Keywords

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FormalPara Key Points

  • Cryosurgery is a simple method for oral medicine with very short healing time.

  • It is very effective in selected benign oral lesions especially in warts, mucocele, fibromas, and vascular lesions (venous lakes, hemangiomas, lymphangiomas).

  • Both liquid nitrogen (LN) and nitrous oxide (NO) can be used as cryogens.

1 Introduction

In oral medicine, cryosurgery has been used for over 40 years. It is a simple, easy-to-use, and effective method which can contribute to the treatment of some diseases of the oral mucosa. Cryosurgery reduces the tissue temperatures to such a level that local cellular damage is evoked [1].

The therapeutic approach of many diseases of the oral mucosa has been influenced by the treatment of similar skin diseases, so cryosurgery has been applied as an alternative therapy in various lesions of the oral cavity.

The purpose of this chapter is to describe the indications and the cryosurgical techniques of benign oral lesions.

2 Oral Cryosurgery

The basis of safe and adequate application of cryosurgery on the oral mucosa is making the right diagnosis, carefully choosing prospective patients, specifying its indications, and applying the right technique [2]. Histologic examination is required to confirm the clinical diagnosis if it is needed.

Cryosurgery in the treatment of benign lesions of the oral cavity competes favorably with other therapeutic methods. Benign lesions usually require superficial freezing. As a general rule, it is better to undertreat than to overtreat and, if it is necessary, then to reapply. Local anesthesia usually is not required.

Both liquid nitrogen (LN) and nitrous oxide (NO) can be applied on oral lesions [2, 3].

Freezing time will depend on the type, size, and location of the lesion, and it usually varies between 5 and 20 s. One single or double freeze-thaw cycle can be used.

3 Advantages of Cryosurgery on the Oral Mucosa

The advantage of applying cryosurgery on the oral mucosa is due to the ability of the cryogen to agglutinate on the tissues and lead to controlled necrosis, aseptic inflammation, hemostasis, and topical anesthesia.

Some of the advantages of cryosurgery specifically in the oral cavity are summarized in Table 10.1 [3, 4]. The indications of cryosurgery in benign oral diseases are summarized in Table 10.2 [5–8].

Table 10.1 Advantages of cryosurgery in the oral cavity
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Table 10.2 Cryosurgery in benign oral diseases
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4 Cryosurgical Techniques for Oral Cavity

Generally, for a lege artis cryosurgical procedure, a proper diagnosis, a good understanding of the basic principles of cryosurgery, a written consent from the patient, adequate illumination, use of sterilized equipment (probes, tips), and a chronometer are required.

For cryosurgery with LN as cryogen, we use the dipstick technique, the open (spray) or semi-open (cone) technique, and mainly the close (probe) technique [2].

Selection of the candidate lesion, its location in the oral cavity, its size, and the number of lesions are critical for a favorable result.

Selection of cryogen (liquid nitrogen vs. nitrous oxide) depends on several reasons. In general, nitrous oxide (NO) is preferred for benign oral lesions. Selection of a cryogen will depend on the experience of the cryosurgeon, availability of cryosurgical equipment, and location, size, and infiltration of the lesion. For instance, in lesions on the lips and posterior oral cavity, both cryogens can be used. For lesions located in the posterior oral cavity NO is used (better control of the technique, avoidance of the liquefaction of LN). For small and superficial lesions, nitrous oxide is preferred. For example, NO is used for superficial mucoceles in children, while LN–CryoProbe technique is preferred for venous lake in the lips [9, 10].

5 Cryosurgery as First-Choice Treatment in the Oral Cavity [4, 5, 7, 11, 12]

There are a number of lesions where cryosurgery stands as the first choice of treatment. It gives extremely satisfactory results in less than a week with almost no scar. The postoperative procedure is very simple, and no local anesthesia is required. It is an office procedure that takes very little time. The treatment protocol is suggested in Table 10.3.

Table 10.3 Treatment protocol
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The lesions are:

  1. 1.

    Venous lake

  2. 2.

    Small hemangiomas (Fig. 10.1a–c)

    Fig. 10.1
    figure 1

    (a) Hemangioma on the right buccal mucosa. (b) Treatment with close (probe) technique, freezing time: 15 s; double freeze-thaw cycles. (c) 1 year later

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  3. 3.

    Lymphangioma

  4. 4.

    Mucocele (Figs. 10.2a–d and 10.3a, b)

    Fig. 10.2
    figure 2

    (a) Mucocele on the lower lip. (b) Close technique (probe), freezing time: 15 s; double freeze-thaw cycles. (c) 1 year later. (d) 4 years later

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    Fig. 10.3
    figure 3

    (a) Mucocele on the lower lip. (b) Open spray technique, nitrous oxide FT: 5 s; double freeze-thaw time

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  5. 5.

    HPV (Fig. 10.4a, b)

    Fig. 10.4
    figure 4

    (a) Condylomata acuminata. (b) Open spray technique, liquid nitrogen FT: 10 s; double freeze-thaw time in 5 sessions

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  6. 6.

    Fibroma

  7. 7.

