The possible causes of a little swelling in the jaw without pain include lymphadenitis, dense osteitis or tumor, etc., as follows. 1. Lymphadenitis: usually secondary to odontogenic and oral infections, it may also originate from maxillofacial skin injuries, boils, carbuncles and so on, resulting in enlarged and hardened lymph nodes, part of lymphadenitis has a long course with mild symptoms, and may be painless. 2. Dense osteitis: often secondary to chronic irritation of periapical inflammation, mostly seen in young people, due to the patient’s strong physical resistance, bone destruction is not obvious, showing proliferative lesions. x-ray film can see obvious bone cortical hyperplasia, showing dense image. 3.Tumor: Tumor in the jaw bone, such as enamel cell tumor, may lead to swelling in the chin, which may not be painful in the early stage, X-ray and pathological examination can confirm the diagnosis, and the treatment needs to do surgical treatment. There may be other reasons for a little swelling in the jaw without pain, it is recommended to go to the hospital in time.