A Study Of Maxillary Anterior Teeth In Individuals Measured And Analysed By Cone Beam Computed Tomography

[Objectives]This study measured and analysed the related anatomy of maxillary anterior teeth to research the condition of the bone and angulation of the maxillary anterior teeth with reference to the alveolus, providing some referential data for clinicians to achieve the best results for implant placement in the esthetic zone.[Materials and Methods]100 adults were screened who didn’t miss the teeth in maxillary anterior region according to the defined inclusive criteriaand divided into six groups (11,12,13,21,22,23),two groups (male52,female48),three groups (young 48, middle-aged 43,older-aged 9).76 adult patients were screened who did miss a single tooth or severalteeth in maxillary anterior region according to the defined inclusive criteria and divided into three groups (center incisors 48, lateral incisors 23 and canines 5), two groups (male 47, female 29), three groups (young 56, middle-aged 15,older-aged 5).Acquire the image by applicating of NewTom VG CBCT imaging system and combining with 3d software NNT-Viewer. Measured the angulation of the maxillary anterior teeth (∠TH)with reference to the alveolus (∠AH),the difference between themΔ=∠TH-∠AH,the thickness(W) and height of the alveolar bone(H) that is 10mm under the top of alveolar ridge in the sagittal plane.The angulation of the maxillary anterior teeth (∠TH’)with reference to the alveolus (∠AH’), the thickness(W’) and height of the alveolar bone(H’) that is 10mm under the top of alveolar ridgewho did miss a single tooth or several teeth were measured in the same way.The data were analyzed and compared by SPSS 21.0. P<0.05 for the difference was statistically significant.[Results]1.Results in 100 normal adults:(1)∠TH23 (74.215±7.356°)>∠THi3>∠TH22> ∠TH2i>∠THi2>∠TH11 (67.076±8.213°) (the numbers at the lower right-hand cornerrepresent the position of the teeth),differences were statistical significance(P< 0.05).(2)The long axis of the alveolar bone∠AH13(56.561±5.865°)>∠AH23>∠AHi2> ∠AH11>∠AH21>∠AH22 (49.381±6.397°), differences were statistical significance(P <0.05).(3)The bone widthW23(9.475±2.165mm)>W2i>Wi3>Wi2>W11>W22 (7.879±1.627mm) differences were not statistical significance(P>0.05).H21 (10.737±2.732mm)>H23>Hi2>H22>Hi3>Hn (9.581±2.755mm), differences were not statistical significance(P>0.05). (4)The female∠TH and ∠AHare more than the male.But there was not significant differences between men and women (P> 0.05).The maleWis more than the female.There was significant differences between men and women in thickness of the palatal bone(P<0.05). The maleH is more than the female.There was significant differences between men and women in height of the palatal bone that is 10mm under the crestal alveolar ridge of the mandibular right lateral incisor (P<0.05).(5)In the same area, there was no significant differences in the angle of the long axes of the bone and thickness of the palatal bone that is 10mm under the crestal alveolar ridge among the young、middle-aged groupand the older(P> 0.05).There was significant differences in the angle of the long axes of the maxillary teeth and height of the palatal bone that is 10mm under the crestal alveolar ridge among them (P<0.05).Results in 76 adult patients:(1) The mean angle is more in the tooth deficiency group. Differences in the maxillary center incisors and lateral incisors were statistical significance(P<0.05).(2) The mean height is more in the control group.Differences between the two groups were statistical significance (P< 0.05) in the maxillary center incisors and lateral incisors.(3) There was significant differences between men and women in thickness and height of the palatal bone that is 10mm under the crestal alveolar ridge of the maxillary center incisors (P< 0.05). (4) There was no significant difference in the angle of the long axes of the maxillary bone, thickness, and height of the palatal bone that is 10mm under the crestal alveolar ridge of the maxillary in the young, middle-aged and older-aged groups(P> 0.05).[Conclusion]There are16.719°to 20.117° between the long axes of the maxillary teeth and bone. To consider the relationship, the long axes of the maxillary teeth is more to the lip side.The data about thickness and height of the palatal bone that is 10mm under the maxillary crestal alveolar ridge will provide some academic bases and references for the immediate implant placement in the esthetic region.The thickness and height of the palatal bone that is 10mm under the maxillary crestal alveolar ridge have gender differences.More women need to have bone surgery than men.The height of the palatal bone that is 10mm under the maxillary crestal alveolar ridge, and the angle of the long axes of the maxillary teeth have age differences. The height in older-aged groups is most of all.The thickness of the palatal bone that is 10mm under the maxillary crestal alveolar ridge, and the angle of the long axes of the maxillary bone have no age differences.In adult patients who did miss a single tooth or severalteeth in maxillary anterior region:the long axes of the maxillary bone in the tooth deficiency group tend to palate. The height of residual alveolar ridge will reduce obviously after teeth missing. The long axes of the female maxillary bone more tend to palate than male. The change of alveolaris irrelevant to the age.