Differences in the mandibular premolar positions in Angle Class I subjects with different vertical facial types: A cone-beam computed tomography study / 대한치과교정학회지

OBJECTIVE: To compare the positions of the mandibular premolars in Angle Class I subjects according to vertical facial type. The results will provide a theoretical basis for predicting effective tooth movement in orthodontic treatment. METHODS: Cephalometric parameters were determined using cone-beam computed tomography in 120 Angle Class I subjects. Subjects were categorized as short, normal, and long face types according to the Frankfort mandibular angle. Parameters indicating the position of the mandibular right premolars and the mandible were also measured. RESULTS: The angle between the mandibular first premolar axis and buccal cortex, the distance between the root apex and buccal cortex, angle of vestibularization, arc of vestibularization, and root apex maximum movable distance were significantly greater in the short face type than in the long and norm face types. The angle between the mandibular second premolar axis and buccal cortex, the distance from root apex to buccal cortex, and the arc of vestibularization were significantly greater in the short face type than in the normal face type. CONCLUSIONS: There are significant differences in the mandibular premolar positions in Class I subjects according to vertical facial type.

Anatomic study of the hypoglossal nerve in hypoglossal-facial nerve anastomosis / 南方医科大学学报

<p><b>OBJECTIVE</b>To determine the optimal position of hypoglossal nerve in hypoglossal-facial nerve anastomosis and the eligibility of hypoglossal-facial nerve anastomosis with the cervical loop.</p><p><b>METHODS</b>The cervical course and adjacent structures of the hypoglossal nerve were observed on 21 adult cadavers. The hypoglossal nerve and facial nerve were taken from 3 fresh specimens, and the number of the fasciculus and the cross-sectional area of the nerve were measured.</p><p><b>RESULTS</b>The facial nerve trunk were monofascicular with a cross-sectional area of 5.1-/+0.2 (range 4.6-5.7) mm(2). The number of the fasciculus and the cross-sectional areas of the nerve trunk and the fasciculus were 1.6-/+0.8 (range 1-4) mm(2) , 7.5-/+0.7 mm(2) (range 6.8-8.0) mm(2), and 4.7-/+0.6 (4.1-5.5) mm(2), respectively, at the proximal segment of the hypoglossal nerve, 3.6-/+0.5 (1-5) mm(2) , 5.6-/+0.5 (4.9-6.1) mm(2) , and 1.6-/+0.4 (0.9-2.2) mm(2) at the distal segment, and 2.4-/+0.8 (1-3) mm(2), 1.1-/+0.7 (0.6-2.2) mm(2), and 0.5-/+0.3 (0.3-1.2) mm(2) at the cervical loop.</p><p><b>CONCLUSION</b>The cervical loop is inadequate for facial nerve anastomosis and the proximal segment is large enough to allow partial harvesting of the hypoglossal nerve for neurotisation of the facial nerve.</p>

Vascular 3D visualization and flap design on the each perforator of anterolateral thigh flap / 中华显微外科杂志

Objective To provide the skin vessels morphologie basis for perforating flap of the antero- lateral thigh(ALT).Methods Six sides lower limbs of adult fresh cadaver specimens perfused with lead oxide-gelatine mixture were used.Observe the peraforators of anterolateral thigh by dissection.The elevated tissue was radiographed by X-ray and MSCT-scanning.Computer techniques was used for the detection and 3D-reconstruction of the regions of each perforators of ALT flap.Results The three-dimensional recostruct- ed digitized visible models perfectly displayed the anatomic structures of arteries on the anterolateral thigh, and,the morphology and distribution of the vascular territory of each perforator from descending branch of LCFA was displayed in the images of 3D-visualization,their effective morphology and distribution were same, and they accord with vascular territory of radiograph.On the 2D-image of X-ray,The margins of the anatomical distribution of each perforator from descending branch of the lateral circumflex femoral artery were determined, their total areas was about 25cm?24cm.Conclusion Since the digitized image of perforator territory can accord with the morphology of anatomy,and can off vascular structure insights into cutaneous perforator anato- my,their 3D visualizative models can be applied in pre-operative designing and virtual operation procedures, and can be helped for study of perforator flap.