**3. Tissue fixation**

It is extremely important to place the biopsy specimen into proper fixative immediately after removal from the patient. Ten percent formalin is the standard fixative used to prevent autolysis, distortion and destruction of the tissues. Most oral pathology laboratories will provide mailing containers, specimen bottles filled with 10% formalin, and history-biopsy request sheet. **Table 1** is a list of fixatives with reference to oral tissue.

**47**

**3.1 Precautions**

**Table 1.**

parts of tap water.

*List of fixatives with reference to oral tissue.*

*Methods of Collection and Transport of Materials to Laboratory from Oral and Dental Tissue…*

a.If the fixative in the mailing container has evaporated, leaving a white powder

b.Another container must be used or the fixative prepared by getting formalin (formaldehyde 37–40%) and mixing 10 parts of formalin solution with 100

residue, it cannot be reconstituted by adding water.

*DOI: http://dx.doi.org/10.5772/intechopen.92677*

*Methods of Collection and Transport of Materials to Laboratory from Oral and Dental Tissue… DOI: http://dx.doi.org/10.5772/intechopen.92677*


#### **Table 1.**

*Oral and Maxillofacial Surgery*

When a patient with a particular lesion is seen, a list of differential diagnosis is formulated, and biopsy is useful at arriving at a definitive diagnosis or to confirm the clinical diagnosis. Oral biopsy was and still is the gold standard for oral diagnostic procedures. It is an invasive procedure with procedural limitations and a psychological effect on patients. It is important that the biopsy specimen be a true representation of the entire lesion. A carefully selected area involving normal as

1.Take tissue specimen, and put it into a wide-mouth container with 10% formalin at least 20 times the volume of the surgical specimen. Care should be taken to be sure that the tissue has not become lodged on the wall of the container

2.Incisional biopsy specimens should be taken from each area showing different characteristics. Even if the lesion clinically looks uniform, it is still wise to sample different areas of a large lesion. Multiple samples must be

3.Vigorous manipulation of lesion should be avoided if it is suspected to be tumor

4.The tissue should never be put on gauze, cotton or paper, as it can lead to

5.If culture is desired, take the material for bacteriologic study before fixing the

6.On the other hand, if the lesion is a large one with variations in its clinical appearance multiple biopsies could be planned for better sampling.

7.Even though the pathologist would like to receive the biggest specimen possible, the minimum size of the biopsy should not be less than 5 mm in diameter,

8.In majority of cases, the most active part of the lesion and, therefore, the most representative are located peripherally. If the biopsy specimen is taken from a necrotic part of the tumor, the diagnosis rendered by the oral pathologist can be only the "necrotic tissue." Therefore, as a rule, it is unwise to biopsy the

It is extremely important to place the biopsy specimen into proper fixative immediately after removal from the patient. Ten percent formalin is the standard fixative used to prevent autolysis, distortion and destruction of the tissues. Most oral pathology laboratories will provide mailing containers, specimen bottles filled with 10% formalin, and history-biopsy request sheet. **Table 1** is a list of fixatives

as it can increase the tumor cell emboli in venous drainage.

to enable the pathologist to obtain well-prepared slides.

center of a lesion, which is probably its least active part [2, 3].

well as pathologic areas can produce good diagnostic specimen.

**2.1 Dos and Don'ts for sample collection**

above the level of the formalin.

dehydration of the tissue specimen.

adequately labeled.

specimen.

**3. Tissue fixation**

with reference to oral tissue.

**2. Biopsy: rationale**

**46**

*List of fixatives with reference to oral tissue.*

#### **3.1 Precautions**


#### *3.1.1 Precautions during transport: freezing*

During winter months in climates where the temperature drops to freezing or below, there is a danger that the biopsy specimens dropped in a mailbox may freeze. The freezing of the tissue forms ice crystals within the cells. These crystals disrupt cell membranes and cause great distortion and introduction of artifacts into the specimen. Thus interpretation of the tissue specimen becomes very tenuous.

Before mailing biopsy specimens during cold weather, one must make sure that they are fixed in 10% formalin at room temperature for at least 2 h before mailing.

#### *3.1.2 Adjunct techniques: electrocautery*

Biopsy specimens can display tissue changes that might interfere with the accurate diagnosis by the use of electrocautery. The frying action of the electric current generating high temperatures in the tissues results in changes.

In the case of a biopsy of an oral mucosa lesion, an eosinophilic homogenization of the fibrous tissue can be seen histologically. Thus, it is especially important not to use electrocautery for excision of small lesions. It is preferable to use a surgical scalpel to remove the biopsy specimen followed by the use of electrocautery to control bleeding [3].

**49**

*Methods of Collection and Transport of Materials to Laboratory from Oral and Dental Tissue…*

Oral exfoliative cytology was developed as a potential diagnostic tool for early

a.Toluidine blue should be used as a supravital stain before the site selection and

b.Label one end of the slide with patient's name, date, and area from which mate-

c.Use a clean cotton tip applicator or wooden spatula for the collection of the smear. If the area to be scraped is dry, moistened the applicator or spatula.

d.Collect the material using a slight rolling motion or scraping of the lesion. (Inadequate slides may be obtained if there is a pseudomembrane, thick saliva,

e.Immediately apply the scraping to the center area of the slide previously marked.

a.Alcohol (70%) is adequate for fixation. Equal parts of ether and 95% ethyl

dropper. Do not allow any drying of the smear before fixation.

b.Immediately immerse the slide in fixative or put the fixative on the slide with a

d.At this point, the slides can be air dried and sent for staining and screening, or

b.Adjunct to biopsy, better to take cytology first, and then if necessary advice

detection of malignant lesion. It is relatively simple, easy to master and least invasive and has high patient acceptance [1]. Though it has been always used as an adjunct to oral biopsy in oral cancer diagnostics, it holds potential in diagnosis of oral dermatosis and certain microbial infections. The specimen obtained can be used for cytomorphometry, DNA cytometry and immunocytochemical studies [1].

*DOI: http://dx.doi.org/10.5772/intechopen.92677*

**3.2 Oral exfoliative cytology**

**3.3 Technique: collection of smear**

rial is to be obtained. Wipe the slide clean.

no moisture or excess bleeding).

alcohol give superior staining qualities.

it can be left in the fixative.

c.Keep the slide in fixative for a minimum of 30 min.

a.Very good, easy, rapid, painless and bloodless procedure.

c.Creates less psychological trauma and fear.

d.Useful in follow-up after radio- and chemotherapy.

smear preparation.

*3.3.1 Fixation of smear*

*3.3.2 Advantages*

biopsy.

*Methods of Collection and Transport of Materials to Laboratory from Oral and Dental Tissue… DOI: http://dx.doi.org/10.5772/intechopen.92677*
