People with type 2 diabetes mellitus are disproportionately at risk of experiencing stroke, because hyperglycemia and other risk factors associated with diabetes accelerate development of cervical carotid artery atheromas. Removal of these atheromas may reduce the incidence of stroke. The authors conducted a study to ascertain if those treated without insulin (noninsulin-treated, or NIT) would have a lower prevalence of atheromas on their radiographs and a lower prevalence of risk factors than those treated with insulin (insulin-treated, or IT).The authors evaluated the panoramic radiographs and medical records of 46 neurologically asymptomatic men (n = 34) and women (n = 12) (age range 62-77 years, mean age 68.5 years) with type 2 diabetes. They used Fisher exact test to perform a statistical comparison of the prevalence of atherogenic atheromas and risk factors between groups.The radiographs showed that 24 percent of the NIT patients and 36 percent of the IT patients had atheromas; this difference was not statistically significant (P = .52). The groups had similar risk factors--that is, high levels of glycosylated hemoglobin A, or HbA1c; smoking; hypertension; and obesity (P > .05). When compared with the 4 percent atheroma prevalence rate among healthy people of similar age, the rates were significantly higher in both the NIT (P = .02) and IT (P = .0006) patients.These results demonstrate that people with type 2 diabetes, irrespective of treatment modality, have high rates of atheromas as visualized on their panoramic radiographs.Dentists treating patients with type 2 diabetes mellitus must review their panoramic radiographs carefully for evidence of atheroma formation. Patients with atheromatous lesions must be referred to their physicians for further evaluation and treatment, because the modification of atherogenic risk factors and the surgical removal of atheromas in certain people have been shown to reduce the likelihood of stroke.