Treatment of Plaque-Like Oral Lichen Planus with CO2 Laser.

Background: Oral lichen planus (OLP) is a chronic autoimmune disease, which annoys the patients for several years. It presents with various clinical forms. Although plaque-like form of OLP is usually asymptomatic, it could transform to a malignant lesion. Therefore, treatment considerations are essential to reduce the development of oral cancer. Laser therapy is a newer modality for treatment of plaque-like lesions. Aims: This study aimed to perform laser therapy for plaque-like lesions of OLP.
Methods: We described some plaque-like OLP lesions evaporated with CO2 laser. The power of 4-7 watt as continuous wave (CW) and defocused mode was employed for evaporation. The complications and recurrence were evaluated in the follow-up sessions.
Results: In some patients, mild keratotic lesions were observed in the follow-up sessions. Most patients were satisfied with treatment process and reported mild burning after treatment. No complication was observed in the patients.
Conclusion: CO2 laser could be employed for OLP lesions; however, some degrees of recurrence may occur. Copyright:

Introduction

Lichen planus is an autoimmune mucocutaneous disease, which manifests as various clinical features in oral mucosa.[1] The exact mechanism is not clear, T-cell mediated immunological process is effective in this condition.[12]

The most cases of OLP were reported among patients who are in the sixth and seventh decades of their life.[13] OLP is more prevalent in the females than the males.[13]

The typical presentation of OLP is as a bilateral keratotic white striae. Keratotic types consist of reticular, annular, popular, and plaque-like are the most common forms of OLP; however, other manifestations including ulcerative, atrophic/erosive, or bullnose lesions are observed in some patients.[14] Some clinical features such as ulcerative and plaque-like lesions have greater susceptibility for transformation to oral SCC. Plaque-like lesions, although are not common presentations of OLP,[3] respect to possibility of malignant transformation of this form, need special consideration and accurate and regular follow-up examinations.

Despite some progression in recent years, there is not a definitive treatment for OLP and most patients suffer from its symptoms for several years. Different modalities are suggested for treatment of OLP, including corticosteroids, immunosuppression drugs, retinoid, natural substances, psychiatric treatments, and laser therapy.[56789]

The effects of laser therapy on OLP lesions have been reported in the previous studies; however, in most literatures, the low-level laser therapy was considered as a suggestive treatment plan.[29101112]

Furthermore, some researchers evaporate the OLP lesions through CO2 laser.[1314]

Finding new strategies for improvement of patients' signs and symptoms is a medical challenge for clinicians. Photodynamic therapy is a relatively new modality, which is considered as main or adjunctive method for OLP treatment. With respect to what is mentioned above, we treated some plaque-like OLP lesions with CO2 laser and evaluated the results and complications of this treatment.

Materials and Methods

Oral examination was performed for all patients by an oral and maxillofacial medicine specialist. When plaque-like OLP was diagnosed through oral assessment, an incisional biopsy was done for confirming OLP.

Subjects

Patients with plaque-like OLP, being confirmed by clinical and histhopathological evaluations, were enrolled to this study. The patients were excluded from the study if any dysplasia was observed in the tissue samples, or they were receiving immunosuppressive drugs, or if they had any systemic diseases, or were pregnant.

Laser properties

After local anesthesia, all plaque-like lesions were evaporated with a CO2 laser system (Ultra dream pulsed laser DS-40UB; Korea). The power of 4–7 watt as continuous wave (CW) and defocused mode with spot size of 0.2 mm was used to evaporate the entire plaque-like lesions. After operation, NSAIDs were prescribed for relieving the pain.

Ethical approval

All patients signed written informed consent forms. The protocol of this study was approved in 2018 by ethical committee of Mashhad University of Medical Sciences (the ethical code: IR.MUMS.DENTISTRY.REC.900098).

