Cone Beam CT Imaging Study Of Mandibular Forward Canal In901 Adults In Guizhou Province

Objective: Based on the study of CBCT imaging characteristics of mandible forward canal in Guizhou,summarize the characteristics and distribution of mandibular forward canal,provide theoretical data reference for clinical mandible surgery,reduce the risk of nerve injury when mandibular implant surgery and mandible branch split osteotomy.Methods: Random selection from January 2018 to January 2021 in Guiyang oral hospital in Guizhou adult patients 901 cases,in strict accordance with the inclusion standards and exclusion criteria into the study sample data,using cone beam CT(cone beam CT,CBCT)to observe the mandible forward canal and the remaining branches,the statistics tube in mandible,molar area,molar area incidence and the distance to the mandible.Results: 1.In this study,901 patients(side 1802,441 males and 460 females)were finally observed,and 386 patients were found,with an incidence of 42.84%.2.There are 571 mandibular nerve tubes in 1802,with an incidence of 31.69%(571 / 1802),according by Naitoh classification: 35.78%(190 / 531),followed by forward tube,the discovery rate of34.27%(182 / 531),posterior molar tube was 29.76%(158 / 531),only 1 buccal-lingual tube was 0.19%(1 / 531).3.Forward canal was found in 182 patients(97 males and 85females),accounting for about 20.20%(182 / 901).Forward canal was found in 225 sides of mandible,101 cases in left mandible and 124 cases in right mandible(P > 0.05).There was no significant difference between gender and left and right sides.The forward canal mainly occurred in the molar area,posterior molar area and ascending branch area,while the starting point of the anterior canal was the best in the ascending branch area,and the ending point was the most in the molar area(P < 0.05).5.The average length(L1)of the front pipe is(10.364 ± 3.833)mm;The average height(L2)from the anterior canal to the main trunk of the mandibular nerve canal was(3.623 ± 2.035)mm;The average height(L3)from anterior canal to alveolar crest was(9.280 ± 3.240)mm;The diameter of the starting point(R)and the diameter of the ending point(R1)of the front pipe were1.333±0.388 mm and 1.089±0.354 mm respectively.There was significant difference in the width of the starting and ending point,and the diameter of the starting point was wider than that of the outlet(P < 0.05).The horizontal distance from the center of the forward canal to the buccal bone wall(D buccal 1)is 6.030±1.710 mm and the horizontal distance to the lingual bone wall(D tongue 1)is 3.933±1.486mm;the horizontal distance between the lumen center and the buccal bone wall(D buccal 2)is 6.582 ± 1.949 mm and the horizontal distance to the lingual bone wall(D tongue 2)is 4.921±2.182 mm.Conclusion:1.Bifid mandibular canal is widespread in the adult group in Guizhou.In this study,901 adults in Guizhou have forward canal in the ascending area starting point distribution is more and more stops in the molar area.2.The results of this study show that the occurrence of forward canal should be observed within 5.66 mm above the mandibular canal affects the design of implant surgery and reduces the available bone height for implant surgery.3.In this study,the forward canal of adults in Guizhou deviated to the lingual side of the mandible.According to the distance to the bone wall,the risk of the buccal bone wall in the mandibular molar area and the buccal bone wall in the 2mm area of the ascending branch area is relatively small.