Key Points
- Genetic coagulation disorders:
⎯haemophilia A (factor VIII)⎯80%
⎯haemophilia B (factor IX)⎯13%
⎯factor XI⎯6% - Bleeding disorders:
⎯haemophilia A⎯1 : 20,000
⎯von Willebrand's disease⎯1 : 1000
16.3.2 Dental management of bleeding disorders
A good history is the best screening device, but a bleeding tendency may only become
manifest after a surgical procedure or trauma. Effective communication with the
child's physician or haematologist is important, not only to establish the aetiology of
any bleeding tendency but also to liaise over any necessary medical treatment that is
required to replace reduced levels of clotting factors. The cornerstone of dental care
is prevention and regular review so that if disease does occur it can be treated at an
early stage. Local anaesthetic infiltrations or intraligamentous injections are unlikely
to cause problems if given carefully. Regional anaesthesia, such as an inferior dental
block, is contraindicated as bleeding in the pterygomandibular region which may
result in asphyxia. Pulp treatment of primary molar teeth may be required to avoid
extractions. Most primary teeth exfoliate spontaneously with little haemorrhage;
however, occasionally when they are very mobile, the soft tissues develop an
inflammatory hyperplastic response and bleeding may be a problem. In these
situations extraction may be necessary with the appropriate haematological
replacement therapy. However, if dental extractions or surgery do become necessary
then the patients are usually best managed in the hospital situation.
Haemophilia
Adequate replacement and careful monitoring of factor VIII and factor IX levels are
required. This is usually done with fresh-frozen plasma or freeze-dried concentrate.
Patients with mild to moderate haemophilia A can often be managed on an out-patient
basis using replacement therapy or DDAVP (1 desamino-8, darginine vasopressin;
also known as desmopressin) which stimulates the release of factor VIII.
Antifibrinolytic agents such as EACA (epsilon-aminocaproic acid), and tranexamic
acid are also given to prevent lysis of the clot. They also significantly reduce the
requirement for replacement of factor VIII. Medications containing non-steroidal,
anti-inflammatory drugs (NSAIDs) or aspirin should not be given (aspirin should not
be given anyway to a child under 16 years because of the risk of developing Reye's
syndrome).
Von Willebrand's disease
Factor VIII concentrates are not usually effective, but DDAVP is used in combination
with EACA or tranexamic acid. Patients with more severe types of von Willebrand's
disease will require fresh-frozen plasma or a cryoprecipitate replacement.
Thrombocytopenia