    Familial acanthosis nigricans

  8. 8.

    Focal epithelial hyperplasia

5.1 Venous Lake

Venous lake of the lips responds favorably to cryosurgery with the close (probe) technique yielding excellent cosmetic results. The freezing time can range between 15 and 30 s. Usually a single freeze-thaw cycle is sufficient [5, 13]. No local anesthesia is needed, and the patient has to be warned of the local edema which will last a few days.

5.2 Small Hemangiomas

Small hemangiomas can respond well to cryosurgical technique. A probe is used with a single or double freeze-thaw time of 10–20 s. Both liquid nitrogen (LN) or nitrous oxide (NO) can be used [14].

5.3 Lymphangiomas

Lesions especially on the tongue have been controlled by repeated applications of close (probe) technique. The probe has to be firmly applied until a halo of 1–2 mm appears [13]. The treatment can be repeated, in due time, as many times as necessary.

5.4 Mucocele

Mucocele responds favorably to cryosurgery. Mucocele of the lip can be frozen solidly with slight pressure until a normal frozen rim appears outside the border of the lesion. The lesion is first de-roofed for evacuation of the gelatinous material. Repeat treatments may be required in 8 week intervals [13].

5.5 HPV Lesions

Warts respond favorably to cryosurgery. The spray technique is used. The entire lesion is frozen with a slight amount of base and surrounding rim [4, 10]. Condylomata acuminata also respond well to cryosurgery with both liquid nitrogen and nitrous oxide [5, 13]. Focal epithelial hyperplasia is especially suited for cryosurgery. Freezing time varies from 10 to 20 s [15].

5.6 Fibroma

Fibroma is the most common benign tumor of the oral cavity. Clinically, it looks like a well-defined, firm, sessile, or pedunculated tumor with a smooth surface of normal epithelium. The open spray technique is used. Freezing time varies between 10 and 15 s [4, 5].

5.7 Familial Acanthosis Nigricans

Cryosurgery is effective in the treatment of familial acanthosis nigricans. The open (spray) technique is used with a freezing time of 15–20 s. For a proper follow-up of patients, it is necessary to register the whole cryosurgical procedure.

6 Special Tips for Oral Cryosurgery

For minimizing complications (Table 10.4) of oral cryosurgery, the basic principles of cryosurgery and these special tips should be applied carefully:

Table 10.4 Complications of oral cryosurgery
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  • Cryosurgery is better used in anterior oral cavity and lips.

  • Contact with the cryogen or liquefaction of the nitrogen in the posterior oral cavity could induce trauma, ulceration, or edema [4].

  • In the oral cavity, application of probe technique is safer compared to other techniques [16, 17]

  • Always protect the healthy mucosa from unexpected damage [11] (Fig. 10.5).

    Fig. 10.5
    figure 5

    Protection of the healthy mucosa

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  • In contact technique (liquid nitrogen), the probe is previously frozen and retracted gently at the end of the freezing time [3, 18]. Never force the probe out. Let it thaw and then remove it.

  • In the event that the probe gets stuck and the operator desires to remove the probe to avoid excessive freezing, running some warm water helps remove it.

  • Only small hemangiomas should be treated with cryosurgery in order to avoid development of excessive edema [4, 6].

  • When cryosurgery is applied in the corners of the mouth, the required freezing time should be shorter because of the risk of constriction [5].

  • The ducts of the major salivary glands should be protected to avoid sialadenitis [4, 17].

  • A local antibiotic ointment is used on the treated lesion of the lips for 10 days [13].

  • In treating mucocele, it is better to evacuate the content of the cyst before treatment [13] (Fig. 10.6).

    Fig. 10.6
    figure 6

    Mucocele: evacuation of the gelatinous material

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7 Posttreatment Care

It is better to provide written instructions after application of a cryosurgical procedure (Table 10.5) [13, 16, 19]. Patients must be informed about the edema, especially when treatment has been done to the lips. Although it will last just a few days, it can be a cause of concern.

Table 10.5 Instructions after cryosurgical treatment in oral diseases
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Essential Tidbits

  • In probe (close) technique on mucosa, keep warm water at hand. If unable to detach the probe, let some warm water run until the frozen probe detaches.

  • Most procedures do not require local anesthesia.

  • Pre-freezing the probe will reduce the possibility of having it stuck to the mucosal surface. When using probes, make sure the patient stays still. Sudden movements can accidentally break a frozen tissue stoke to a probe.

8 Conclusions

Cryosurgery is a simple, easy, effective, and well-tested method. It is the first treatment option for many common lesions and can constitute a useful treatment alternative for a variety of diseases of the oral mucosa. The basic principles for safe and proper cryosurgery generally (and particularly in the mouth) are proper selection of patients, correct diagnosis, and good knowledge of cryosurgical techniques adapted to the oral cavity.

Lege artis :

Doing something exactly according to fixed and approved rules of the artist and not by any improvised method

Nitrous oxide :

A cryogen with a boiling point of −88.48 °C. The temperature achieved at site is sufficient for benign lesions of the oral mucosa