## 4 Discussion  
The results of the present study show that there are no statistically significant differences in salivary BALP and OC levels among pre-pubertalal, pubertal, and post-pubertalal patients. The lack of statistical significance leads to the conclusion that the two biomarkers under investigation cannot be clinically used for the skeletal age estimation of young individuals at the moment. However, despite the lack of statistical significance concerning BALP, peak levels seem to coincide with growth spurts (CS3), while reduced levels are seen in the previous and \begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Pubertal Stages** & **n** & **Mean (SD)** & **Median (Min, Max)** & \(p\)**-Value \({}^{*}\)** \\ \hline Pre-mature (CS1–CS2–CS3) & 28 & 1.54 (1.54) & 0.91 (0.06, 5.64) & \\ Late mature (CS4–CS5–CS6) & 25 & 1.37 (1.51) & 0.56 (0.04, 5.68) & \\ \hline
**Total** & 53 & 1.46 (1.51) & 0.66 (0.04, 5.68) & \\ \hline \hline \end{tabular} \({}^{*}\)Mann-Whitney test; CS: Cervical stage; SD: Standard deviation; OC: Osteocalcin.  
\end{table} 
Table 6: Level of OC (ng/mL) in saliva according to maturation stage. following maturational stages. OC levels seem to follow a similar pattern to BALP, with higher values in CS2 and CS3 and lower in CS4 and CS5. It is worth mentioning that BALP levels in the saliva have not been investigated thoroughly until now. Regarding the levels of salivary BALP, our findings agree with those of [PERSON] et al. (2017) [20], who analyzed data from 136 growing patients and found no statistically significant differences among growing patients and BALP levels, with the use of the CVM method for skeletal age assessment of the sample. On the other hand, [PERSON] et al. (2017) [21] found statistically significant differences among patients, with peak levels of ALP in the saliva, which coincided with the growth spurt as depicted in the CVM. Also, [PERSON] et al. [10] and [PERSON] et al. [22] found a statistically significant correlation among patients between ALP and BALP levels in saliva and the growth spurt, respectively, by using hand-wrist radiographs for skeletal age estimation instead of the CVM. [PERSON] et al. (2019) [23], according to their conclusions, found that ALP activity in the saliva of 79 patients was correlated with the growth spurt. It is worth mentioning that inter-examiner reliability concerning the CVM method and categorization of the subjects according to vertebrae shape was poor in this study. Nevertheless, in a recent systematic review by [PERSON] et al. (2023), which aimed to assess the reliability of various salivary biomarkers as skeletal maturity indicators, the evidence suggested that up until now, salivary ALP could not be used as a diagnostic tool for skeletal maturation assessment, but only as an adjunct to other reliable methods, which is in accordance with the results of this study. The systematic review concluded that there is still a need for further research with longitudinal studies in this field [11]. Osteocalcin is a biomarker that has not been explored in saliva in relation to the pubertal growth phases before and evidence of a possible correlation between salivary OC and skeletal maturation is not available in the literature. Up until now, only one study has examined the potential role of osteoclastin as a growth biomarker in the blood serum of 150 patients and found that serum peak values were met in maturation stages CS5 in males and CS3 in females, but with insignificant differences between stages. The findings of the present research found insignificant differences in osteoclin levels in the saliva among growing patients and agree with the abovementioned results in the serum [19]. The collection of saliva is a noninvasive method [27] and it can be easily collected and stored [4]. Droeling saliva passively was the chosen method for this study, since passive drooling is the 'gold standard' of saliva collection for obtaining many saliva components [28].