After extreme overexposure to cold a 42-year-old patient complains of headache in the left frontal lobe and the left upper jaw. Objectively: the face is symmetrical; left nasal meatus breathing is obstructed, and serous-purulent discharge is being produced; palpation of the suborbital area and further along the mucogingival fold in the 24 and 25 teeth projection reveals slight pain. Percussion of these teeth is painless. The 24 tooth is filled. The alveolar process mucosa has no visible alterations. X-ray imaging shows decreased pneumatization of the left maxillary sinus. What is the provisional diagnosis?