This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Oral cavity & Oesophagus, Subject name: ENT
True about Ludwig&;s angina 
Select and explain. 
A. Most common cause is dental infection, B. Aphthous ulcers in the pharynx, C. Spreads by lymphatics, D. Bilateral
A: Most common cause is dental infection
Answer: A: Most common cause is dental infection 
Explanation: LUDWIG'S ANGINA Submandibular space lies between mucous membrane of the floor of mouth and tongue on one side and superficial layer of deep cervical fascia extending between the hyoid bone and mandible on the other. It is divided into two compaments by the mylohyoid muscle: 1. Sublingual compament (above the mylohyoid). 2. Submaxillary and submental compament (below the mylohyoid). The two compaments are continuous around the posterior border of mylohyoid muscle. Ludwig's angina is infection of submandibular space. AETIOLOGY : 1. Dental infections: They account for 80% of the cases. Roots of premolars often lie above the attachment of mylohyoid and cause sublingual space infection while roots of the molar teeth extend up to or below the mylohyoid line and primarily cause submaxillary space infection. 2. Submandibular sialadenitis, injuries of oral mucosa and fractures of the mandible account for other cases. Ref:- Dhingra; pg num:-263,264