the Pan-Pearl River Delta Regional Cooperation and Development Forum ; Pan-Pearl River Delta Regional Cooperation and Development Forum
regional cooperation in the pan-Pearl River Delta ; Pan-PRD regional cooperation ; PPRD
economic cooperation in the pan-Pearl River Delta
三角区通常指的是面部三角区,通常指的是两侧口角至鼻根联线所形成的三角形区域。为何称其为危险区域呢?这和口腔颌面部特有的解剖生理有关。颜面部的浅静脉包括面前静脉及颞浅静脉,面前静脉的瓣膜发育不良,少而薄弱,同时封闭不全,通常在肌肉收缩下,可使血液转而逆行。