lymphatic drainage of the oral structures- mcq review

1.You notice that your patient's submandibular lymph nodes are enlarged. You would look for potential infection sites in the

a) hard palate.

b) hard palate and upper lip.

c) hard palate, upper lip and upper central incisor.

d) hard palate, upper lip, upper central incisor and lower first molar.

2.The regional lymphatic drainage of the left side of the tip of the tongue is to the

a) left submental lymph node.

b) left and right submental lymph nodes.

c) left submandibular lymph node.

d) left and right submandibular lymph nodes.

The skin of the head and neck drains

The scalp drains into the occipital, mastoid and parotid nodes.

Lower eye lid and anterior cheek drains into buccal LNs.

The cheeks drain into the parotid, buccal and submandibular nodes.

The upper lips and sides of the lower lips drain into the submandibular nodes.

 The middle third of the lower lip drains into the submental nodes

The skin of the neck drains into the cervical nodes.

The drainage of the oral structures

The gingivae drain into the submandibular, submental and upper deep cervical lymph nodes.

The palate lymph vessels may pass to submandibular or superior deep cervical nodes (level II). Retropharyngeal nodes are very rarely involved.

Teeth drain into the submandibular and deep cervical lymph nodes.

Anterior part of mouth floor drain into submental and upper deep cervical.

Posterior part of mouth floor  into submandibular and upper deep cervical.

Inferior alveolar nerve block- mcq review

During an inferior alveolar nerve block the needle ideally passes

a) posterior and medial to medial pterygoid.

b) anterior and lateral to medial pterygoid.

c) through medial pterygoid.

d) inferior to medial pterygoid.

SAQS for Dentistry- Anatomical landmarks in maxilla

Anatomical landmarks in maxilla

 Limiting structures

Labial frenum

Single band of fibrous connective tissue, must be properly relieved.

Labial vestibule

Extends from labial frenum to buccal frenum. Proper lip support should be provided.

 Buccal frenum

Consist of one or more bands. Must be Relieved

Influenced by 3 muscles-  Orbicularis oris (forward), Buccinator (backward),  Caninus (position)

Buccal vestibule

Buccal frenum to hamular notch

Influenced by Buccinator, Modiolus, Coronid process of mandible

Hamular notch

Pterygomaxillary notch, Distal extension of denture ,Situated between the tuberosity and hamulus of the medial pterygoid plate.

Posterior palatal seal area

the soft tissues along the junction of the hard and soft palates on which pressure within the physiologic limits of the tissues can be applied by a denture to aid in the retention of the denture.

Synonyms: post dam area, postpalatal seal area

Supporting structures

Hard palate

Flat areas as secondary retentive areas.

Flat palate (not good support), V shaped palate (least favorable).

Residual ridge

Ridge left after the extraction of teeth. Mucosa is firmly attached to the periosteum of the bone. Consist of dense collagenous fibers.

Considered as a secondary stress-bearing area  because it is subject to resorption contrary to horizontal portion of hard palate.

Palatal rugae

Resist the horizontal forces against the denture, Should not be over  compressed.

Relief areas

 Incisive papilla

Pad of fiberous connective tissue over incisive foramen, Proper relief should be given.

Aid in arrangement of anterior teeth and jaw relation.

 Mid palatine raphe

Junction of palatine process of maxilla. Covered by a thin mucosa, Slightly elevated or raised.

Proper relief required.

Fovea palatine

Formed by coalescence of several mucous gland ducts. Landmark for location of vibrating line.

Maxillary Tuberosity

The medial & lateral walls resist the horizontal and torquing forces which would move the denture base in lateral or palatal direction.

Therefore, maxillary denture base should cover the tuberosities and fill the hamular notches.  

MANDIBULAR FRACTURES MCQ REVIEW

TYPE OF FRACTURE

Simple

Includes a closed linear fractures of the condyle, coronoid, ramus and edentulous body of the mandible.

Compound

Fractures of tooth bearing portions of the mandible, into d mouth via the periodontal membrane and at times through the overlying skin.

