Clinical Aspects, Imaging Features, and Considerations on Bisphosphonate-Related Osteonecrosis Risk in a Pediatric Patient with Osteogenesis Imperfecta

Table 1

Classification of osteogenesis imperfecta into the four most frequent types^∗.

Types**	Main features
Type IA	Mild absence of bone deformity; Caused by mutations in COL1A1 or COL1A2; Affects approximately 60–70% of carriers of OI; Blue sclerae; Normal stature
Type IB	Dentinogenesis imperfecta associated with type IA
Type II	More severe form; High antenatal mortality rate due to extreme bone fragility
Type IIIA	Presence of progressive bone deformities and short stature; Presence of extreme ligamentous laxity; Affects approximately 20% of carriers of OI
Type IIIB	Dentinogenesis imperfecta associated with type IIIA
Type IVA	Mild deformities with variable degrees of short stature; Diversified form; Blue and white-grayish sclerae; Associated hearing loss; Mutations in COL1A1 or COL1A2; Affects approximately 10% of carriers of OI
Type IVB	Dentinogenesis imperfecta associated with type IVA

*Modified from Sillence et al. [14].
**Additional subtypes: I-A and I-B (Levin et al. [15]); III-A and III-B (adopted in the present study); IV-A and IV-B (Paterson et al. [16]).
Footnote. OI may also be classified into types V (Glorieux et al. [17]), VI (Glorieux et al. [18]), VII (Ward et al. [19]), and VIII (Cabral et al. [20]) based on clinical and bone histological parameters.