Study On Alveolar Bone Morphology Of Maxillary Premolars In Adults In Central China

Objective:This study is to obtain anatomical data of normal maxillary premolars bone morphology in central China,and provide corresponding reference for the establishment of clinical implantation treatment plan and postoperative evaluation of maxillary premolars.Materials and methods:Cone beam CT(CBCT)scans were performed on 210 eligible occlusal adults in central China,and the alveolar bone morphology of maxillary premolars(14/24 、15/25)was measured and analyzed.The measurement contents include the bone plate thickness at different heights 、 the distance from the alveolar crest to the enamel cementum boundary、 the available bone height、teeth/alveolar long axis angle、the angle between the long axis of the tooth and the long axis of the alveolar bone、the positional relationship between the root apex and the sinus floor of the maxillary、different types relation of root apex and the sinus floor of Statistics of the included angle,etc.Spss23.0 was used for statistical analysis.Results:1 The labial bone plate thickness of the 3mm below the enamel cementum of14/24 is 0.74±0.79 mm,and the palatal bone plate is 0.81±0.78 mm,but other 5mm、7mm bone plate thickness are greater than 1mm.The labial palatal bone plate thickness of the 3mm、5mm、7mm below the enamel cementum of 15/25 are greater than 1mm.2 The distance from the enamel cementum to the alveolar crest of 14/24 labial is 3.06±1.15 mm and palatal is 2.74±1.02 mm.The 15/25 labial is 2.51±1.10 mm andpalatal is 2.54±1.01 mm.The 14/24 is longer than 15/25(p<0.01).3 The available bone height of the 14/24 is 19.97 ± 3.49 mm,and the 15/25 is16.76±4.82 mm.The 14/24 is longer than 15/25(p<0.01).4 The 14/24 that the angle between the long axis of the teeth and the long axis of the alveolar bone is 22.54±8.85 degree,but the 15/25 is 17.73±7.21 degree.The 14/24 is greater than the15/25(p<0.01).5 The relationship between the root tip of the maxillary premolars and the position of the maxillary sinus floor,the 14/24 has the most type I,and the 15/25 has the most type II;The distance between the root apex and the sinus floor is mostly3-6mm,next is 6-9mm.6 The relationship between the root tip of the maxillary premolars and the position of the maxillary sinus floor,the angles between the Class I teeth of the maxillary premolars and the long axis of the alveolar bone,and the available bone height are maximum.Conclusion:The maxillary premolar has relatively sufficient bone mass,there is a certain degree of clamping between teeth and bone,and some root tips are close to the maxillary sinus floor.It is best to evaluate before clinical implant operation to avoid damage to the alveolar bone and maxillary sinus.