The Spiral CT Study Of The Effection Of Different Type Of Mandibular Fractures To The Upper Airway Space Changes

Objective: The aim of this study was to analyze the effection of different type of mandibular fractures to the upper airway space changes by spiral CT, and provide a reference for assessing the clinical condition and taking the preventive measures.Material and Methods:1 Patients: Total 188 patients including14 patients with unilateral condylar fracture and 14 patients with bilateral condylar fracture; 18 patients with unilateral mandibular angle fracture and 18 patients with bilateral mandibular angle fracture; 20 patients with unilateral mandibular body fracture and 20 patients with bilateral mandibular body fracture; 27 patients with parasymphyseal single line fracture and 27 patients with parasymphyseal crushed fracture; 30 patients with normal occlusion. All patients were adult males and mean age was 32.5 years old (from 18 to 45 years).2 Research Methods: Took spiral CT scan to the upper airway of 188 patients under the same conditions, and measured the minimum cross-sectional area of different regions of upper airway and compared the difference between patients with normal occlusion and patients with condylar fracture, mandibular angle fracture, mandibular body fracture and parasymphyseal fracture by analysis of variance and further compared the difference between normal patients and unilateral or bilateral mandibular fracture of the same type by Dunndtt-t analysis of multiple comparison .Results:1 Patients with condylar fracture group: By the analysis of variance and Dunndtt-t analysis of multiple comparison,the minimum cross sectional area of nasopharyngea (NP), velopharyngeal (VP), glossopharyngeal (GP) and laryngopharynx(LP) of upper airway of unilateral condylar fracture group had no significant difference compared with that of the normal occlusion group. The GP of upper airway space of bilateral condylar fracture group decreased compared with the unilateral condylar fracture group , which was close to the statistically significant difference(P=0.055).The GP of upper airway space of bilateral condylar fracture group decreased compared with the normal occlusion group, which was close to the statistically significant difference(P=0.052)2 Patients with mandibular angle fracture group: By the analysis of variance and Dunndtt-t analysis of multiple comparison, the minimum cross sectional area of upper airway space of NP, VP and GP with unilateral mandibular fracture group have no significant difference compared with the normal occlusion group; minimum cross sectional area of LP decreased, which was close to statistically significant difference (P=0.056). Compared with the normal occlusion group, he minimum cross sectional area of upper airway space of GP significantly decreased (P=0.02); Compared with the unilateral mandibular fracture group,the minimum cross sectional area of GP significantly decreased (P=0.03).3 Patients with mandibular body fracture group: By the analysis of variance and Dunndtt-t analysis of multiple comparison, the minimum cross sectional area of NP and VP with unilateral mandibular body fracture had no significant difference compared with the normal group,however the minimum cross sectional area of GP (P=0.02) and LP (P=0.00) has significantly difference .The minimum cross sectional area of GP and LP with bilateral mandibular body fracture significantly decreased compared with the normal occlusion group and the unilateral mandibular body fracture group (P<0.05).4 Patients with parasymphyseal fracture group: By the analysis of variance and Dunndtt-t analysis of multiple comparison, there was no significant difference of the minimum cross sectional area of parasymphyseal single line fracture group, compared with the normal occlusion group(P>0.05). Compared with the normal occlusion group and parasymphyseal single line fracture group, the minimum cross sectional area of GP and LP of crused parasymphyseal fractures group significantly decreased (P<0.05).Conclusions:1 Different type of mandibular fracture had different effection to the changes of upper airway space.1.1 There was no significant changes of upper airway space after unilateral condylar fracture, unilateral mandibular angle fracture and parasymphyseal single line fracture.1.2 The GP of upper airway space decreased after bilateral condylar fractures, which was close to statistically significant difference (P=0.052).1.3 The LP of upper airway space significantly decreased after bilateral mandibular fractures(P=0.02).1.4 The GP of upper airway space decreased, which was close to statistically significant difference (P=0.064), however the LP of upper airway space significantly decreased(P=0.03), after unilateral mandibular body fracture.1.5The GP and LP of upper airway space significantly decreased after bilateral mandibular body and crushed parasymphyseal fracture (P<0.05), which consequently affected the ventilation function of patients.2 Spiral CT has superiority for upper airway space studies compared with the X-ray cephalometry.