Journal of Indian Academy of Oral Medicine and Radiology

: 2021  |  Volume : 33  |  Issue : 4  |  Page : 352--356

Oral manifestations in diabetes mellitus- a review

Subham Kumari1, N Gnanasundaram2,  
1 Dental Surgeon, Cosmetica-The Total Dentofacial Solutions, Patna, Bihar, India
2 Department of Oral Medicine and Radiology, Faculty of Dental Sciences, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India

Correspondence Address:
Dr. Subham Kumari
Dental Surgeon, Cosmetica-The Total Dentofacial Solutions, Kankarbagh, Patna, Bihar


This article deals with the characteristic of clinical findings of diabetes mellitus (DM) in the mouth and teeth. Identification of these findings in the examination of the mouth will help to diagnose DM. Symptoms such as dryness of the mouth (xerostomia), burning sensation, painful gingival swelling, and mobility of teeth due to uncontrolled DM are explained. Signs such as gingivitis, periodontitis, multiple periodontal abscesses, and fungal lesions such as Candidiasis are explained. Oral symptoms and signs may enable medical and dental specialists to diagnose diabetes. Proper diagnosis will ensure proper treatment. “Diabetes is a good disease with bad companions” quoted Dr. Sam G. P. Mosses, a renowned diabetologist in India. It is true. Diabetes is a biochemical disorder where there is a failure of peripheral utilization of sugar in cells due to insulin deficiency or defectiveness causing accumulation of excess sugar in the tissues, thus leading to hyperglycemia, glycosuria, polyuria, polyphagia, and polydipsia. It is difficult to find out when exactly the disease develops with a hyperglycemic state and how to identify the disease in the early stages. Diabetes is a reversible disease and can be controlled by restoring sugar metabolism by correcting insulin deficiency or defectiveness. Thus, the complications are considered as the bad companions of this disease. DM is a disease with systemic involvement affecting various structures and organs. The mouth is also affected by DM. If a medical or dental specialist is fully familiarized with Oral changes in DM, they can diagnose the undiagnosed diabetes through the examination of the mouth. Further confirmation of diagnosis can be made by a biochemical study of blood and urine. This article elaborates and explains the various mouth changes in diabetics for diagnosis and management.

How to cite this article:
Kumari S, Gnanasundaram N. Oral manifestations in diabetes mellitus- a review.J Indian Acad Oral Med Radiol 2021;33:352-356

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Kumari S, Gnanasundaram N. Oral manifestations in diabetes mellitus- a review. J Indian Acad Oral Med Radiol [serial online] 2021 [cited 2022 Jan 27 ];33:352-356
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Diabetes Mellitus is a biochemical disorder in which there is a failure of peripheral utilization of sugar in cells and retention of sugar in the cells. This affects the body organs and is characterized by hyperglycemia, glycosuria, polyuria, polyphagia, and polydipsia. In diabetes mellitus sugar accumulates in the tissues. It is a “Good disease with bad companions.” Untreated diabetes leads to many complications in body structures. Diabetes is broadly classified into Insulin dependant Diabetes Mellitus (IDDM) and Non Insulin dependant diabetes mellitus (NIDDM).

Whatever may be the type of diabetes, the oral tissues reacts and produce characteristic manifestations. These manifestations not only destroy the oral and dental structures but also appears as diagnostic point to diagnose diabetes in the routine examination of mouth and in screening programme of mouth in detection of oral diseases.

The role of Oral diagnostician is not only to diagnose various oral diseases of local origin but also identify the various oral manifestations of systemic diseases so as to help to diagnose systemic disease through oral changes.

 Dryness Of Mouth (Xerostomia)

Dryness of the mouth is one of the changes in diabetes mellitus (DM). Dryness of mouth is a reduction in the rate of salivary flow. It is also associated with parotid gland enlargement in diabetic patients. Parotid gland enlargement may be due to cellular hypertrophy of the gland as it has to over function to produce saliva as saliva is decreased in diabetic patients. Parotid gland enlargement may be also due to fat accumulation and fluid accumulation in the cells. Alteration of salivary secretion may result due to neuropathy of secreto-motor fibers that supply to the salivary gland. Dryness of the mouth may be due to the action of certain drugs given to the patients for other diseases [Figure 1].{Figure 1}

 Dental Caries

The influence of DM on dental caries is controversial. Some studies have shown increased carious rates in diabetes, but some studies have revealed that diabetes has no relevance in carious development. Dental caries is a progressive, irreversible, destruction of the tooth due to demineralization of inorganic portion and dissolution of organic portion. In DM, due to the reduction of salivary secretion, the self-cleansing action and antibacterial action of saliva are reduced, causing accumulation of sugar in the pits and fissure of the tooth. Acidogenic bacteria in saliva act on accumulated sugar and produces acid. This acid demineralizes the inorganic portion of the enamel. The proteolytic bacteria produce proteolytic enzymes which dissolve the organic portion of the tooth. Thus, the demineralization of inorganic portion and dissolution of organic portion develops as carious lesions. Further, the fluid present in the gingival sulcus between the gingiva and the tooth contains more sugar in diabetes, and this may also initiate caries formation in hyperglycemic states. As known diabetic patients under treatment have sugar controlled, they do not develop caries in the teeth. However, the genesis of carious teeth due to diabetes is controversial as caries formation requires a different chemical process [Figure 2].{Figure 2}