Patient No. 1

A 45-year-old man was referred to the dental school with a keratotic plaque lesion of size 49 × 11 mm on the right buccal mucosa. The patient mentioned that he saw this white lesion about one year ago, although he did not complain of any pain or burning. An incisional biopsy performed and histopathological evaluation showed OLP.

The lesion was evaporated with CW and defocused CO2 laser with a power of 7 watt. The irradiation continued until removing the white plaque [Figure 1a].

Figure 1

(a) buccal Buccal mucosa in the patient no.1 at the first session of laser application; (b) map-like ulcer one week later; (c) mild keratotic striae, two months later; (d) keratotic and atrophic lesions on right buccal mucosa, 10 years later; (e) plaque-like lesion on left buccal mucosa, 10 years later

Follow-up sessions

In follow-up visit at one week later, the map-like ulcer coated with pseudomembrane was observed in the operation site [Figure 1b]. The patient reported mild burning. About 40 days later, a mild keratotic lesion was seen on the right buccal mucosa. Two months later, mild keratotic striae were observed [Figure 1c]. In that session, another plaque-like lesion of size 20 × 8 mm on the left buccal mucosa was under laser irritation with the same properties.

The patient referred about 10 years later. He had not used any drug during these years and did not suffer from burning on the laser therapy region.

The plaque form of OLP was not observed on the right buccal mucosa; however, there was a mild atrophic patch about 20 × 10 mm associated with reticular white striae without any burning [Figure 1d]. On the left buccal mucosa, a thin white plaque with size of 10 × 5 mm was seen [Figure 1e].

On the right border of tongue, a mild keratotic lesion and atrophic patch were observed, which were associated with mild burning. He was advised to use dexamethasone and nystatin mouthwashes for atrophic lesions. After 3 weeks, a noticeable improvement in theses lesions occurred.

Patient no. 2

A 40-year-old female referred with a complaint of burning since 2 years ago. In the clinical examination, there was a keratotic plaque with size of 25 × 20 mm on the left buccal mucosa. Also, keratotic reticular lesion was observed on the left lateral border of the tongue.

The buccal lesion was evaporated with continuous mode of CO2 laser using a power of 7 watt. The irradiation continued until removing the plaque-like lesion.

Follow-up sessions

The map-like ulcer coated with pseudomembrane was observed one week later. The patient reported mild burning. Three months later, mild keratotic reticular striae were seen on the left buccal mucosa. The patient was prescribed topical dexamethasone and nystatin mouthwashes.

Four months later, mild keratotic and atrophic lesions were observed on the buccal mucosa and lateral border of the tongue. Topical treatment was continued.

During one year later, with regular visits every 2 months, no recurrence of plaque lesion was seen; however, there were mild keratotic and atrophic lesions on the tongue and buccal mucosa.

Patient no. 3

A 34-year-old man referred to the dental school complaining of white patch on his buccal mucosa since 2 years ago.

In clinical examination, a keratotic plaque-like lesion was observed on his right buccal mucosa adjacent to the second molar extending to his oral commissure. There was a mild keratotic reticular lesion on the lateral border of the tongue.

Continuous mode of CO2 laser with a power of 5 watt was used for excision of the plaque in two sessions [Figure 2].

Figure 2

Buccal mucosa in the patient no. 3; one week after laser therapy; maplike ulcer was seen

Follow-up sessions

After one week, a map-like ulcer with erythematous halo was seen in the operation site. The patient suffered from moderate burning. Diphenhydramine mouthwash was prescribed for pain relief.

Two weeks later, there were ulcer scar and mild keratotic striae at the site of laser operation; the patient did not report any burning sensation.

Patient no. 4

A 77- year-old woman referred to the dental school complaining of burning tongue since 4 years ago.

There was a 30 × 10 mm keratotic plaque on the right border of her tongue. Also, there were bilaterally atrophic and keratotic lesions with Wickham's striae on her tongue and buccal mucosa.