Communited

Usually compound fractures characterized by fragmentation of bone

Pathological

Results from an already weakened mandible by pathological conditions.

SITE OF FRACTURE

Dentoalveolar

Condyle

Coronoid

Ramus

Angle

Body (molar and premolar areas)

Parasymphysis

Symphysis

CAUSES OF GINGIVAL RECESSION MCQ REVIEW

What  is Periodontal fremitus

Periodontal fremitus occurs in either of the alveolar bones when an individual sustains trauma from occlusion. It is a result of teeth exhibiting at least slight mobility rubbing against the adjacent walls of their sockets, the volume of which has been expanded ever so slightly by inflammatory responses, bone resorption or both. As a test to determine the severity of periodontal disease, a patient is told to close his or her mouth into maximum intercuspation and is asked to grind his or her teeth ever so slightly. Fingers placed in the labial vestibule against the alveolar bone can detect fremitus.

Orofacial granulomatosis MCQ review

Best of five Review - Angular cheilitis

Angular cheilitis

Angular cheilitis is a combined staphylococcal, streptococcal, and candidal infection, involving the tissues at the angle of the mouth, often with an underlying precipitating factor, e.g. iron deficiency and B12 deficiency anaemia. Therefore, haematological deficiency should be investigated with a FBC red cell folate, B12, and glucose.

Anecdote suggests an inadequate OVD can also predispose, but correction of this alone will not resolve the condition. Often associated with chronic atrophic candidosis. Clinically, see red, cracked, macerated skin at angles of the mouth, often with a gold crust.

Infecting organisms can be identified on culture of swabs of the area, although it is usual to make a clinical diagnosis.

Rx: miconazole cream, which is active against all three infecting organisms. Rx needs to be prolonged, up to 10 days after resolution of clinical lesion, and carried out in conjunction with elimination of any underlying factors.

Unless the classic golden yellow crusts associated with S. aureus are present, treatment should be commenced with antifungal drugs, e.g. a combined miconazole/hydrocortisone cream (miconazole has some antibacterial properties).

When clinical features indicate S. aureus infection, fusidic acid cream is appropriate. If intra-oral candidiasis is present, this must be treated concurrently or recurrence of the angular stomatitis will occur. Iron deficiency is a significant aetiological factor in angular cheilitis.

Patterson–Brown-Kelly syndrome (Plummer–Vinson syndrome)

Dysphagia (due to a post-cricoid candida web), microcytic

hypochromic anaemia, koilonychia and angular cheilitis (secondary to the anaemia)

10 Questions and Answers About Blood Borne Infections And Vaccination....Extracted From Dental Secrets SE By Stephen T.Sonis, D.M.D., D.M.Sc.

01. What are universal precautions?

Universal precautions a concept of infection control, assume that any patient is potentially infectious for  a number of bloodborne pathogens. Blood, blood-derived products, and certain other fluids that are contaminated with blood  are considered infectious for human immunodeficiency virus (HIV), hepatitis B  virus (HBV), hepatitis C virus (HCV), and other bloodborne pathogens. Standard precautions are procedure-specific, not patient-specific. In dentistry, saliva is normally considered to be blood-contaminated.

02. What is the chain of infection?

The chain of infection refers to the prerequisites for infection (by either direct or indirect contact):

1. A susceptible host

2. A pathogen with sufficient infectivity and numbers to cause infection

3. An appropriate portal of entry to the host (e.g., a bloodborne agent must gain access to the bloodstream, whereas an enteric agent must enter the mouth [tract]).

03. Which factor is easiest to control: agent, host, or transmission?

Agent and host are more difficult to control than transmission. Standard precautions are directed toward interrupting the transfer of microorganisms from patient to health care worker and vice versa.

04. What is one of the single most important measures to reduce the risk of transmission of microorganisms?

Hand washing is one of the most important measures in reducing the risk of transmission of microorganisms. Hands should always be thoroughly washed between patients, after contact with blood or other potentially infective fluids, after contact with contaminated instruments or items, and after removal of gloves. Gloves  also  play  an  important  role  as  a  protective  barrier  against  cross-contamination and reduce the likelihood of transferring microorganisms from health care workers to patients and from environmental surfaces to patients. A cardinal rule for safety is never to touch a surface with contaminated gloves that will subsequently be touched with ungloved hands.