 Burning Sensation of Mouth

Diabetic neuropathy is an established neural change in DM; nerves of the oral mucosa are also affected, causing a burning sensation. The burning sensation of the tongue is called glossopyrosis, and the whole oral mucosa is called stomatopyrosis. Glossopyrosis and stomatopyrosis are very severe in diabetic patients as compared to non-diabetics. If the burning sensation is more, the patient develops pain in that area. When neuropathy affects the nerves of the taste buds, it produces an altered taste sensation. Many diabetic patients also show numbness and tingling sensation of the tongue due to neuropathy.


Gingiva is that part of the oral mucosa which covers the alveolar process of the jaws and gives attachment to the tooth in the neck portion. Gingiva covers the neck portion of the tooth. Gingivitis is inflammation of the gingiva. The gingiva is slightly swollen, reddish, painful, and bleeds. Commonly, gingivitis is associated with the accumulation of debris, food particles, and calculus in poor oral hygiene. Gingivitis can also develop in certain systemic diseases. In DM, gingivitis develops due to dryness of the mouth and failure of the antibacterial action of saliva. Even in a normal mouth without irritating factors such as debris, food particles, and calculus, the normal gingiva is affected with gingivitis with bacterial action. Gingivitis due to irritation will regress and disappear if debris and calculus are removed by scaling and polishing of teeth but gingivitis due to microorganisms in DM will not regress if the patient is subjected to scaling and polishing. Gingivitis in DM will improve only by treating DM by insulin therapy. Uncontrolled gingivitis in DM leads to periodontitis [Figure 3].{Figure 3}


Periodontitis is the inflammation of the periodontium, the structures around the tooth, namely gingiva, alveolar bone, and the periodontal membrane. Peri means around and dontium means tooth. The tooth is kept in the alveolar socket of the maxilla and mandible and attached to the alveolar bone by the periodontal membrane. Normally, periodontitis occurs as chronic periodontitis due to irritation by food particles, debris, and calculus, and it develops from gingivitis. In DM, the periodontal membrane and alveolar bone are affected because of the accumulation of excess sugar in the tissues. The excess sugar in the tissues favors microorganisms to invade the tissues and cause inflammation. In periodontitis, the gingiva is inflamed with redness, pain, and bleeding, and is further associated with deepening of the gingival sulcus to form gingival pockets, destruction of alveolar bone, and periodontal membrane, causing mobility and pain in the tooth. The progress of periodontitis is rapid and severe in DM than the progress of periodontitis in non-diabetic patients. Treatment of periodontitis such as curettage help in reversing changes in non-diabetic patients but in diabetic patients, the disease cannot be cured with normal curettage but requires treatment of DM. In periodontitis due to DM, the patient will lose teeth in the mouth due to the rapid destruction of periodontal tissue containing excess sugar [Figure 4].{Figure 4}

 Periodontal Abscess

The periodontal abscess is a localized collection of pus in the periodontal space around the tooth and is associated with gingival inflammation, redness, pain, pus formation, and swelling. The swelling is warm, soft, and tender, and the teeth involved are mobile. A periodontal abscess can develop in non-diabetic patients as well, but in diabetic patients, the development of periodontal abscess is more rapid, severe, and painful. The periodontal abscess presents as multiple periodontal abscesses in upper and lower jaws in diabetic patients. The periodontal abscess is treated by removing the pus, but their recurrence is more common and causes halitosis. Control of periodontal abscess is favorable in non-diabetics, but the control of periodontal abscess in diabetic patients is difficult even after the administration of antibiotics. Early loss of multiple teeth due to periodontal abscess is a feature in diabetics and the patient has difficulty in mastication.

In DM, the periodontal tissue develops resistance and reduction of tissue immunity. The rapid progress of periodontal abscess with much destruction of tissues is due to the excessive sugar content in the periodontal tissue. Unless the DM is treated by suitable therapy and the sugar level is controlled, the periodontal abscess cannot be treated successfully [Figure 5].{Figure 5}

 Fungal Infection

Oral mucosa and jawbones are affected by various fungal infections, but in DM, Candidiasis and Mucormycosis are the common fungal infections that affect oral mucosa and jaw bone as an opportunistic infection.

