OBJECTIVE: The aim of the study is to determine the different stages of cervical vertebrae maturation among different age groups and in both sexes.
MATERIALS AND METHODS: Pre-treatment CBCT of 16 patients were taken and divided into 2 groups based on age, Group 1contains 8 patients of 10 – 12 years of age and Group 2contains 8 patients of 13 – 15 years of age. Each group was divided into subdivision A and B consisting of 4 boys and 4 girls respectively. Cervical vertebrae development of the sample was evaluated by Hassel and Farman’s method on CBCT.
RESULTS: Mean CVMI of 1.75±0.96 was found among Group 1A patients and in Group 1B patients the mean CVMI was found to be 2.75±0.5. In Group 2A the mean CVMI was 3.75±0.5 whereas in Group 2B the mean CVMI was 5.25±0.5.
CONCLUSION: In this study, a conventional cervical vertebrae maturation method (CVMI) using cervical vertebrae C2 and C3 was applied to assess skeletal maturation in CBCT images. It was found that from this study CBCT can be used for assessing skeletal maturation using cervical vertebrae. However, further studies are required with larger sample size.
Proper timing for dentofacial orthopedics is linked intimately to the identification of periods of accelerated or intense growth that can contribute significantly to the correction of skeletal imbalances in the individual patient. Because of wide individual variation in the timing of the pubertal growth spurt, chronologic age is an unreliable guide for assessment of children’s development status.
Many authors have attempted to determine the best indicators of the degree of maturity. Sexual maturation characteristics, chronological age, dental development, height, weight, skeletal development, and vertebral development are some of the parameters that have been used to identify the stage of growth.1-20
Cone Beam Computed Tomography (CBCT) has been considered the examination of choice in many instances since it provides high-resolution imaging, diagnostic reliability, and risk-benefit assessment. Its use is recommended in orthodontic practice for impacted teeth, temporomandibular joint evaluations, 3D views of the upper airways, assessment of maxillofacial growth and development, and dental age estimation. CBCT has also demonstrated validity for biomechanical simulations, models of bone remodeling, simulations for orthodontic surgical planning, and measurements were taken by digitizing points in 3D coordinates.21-26 Because of these advantages and possibilities in orthodontic assessment, treatment, and follow-up, and its relatively low cost, many orthodontists use CBCT routinely for all patients. Not many studies have been performed for assessing skeletal maturation for determining of chronological age using CBCT. Therefore this article aims at providing a guideline for assessing cervical vertebrae maturation for determination of skeletal maturation using CBCT.
OBJECTIVES OF THE STUDY:-
1. To determine the cervical vertebrae maturation index (CVMI) using CBCT.
2. To determine the association between age and cervical vertebrae maturation index using CBCT.
3. To determine the association between sex and cervical vertebrae maturation index using CBCT.
Pre-treatment CBCT of 16 patients were taken and divided into 2 groups based on age, Group1: 8 patients of 10 – 12 years age and Group2: 8 patients of 13 – 15 years of age. Each group was divided into subdivision A and B based on gender consisting of 4 boys and 4 girls respectively.
· Between 10 to 15 years of age.
· Un co-operative patients.
· Patients with bone disorders.
· Medically compromised patients.
The CBCT images were interpreted on a computer and analyzed using the software -Planmeca Romexis viewer 3.2 version. The radiographic scans of the patients are converted into 3D images by Romexis software (Fig 1 and 2). The sagittal plane view was maximized and cervical vertebrae maturation index was assessed using Hassel and Farman’s method7 (Fig 3) on CBCT by a single observer (Fig 4-7).
Pre-treatment CBCT of 16 patients were taken and divided into 2 groups based on age and subdivided based on gender A and B consisting of 4 boys and 4 girls respectively. Cervical vertebrae development of the sample was evaluated by Hassel and Farman’s method on CBCT.
Mean CVMI of 1.75±0.96 was found among Group 1A patients and in Group 1B patients the mean CVMI was found to be 2.75±0.5. In Group 2A the mean CVMI was 3.75±0.5 whereas in Group 2B the mean CVMI was 5.25±0.5 (Table 1). There is a statistically significant difference between CVMI stages found among each group (Table 2).
