Material and methods

In our department, a Scalpel-1, Tungsram TLS 62, Sharplan 1040, CO 2 laser, Medi-YAG 100 Nd YAG laser, Combo 5050 Lasermatic CO2+Nd YAG laser were used. Between January 1, 1987 and December 31, 1993, 1089 oral precancerosis were removed with laser surgery (Table 1.).

692 of them were leukoplakia and 195 were of cheilitis chronica.There were 755 male and 334 female patients, with a mean age of 51,7 years (range:19 to 94 years).

The precancerosis most frequently occurred on the lower lip (33.8%) and on the tongue (12.4%). In 73.5% a single, in 19.1% double, and in 7.4% a multiple occurrence was observed (Table 2.).

Fifty-two percent of the patients were treated by previous conservative therapy, 31.4% conservative and some sort of surgical treatment, while 16.6% had untreated lesions. Twenty of those operated on suffered from clotting disturbances ( 8 patients with thrombocytopenia, 12 with hypothrombinemia) and 68 were assigned to risk groups for other reasons:

• 49 patients with cardiac and vascular disease (cardiac rhythm disorder, hypertension, coronary circulatory disorder)
• 3 patients with renal disease (renal insufficiency)
• 9 patients with hepatic disease (cirrhosis, chronic hepatitis, hepatic insufficiency)
• 7 patients with endocrine disease (diabetes insipidus, Addison s disease, diabetes mellitus)

The majority of the patients who underwent laser surgery presented for stomatologic consultation performing regional tasks as well, with dental or stomatosurgical reference. Prior to surgery, a tissue sample was taken for histological examination.

The operations were performed under local anaesthesia (2% lidocaine, 0,001% adrenaline). During surgery for simple leukoplakia, the lesion was removed with 1 mm , in verrucosus case with 2 mm , and in ulcerous case at least with 3 mm of healthy tissue. Three types of laser operations were performed :

• Coagulation (simple leukoplakia, cheilitis, ) using a 5 W power defocused CO2 laser beam.
• Vaporisation (verrucosus leukoplakia, cheilitis, lichen, etc.) using a 10 to 15 W focused or defocused CO2 laser beam.
• 25 W Nd YAG focused or defocused laser beam
• 15 -30 W focused combi laser beam.
• Excision (ulcerous leukoplakia, cornu cutaneum, erythroplakia etc.) using a 20 to 25 W CO2 laser beam
• 30 W Nd YAG laser beam
• 15-30 W combi laser beam.

(Table 2., Table 3.)

In the first two types, the tissues are touched only by the laser beam: in the third one, the excision is made by applying continuous traction to the pathologic area. The minor vessels are coagulated by the laser beam during cutting: vessels with a diameter larger than 1 mm ( CO2) or 2- 3 mm ( Nd YAG and combi) are identified and severed between the ligatures.