Removal of benign tumors using the CO 2 laser

Oral crest lengthening for increasing removable denture retention by means of CO2 laser

The loss of teeth and their replacement by artificial denture is associated with many problems. The denture needs a certain amount of ridge height to give it retention and a long-term function. Crest lengthening procedures are performed to provide a better anatomic environment and to create proper supporting structures for more stability and retention of the denture. The purpose of our study is to describe and evaluate the effectiveness of CO₂ laser-assisted surgery in patients treated for crest lengthening (vestibular deepening). There have been various surgical techniques described in order to restore alveolar ridge height by pushing muscles attaching of the jaws. Most of these techniques cause postoperative complications such as edemas, hemorrhage, pain, infection, slow healing, and rebound to initial position. Our clinical study describes the treatment planning and clinical steps for the crest lengthening with the use of CO₂ laser beam (6–15 Watts in noncontact, energy density range: 84.92–212.31 J/cm², focus, and continuous mode with a focal point diameter of 0.3 mm). At the end of each surgery, dentures were temporarily relined with a soft material. Patients were asked to mandatorily wear their relined denture for a minimum of 4–6 weeks and to remove it for hygienic purposes. At the end of each surgery, the deepest length of the vestibule was measured by the operator. No sutures were made and bloodless wounds healed in second intention without grafts. Results pointed out the efficiency of the procedure using CO₂ laser. At 8 weeks of post-op, the mean of crest lengthening was stable without rebound. Only a loss of 15% was noticed. To conclude, the use of CO₂ laser is an effective option for crest lengthening.

Nd:YAG laser versus traditional scalpel. A preliminary histological analysis of specimens from the human oral mucosa

Hyperplastic fibro-epithelial lesions are the most common tumor-like swellings in the mouth. The neodymium yttrium aluminium garnet (Nd:YAG) laser appears to be useful for the surgical treatment of these lesions. Some controversies of laser surgery concern the accuracy of pathological diagnosis as well as the control of thermal damage on the target tissue. The aim of this study was to establish if the thermal changes induced by the Nd:YAG laser may affect the histopathological diagnosis and the evaluation of the resection margins. Furthermore, we compared the histological features of oral benign fibro-epithelial lesions excised through Nd:YAG laser and traditional scalpel. Twenty-six benign fibro-epithelial oral lesions from 26 patients, localized in the same oral subsites (cheek and buccal mucosa), were collected at the Unit of Oral Pathology and Oral Laser-assisted Surgery of the Academic Hospital of the University of Parma, Italy. Specimens were subclassified into three groups according to the tool used for the surgical excision. Group 1 included six specimens excised through Nd:YAG laser with an output power of 3.5 W and a frequency of 60 Hz (power density 488,281 W/cm2); Group 2 included nine specimens excised through Nd:YAG laser with an output power of 5 W and a frequency of 30 Hz; Group 3 included 11 specimens excised through a Bard-Parker scalpel blade no. 15c. Epithelial changes, connective tissue modifications, presence of vascular modifications, incision morphology and the overall width of tissue modification were evaluated. Differences between specimens removed with two different parameters of Nd:YAG laser were not significant with regard to stromal changes (p=0.4828) and vascular stasis (p=0.2104). Analysis of regularity of incision revealed a difference which was not statistically significant (p=1.000) between group 1 and group 2. Epithelial and stromal changes were significantly more frequent in specimens with a mean size less than 7 mm (p<0.0001). Nd:YAG laser induced serious thermal effects in small specimens (mean size less than 7 mm) independently from the frequency and power employed. The quality of incision was better and the width of overall tissue injuries was less in the specimens obtained with higher frequency and lower power (group 1: Nd:YAG laser at 3.5 W and 60 Hz).

Comparison of carbon dioxide laser and scalpel for breast lumpectomy: a randomized controlled trial

OBJECTIVE

To investigate whether the CO2 laser is superior to conventional surgical techniques for minor breast surgery in a randomized clinical trial.

BACKGROUND DATA

It has been suggested in the literature that application of CO2 laser in breast surgery might be superior to conventional surgery in some aspects.