Oral Candidiasis is caused by Candida Albicans and it commonly occurs among patients who have used antibiotics, corticosteroids, and cytotoxic drugs for a prolonged period and is also associated with diseases such as leukemia and lymphoma. In DM, the dry oral mucosal surface is favorable for penetration of Candida albicans, causing the disease process. As the tissue contains glucose it causes lowered tissue resistance and the Candida easily affects the tissues producing Candidiasis. In DM, the patient will develop pseudomembranous Candidiasis, either chronic or acute. Clinically, multiple curd-like white patches develop because of precipitation of tissue proteins by Candidial infection, and this white patch is scrapable. On eliminating the white patch, the area is erythematous and produces a burning sensation.

In DM, Mucormycosis develops in patients with hyperglycemic conditions and diabetic ketoacidosis. Fungi such as Rhizopus, Mucor, and Absidia affect the tissues and produce ulceration, necrosis, and sometimes gangrene. In DM, oral mucosal Mucormycosis spreads very rapidly involving the bone. Commonly, it occurs in the palatal mucosa and spreads into the maxilla destroying the maxillary antrum, zygomatic bone, and sometimes even lifting the orbit. Fast-growing Mucormycosis in maxillary bone is suggestive of fungal infection in DM [Figure 6].{Figure 6}

 Gingival Vascular Changes

Angiopathy of minute blood vessels appears in DM in the patient's histopathological sections. Microangiopathy of gingival blood vessels occurs in hyperglycemic states of diabetes mellitus and before DM develops. Gingival microangiopathy before DM develops is considered as a diagnostic marker to detect prediabetic states. Thus, microangiopathy in the gingiva helps to diagnose prediabetic and diabetic conditions.

Vascular changes occur in minute blood vessels or fibrous connective tissue in the lamina propria of the gingiva. The capillary walls are thickened and the lumen is narrow, the proliferation of the endothelial cell and swollen cells are seen along with the thickening of the basement membrane and blood vessels. These changes are due to metabolic specify the cells in DM. These changes can be seen in the vessels of the gingiva in the histological sections by using periodic acid Schiff's reagent (PAS). These changes are described as PAS-positive material and PAS-positive reaction in microangiopathy of gingiva seen in both diabetic and prediabetic patients [Figure 7].{Figure 7}

 Delayed Healing of Wounds and Ulcers

In oral mucosa, wounds develop due to trauma, chemical, and thermal reactions, and surgical wounds. Ulcer develops in oral mucosa due to pathological changes.

Particularly in the oral mucosa after the extraction of tooth, the socket is empty and has to heal. Normally wounds, extracted sockets, and ulcers heal spontaneously. In DM, the healing process is very much delayed as a result of the accumulation of excess sugar in the tissues. Sometimes, instead of healing, further infection and suppuration occur. In many cases, due to DM, the extraction gets infected and osteomyelitis develops. In unknown diabetic patients, if we find a delayed healing process and secondary infection, it may suggest that the person is having DM, and investigations have to be carried out to diagnose DM. Dental extraction has to be carried out with proper antibiotic coverage for diabetic patients.

 Attrition Pattern

Attrition pattern of first permanent molar to diagnose DM?

During the clinical examination of the mouth and the teeth to diagnose various diseases, attrition of a permanent first molar was noticed in certain patients. Anatomically, the first molar has well-defined cusps, pits, and fissures in the crown of the teeth, but the peculiar tooth has flattening the cusps, saucer-shaped small cavitations, indistinct pits, and fissures with mild yellowish discoloration with slight loss of enamel. The first permanent molars are usually affected, whereas other teeth have a normal anatomical pattern. As the tooth shows destruction in the grinding surface, it is called the attrition pattern. On the evaluation of the systemic status with urine and blood examination for sugar, it was found that many patients who had attrition patterns were suffering from DM or many people on observation had developed diabetes over time. Studies of gingival biopsy in those patients who had attrition patterns were found to have PAS-positive material in the microangiopathy of the blood vessels of the lamina Dura. Thus, it is believed that the attrition pattern of the tooth is a marker to diagnose diabetes. As the first permanent molars and the pancreas develop during the same embryological period, there may be a developmental disturbance affecting both the tooth germ and the developing pancreas. The affected tooth germ produces attrition and the pancreas is responsible for DM. Though it requires further studies, clinicians should be aware and alert in identifying this tooth to diagnose diabetes as the existing information is positive [Figure 8].{Figure 8}


In conclusion, characteristic and pathognomic clinical changes in tissues of the mouth caused by diabetes are helpful for experts in medicine and dentistry to diagnose and treat diabetes. Thus, every clinician should be familiar with mouth changes of diabetes. Further, DM is a risk factor for periodontal diseases such as gingivitis, periodontitis, and periodontal abscess. Control of diabetes is necessary to prevent periodontal diseases and loss of a tooth. As fungal diseases such as Moniliasis and Mucormycosis are rapidly progressive and cause extensive destruction of both hard and soft tissues in the mouth, diabetes has to be treated to prevent the development of such fungal diseases.

Knowledge of mouth changes in diabetes not only helps to diagnose and treat diabetes but also helps to preserve oral health for sound general health.

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