For excision of the keratotic plaque, defocused continuous CO2 laser with a power of 4–7 watt was employed. The irradiation continued to evaporate the plaque-like lesion completely.

Follow-up sessions

After 20 days, the irregular wound of size 20 × 10 mm was observed. Because of some atrophic lesions on her tongue and buccal mucosa, the patient was prescribed topical dexamethasone and nystatin mouthwashes.

Patient no. 5

A 30 × 10 mm keratotic plaque was observed on the right buccal mucosa extended to commissure region in a 36-year-old man [Figure 3a]. There were mild keratotic striae around the plaque. The patient had seen the lesions 14 months ago and complained of moderate burning. After confirming the diagnosis of OLP through incisional biopsy and pathological assessment, the plaque-like lesion was irradiated with CO2 laser [Figure 3b].

Figure 3

(a) Keratotic plaque on right buccal mucosa in the patient no. 5. (b) carbonization layer immediately after laser evaporation

Follow-up sessions

Two weeks later, the ulcer healed partially. The patient reported mild burning and was satisfied with the improvement process.

The patient was under examination every 6 months for 4 years. In this part of buccal mucosa, no plaque-like lesion was observed.

Patient no. 6

A 62-year-old woman referred to a dental clinic with a complaint of white lesions on alveolar mucosa and floor of mouth and lateral border of her tongue [Figure 4a]. After incisional biopsy and histopathological assessment, OLP was diagnosed. At the first session, CO2 laser was employed for surgery of plaque-like lesions of alveolar ridge and some parts of floor of mouth [Figure 4b]. After 2 weeks, the rest of lesions on floor of mouth and ventral surface of her tongue were removed with laser.

Figure 4

(a) Plaque-like lesion on alveolar ridge in the patient no. 6; (b) ulcer in the operation site after laser evaporation of the lesion

Follow-up sessions

The follow-up of the patient was continued every 2 months. No recurrence occurred until 8 months later.

Patient no. 7

A 60-year-old man with plaque-like and reticular white lesions on his left maxillary ridge and hard palatal mucosa referred to a dental clinic. He did not suffer from any burning. CO2 laser was used for evaporation of plaque-like lesion.

Follow-up sessions

After 2 weeks, the ulcer due to laser irradiation on the ridge was partially epithelized. During 2-year follow-up examinations, recurrence did not happen.

Patient no. 8

A keratotic plaque was observed on floor of mouth in a 30-year-old man. The clinical examination revealed an extensive keratotic plaque with different thickness. Bilaterally keratotic lesions were seen on ventral surface of his tongue and the right lingual alveolar mucosa and interdental gingival mucosa between the canine and the pre-molars teeth.

After confirming the OLP diagnosis by incisional biopsy, CO2 laser was employed for evaporation of some parts of the plaques. As the lesion extended from alveolar mucosa to the tongue, the laser therapy was performed in four sessions with an interval of 3 months.

Follow-up sessions

After 6 months, mild keratotic lesions were observed in some parts, which were evaporated with laser radiation, again. The patient was under regular follow-up examinations for 3 years. There were mild keratotic lesions without any pain or burning; the patient was satisfied with the treatment process.

Discussion

Plaque-like lesion is one of the keratotic types of OLP, which is susceptible for malignant transformation.[15] Two articles in Brazil and Croatia reported that 8% and 5.7% of OLP lesions were plaque-like.[316] A review article reported that the rate of malignant transformation of OLP in different studies is from 0 to 12.5%.[15] This type of OLP might be misdiagnosed as leukoplakia.

Plaque-like OLP without burning may not need immediate treatment;[6] however, incisional biopsy for confirming the diagnosis and ruling out the dysplasia is necessary. This form might be resistant to conventional therapies of OLP and needs regular follow-up for decreasing the possibility of malignancy. Patients may look for new treatments for several years.