05. What are standard procedures?

Standard procedures are designed to reduce the risk of transmission of microorganisms from both recognized and unrecognized sources of infection in hospitals. They are a combination of universal precautions and body substance isolation precautions and apply to blood, all bodily fluids (whether or not they contain blood), non intact skin, and mucous membranes.

05. Is exposure synonymous with infection?

No. An exposure is a contact that has a reasonable potential to complete the chain of infection and result in disease of the host.

06. What are hepatitis B and delta hepatitis?

Hepatitis B is one of most common reportable diseases in the United States. HBV is transmitted through blood and sexual fluids: it is highly transmissible because of the large numbers of virus in the blood of infected persons (about 100 million per ml). Delta hepatitis is caused by a defective virus (hepatitis D virus [that relies on HBV for its pathogenicity and can infect only in the presence of HBV. HBV and HDV co-infection, however, results in a fulminant course of liver disease.

07. Why is hepatitis B vaccination so important?

HBV is the major infectious occupational hazard to health care workers. Transmission has been documented from providers to patients and vice versa. In 1982, a vaccine became available to provide protection from HBV infection. The first-generation vaccine was plasma-derived, but the vaccine in current use is genetically engineered. The safety and efficacy of the vaccine are well established, and there is no current recommendation for booster doses. Furthermore, protection from I-JBV also confers protection from HDV.

08. If you are employed in a dental practice, who pays for the HBV vaccine—you or your employer?

If an employee may be exposed to blood or other potentially infectious fluids during the course of work, it is the obligation of the employer to offer and pay for the series of vaccinations. The employer is not required to pay titer test costs because this test is not recommended by the United States Public Health Service (USPHS), the agency on which OSHA relies for advice.

09. What if I refuse the vaccination?

In most states, you have a right to refuse the vaccination. You should realize, however, that without the HBV vaccination series or evidence of previous infection you remain at risk for acquiring HBV infection. Because OSHA considers the HBV vaccination one of the most important protections that a health care worker can have, the agency requires the employee to sign a waiver if the vaccination is refused. Signing the waiver does not mean that, if you change your mind in the future, the employer does not have to pay.

10. What is the risk of HIV transmission associated with percutaneous mucous membrane exposures to blood known to be HIV-positive?

The risk is about 0.3% (1/300) for percutaneous and about 0.09% (1/900) for mucous membrane exposures. Many factors, however, influence the likelihood of transmission. Accumulated data from studies involving health care worker exposures suggest a 0.2—0.4% risk of HIV infection with the worst case scenario of a severe percutaneous injury involving exposure to blood from a terminal HIV patient.

10 Questions and Answers About Dental Radiographic Interpretation

01.  What is the earliest radiographic sign of periapical disease of pulpal origin?

The earliest radiographic sign is widening of the periodontal ligament space around the apex of the tooth.

02 . What is the second most common radiographic sign of periapical disease of pulpal origin?

The second most common radiographic sign is loss of the lamina aura around the apex of the tooth.

03.    Describe the radiographic differences that allow one to distinguish among periapical abscess, granuloma, radicular (periapical) cyst, and an apical surgical scar.

One cannot distinguish among periapical abscess, granuloma, or radicular (periapical) cyst on radiographic grounds alone. All of these lesions are radiolucent with well-defined borders. Whereas an abscess may be expected to be less well corticated than a radicular cyst, this feature is not marked or constant enough to be of real utility. An apical surgical scar may be radiographically distinguishable from the other three lesions if there is radiographic evidence of surgery, such as a retrograde amalgam. Of course, a history should elicit the fact of surgery.

04.    How does the radiographic appearance of pulpal pathology that has extended to in volve the bone differ in primary posterior teeth from the picture commonly seen in perma nent posterior teeth?

In permanent teeth, widening of the periodontal ligament space is seen around the apex of the tooth. In primary teeth, by contrast, the infection presents as widening of the periodontal ligament space or an area of lucency in the furcation area.