PATIENTS AND METHODS

Sixty women whose breast masses were suitable for excisional biopsy were randomly allocated to laser and control (conventional surgical technique with scalpel) groups. Perioperative and postoperative variables were recorded and analyzed.

RESULTS

The patients' ages ranged from 16-63 y. There were no significant differences between the two groups in total operative time (17.4 min with laser and 17.5 min with scalpel). There was a significant decrease in the required dose of lidocaine in the laser group (9.3 mL) compared to the scalpel group (12.4 mL; p = 0.01). In addition, hemorrhage was significantly lower in the laser group (6.6 mL) compared to the control group (11.9 mL; p = 0.006). There was no difference in the grade of the scar or postoperative pain between the two groups.

CONCLUSION

Use of the CO2 laser in breast mass biopsy has some advantages, including a lower requirement for local anesthetic and a lower rate of intraoperative bleeding. Furthermore, using the laser does not prolong the operative time.

Use of a Powered Shaver to Remove Multiple Oral Cavity Papillomas

We report a previously undescribed method of removing multiple oral papillomas, which we performed on 5 men with human immunodeficiency virus (HIV) infection. Patients were brought to the operating room and placed under general anesthesia. In addition, 1% lidocaine with 1:100,000 epinephrine was injected under and around the lesions. We then removed the lesions with a Tricut laryngeal blade attached to a handheld powered shaver. Postoperatively, patients were sent home on clindamycin, a pain medication, and Peridex. At the 1-week follow-up, patients reported only minimal pain, and their wounds were well healed. We observed no adverse events associated with the shaving procedure. Our method expedites the process of removing multiple oral cavity papillomas while reducing the morbidity generally associated with other procedures.

Assessment of the behavior of myofibroblasts on scalpel and CO(2) laser wounds: an immunohistochemical study in rats

OBJECTIVE

The aims of this study were to quantitative and statistically assess the presence of myofibroblasts on both conventional and CO(2) laser wounds.

BACKGROUND DATA

Wound contraction of both traumatic and surgical origin may reduce or limit the function of the tissue. Myofibroblasts are cells involved in the process of wound contraction, which is smaller in CO(2) laser wounds.

MATERIALS AND METHODS

Thirty-two animals (rattus norvegicus) were divided into four groups and treated using either the CO(2 )laser (groups 1 and 2) or conventional scalpel (groups 3 and 4). The animals were sacrificed eight days post-operatively (groups: 1 and 3) and 14 days after surgery (groups: 2 and 4). The specimens were routinely processed to wax and stained with alpha-smooth muscle actin (alpha SMA) and analyzed under light microscopy (40x) using a calibrated eyepiece and a graticule. Two standard areas around the wound of each slide were selected and used to count the number of myofibroblasts present.

RESULTS

The results of this study show that it is possible to determine the number of myofibroblasts present in wounds produced by the laser or the scalpel at both eight and 14 days after surgery. However the number of myofibroblasts at day eight was significantly higher than at day 14 (laser, p = 0.007 and scalpel, p = 0.001). The number of cells present in group 3 was significantly higher than in group 1 (p = 0.001). However on the 14th day there was no such difference (p = 0.072).

CONCLUSION

It is concluded that the small number of myofibroblasts at day eight after wounding with the CO(2) laser may be the reason that contraction on this wound is smaller than the one observed in conventional surgery.

Scanning electron microscopic and immunocytochemical studies of contraction during secondary CO2 laser wound healing in rat tongue mucosa

An experimental model was established in which the decrease in surface area of CO2 laser wounds on rat tongues was measured during the healing process. Scanning electron microscopy was used to measure and delineate the outlines of the initial wounds and those of the residual wounds. A 50% decrease in the surface area of the wounds was observed 10 days after surgery during the healing process. At day 30, the scar surface area was less than 10% (7.4%) of the wound surface area at day 2. This contrasts with studies reported elsewhere where only minimal contraction was observed during the healing of CO2 laser wounds. Immunoperoxidase techniques revealed that three different phenotypes of myofibroblasts were present inside the healing area, expressing vimentin, actin and desmin. These persisted until day 30 after CO2 irradiation.