Study Of Anterior Palatal Support Tissues In Mouth-breathers With High-narrow Palates Versus Nose-breathers With Normal Palates In Children And Adolescent

Objectives:The aim of this study was to evaluate the palatal support tissues for placement of orthodontic mini-implants?OMIs?in mouth-breathers with high-narrow palates versus nose-breathers with normal palates and provide clinical guidance for OMIs insertion in this area.Methods:The sample consisted of 37 mouth-breathers with high-narrow palates?Study Group,SG?and 37 nose-breathers with normal palates?Control Group,CG?.Upper plaster models were superimposed with corresponding lateral cephalograms,then the palatal total support tissues?TSTs?and bone support tissues?BSTs?vertical to the curvature of palatal mucosa were measured at 17 sites?A₁-A₈,P₁-P₈,R?around the third ruga?R?.Descriptive statistics and paired t test were used for statistical analysis.Results:The greatest TSTs and BSTs values were both found at the site 1mm posterior to R?P₁?,the mean values were 10.95±1.79mm and 8.52±1.70mm in study group and11.81±1.67mm and 9.54±1.76mm in control groups.There were greater TSTs and BSTs in the area between 3mm anterior and 4mm posterior to R?A₃-P₄?with sufficient palatal support?mean TSTs over 8.5mm and mean BST over 5.0mm?for OMIs insertion.The mean values of TSTs and BSTs in SG were smaller than that in CG in the above area.Significant differences were found at P₁ and R sites for TSTs and A₂-P₁ for BSTs.Conclusions:Mouth-breathers with high-narrow palates may have less palatal support tissues than nose-breathers with normal palates.The area between 3mm anterior and 4mm posterior to the third ruga is the relative safe region for 8mm-long OMIs implantation.