There are multiple definitions:

1. global thoracic angle(English)

   • GCA, GL, GLA, PI, PT, SVA
   • Spine (or spinal cord)
   • https://doi.org…000000000003379

2. genial tubercle advancement(English)

   • for treatment of obstructive sleep apnea
   • ANB, MMA, OSA, SNA
   • Sleep medicine, Therapeutic approaches
   • https://doi.org…oms.2014.10.018