International Journal of Clinical Case Reports 2017, Vol.7, No.7, 28-32
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2 Discussion
Around 30% of bone tissue is composed of organic compounds of which 90 to 95% is collagen type I. Type I
collagen is, also, the most abundant protein in the skin, bone, tendons and ligaments, blood vessels, placenta and
other tissues providing strength and structure to the body. (FM Pope et al., 1983) In OI, the bone matrix is affected
with abnormal type I collagen which may be through inheritance or, mutation. Type I collagen is a triple helical
structure consisting of two A1 chains and one A2 chain. The A1 chain is controlled by the COL1A1 gene in the
17th chromosome while the A2 chain is controlled by the COL1A2 gene in the 7th chromosome. Disturbance in
alignment of the peptides in the triplet structure caused by the said gene changes eventually leads to the
production of abnormal type I collagen. (Gerhard DS et al., 2004) Sillence classified OI initially in 1979 into four
types (Table 2). (Sillence DO et al., 1979) The said classification was later extended to eight types in the year
2004 by Rauch et al. (van Dijk FS et al., 2011) OI patients are medically compromised and need cautious dental
care. Patients with OI have increased vascular fragility (abnormal type 1 collagen). The coagulation defect appears
to be primarily related to the effects of the abnormal collagen on platelet-endothelial cell interactions. Also, there
is reduced clotting factor VIII (as it interacts with collagen type 1) aiding in clotting and abnormal platelet
function (collagen induced platelet aggregation is affected). Even in cases with normal coagulation, post-operative
bleeding is still possible. If the platelet count is less than 20,000/L and with reduced factor VIII concentration,
blood transfusion becomes mandatory and fresh blood containing all clotting factors is the best choice. (Oakley I
and Reece LP et al., 2010) Patient with OI can, also, suffer from airway obstruction as the strength of the chest
muscles is weak. (Edge G et al., 1997) Also, abnormal type I collagen in OI patients makes them prone to delayed
wound healing. Most often patients with OI are on oral or, intra-venous bisphosphonate therapy, so, there are
increased chances of osteonecrosis of the jaws as bisphosphonates reduce the bone turnover. (Gl Borromeo et al,
2011) Management of OI patients includes various disciplines. It consists of pharmacological treatment,
orthopedic treatment, physical medicine, dental treatment, treatment for hearing deficits and prevention of primary
(e.g. basilar impression) and secondary (e.g. problems due to general medical disciplines) complications. (van
Dijk FS et al., 2011) Oral and intra-venous bisphosphonates are commonly prescribed for all types of OI in adults
as well as in children.
Table 2 Differentiating Features of Types of Osteogenesis Imperfecta (OI)
Type I
Is the mildest type, manifested by osteoporosis, multiple fractures and presence of blue sclerae, fractures are
common in the neonatal period but rare in the uterus or, after adulthood has been reached.
Type II
Is the most severe type, most cases dying before, or, shortly after birth, severe osteoporosis, poor
mineralization, beading of ribs, shortening of the long bones, and multiple fractures occur in this type.
Type III
Is milder than type II but the most serious type affects children in which affected children rarely survive past
infancy, blue sclerae are rare in this type but the incidence of fractures and clinical severity increase with time
and only rare cases survive into adulthood.
Type IV
Is not associated with blue sclerae but the rest of their clinical symptoms are similar to type I, however,
shortening of the long bones is more obvious after adulthood has been reached.
Type V
The gene changes in types V and VI are obscure, a feature of type V is hypertrophic bony callus after trauma
or, surgery which needs to be distinguished from chondrosarcoma, in addition, the inter-osseous membrane in
this type tends to develop calcifications with secondary dislocation of the head of the radius and limited
rotational ability.
Type VI
The characteristic of type VI is a defect in the mineralization of cartilages.
Types VII and VIII
Are thought to be related to CRTAP and the LEPRE1 genes, type VII patients tend to have skeletal
abnormalities and brittle bones while type VIII patients have defects in growth and mineralization.
3 Conclusion
The present case report discusses some of the most relevant features of children with OI. The physical disabilities
and limitations and medical problems in these children are so demanding that dental care is understandably not
considered a priority. However, parents must be instructed and made aware of that inadequate oral hygiene habits
in these children leads to dental problems that inherently bring additional unavoidable pain, discomfort and
