to measure alveolar bone width and height changes on the lingual and labial surfaces of
mandibular incisors. Width measurements were made at 2.5, 5, 7.5 and 10 mm apical to the cementoenamel
junction(CEJ).HeightmeasurementsweremadefromthemarginalbonecresttotheCEJ.Linearregressionwas
appliedtocorrelatebonechangeswithachangeintheincisormandibularplaneangle,labio-lingualandocclusogingivalmovementoftheincisaledgeandrootapex.Regressionmodelstoadjustforallparametersandwith
specificinteractionsbetweenselectedparameterswerealsoapplied.
RESULTS:Every1degreeincreaseintheincisormandibularplaneanglereducedlabialbonewidthby0.07mm
(P=0.009),andincreasedlingualwidthby0.09mm(P=0.003)at2.5mmapicaltotheCEJ.For1mmoflabial
movementoftheincisaltip,boneheightdecreasedby0.31mm(P=0.012)onthelabialandby0.28mm(P=
0.040)onthelingual.For1mmofextrusionoftheincisaltip,boneheightdecreasedby0.50mm(P=0.030)on
thelabialandby0.24mm(P=0.001)onthelingual.
CONCLUSIONS:Alveolarbonewidthdecreasedonthelabialandincreasedonthelingualsurfaceswithincisor
proclination.Boneheightdecreasedonthelabialandlingualsurfaceswithincisoradvancementandextrusion.
Significantchangesofthealveolarenvelopeoccurredwithorthodontictoothmovement.