The inner part of symphysis menti possesses four tubercles known as genial tubercles or mental spines set into two pairs: upper and lower. The upper pair connects with genioglossus muscles and lower pair connects with geniohyoid muscles.
- Mylohyoid line runs obliquely anterior and inferior, behind the 3rd molar tooth which is nearly 1 cm inferior to the alveolar border towards the symphysis menti below the genial tubercles.
- Geniohyoid Muscle originates from inferior genial tubercle.
- Genioglossus Muscle originates from superior genial tubercle.