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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Sinusitis which is least involved is?
assistant
The correct answer is  Sinusitis is least involved in the sphenoid sinus. Isolated involvement of this sinus is rare. It's often pa of pansinusitis or is associated with infection of posterior ethmoid sinuses. (Reference: Textbook of PL Dhingra and Shruti Dhingra; 7th edition, pg no. 216)