Measure And Analyze The Anterior Loop Of The Inferior Alveolar Nerve, Mandibular Incisive Canal, Mental Foramen And Accessory Mental Foramen In The Mandibular Interforaminal Area By CBCT

Objectives:The purpose of this experiment is to use three-dimensional reconstruction techniques to measure and analyze the mental foramen,accessory mental foramen,anterior loop of the inferior alveolar nerve and mandibular incisive canal in the mandibular interforaminal area,which could make the clinicians understand this area more intuitively.Material and Methods:Mimics 19.0 was used to reconstruct and measure the mandibular interforaminal area's related anatomical indexes by 70 adults of Han ethnic CBCT data.The statistical analysis was carried out by SPSS 22.0.Results:1.The incidence of AL was as high as 83.6%,and the ALL was 3.65±1.10mm,and the HAL was 5.87±1.18mm.ALL and HAL had no statistical differences in the left and right groups and age groups,but in the gender groups,p<0.05.both ALL and HAL of the male were longer than the female's.2.The incidence of MIC was as high as 100%,the length of MIC was 9.93±1.81mm,and there were no statistical differences between the left and right groups,in gender groups or age groups.3.The MFVD was 3.65±1.10mm,and MFVD had no statistical differences in the left and right groups and age groups,but in the gender groups,p<0.0001,the male's MFVD was longer than the female's.The MFHD was3.52±0.65mm,and there were no statistical differences between the left and right groups,in gender groups or age groups.4.The incidence of AMF was 4.3%,the average vertical diameter was 1.09mm,and the average horizontal diameter was 1.71,and the average distance from AMF to MF was 4.15mm.Conclusions:1.CBCT can clearly show the anatomical structure of the anterior region of the mandible,which means that the routine CBCT examination before operation should be done,and the AL should be as an important reference mark for the operation.If the CBCT examination is unconditional,the safe area is at least 4mm in front of the mental foramen and 6mm under the antapex of foramen.2.The incidence of AL was as high as 83.6%,the AL was almost symmetric,It wouldn't change with age,but men's ALL were longer than women's,as well as CAL,which suggested that men's risk of injuring the AL in operation was more than women in the mandibular interforaminal area.3.The incidence of MIC was as high as 100%,the length of MIC was nearly symmetrical in left side and right side,and it was basically the same between men and women,not changing with age.4.Both MFVD and MFHD were nearly symmetrical in left side and right side,not changing with age.The male's MFVD were longer than the female's,but the MFHD had no statistic differences in gender groups.5.The mean ratio of MFVD and MFHD was 0.82,and the mean ratio of AMF vertical diameter and horizontal diameter is 0.64.So the shapes of MF and AMF were oval,and AMF is more elongated than MF.The incidence of AMF was only 4.3%,but there were more variations in its position,which could be seen above the rear of the MF,below the rear of MF or below the front of MF.