05. Does any radiographic sign permit the diagnosis of a nonvital tooth?

It is frequently stated that tooth vitality cannot be determined by radiographs alone, but this is not so. The presence of a root canal filling in a tooth provides virtually conclusive proof of its nonvitality, as does the presence of a retrograde filling, usually amalgam.

06.  At times it may be difficult to distinguish between hypercementosis and condensing or sclerosing osteitis around the apex of a tooth. What radiographic feature permits a definitive diagnosis when one is confronted with this dilemma?

If hypercementosis is present, the periodontal ligament space is visible arou nd the added cementum; that is, the cementum is contained within and is surrounded by the periodontal ligament space. Condensing osteitis, by contrast, is situated outside the periodontal ligament space.

07.  What is the radiographic sign of an ankylosed tooth?

The radiographic sign of an ankylosed tooth is loss of the periodontal ligament space and lamina aura.

08.  What is the earliest radiographic sign of periodontal disease?

The earliest radiographic sign of periodontal disease is loss of density of the crestal cortex, which is best seen in the posterior regions. In the anterior part of the mouth, the alveolar crests lose their pointed appearance and become blunted. In the posterior areas, the alveolar crests usually meet the lamina aura at right angles. In the presence of periodontal disease, these angles become rounded.

09.    What is the earliest radiographic sign of furcation involvement due to periodontal disease? 

In periodontal disease, one may see the loss of a cortical plate, either the buccal or lingual plate, on an intraoral film. The plate may be lost so that the crest now occupies a position apical to the furcation. This appearance, however, does not permit a diagnosis of furcation involvement. Widening of the periodontal ligament space in the furcation area is the earliest radiographic sign of furcation involvement.

10 . What is the radiographic differential diagnosis of a radiolucency on the root of a peri odontally healthy tooth?

Internal resorption, external resorption, and superimposition are the most common causes. Note that the question refers to a periodontally healthy tooth. If bone loss has resulted in exposure of the root, caries and abrasion, among other potential possibilities, enter the picture.

10 Questions and Answers About complications of tooth extraction

1.  What are the major complications of tooth extraction?

Fracture of the root or alveolar plate            Infection

Displacement of a root tip                            Perforation of the maxillary sinus

Bleeding                                                      Paresthesia

Dry socket (localized osteitis)                      

Soft-tissue injury 

Fracture of the tuberosity

2.  What is the most common complication of tooth extraction? How can it be prevented?

The most common complication of tooth extraction is root fracture. The best method of prevention is to expose the tooth surgically and to remove bone before extraction.

3.  Which tooth root is most likely to be displaced into an unfavorable anatomic site during extraction?

The palatal root of the maxillary first molar is most likely to be displaced into the maxillary sinus during extraction.

4.  Describe the prevention and treatment of postoperative bleeding.

A thorough preoperative medical history helps to identify most patients at systemic risk for postoperative bleeding. On leaving the office, patients should receive both verbal and written instructions for postoperative wound care. Of particular relevance regarding bleeding is the avoidance of rinsing, spitting, and smoking during the first postoperative day. The patient should be specifically instructed to avoid aspirin. Patients should be instructed to bite on a gauze sponge for 30 minutes after the extraction.

A patient with postoperative bleeding should return to the office. The wound should be cleared of residual clot or debris, and the source of the bleeding identified. Local anesthesia should be administered, and existing sutures removed. The wound should be irrigated copiously with saline. Residual granulation tissue should be removed. A hemostatic agent, such as gelatin sponge, oxidized cellulose, or oxidized regenerated cellulose, may be placed into the extraction site. The wound margins should be reapproximated and carefully sutured.

5.  What is a dry socket?

Dry socket is a localized osteitis of the extraction site that typically develops between the third and fourth postoperative day. The term applies to the clinical appearance of the socket, which is devoid of a typical clot or granulating wound. Consequently, patients develop moderate-to-severe throbbing pain. The frequency of dry socket after routine tooth extractions is around 2%. However, the condition may occur in as many as 20% of cases after extraction of impacted mandibular third molars.