The growth factor is a crucial variable in orthodontic treatment. A treatment plan can vary from orthognathic surgery to extraction of teeth to nonextraction of teeth depending on growth. By observing the cervical vertebrae on CBCT, the orthodontist can evaluate the skeletal maturity of the patient. A reasonable idea of how much growth should be factored into anticipated treatment can thus be obtained.
Lamparski2 was the first to suggest the use of cervical vertebrae to determine skeletal maturity. Later it was modified by Hassel and Farman7 in 1995.They proposed 6 stages of CVMI by using lateral profiles of the second, third, and fourth cervical vertebrae.
The aim of the present study was to evaluate the skeletal maturity of an individual by assessment of cervical vertebrae as seen on CBCT and to correlate the changes in the morphologic characteristics of cervical vertebrae maturation among males and females and among different age groups.
The results of the present study were compared to a similar study conducted by Laila Baidas, in Saudi adolescents27. The males with mean age of 10.75 years have a mean CVMI 1.75 which is comparable to the mean age group of 11.21 year old males having CVMI of 2 in the similar previous study. Similarly, males with mean age of 13.75 years have a mean CVMI 3.75 which is comparable to the mean age of 14.12 years old males having CVMI of 4 in the similar previous study.
The females with mean age of 11.5 years have a mean CVMI 2.75 which is comparable to the mean age group of 11.7 year old females having CVMI of 3 in the similar previous study. Similarly, females with mean age of 14 years have a mean CVMI 5.25 which is comparable to the mean age of 14.15 years old females having CVMI of 5 in the similar previous study. So the present study is in correlation to previously conducted studies. The small differences between mean CVMI of two studies may be due to variation in Saudi and Indian population.
In the present study, the mean CVMI among females (CVMI 2.75) was higher than males (CVMI 1.75) of the similar age group of 10-12 years. This may due to the increased mean age of females patients (11.5 years) than male patients (10.75 years) among the age group of 10-12 years. Whereas it was noticed that skeletal maturity in female subjects(CVMI 5.25) was much faster compared with male subjects(CVMI 3.75) who had similar mean age (13.75 and 14 years of males and females respectively) among the age group of 13-15 years. These findings are similar to results in the study conducted by Shi et.al (2007)28 which found that the developed segmentation algorithm separated individual cervical vertebrae successfully which was robust and efficient. Observed 3D cervical vertebral morphologic features from the 3 examples matched the known 2-dimensional sagittal shape changes of the cervical vertebra with respect to subject age and skeletal maturation. These results are also similar to the study conducted by Joshi et.al(2012)29 which concluded that cervical vertebrae maturity assessment with CBCT provided a reliable assessment of pubertal growth spurt, and therefore CBCT can be used to assess skeletal maturity.
It should be noted that skeletal maturation is a continuous process. Skeletal maturity indicators in the cervical vertebrae are categorized by distinct events in this continuous process. Each stage of maturation blends into the next, and it is sometimes difficult to differentiate borderline cases. Clinically, these differences should not be of great importance.
Because properly observed cervical vertebrae may provide a reliable assessment of the pubertal growth spurt, it would be beneficial to use CBCT for the assessment of skeletal maturity and thereby eliminate the need for an additional radiogram (hand-wrist radiography). Skeletal maturity can be assessed by observing morphologic changes in the cervical vertebrae with the use of CBCT. However, not every patient for orthodontic treatment requires CBCT scanning with a large FOV scanning protocol. Here it should be noted that CBCT should not be used solely for the purpose of evaluation of skeletal maturity; instead, when used as an investigating tool for the purpose of orthodontic treatment, then skeletal maturity should be assessed by observing morphologic changes in the cervical vertebrae and thus hand-wrist radiography can be avoided. This will not only reduce the cost but also reduce the radiation exposure to the patient.
In this study, a conventional cervical vertebrae maturation method (CVMI) using cervical vertebrae C2 and C3 was applied to assess skeletal maturation in CBCT images. Measured CVMI values were used to address the potential adaptation of the method in CBCT imaging and to provide directives for development of a three-dimensional cervical vertebrae maturation method. It was found that from this study CBCT can be used for assessing skeletal maturation using cervical vertebrae. However, further studies are required with larger sample size.