# Analysis of Craniocervical Abnormalities in Osteogenesis Imperfecta during Growth
## 3 Results
### Reference Value in the Control Sample  
Given that the CCJ changes with growth, Table 1 shows the reference values obtained from the control sample presented by age groups and establishing the limit value of 2.5 SD above which pathology can be suspected.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Variables**} & \multicolumn{4}{c}{**Non-OI Patients (Mean \(\pm\) SD)**} \\ \cline{2-5}  & **6–8 Years** & **9-11 Years** & **12-14 Years** & **15-18 Years** \\  & **(n = 10)** & **(n = 16)** & **(n = 14)** & **(n = 26)** \\ \hline D-McRae line & \(-4.35\pm 2.44\) & \(-5.03\pm 1.62\) & \(-5.00\pm 1.74\) & \(-4.42\pm 2.42\) \\ Mean + 2.5 SD & 1.75 & \(-0.98\) & \(-0.65\) & \(1.63\) \\ \hline D-Chamberlain line & \(-1.99\pm 2.85\) & \(-2.07\pm 2.38\) & \(-1.73\pm 2.70\) & \(-1.98\pm 3.79\) \\ Mean + 2.5 SD & 5.12 & 3.88 & 5.01 & 7.51 \\ \hline D-Modified McGregor line & \(-0.03\pm 2.74\) & \(-0.08\pm 2.56\) & \(-0.42\pm 2.58\) & \(-0.77\pm 4.00\) \\ Mean + 2.5 SD & 6.83 & 6.32 & 6.03 & 9.24 \\ \hline D-Kovere line & \(-4.71\pm 2.77\) & \(-5.05\pm 3.18\) & \(-4.82\pm 3.66\) & \(-5.09\pm 4.68\) \\ Mean + 2.5 SD & 2.21 & 2.91 & 4.34 & 6.61 \\ \hline D-Wackenlin line & \(-2.52\pm 2.22\) & \(-3.75\pm 1.81\) & \(-3.45\pm 2.10\) & \(-2.02\pm 1.91\) \\ Mean + 2.5 SD & 3.02 & 0.78 & 1.79 & 2.76 \\ \hline Ranawat line & \(12.49\pm 1.65\) & \(14.55\pm 1.79\) & \(15.63\pm 1.86\) & \(14.91\pm 1.80\) \\ Mean + 2.5 SD & 8.36 & 10.09 & 10.98 & 10.41 \\ \hline Modified Ranawat line & \(23.31\pm 2.12\) & \(26.20\pm 2.27\) & \(28.58\pm 2.93\) & \(26.90\pm 2.62\) \\ Mean + 2.5 SD & 18 & 20.52 & 21.27 & 20.34 \\ \hline Redlund-Johnell method & \(29.12\pm 4.74\) & \(32.41\pm 3.41\) & \(35.86\pm 5.06\) & \(34.97\pm 4.00\) \\ Mean + 2.5 SD & 17.27 & 23.88 & 23.23 & 24.96 \\ \hline Arponen angle & \(7.06\pm 4.38\) & \(8.05\pm 4.93\) & \(9.34\pm 5.24\) & \(10.20\pm 4.91\) \\ Mean + 2.5 SD & 18.01 & 20.37 & 22.43 & 22.47 \\ \hline Cranivertebral angle & \(89.45\pm 7.13\) & \(95.73\pm 6.55\) & \(91.77\pm 8.14\) & \(90.74\pm 7.66\) \\ Mean + 2.5 SD & 71.63 & 79.35 & 71.42 & 71.58 \\ \hline Civius-canal angle & \(145.31\pm 7.34\) & \(154.15\pm 7.71\) & \(150.43\pm 9.72\) & \(153.30\pm 6.55\) \\ Mean + 2.5 SD & 126.97 & 134.87 & 126.13 & 136.94 \\ \hline Anterior cranial base angle & \(135.72\pm 5.16\) & \(132.43\pm 4.42\) & \(132.47\pm 3.77\) & \(128.98\pm 6.60\) \\ Mean + 2.5 SD & 148.61 & 143.48 & 142.17 & 145.47 \\ \hline Boogard angle & \(123.47\pm 6.09\) & \(120.62\pm 5.82\) & \(121.42\pm 7.80\) & \(118.04\pm 5.84\) \\ Mean + 2.5 SD & 138.7 & 135.18 & 140.92 & 132.63 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Reference values in the control sample marking the level of pathology from 2.5 SD.  
In the light of the data reflected in Table 1, the authors conclude that there are variables such as the McRae D-line, Chamberlain D-line, or Kovero D-line distances that do not show a clear trend associated with growth. However, in the case of the modified D-McGregor's line, it can be deduced that the odontoid process is more caudal with increasing age with respect to the base of the skull. The Ranawat line as well as the modified Ranawat line increase with growth, stabilizing at 14 years of age and even decreasing thereafter; the same happens with the Redlund-Johnell method.  
In the case of measurements such as the Arponen angle, it can be deduced that the odontoid process has a more caudal location with respect to the base of the skull the smaller the patient is, and this becomes closer with growth. The angle of the anterior cranial base decreases with age, with similar values between 9 and 14 years of age.