Diabetes mellitus is a systemic disease characterized by increased blood glucose levels and abnormalities of lipid metabolism due to absence or decreased level of insulin. It affects all the body organs and their functions either directly or indirectly. Every dentist should have a basic understanding of the etiopathogenesis, oral and systemic manifestations of this disease. The periodontal diseases are a consequence of extension of the gingival inflammation into the underlying supporting structures of the periodontium, initiated by the presence of plaque and its products on the surfaces of the teeth and the adjoining structures. The progression of periodontal disease is influenced by variety of factors like microorganisms, host response, systemic background, and genetic makeup of the host. Amongst them, diabetes mellitus tops the list. Diabetes and periodontitis influence the clinical outcome of each other and control of both influences the clinical improvement of each.

Encephalotrigeminal angiomatosis (Sturge–Weber syndrome) is a rather uncommon congenital condition characterized by the combination of venous angioma of the leptomeninges over the cerebral cortex with ipsilateral angiomatous lesions of the face, and sometimes the skull, jaws, and oral soft tissues. A case of portwine stain with intraoral gingival hemangioma is presented. There were no other systemic manifestations. Patient reported with a complaint of localized tumor-like swelling in gums. Based on the presence of sharply demarcated vascular lesion unilaterally on the face and with ipsilateral intraoral vascular hyperplasia in the lip and gingiva, a variant of encephalotrigeminal angiomatosis was diagnosed. Ultrasound Doppler flowmetry was used to determine the blood flow. Dental management included plaque control instructions, scaling, root planning, and excision of the lesion done under general anesthesia. Close follow-up and meticulous plaque control have kept the oral condition under fairly good control.