After supercooling a 42-year-old patient presented with headache in the left frontal region and left upper jaw. Objectively: the face is symmetric, breathing through the left nasal meatus is obstructed, seropurulent discharges are present. Palpation is slightly painful in the infraorbital region as well as along the mucogingival fold in projection of the 24, 25 teeth. Percussion of these teeth is painless. The 24 tooth is filled. Mucuous membrane of alveolar process has no visible changes. X-ray picture shows reduced pneumatization of the left upper jaw sinus. What is the provisional diagnosis?