The Distance Of Mucogingival Junction To The Alveolar Crest And The Relationship Between The Distance And Dentoskeletal Patterns

Objective: Anchorage is a key factor affecting the result of orthodontic treatment.The application of the mini-implant greatly widened the range of the orthodontic treatment,improved the effect,and been favored by the orthodontist and patients.But the stability of the mini-implant is not impressive,easily falling off,even though it is small and easily to be implanted.The primary causes for its stability are the condition of the implanted alveolar bone and the way to do the operations.What everyone concerns the most are how the thickness,hardness of the alveolar,and the bone around implant affect the choice of implant size and shape,operation method and loading.Many scholars have studied the distribution of the bone thickness of the alveolar on the different heights and hardness and the interradicular distance.Many studies have shown that the horizontal distance of interradiculars is related to the skeletal facial form.A large number of clinical trials showed that its stability is higher if applying the mucogingival junction line as mini-implant implantation sites.Because the distance of mucogingival junction to the alveolar crest is different,and with obvious individual differences,the distribution of the distance between the mucogingival junction of mini-implant commonly implanted sites and the alveolar crest has not been published.This experiment is to explore the possibility of gingival papilla height as a reference mark,the distribution of the distance between the mucogingival junction and the alveolar crest,the relationship between the distance and the skeletal facial forms,and provide theoretical basis for the mini-implant clinical application by measuring the gingival papilla heights where mini-implant is commonly implanted and the distance between mucogingival junction and the alveolar crest.Methods: locations: maxillary incisor and lateral incisor(U12),the second premolar and the first molar(U56);mandibular incisor and the lateral incisor(L12),the second premolar and the first molar(L56),the first molar and second molar(L67).Measurments: gingival papilla height,the distance of mucogingival junction to the alveolar crest,and Lateral Cephalometric Measurements.1 The height of the gingival papilla(d1): To gently insert the periodontal probe along the gingival papilla to the bottom of distal gingival sulcus until there is a slight resistance,and then to record the number on the periodontal probe.2 The distance of mucogingival junction to the alveolar crest 2.1 The height of the gingival papilla(d1): same to the above.2.2 The distance of the gingival papilla to mucogingival junction(d2): starting from the long axis of the teeth,to measure the distance between the gingival papilla and mucogingival junction.2.3 The width of attached gingiva: the distance of the tip of gingival papilla to mucogingival junction minus the distance of the gingival papilla to the bottom of gingival sulcus is the attached gingiva width(d2-d1).2.4 The distance of mucogingival junction to the alveolar crest(d):the width of attached gingiva minus 2 mm(biological width BW). d=d2-d1-2mm.3 Lateral Cephalometric Measurements.Lateral cephalometric measurements were obtained using Smart'n Ceph Researcher V 9.0 software(Y&B Products,Chiang Mai,Thailand)that was designed for measuring the angle of SNA,SNB,ANB.SNA: SN and NA wired Angle(82.8 °±4.0 °)SNB: SN and NB wired Angle(80.1 °±3.9 °)ANB: NA and NB wired Angle(2.7 °±2.0 °)Result:1 There is no statistical significance in the same name teeth or gender of the distance that is between mucogingival junction and the alveolar crest(P<0.05),so the data could be merged.2 The distance of the gingival papilla to alveolar crest: There is no statistical significance in the same name teeth of the left or right or in the gender of the distance that is between the gingival papilla and alveolar crest(P>0.05).U56 and U12,L12,L56,L67 are statistically significance respectively(P<0.05).But U12,L12,L56,L67 are no statistically significant difference(P>0.05).3 The distance of mucogingival junction to the alveolar crest: the distance of the mucogingival junction to alveolar crest in the maxillary is slightly larger than mandible;The distance in the anterior of Jaw is larger than in the posterior.The distance of U12 and U56 is 7.3±1.2mm,6.5±1.7mm,the distance of L12,L56,L67 is 5.5±1.0mm,5.0±1.2mm and 4.8±1.5mm.There are statistical significance among U56,U12,L12,L56,L67 besides between L56 and L67(P<0.05).4 There are no statistical differences between the mucogingival junction to the alveolar crest among different skeletal facial forms(P>0.05).Conclusion:1 There are no statistical differences between the mucogingival junction to the alveolar crest among different skeletal facial forms.2 The distance of mucogingival junction to the alveolar crest in the maxillary is slightly larger than mandible;in the anterior of Jaw is larger than in the posterior.