6.    How can dry socket be prevented?

Prevention of dry socket is somewhat controversial. It is generally agreed that careful technique to minimize trauma reduces the likelihood of this complication. In addition, preoperative rinsing with chlorhexidine gluconate 0.12% may be of benefit. Placement of antibiotic-impregnated gelfoam or injection of polylactic acid granules into the socket before suturing may be of value, although these interventions are far from being universally accepted.

7.    How is dry socket treated?

Curettage of the extraction site is contraindicated. The extraction site should be gently irrigated with warm saline. A medicated dressing is then placed into the socket. The medication used for this purpose has been the topic of much discussion. One alternative consists of eugenol, benzocaine, and balsam of Peru. Alternatively, a gauze dressing impregnated with equal amounts of zinc oxide, eugenol, tetracycline, and benzocaine may be used.

8.    What substances should never be placed into a healing socket? Petrolatum-based compounds and tetracycline powder.

9.    Describe pain control after extraction.

For most patients, adequate control of postoperative pain is obtained with nonsteroidal antiinflammatory drugs (NSAIDs). A large number of compounds are available. Data indicate that postoperative pain can be minimized if the first dose of NSAIDs is administered immediately after the procedure. No evidence indicates that preoperative administration of NSAIDs favorably alters the postoperative course. For patients unable to take NSAIDs because of allergies, ulcer disease, or other contraindications, various narcotic analgesics are available. Patients taking such medications must be cautioned about drowsiness and concurrent use of alcohol or other medication. In no instance is persistent postoperative pain (>2 days) to be expected, and patients should be instructed to call if they have prolonged discomfort, which may indicate infection or another complication.

10.    What percent of patients request pain medication after third-molar removal?

90%.

10 Questions and Answers About Gingival and Periodontal tissues

1. What is gingival hypertrophy?

Gingival hypertrophy indicates that the gingivae have increased in size and not number. Hypertrophy indicates inflammation, whereas hyperplasia may not.

2. What causes gingival recession?

The major causes are tooth brush or floss abrasion, parafunctional habits, periodontal disease, and orthod ontics (if the bands are improperly placed).

3. Which area of the oral cavity has the least amount of attached gingiva?

The buccal mandibular premolar area commonly has the least amount of attached tissue.

4.What is a long junctional epithelium?

After a periodontal pocket has been scaled, root planed, and curetted, a soft tissue reattachment to the root surface may occur. This reattachment is called a long junctional epithelium. Pocket reduction is due to a gain in attachment, not to a decrease of inflammation. Fibrous reattachment is also possible.

 5. What is the term for gingival cells that attach to the root cementum? How do they attach to the root?

The term is junctional epithelium; the cells attach by hemidesmisomes.

6. What is a mucogingival defect?

Mucogingival defects are defined by periodontal pocketing that goes beyond the mucogingival junction.

7.What are the major risk factors for periodontitis?

Major risk factors for periodontal disease include increased age, poor educa tion, neglect of dental care, previous history of periodontal disease, tobacco use, and diabetes.

8.Is periodontal disease a risk factor for other disease?

Some epidemiologic evidence indicates that periodontal disease and other chronic infective diseases may be associated with coronary artery disease and stroke.

9.What is the crown-to-root ratio in a healthy dentition?

As a general rule, the crown-to-root ratio in a healthy dentition is 1:2 (for each tooth).

10. What root shapes generally have a more favorable prognosis? As the preceding question suggests, the crown-to-root ratio is very important. Long, taper ing roots are usually sturdier than short, conical roots.

