A man complains of pain in his lower right jaw and impaired mouth opening. Objectively on visual examination his face is symmetrical, mouth opening is slightly impaired, trismus of the 1 degree is observed. Mucosa behind tooth 47 is swollen, hyperemic, and painful on palpation. Medial cusps of tooth 48 are visible, while the tooth itself has not fully erupted. What provisional diagnosis can be made?