目的　为经口咽下颌骨劈开扩大入路提供解剖学依据。  方法　6例新鲜成人头颈部标本，以模拟手术方式，依次行经口下颌骨劈开（保留舌体）和经口下颌骨、舌体劈开扩大入路解剖至颈髓，依次测量并记录两种入路的显露范围，探查性操作范围及重建性操作范围，测量双侧椎动脉相关解剖数据。  结果　两种扩大入路的显露角度分别为（63.67±3.50）°和（74.14±1.47）°。最大探查性操作范围分别为斜坡下1/3→C5上终板和斜坡下1/3→C6上终板，最大重建性操作范围分别为C2下1/2→C5上终板和C2下1/2→C6上终板。椎动脉距中线C2/3为(16.88±0.75)mm；C3/4为(16.48±1.47)mm，C4/5为(16.30±1.09)mm；距门齿垂直深度C2/3为(96.44±3.59)mm；C3/4为(97.94±4.51)mm，C4/5为(99.83±4.77)mm。  结论　经口咽下颌骨劈开扩大入路是处理张口受限和颈脊髓腹侧长节段病变的安全、有效的入路，需据手术范围确定是否劈开舌体。

Objective　This study was designed to investigate the anatomic foundation for the transoral approach with mandibulutomy and mandibuloglossotomy.　Methods　Transoral approach with mandubulutomy and mandibuloglossotomy were simulated in 6 fresh cadavers to cervical spinal cord; the cephalic and caudal limits of exposure  and the distances between the vertebral artery(VA) of each side to the midline and the vertical depth between the VA of each side to the fore-teeth of the two approaches were measured. Furthermore, the exploratory operational range and reconstructive operational range were described. Results　The exposure angle of mandibulotomy and mandibuloglossotomy were 63.67°±3.50°and 74.14°±1.47°, respectively.The widest EOR of mandibulotomy and mandibuloglossotomy were the lower third of the clivus to the upper edge of C5 and the lower third of the clivus to the upper edge of C6, respectively.The widest ROR of mandibulotomy and mandibuloglossotomy were the lower half of axis to the upper edge of C5 and the lower half of axis to the upper edge of C6, respectively. The distance between the vertebral artery(VA) of each side to the midline is  (16.88±0.75)mm at C2/3, (16.48±1.47)mm at C3/4 and (16.30±1.09)mm at C4/5, respectively. Furthermore, the vertical depth between the VA of each side to the fore-teeth of the two approaches was (96.44±3.59)mm at C2/3,(97.94±4.51)mm at C3/4 and (99.83±4.77)mm at C4/5, respectively. Conclusions　The transoral approach with mandibulotomy and mandibuloglossotomy is safe and effective in dealing with patients with limitation of mouth opening and long segmental ventral decompression of the cervical spine; However,whether glossotomy is performed or not depends on the particular range of the surgery.