10 QUESTIONS AND ANSWERS ABOUT USE OF ANTIBIOTIC PROPHYLAXIS IN DENTISTRY

1. For what cardiac conditions is prophylaxis for endocarditis recommended in patients receiving dental care?

High-risk category

• Prosthetic cardiac valves, including both bioprosthetic and homograft valves

• Previous bacterial endocarditis

• Complex cyanotic congenital heart disease (e.g., single ventricle states, transposition of the great arteries, tetralogy of Fallot)

• Surgically constructed systemic pulmonary shunts or conduits Moderate-risk category

• Most congenital cardiac malformations other than above and below (see next question)

• Acquired valvular dysfunction (e.g., rheumatic heart disease)

• Hypertrophic cardiomyopathy

• Mitral valve prolapse with valvular regurgitation and/or thickened leaflets

2. What cardiac conditions do not require endocarditis prophylaxis? Negligible-risk category (no higher than the general population)

• Isolated secundum atrial septal defect

• Surgical repair of atrial septal defect, ventricular septal defect, or patent ductus arteriosus (without residua beyond 6 months)

• Previous coronary artery bypass graft surgery

• Mitral valve prolapse without valvular regurgitation

• Physiologic, functional, or innocent heart murmurs

• Previous Kawasaki disease without valvular regurgitation

• Previous rheumatic fever without valvular regurgitation

• Cardiac pacemakers (intravascular and epicardial) and implanted defibrillators

3. What are the antibiotics and dosages recommended by the  American Heart Association (AHA) for prevention of endocarditis from dental procedures?

The AHA updates its recommendations every few years to reflect new findings. The dentist has an obligation to be aware of the latest recommendations.

The patient’s well-being is the dentist’s responsibility. Even if a physician recommends an alternative prophylactic regimen, the dentist is liable if the patient develops endocarditis and the latest AHA recommendations were not followed.

Standard regimen

Amoxicillin, 2.0 gm orally 1 hr before procedure

For patients allergic to amoxicillin and penicillin

Clindamycin, 600 mg orally 1 hr before procedure or

Cephalexin* or cefadroxil,* 2.0 gm orally 1 hr before procedure or

Azithromycin or clarithromycin, 500 mg orally 1 hr before procedure

 Patients unable to take oral medications

Ampicillin, intravenous or intramuscular administration of 2 gm 30 mm before procedure

 For patients allergic to ampicillin, amoxicillin, and penicillin 

Clindamycin, intravenous administration of 600 mg 30 mm before procedure  or Cefazolin,* intravenous or intramuscular administration of 1.0 gm within 30 mm before procedure

* Cephalosporins should not be used in patients with immediate-type hypersensitivity reaction (urticaria, angioedema. or anaphylaxis) to penicillins.

4. For what dental procedures is antibiotic premedication recommended in patients identified as being at risk for endocarditis?

• Dental extractions

•Periodontal procedures including surgery, scaling and root planing, probing, and recall maintenance

• Dental implant placement and reimplantation of avulsed teeth

• Endodontic (root canal) instrumentation or surgery only beyond the apex

• Subgingival placement of antibiotic fibers or strips

• Initial placement of orthodontic bands but not brackets

• Intraligamentary local anesthetic injections

• Prophylactic cleaning of teeth or implants if bleeding is anticipated

5. For what dental procedures is antibiotic premedication not recommended in patients identified as being at risk for endocarditis?

•Restorative dentistry (including restoration of carious teeth and prosthodontic replacement of teeth) with or without retraction cord (clinical judgment may indicate antibiotic use in selected circumstances that may create significant bleeding)

• Local anesthetic injections (nonintraligamentary)

• Intracanal endodontic treatment (after placement and build-up)

• Placement of rubber dams

• Postoperative suture removal

• Placement of removable prosthodontic or orthodontic appliances

• Making of impressions

• Fluoride treatments

• Intraoral radiographs

• Orthodontic appliance adjustment

• Shedding of primary teeth

6. Should a patient who has had a coronary bypass operation be placed on prophylactic antibiotics before dental treatment?

No evidence indicates that coronary artery bypass graft surgery introduces a risk for endocarditis. Therefore, antibiotic prophylaxis is not needed.

7. What precautions should you take when treating a patient with a central line such as a Hickman or Portacath?

Patients with central venous access are usually receiving intensive antibiotic therapy, chemotherapy, or nutritional support. It is imperative to consult with the patient’s physician before performing any  dental procedures. If it is determined that the dental procedure is necessary, the patient should receive antibiotic prophylaxis to protect the central venous access line from infection secondary to transient bacteremias. The same antibiotic regimen recommended for the prevention of endocarditis should be prescribed.

