Dental Abscess or Infection: The presence of minimal tenderness and swelling in the lower jaw suggests a localized infection, which is commonly associated with dental issues. The fact that the swelling is not significant upon palpation could indicate an early stage of infection.

Salivary Gland Infection or Blockage: Infections or blockages of the salivary glands, particularly the submandibular gland located under the jaw, can cause swelling and tenderness in the lower jaw area.
Mandibular Fracture: A fracture of the lower jaw (mandible) could cause swelling and tenderness, although significant trauma would typically be recalled by the patient.
Soft Tissue Injury: An injury to the soft tissues of the lower jaw, such as a bruise or a minor cut, could also present with swelling and minimal tenderness.

Lymphoma or Other Malignancies: Although less common, swelling in the jaw area could be a sign of lymphoma or other malignancies affecting the lymph nodes or salivary glands. Early detection is crucial for effective treatment.
Osteomyelitis of the Jaw: A bone infection of the jaw, which can be a complication of dental infections or trauma, requires prompt treatment to prevent serious complications.
Parotid Gland Tumors: Tumors of the parotid gland, whether benign or malignant, can cause swelling in the jaw area and should not be overlooked.

Actinomycosis: A rare bacterial infection that can cause swelling and abscesses in the jaw area, often associated with poor dental hygiene or recent dental procedures.
Sarcoidosis: A systemic disease that can affect various parts of the body, including the salivary glands, leading to swelling and other symptoms in the jaw area.
Giant Cell Arteritis: An inflammatory disease affecting the blood vessels, which can rarely cause jaw claudication (pain in the jaw when chewing) and swelling, although it is more commonly associated with symptoms like headache and visual disturbances.