Objective:The palatonasal recess(PNR)is a concave structure in the medial wall of the maxillary sinus.Anatomical features of the palatonasal recess could determine the difficulty of the maxillary sinus augmentation,which is one of the important factors affecting the difficulty of operation and mucosa perforation during maxillary sinus augmentation.In this study,the anatomical features of PNR were investigated by cone beam CT(CBCT)to provide reference for maxillary sinus augmentation.Methods:CBCT images of 189 patients with maxillary posterior tooth loss were selected from the Department of Dentistry,the First Medical Center of PLA General Hospital.The detection rate of PNR,the angle of PNR and the distance between PNR and alveolar ridge crest well as the lateral wall of maxillary sinus were measured,and the rate of risk sites with the angle of PNR＜90 and the distance from the alveolar ridge crest＜15 mm was calculated.Results:PNR was observed in 176 patients(93.12％),with 202 PNR(90.58％)sites in total.The average PNR angle was(123.81±25.15)°,and the angle increased gradually from the first premolar to the second molar.The average distance between PNR and alveolar ridge crest was(12.89±2.85)mm,and the distance between PNR and alveolar ridge crest was farthest at the second premolar site and closest at the second molar site.The average distance between PNR and the lateral wall of maxillary sinus was(16.93±4.57)mm,and PNR at the first molar site was farthest from the lateral wall of maxillary sinus.The highest rate of PNR risk sites was found in the first premolar.Conclusion:PNR is a common anatomical structure in the medial wall of the maxillary sinus,and the anatomical features of PNR should be examined by CBCT before maxillary sinus augmentation,in order to reduce the incidence of sinus mucosa perforation of the maxillary sinus.
维普
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