One of the treatments recommended recently is laser therapy. Some benefits of evaporation of these lesions with laser irradiation consist of complete elimination of the lesion in one or few sessions, fewer complications of operation including less pain and bleeding or scar formation, shorter time of operation, and consequently patient satisfaction.[171819]

In some studies, effects of CO2 laser therapy were evaluated. The wavelength of CO2 is 10600 nm and its energy was absorbed through water of oral tissues. Surgery with CO2 laser accelerates wound healing as compared to scalpel surgery.[1820]

Post-surgery coagulation could accelerate with defocused irradiation of CO2 laser, which evaporates the superficial tissues and produces carbonized layer and reduces the diameter of small vessels. Therefore, this type of laser could be employed for soft tissue surgeries including frenectomy, periodontal surgery, and excision of oral lesions.[21]

One study in Tehran compared the effects of CO2 laser and diode laser on 57 OLP lesions. The lesions of one group received CO2 laser (3 W) and others were irradiated with diode laser (633 nm, 0.3-0.5 J/cm2); after 3 months, partial (85%) and complete (100%) improvement were observed in clinical signs, respectively.[13]

Another study was performed by Van der Hem et al.[14] on 21 patients with 39 different lesions of OLP, in which the researchers used CO2 laser with output power of 15–20 watt and energy density of 1.5-2 J/cm2 for removal of the lesions. They enrolled all types of OLP in the study and 62% of lesions did not have any pain or recurrence in the follow-up sessions. However, among six plaque-like lesions, recurrence happened in two cases; they concluded that clinical presentation of OLP is not related to the rate of recurrence.

Concurrent with similar studies, which applied CO2 laser for OLP lesions,[1314] in the present study, the plaque-like OLP were removed with CO2 laser and after surgery topical treatments of OLP were not prescribed for them and just conventional analgesics were prescribed for post-surgery pain.

The studies reported a range of 21.05%–44% for recurrence of pre-malignant lesions of oral mucosa, including OLP and leukoplakia, after CO2 laser evaporation.[2223242526] This wide range of reported recurrences could be related to various follow-up times and different types of lesions and different techniques for using CO2 laser, which leads to various degree of destruction of the cells.[2223] Deppe's study revealed that treatment of pre-malignant lesions using defocused CO2 irradiationhas better results than other techniques of laser therapy. It seems that deeper penetration of laser light to oral tissues leads to lower rates of recurrence.[23]

In the present study, defocused radiation was used for evaporation of OLP lesions. No side-effects were observed in the follow-up sessions. In some patients, some degrees of recurrence happened; however, recurrence mostly occurred as mild keratotic lesions. For three patients, who had burning sensation, dexamethasone and nystatin mouthwashes were prescribed after recurrence.

Since some remission and exacerbation periods during the autoimmune process are not uncommon, various recurrence rates are reported in different treatment modalities for OLP lesions. Lichen planus is an autoimmune condition, in which keratinocyte surface antigens present as targets for cytotoxic cellular response. Laser therapy destroys keratinocyte surface antigens and decreases autoantibodies and lymphocytic infiltration.[2] For reducing the rate of recurrence, eradication of plaque-like lesions with an enough depth for removal of surface antigens is advised. Moreover, in some severe and extended cases, topical therapy may be beneficial. Since some risk factors such as smoking and alcohol consumption are effective in relapse of plaque-like lesions, elimination of these risk factors is recommended to decrease the recurrence rate.[27]

Briefly, it seems that laser therapy does not have any side-effect and could be suggested as an alternative treatment for the OLP lesions, which do not respond to conventional treatments.[14]

Conclusions

Plaque-like lesion is a keratotic form of OLP, although is mostly asymptomatic, it needs some interventions to decrease the risk of malignant transformation. Laser therapy is a recently recommended strategy for removalof the plaque-like lesions.

With respect to minimal side-effects and appropriate comfort level for the patients and physicians, laser therapy could be suggested, especially for refractory and extensive lesions, for which surgery has somedifficulties.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.