Metastasis of carcinoma buccal mucosa goes to
The spread of carcinoma of buccal mucosa 

Buccal carcinoma spread locally and to regional lymph nodes.

1) Local spread: - From its site of origin, the lesion may spread deeply involving submucosa → muscle → Subcutaneous fat → skin. Involvement of buccinator muscle or anterior masseter causes trismus.
2) Lymphatic spread: - Nodal involvement occurs in about 50% of cases. Submandibular and later the upper jugular nodes may get involved. Upper jugular nodes may also be involved, directly skipping the submandibular group.
Regional lymph node
Liver
Heart
Brain