8. Should a patient with a prosthetic joint be placed on prophylactic antibiotics before dental treatment?

Case studies support the hematogenous seeding of prosthetic joints. However, it is questionable whether organisms from the oral cavity are a source for late deep infections of prosthetic joints. The decision whether to premedicate should be determined by the dentist’s clinical judgment in consultation with the patient’s physician or orthopedic surgeon. Patients considered at high risk for developing a late infection of a prosthetic joint should be premedicated. Such patients can be grouped based on predisposing systemic conditions, issues associated with joint prostheses, or presence of acute infection at sites distant to the joint prosthesis.

High-risk Patients with Total Joint Replacements

Predisposing systemic conditions

Rheumatoid arthritis                                    

Insulin-dependent diabetes mellitus

Systemic lupus erythematosus                                                          

Hemophilia

Disease-, drug-, or radiation-induced immunosuppression           

Malnourishment

Issues associated with joint prostheses

First 2 years after joint replacement         

Loose prosthesis

History of replacement of prosthesis     

History of previous infection of prosthesis

Acute infection located at distant sites: skin, oral cavity, other

9. What are the antibiotics and dosages recommended by the American Dental Association and the American Academy of Orthopaedic Surgeons to prevent late joint infections in patients considered to be at high risk?

Standard regimen

Cephalexin* or cephradine* or amoxicillin, 2 gm orally 1 hr before procedure

 For patients allergic to amoxicillin and penicillin

Clindamycin, 600 mg orally 1 hr before procedure

Patients unable to take oral medications

Cefazolin,* intravenous or intramuscular administration of 1.0 gm 1 hr before procedure or

Ampicillin, intravenous or intramuscular administration of 2.0 gm 1 hr before procedure

For patients allergic to ampicillin, amoxicillin, and penicillin

Clindamycin, intravenous or intramuscular administration of 600 mg 1 hr before procedure

* Cephalosporins should not be used in patients  with immediate-type hypersensitivity reaction (urticaria, angioedema, or anaphylaxis) to penicillins.

10.Is it necessary to prescribe prophylactic antibiotics for a patient on renal dialysis?

Patients on dialysis with arteriovenous (AV) shunts should be premedicated before any dental treatment that has  the potential of producing a transient bacteremia. The dosages for antibiotic coverage are as follows:

Standard regimen

Amoxicillin, 2.0 gm orally 1 hr before procedure

For patients allergic to amoxicillin and penicillin

Clindamycin, 600 mg orally 1 hr before procedure or

Cephalexin* or cefadroxil,* 2.0 gm orally 1 hr before procedure

Azithromycin or clarithromycin, 500 mg orally 1 hr before procedure

Patients unable to take oral medications

Ampicillin, intravenous or intramuscular administration 2.0 gm within 30 mm before procedure

For patients allergic to ampicillin, anioxicillin, and penicillin

Clindamycin, intravenous administration of 600 mg within 30 mm before procedure or

Cefazolin,* intravenous or intramuscular administration of 1.0 gm within 30 mm before procedure

* Cephalosporins should not be used in patients  with immediate-type hypersensitivity reaction (urticaria, angioedema, or anaphylaxis) to penicillins.

10 Questions and Answers About Mx of DISORDERS OF HEMOSTASIS in DENTISTRY

  1. How do you screen a patient for potential bleeding problems?

The best screening procedure for a bleeding disorder is a good medical history. If the review of the medical history indicates a bleeding problem, a more detailed history is needed. The following questions are basic:

1. Is there a family history of bleeding problems?

2. Has bleeding been noted since early childhood, or is the onset relatively recent?

3. How many previous episodes have there been?                               

4. What are the circumstances of the bleeding?

5. When did the bleeding occur? After minor surgery, such as tonsillectomy or tooth extraction? After falls or participation in contact sports?

