Final answer:
The most likely diagnosis for a patient who develops sudden, severe, throbbing pain around a tooth that is very painful to touch or percussion is acute apical periodontitis. It indicates inflammation at the root tip of the tooth, typically from bacteria spreading from a cavity to the pulp and then to the root.
Step-by-step explanation:
If a patient develops a constant, severe, throbbing pain centered around a tooth that is also very painful to touch or percussion overnight, the most likely diagnosis is B. acute apical periodontitis. This condition indicates inflammation at the tip of the tooth's root, which can occur when bacteria from a tooth cavity reach the pulp and then proceed down to the root, causing intense pain, especially when pressure is applied to the tooth. In contrast, early acute pulp disease might not be as severe or localized, an acute exacerbation of a chronically inflamed pulp might have a more fluctuating course, and root fracture due to bruxism would likely manifest differently.
Conditions like trench mouth (acute necrotizing ulcerative gingivitis) and periodontitis involve bacterial infection but generally present with symptoms like gum erosion, bad breath, or tooth mobility, which are not described in this scenario. Therefore, diagnosing acute apical periodontitis requires the history of abrupt onset of severe pain, the clinical presentation of pain on percussion, along with dental X-rays to confirm the inflammation of the apical tissue around the affected tooth.