CT Diagnosis of the Fracture of Anterior Nasal Spine

Abstract

Objective: To study anterior nasal spine fractures, including the incidence, missed diagnosis rates, and relationship with shapes using computed tomography (CT). Methods: Two hundred cases of axial CT images performed for maxillofacial trauma were reviewed. The incidence, correct, and missed diagnosis rates of anterior nasal spine fractures were studied. The relationship between the fracture and the shape of the anterior nasal spine was also analyzed. Results: The rate of anterior nasal spine fractures was 22.00% (44 of 200). The diagnostic accuracy was 4.55% (2 of 44) and the missed diagnosis rate was 95.45% (42 of 44). The fracture rates of the double rod, single rod, triangle, and irregular anterior nasal spine were 33.85% (22 of 65), 32.26% (10 of 31), 12.24% (12 of 98), and 0.00% (0 of 6), respectively. The double and single rod types of anterior nasal spine were most likely to be fractured than the type of triangle (χ2 = 11.05, 6.67, P < .0167). No fracture was found in the irregular type of anterior nasal spine. Conclusion: Anterior nasal spine fractures are not rare and the high missed diagnostic rate results from unfamiliarity with the structure. Double and single rod types of anterior nasal spines are easy to fracture. Bony reconstruction and thin thickness of CT images are necessary for diagnosis.

Volumetric Analysis of Unilateral Alveolar Bone Defect Using Modified Subtraction in Older Chinese Patients

“…Although the anterior nasal spine (ANS) is an important anatomic marker of the maxilla, in some patients the ANS is absent or too prominent. 32 As such, the previous CAE 3D measurement method, which uses ANS as a reference point to determine the upper margin of the cleft, cannot be used in this group of patients. In contrast, the modified subtraction method can account for abnormal ANS positioning, taking the lowermost points of the inferior margins of the piriform aperture as the upper bound on the 3D virtual mask.…”

“…Second, the modified subtraction method has wide applicability. Although the anterior nasal spine (ANS) is an important anatomic marker of the maxilla, in some patients the ANS is absent or too prominent 32. As such, the previous CAE 3D measurement method, which uses ANS as a reference point to determine the upper margin of the cleft, cannot be used in this group of patients.…”

Evaluation of Optimal Insertion Sites and Angles for Orthodontic Mini-Implants at the Anterior Nasal Spine Region Based on Cone-Beam Computed Tomography

“…At the 22 mm peak, most of the images were observed to manifest a continuous palatal plate full of cortical bone, as was indicated by 2 times the CBT value of the 20 mm height. You et al [24] classified the morphology of the ANS region into four categories (double rod, single rod, triangular, and irregular) based on 1000 pieces of transverse CT samples, which is a perfect illustration of the anatomic variations in ANS morphology. The trend could be attributed to the anatomical variations in the ANS, such as in an irregular phenotype in which the loss of ANS prominence may result in a dramatic decrease at 24 mm.…”

Open Reduction of an Isolated Anterior Nasal Spine Fracture: A Case Report and Review of the Literature

“…You et al [7] recently reported that the rate of ANS fracture is 22% and that the diagnosis was missed in 95% of 200 cases of axial CT images performed for maxillofacial trauma in a single hospital.…”

“… 1 4 5 6 On the other hand, the actual incidence of ANS fracture may not be as low as predicted. You et al 7 recently reported that the rate of ANS fracture is 22% and that the diagnosis was missed in 95% of 200 cases of axial CT images performed for maxillofacial trauma in a single hospital.…”