Findings:
Left sided masticator space abscess, with a collection deep to the masseter overlying the buccal surface of the mandible at the left mandibular angle, measuring approximately 1.6 x 0.6 x 1.4 cm. The masticator muslces are swollen, but there is no spread of the collection superior to the zygoma.
Mesioangular impacted and carious left lower third molar, surrounded by extensive lucency with erosions and cortical breach of the overlying buccal cortex and inflammatory periosteal reaction at the inferior border of the mandible on the left side.
The inferior alveolar nerve canal courses along the posterior and inferior aspect of the left lower third molar as well as at the inferior aspect of the lytic lesion with area of dehiscence of its superior canal wall.
Enlarged bilateral level I lymph nodes are seen. The parotid glands are unremarkable.
The paranasal sinuses and the mastoid air cells are clear.
Conclusion:
Carious mesioangular impacted left lower third molar with osteomyelitis of the left mandibular body and angle and a small abscess formation in the left masticator space.
Extensive oedematous changes of the masticator muslces as well as extensive periosteal reaction at the left hemimandible.
Reactive bilateral submandibular lymphadenopathy.