6. What medications was the patient taking when the bleeding occurred?

7. What was the duration of the bleeding episode(s)? Did the episode involve prolonged oozing or a massive hemorrhage?

8. Was the bleeding immediate or delayed?

 2. What laboratory tests should be ordered if a bleeding problem is suspected?

• Platelet count: normal values = 150,000—450,000

• Prothrombin time (PT): normal value = 10—13.5 seconds

• Partial thromboplastin time (PTT): normal value = 25—36 seconds

• Bleeding time: normal value = < 9 minutes (bleeding time is a nonspecific  predictor of platelet function)

Normal values may vary from one laboratory to another. It is important to check the normal values for the laboratory that you use. If any of the tests are abnormal, the patient should be referred to a hematologist for evaluation before treatment is performed.

  3. What are the clinical indications for use of 1-deamino-8 vasopressin (DDAVP) in dental patients?

DDAVP (desmopressin) is a synthetic  antidiuretic hormone that controls bleeding in patients with type I von Willebrand’s disease, platelet defects secondary to uremia related to renal dialysis, and immunogenic thrombocytopenic purpura (ITP). The dosage is 0.3 mg/kg. DDAVP should not be used in patients under the age of 2 years; caution is necessary in elderly patients and patients receiving intravenous fluids.

  4. When do you use epsilon aminocaproic acid or tranexamic acid?

Epsilon aminocaproic acid (Amicar) and tranexamic acid are antifibrinolytic agents that inhibit activation of plasminogen. They are used to prevent clot lysis in patients with hereditary clotting disorders. For epsilon aminocaproic acid, the dose is 75—100 mg/kg every 6 hours; for tranexamic acid, it is 25 mg/kg every 8 hours.

  5. What is the minimal acceptable platelet count for an oral surgical procedure?

Normal platelet count  is 150,000—450,000. In general, the minimal count for an oral surgical procedure is 50,000 platelets. However, emergency procedures may be done with as few as 30,000 platelets if the dentist is working closely with the patient’s hematologist and uses excellent techniques of tissue management.

  6. For a patient taking warfarin (Coumadin), a dental surgical procedure can be done without undue risk of bleeding if the PT is below what value?

Warfarin affects clotting factors II, VII, IX, and X by impairing the conversion of vitamin K to its active form. The normal PT for a healthy patient is 10.0—13.5 seconds with a control of 12 seconds. Oral procedures with a risk of bleeding should not be attempted if the PT is greater than 1½ times the control or above 18 seconds with a control of 12 seconds.

  7. Is the bleeding time a good  indicator of pen, and postsurgical bleeding?

The bleeding time is used to test for platelet function. However, studies have shown no cor relation between blood loss during cardiac or general surgery and prolonged bleeding time. The best indicator of a bleeding problem in the dental patient is a thorough medical history. The bleeding time should be used in patients with no known platelet disorder to help predict the potential for bleeding.

  8. Should oral surgical procedures be postponed in patients taking aspirin?  

Nonelective oral surgical procedures in the absence of a positive medical history for bleeding should not be postponed because of aspirin therapy, but the surgeon should be aware that bleeding may be exacerbated in a patient with mild platelet defect. However, elective procedures, if at all possible, should be postponed in the patient taking aspirin. Aspirin irreversibly acetylates cyclooxygenase, an enzyme that assists platelet aggregation. The effect is not dose-dependent and lasts for the 7—10-day life span of the platelet.

  9. Are patients taking nonsteroidal medications likely to bleed from oral surgical procedures?

Nonsteroidal antiinflammatory medications produce a transient inhibition of platelet aggregation that is reversed when the drug is cleared from the body. Patients with a preexisting platelet defect may have increased bleeding.

  10. If a patient presents with spontaneous gingival bleeding, what diagnostic tests should be ordered?

A patient who presents with spontaneous gingival bleeding without a history of trauma, tooth brushing, flossing, or  eating should be assessed for a systemic cause. Etiologies for gingival bleeding include inflammation secondary to localized periodontitis, platelet defect, factor deficiency, hematologic malignancy, and metabolic disorder. A thorough medical history should be obtained, and the following laboratory tests should be ordered: (1) PT, (2) PIT, and (3) complete blood count (CBC).