Patients with DIGO typically presents with gingival hypertrophy, pain during mastication, and cosmetic disfigurement one to three months after starting treatment with one of the drugs associated with the disease. They will report a past medical history of hypertension, angina, epilepsy, or have received an organ transplant recently.

Clinical Findings

1. Firm, painless, nodular enlargement of the interdental papilla, limited to the keratinized portions of the gingiva and extending to the facial and lingual gingival margins.
2. In severe cases, a huge fold of hypertrophied gingival tissue is observed covering the crowns.
3. At times, it appears firm and pale pink with minute lobulations, pouting from underneath the gingival margin, delineated by a groove of tissue which does not bleed on touch.
4. If secondary inflammation exists, the gingiva appears smooth, and the enlargement is greater in the maxillary and anterior mandibular regions.
5. Typically, it is not seen in edentulous areas of the gingiva [14].

According to histological and histomorphometric analyses, phenytoin-induced lesions are the most fibrotic. Ciclosporin-induced lesions are more inflamed and show a low fibrotic component, and nifedipine lesions are mixed [15].

The diagnosis of drug-induced gingival overgrowth is made by clinical examination and the patient's past medical history.

• A periodontal examination is necessary to evaluate for the presence of periodontal disease.
• Full mouth periapical radiographs and orthopantomography are to be taken before beginning any treatment to rule out periodontal disease.
• Scaling and root planning must be carried out.
• Complete blood count (CBC) is indicated in patients with gingival enlargement if there is a presence of profuse gingival bleeding even if it is drug-induced to rule out anemia and leukemia.
• Tissue biopsy should be carried out in case the presentation of the disease is unusual.
• Histopathological examination of persisting overgrowths is mandatory to evaluate malignant changes [16].
• Candidiasis and other infections may be ruled out by taking a culture.

The aim of treatment in DIGO is to alleviate the patient's discomfort, to be able to do simple acts like eating and chewing pain-free, treat the inflammation, reduce the swelling, and give a better cosmetic appearance to the gingiva.

The modalities of treatment are medical and surgical. Medical management is the first line of treatment, and surgery is reserved for recurrences or cases that persist despite good medical treatment.

Discontinuing or changing the medication must be placed under consideration [17][11]. An alternative to phenytoin includes carbamazepine and valproic acid, which have shown a lower impact in gingival enlargement. Diltiazem and verapamil exhibit lower prevalence of gingival enlargement compared to nifedipine. Cyclosporin substitution is more complicated because there are limited options available. Cyclosporin can be substituted by tacrolimus, and the use of azithromycin in combination with cyclosporin has shown a decrease in the severity of DIGO [18].Plaque control should be the first step in the treatment of DIGO, correct oral hygiene, and professional plaque removal, including tooth surface cleaning and periodic scaling, which are essential [19][20].

Control of inflammation, including non-steroidal anti-inflammatory agents, antibiotics to control infection, and topical antifungal medication like nystatin, may also be utilized. Folate supplementation has also been used [21].

A sufficient period of six to twelve months should be allowed to elapse after discontinuing the inducing drug before surgery is considered [18].The surgical methods include gingivectomy and periodontal flap surgery.Electrocautery may be used in difficult cases, children, or where the gingiva is fragile and likely to bleed.

The CO2 laser has a wavelength of 10600 nm; hence, it is readily absorbed by water and therefore is effective in the surgery of soft tissues with high water content like the gingiva. Blood vessels up to a diameter of 0.5 mm can be sealed effectively and provide a dry field for better visibility of the surgical field. A laser is preferred over the scalpel as it has strong bactericidal and hemostatic effects [19][22].

1. False enlargement of gingival tissue: This is pseudo-enlargement of the gingiva, which is actually because of enlarged underlying bony tissue. The gingiva here has no abnormality.
2. Inflammation: Chronically inflamed gingival tissue is red or violaceous smooth and bleeds on touch.
3. Familial or hereditary: The tendency runs in the family. The gingiva is pink, non-tender, involves the attached gingiva, the gingival margin, and the interdental papillae, and has a firm and leathery consistency. Examples include familial fibromatosis, idiopathic fibromatosis, gingivomatosis, and hereditary gingival hyperplasia.
4. Physiological states: Puberty and pregnancy are associated with gingival enlargement.
5. Scurvy: Vitamin C deficiency can produce very tender bleeding gingiva.
6. Systemic diseases: Leukemias, tuberculosis, sarcoidosis. Their diagnosis can be corroborated hematologically.

In all these conditions, a thorough history, physical examination, and investigations, including biopsy, may be required to confirm the etiology.

Conditions Similar to Gingival Enlargement

1. Fibrous epulis/peripheral fibroma
2. Angiogranuloma/Pyogenic granuloma 
3. Gingival cysts
4. Neoplasms: They can be benign or malignant. Benign lesions include fibroma, peripheral and central giant cell granuloma, papilloma, leukoplakia, nevus, hemangioma,  leukoplakia, nevus, myoblastoma, hemangioma, neurilemoma, neurofibroma, ameloblastoma. Malignant tumors are squamous cell carcinoma, Kaposi's sarcoma, etc. [23].

If the medication inducing the gingival overgrowth can be changed to a drug that is less associated with this complication, the gingival tissue may return to normal with the aid of adequate plaque control. The gingival enlargement can persist, despite drug substitution and good plaque control, and in this case, surgical management to restore normal gingival contours is performed. These modalities of treatment, although effective, do not always prevent the recurrence of the enlargement. The recurrence of DIGO in surgically treated cases, which are common, may appear as soon as three to six months after the procedure. In general, the results last for at least twelve months [22].

• Functional difficulties
• Esthetic concerns
• Increased incidence of caries
• Delayed eruption of teeth
• Pathological drifting of teeth
• Prolonged retention of the primary dentition
• Diastemas and spacing problems
• Poor plaque control leading to periodontal complications [22]

Some studies indicate that bacterial plaque is a prerequisite for the disease to occur. On the contrary, others believe that the presence of dental plaque is a consequence of the difficulty that the gingival enlargement represents to dental hygiene, which then exacerbates the severity of the overgrowth [22]. In any case, one thing is certain, bacterial plaque does play an important role in the development of DIGO, and patients must be educated about adequate dental brushing and flossing techniques that may be accompanied by chlorhexidine gluconate rinses to control the levels of bacterial plaque. Regular appointments with their dentist must be accomplished to perform professional cleaning of the teeth. These measures can prevent or decrease the rate and the degree at which recurrence occurs.

Since this condition is entirely drug-induced, patient education about the side-effects of these drugs before starting treatment is warranted, and the importance of good dental hygiene should be emphasized [22]. Drug-induced gingival enlargement has a good prognosis and is generally reversible on stopping or substituting the offending drug. An interdisciplinary approach is needed as the primary clinician, the dentist, and the healthcare team should work together to address the patient's signs and symptoms adequately (level V).