Correlation between Chronological Age, Cervical Vertebral Maturation and Fishman’s Skeletal Maturity Indicators in Central India Population

Introduction: Skeletal maturity indicators are very important indicators when diagnosing and panning the treatment in growing population. Cervical Vertebrae Method( CVM) and Fishman’s Skeletal Maturity Indicators are two commonly used methods for the diagnosis and treatment planning. The aim of the study was to investigate the correlation between cervical vertebral maturation (CVM)and Fishman’shand-wrist skeletal maturity indicator and chronological age by including subjects within the range of circumpubertal growth spurt in Central India. Materials & Method: One Twenty Five contemporary hand-wrist and lateral cephalometric radiographs from population of Central India were randomly selected and analyzed. All subjects were within the circumpubertal period i.e. female subjects were between 10 and 15 years of age, and the male subjects were between 12 and 17 years of age. The hand-wrist bone analysis was evaluated using the method developed by Fishman whereas cervical vertebra bone analysis was evaluated using the method developed by Baccetti and coworkers. These two methods and chronological age were correlated using the Spearman rank correlation analysis. Result: CVM was significantly correlated with hand-wrist maturation (r=0.8868).However low correlation was found between the CVM and chronological age( r =0.7139) and little correlation was found between the HWM and chronological age ( r =0.6892). Conclusion: CVM is a valid indicator of skeletal growth during the circumpubertal growth period and has a high correlation with the HWM for the Central India population. Howeverchronological ageis not suitable to measure skeletal maturity as shown by the low correlations found between the chronological age and both CVM and HWM.


INTRODUCTION
a biologic indicators series were used.These methods includes characteristics of sexual maturation, facial growth and peak height velocities, chronological age, dental development, body weight,body height and handwrist maturity. 4 Successful growth modification in orthodontics is dependent on skeletal maturation.5 Hand wrist maturation (HWM) analysis is the most widly used and a classical method for evaluation of skeletal age. HWM is the highly reliable method done by radiograph.
However, an addition exposure of ionizing radiation of the orthodontic patient required to the routine radiographic records for this analysis. 6 The assessment of the degree of cervical vertebral maturation (CVM) is another method of assessingskeletal maturation. In case of CVM assessment lateral cephalometric radiograph is needed which is routinely taken for orthodontic treatment planning so no need of any extra ionizing radiation exposure required . 7 Lamparski studied the development of the cervicalvertebrae and demonstrated the efficacy of the CVM method in assessing skeletal age. 8 The use of a lead collar to protect the thyroid mayhinder full In previous studies subjects with wide age range were included ( between 5 year to 18 years) forcorrelation of the CVM methodwith skeletal maturity.10So due to the wide age range of subjects inclusion before and after the pubertal growth spurt correlation coefficient may be affected.Therefore, in this study we investigated the correlationof the CVM and HWM byincluding near or within the pubertalgrowth spurtsubjects, using the Central India as a studypopulation.

MATERIALS AND METHOD
One Twenty Five hand-wrist and lateral cephalometric The subjects selected for study were based on the following inclusion and exclusion criteria.

Inclusion Criteria
The selection criteria of the subjects are as follows: • The radiograph is taken within the circumpubertal period; with female age range 10 to 15 years and male age range 12 to 17 years.
• The bones should appear clearly and should have been unaffected by systemic disease.
• Cephalograms showing all first four vertebrae clearly.
• The hand-wrist radiograph is of left hand.

Exclusion Criteria
• Patient with facial asymmetry.
• Patients with history of trauma and surgery in dentofacial region.
• Patient with congenital abnormalities affecting growth and development and traumatic lesions of cervical vertebrae.
• Patient suffering from systemic disease.

Kodak 8000C Digital Panoramic and Cephalometric
System is used to take the lateral cephalogram and hand wrist radiograph. Radiographs of high quality and good contrast were used.The CVM was evaluated using the method developed by Baccetti and coworkers (Fig.1). The hand-wrist maturation (HWM) of the same patient was evaluated using the Fishman's method (Fig.2).

Figure 1: Kodak 8000C Digital Panoramic and Cephalometric
System is used to take the lateral cephalogram

Statistical Analysis
The skeletal maturity indicator (SMI) scores and cervical vertebrae maturity indicator (CVMI) scores were obtained and analyzed with reference to chronological age. The SMI and CVMI were compared with each other and with chronological age and their correlation was established statistically by using Spearman rank correlation coefficient.

Method Errors
The intraexaminer error was calculated for 25 patients. Randomly selected lateral cephalometric and handwrist radiographs for both methods were evaluated by the investigator and then reevaluated by the same investigator after 3 weeks. 20 of 25 interpretations were the same at the second examination. The method error was insignificant. The Kappa statistic for concordance was 0.811.

Correlation between CVMI and HWM (SMI) (Graph 1)
This study shows that CVM (CS) was significantly correlated with HWM (SMI) (Spearman r=0.8868 and r2 = 0.786).The correlation plot appeared linear. There was a linear relationship between the CVM (CS) and the HWM (SMI).This indicates that the eleven discrete stages of SMI can be confidently correlated to corresponding 6 stages of CVMI.

Correlation between CVMI and Chronological Age (Graph 2)
There was low correlation between the CVM (CS) and Graph 1: Bar graph representing correlation coefficient between SMI and CVMI at different age group This study also reveals that the low correlations found between the chronological age and CVM and the chronological age and HWM showed that chronological age was not suitable to measure skeletal maturity.

CONCLUSION
The CVM method shows high correlation with the HWM method in the central India population.
Low correlations were found between chronological age and HWM, and between chronological age and CVM in the central India population. Chronological Age chronological age (Figures 3 and 4). The correlation plots appeared scattered widely (Spearman r =0.7139 and r2=0.5096).

Correlation between SMI and Chronological Age (Graph 3)
There was little correlation between the HWM (SMI) and chronological age (Figures 5 and 6). The correlation plots appeared scattered widely (Spearman r =0.6892 and r2= 0.4749).