[Applied anatomic study for genioglossus advancement].

Objective: To provide anatomic basis for genioglossus advancement.

Method: Forty adult cadaver heads (male=29, female=11) were dissected to measure genial tubercles and observe the start-stop points of genioglossus muscle and geniohyoid muscle.

Result: The genioglossus muscle originates from the superior mental spine, and the geniohyoid muscle originates from the inferior mental spine. The height, width and process of the superior mental spin were (5.82 +/- 0.71)mm, (6.98 +/- 1.35)mm, (2.92 +/- 0.97)mm respectively, while (5.97 +/- 1.39)mm, (3.81 +/- 0.52)mm, (0.77 +/- 0.62)mm in the inferior mental spine. The distance from the menton to the inferior edge of the inferior mental spine was (5.11 +/- 1.33)mm. The thickness of the mandible at the genial tubercle was (11.95 +/- 1.59)mm in total. The distance from the apices of the incisors to the superior edge of the superior mental spine was (15.57 +/- 1.82)mm in male, (9.36 +/- 2.79)mm in female, which had statistically difference (t = 6.21, P < 0.01). There are statistical difference at width, process between superior mental spine and inferior mental spine,not at height.

Conclusion: The distance from the apices of the incisors to the superior edge of the superior mental spine in male is greater than that in female. When the genioglossus and geniohyoid are advanced simultaneously, the inferior horizontal bone cut should be approximately 5 mm above the menton, which should be 11 mm if the genioglossus is advanced single. The superior horizontal bone cut should be approximately 18mm above the menton. The lateral vertical cut should be 4 mm lateral to midline. It is visible, practicable and exact that the osteotomy is located with the menton and midline as marks.