The relative location between the mandibular third molar and inferior alveolar canal studied by CBCT
	    		
		   		
		   			
		   		
	    	
    	 
    	10.3969/j.issn.1001-3733.2018.01.025
   		
        
        	
        		- VernacularTitle:应用CBCT分析阻生下颌第三磨牙牙根与下颌管的相对位置关系
 
        	
        	
        	
        		- Author:
	        		
		        		
		        		
			        		Yunpeng DING
			        		
			        		
			        		
			        			1
			        			
			        		
			        		
			        		
			        		
			        		;
		        		
		        		
		        		
			        		Shengjiao LI
			        		
			        		;
		        		
		        		
		        		
			        		Hanyu QIAN
			        		
			        		;
		        		
		        		
		        		
			        		Jianping ZHOU
			        		
			        		;
		        		
		        		
		        		
			        		Li ZHANG
			        		
			        		;
		        		
		        		
		        		
			        		Keji ZHU
			        		
			        		;
		        		
		        		
		        		
			        		Xuetao WANG
			        		
			        		;
		        		
		        		
		        		
			        		Lingxia KONG
			        		
			        		;
		        		
		        		
		        		
			        		Xiaoming CHEN
			        		
			        		
		        		
		        		
		        		
		        		
		        			
			        		
			        		Author Information
			        		
		        		
		        		
			        		
			        		
			        			1. 200072 上海,同济大学附属口腔医院颌面外科教研室,上海牙组织修复与再生工程技术研究中心
			        		
		        		
	        		
        		 
        	
        	
        	
        	
        		- Keywords:
        			
	        			
	        				
	        				
			        		
				        		Impacted mandibular third molar(IMTM);
			        		
			        		
			        		
				        		Mandibular canal(MC);
			        		
			        		
			        		
				        		Cone beam CT(CBCT)
			        		
			        		
	        			
        			
        		
 
        	
            
            
            	- From:
	            		
	            			Journal of Practical Stomatology
	            		
	            		 2018;34(1):113-116
	            	
            	
 
            
            
            	- CountryChina
 
            
            
            	- Language:Chinese
 
            
            
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		        	Abstract:
			       	
			       		
				        
				        	Objective: To determine the positional relationship between impacted mandibular third molar(IMTM) and mandibular canal(MC) by CBCT. Methods: 664 IMTMs with root apexes contacted to MCs on panoramic radiograph were further examined by CBCT,the exact positional relationship between IMTMs and MCs was observed and analyzed by I-Dixel software. Results: The 664 cases were divided into lowly(6. 3%),intermediately(60. 7%) and highly(33. 0%) impacted groups by the depth of IMTMs in mandibulae showed on CBCT images. The distance(mm) from the root apexes of IMTMs to the intact superior wall of MCs(n = 329) in lowly, intermediately and highly impacted cases were 1. 39 ± 1. 38,1. 28 ± 1. 03 and 1. 79 ± 1. 54 respectively(P < 0. 05). MCs on the buccal side,lingual side,under the IMTMs and between the root apexes were found in 49. 8%,12. 0%,36. 6% and 1. 5% of the cases; the MC wall deffect was found in 65. 8%,27. 5% and 95. 0% of the cases with the MCs under,on buccal and lingual side of the IMTMs, respectively(P < 0. 001). Conclusion: CBCT examination is necessary for the determination of the positional relationship between MC canal and IMTM with the root apex cotacted or overlapped to MC.