Analysis Of The Location And Security Assession In Middle Meatus Antrostomy By CT

Objective: To preliminarily localise the anatomical position of the leading edge of uncinate process(UP)and posterior fontanelle(PF)before operation, assess the surgical security of Middle Meatus Antrostomy(MMA) by uncinate process approach and by posterior fontanelle approach and compare between the two different approaches through analyzing the related data of coronal sinus CT image, aiming to provide a referential theory evidence for choosing different operations of MMA and accurate intraoperative localization.Methods: Divide 80 cases of coronal sinus CT image into 3 groups,including a normal bilateral sinus group with 30 cases(NS Group), a bilateral chronic maxillary sinusitis group with 30 cases(BS Group), an unilateral chronic maxillary sinusitis group with 30 cases(US Group). ①Record the number of all inferior turbinate’s plies(N) and the designated ply corresponding to the first ply of UP(N1)and the counted ply of PF(N2) in each nasal cavity. Then the anatomical position of the leading edge of UP and PF were described by N1/N and N2/N respectively.②Measure the vertical distance from the attachment point of IT and medial and lower orbital angle in the first ply of UP(H1) and the counted ply of PF(H2). ③.Compare the anatomical position of the leading edge of UP and PF between NS Group and BS Group; compare H1 and H2 between NS Group and BS Group; compare H1 and H2 between the uninjured side and injured side in US Group; compare H1 and H2 in all nasal cavities; then analyze the result statistically.Results: ①N1 / N was 0.361±0.052(),. N2 / N, was 0.65 ± 0.082(),.The difference of the anatomical position of the leading edge of UP and PF neither were statistically significant between the NS Group and BS Group(p>0.05).② In the NS Group and BS Group, H1 was respectively( cm): 1.074±0.53,1.079±0.477, Between the two groups, the difference was not statistically significant(p>0.05); H2 was respectively( cm): 1.648±0.31, 1.537±0.374,between the two groups, the difference was not significant statistical(p>0.05).③ In the uninjured side and injured side of the US Group, H1 was respectively( cm): 1.24±0.499,1.187±0.484,1.567±0.243, between the two sides, the difference was not significant statistical(p>0.05); H2 was respectively( cm): 1.567±0.243,1.525±0.263, the difference was not significant statistical(p>0.05).④ In all 160 nasal cavities, H1 was( cm)1.111±0.5, H2 was( cm) 1.58±0.325, the difference in the two plies was significant statistical( p<0.05). ⑤ In all 160 sides, the distribution of H1was:13sides were smaller than 0.5cm(8.13%); 61 sides fell in between 0.5cm and1.0cm(38.13%); 78 sides fell in between 1.0cm and 2.0cm(48.75%);8 sides were bigger than2.0cm(5%). the distribution of H2 was: 0sides were smaller than 0.5cm(0%); 8 sides fell in between 0.5cm and 1.0cm(5%); 137 sides fell in between 1.0cm and 2.0cm(85.63%); 15 sides were bigger than2.0cm(9.38%). the difference in the distribution of H1 and H2 was significant statistical(p<0.05).Conclusions: ①Through analyzing coronal sinus CT image preoperation, the anatomical position of UP’s leading edge and PF can be preliminarily identified as locating over the former 1/3 junction of IT on the lateral nasal wall and over the later1/3 junction of IT respectively, and the position and range of window in MMA was located over the middle 1/3 IT on the lateral nasal wall. ②the vertical distance between the attachment point of IT and medial and lower orbital angle was irrelevant with the chronic maxillary sinusitis.③In the mass, the possibility, damaging the medial and lower orbital angle,during the MMA by PF approach was smaller than that by UP approach generally. ④In the overwhelming majority of case, the surgical security of MMA by UP approach and by PF approach are both high, so the performer could choose either operating method as he likes. But, in the minority case, the vertical distance from the attachment point of IT and medial and lower orbital angle in the leading edge of UP is smaller and that in PF is bigger, the the surgical security of MMA by UP approach is low relatively, then the MMA by PF approach can be suggested to choose, in order to reduce the possibility of surgery complications.