Abstract Growth of the maxilla and mandible can be evaluated by skeletal maturity assessments from hand-wrist radiographs; however, additional doses of radiation are required in spite of available panoramic radiographs from routine dental care. Therefore, this cross-sectional study aimed to evaluate the correlation between the Demirjian tooth development method from panoramic radiographs and Fishman skeletal maturity from hand-wrist radiographs in a population in southern Thailand. We further aimed to appraise skeletal age from dental development easily seen on a routine panoramic radiograph. Samples consisted of 328 pairs of radiographs (177 males and 151 females) aged between 9 and 15 years. The Demirjian tooth development method identified tooth development in stages from A to H of the left mandibular canine, first and second premolars, and the second molar. Fishman identified 11 skeletal growth indicators (SMIs) that can be grouped into three growth periods: pre-peak (SMI 1-4), peak (SMI 5-7), and post-peak (SMI 8-11). The relationship was analyzed using Spearman correlation coefficients. The results found that tooth 34 and tooth 37 in males demonstrated potential as reliable indicators to identify the transition from pre-peak to peak growth periods. However, in females, the peak period showed considerable variability and overlapping that made it challenging to pinpoint the peak period with certainty. However, teeth 33, 34, 35, and 37 clearly identified the pre-peak and post-peak growth periods. Therefore, additional diagnostic methods may be necessary to accurately identify the peak growth period for clinical decision-making.

Keywords: Hand-wrist radiograph, Panoramic radiograph, Skeletal maturity, Thai population, Tooth development

Funding: This research project was supported by Research and Academic Service’s Fund, Grant Number MD67-08, School of Medicine, University of Phayao.

Citation: Nabheerong, P., Duangto, P., Jeamtrakool, S., Charoemratrote, C., and Theerasopon, P. 2025. Relationship agreement between demirjian tooth development and fishman skeletal maturity in Thai children and adolescents. Natural and Life Sciences Communications. 24(4): e2025057.

INTRODUCTION

Growing patients in mixed dentition and early permanent dentition have numerous physical changes in the whole body that offer several parameters for evaluation that include chronological age, skeletal age, dental development, height, weight, and secondary characteristics. In orthodontic treatment, the desirable outcome is good occlusion on the alveolar bone housing. In order to achieve this goal, growth of the maxilla and mandible must be considered. Therefore, a skeletal growth evaluation in growing patients is needed to obtain the essential data for a diagnosis, treatment plan, treatment goal, and an evaluation of the treatment results (Theerasopon and Karnpanich, 2020). A skeletal growth assessment from a hand-wrist radiograph is considered to be the most reliable method to indicate skeletal growth (Flores-Mir et al., 2004). However, hand-wrist radiographs require additional radiation beyond the routine dental radiographs. Fishman (1982) described skeletal maturity from hand-wrist radiographs into 11 skeletal maturity indicators (SMIs) from the onset of pubertal growth (SMI 1-4) through the pubertal growth spurt (SMI 5-7) until the cessation of pubertal growth (SMI 8-11). The SMI results can cross-sectionally indicate the clinical stage of skeletal maturation.

A panoramic radiograph is one of the routine dental imaging methods widely used by orthodontists and all dentists. It provides an X-ray image of both jaws and teeth but the ratio and proportion of the structures are distorted in the X-ray process. In spite of the distortion, the development of all teeth can be clearly seen in a panoramic radiograph and allows for categorization of the development stages according to the Demirjian et al. classification method (Demirjian et al., 1973).

If the association between skeletal maturity and tooth development can be shown to be sufficiently strong, evaluating dental development from a panoramic radiograph might become a screening tool to assess the level of skeletal maturity that would replace hand-wrist radiographs. It was reported that tooth development from the Demirjian et al. classification offered perfect discrimination, accuracy, and reproducibility (Theerasopon et al., 2024).

Both skeletal maturity and tooth development are factors that are mostly affected by genetics and less affected by environmental and nutritional factors. Previous studies found various relationships between skeletal maturity and tooth development due to ethnic and racial differences (Krailassiri et al., 2002; Kumari et al., 2022). However, little is known of these associations in the Thai population, especially in the southern region of Thailand where the weather, skin color, food, and other factors are different from other regions of Thailand. Therefore, this study aimed to assess the relationship between skeletal maturity and tooth development in a population of southern Thailand.

MATERIAL AND METHODS

Sample collection

The research protocol of this study obtained ethical approval from the Human Research Ethics Committee of the Faculty of Dentistry, Prince of Songkla University, Songkhla, Thailand (EC 6707-035). This cross-sectional study required samples of radiographs that consisted of 1) digital panoramic radiographs and 2) digital hand-wrist radiographs that were obtained from the Dental Hospital, Faculty of Dentistry, Prince of Songkla University, Songkhla, Thailand. The radiographs were acquired in JPEG file format using the GXDP-700 PANOREX + cone beam machine (Gendex Dental Systems, Hatfield, PA, USA) between 2015 and 2024. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist with all relevant aspects was reported (Supplementary Table 1).

A sample size calculation was done using G*Power software version 3.1.9.7 by a correlation test with a study power of 95%, and the significance level was set at 5% with an effect size of 0.2. The minimum calculated sample size was 327 samples. Digital radiographs of 328 samples (177 males and 151 females) aged 9-15 years old who were registered in the southern region of Thailand were randomly sampled into this study. The exclusion criteria applied to all radiographs included unclear radiographs, extracted or missing tooth in the panoramic radiographs, and patients who previously received orthodontic treatment or were currently under treatment. The demographic data, which included sex, date of birth, and date of the radiograph taken, were confidentially recorded by one board certified orthodontist (PT). The chronological age was expressed as years with two decimal numerals, which was calculated by subtraction of the birth date from the radiograph date.

Assessment of dental and skeletal maturation

The eight stages (A to H) of tooth development according to the Demirjian et al. classification method (Demirjian et al., 1973) were determined from the digital panoramic radiographs of the mandibular left canine (tooth 33), first premolar (tooth 34), second premolar (tooth 35), and the second molar (tooth 37) (Table 1). Skeletal maturity (SMI 1 to 11) according to the Fishman classification (Fishman, 1982) were evaluated from digital hand-wrist radiographs (Table 2). The 11 stages were then grouped into three periods of growth based on the timing of pubertal growth. SMI stages 1-4 were designated as the pre-pubertal growth stage, SMI stages 5-7 were designated the pubertal growth stage, and SMI 8-11 stages were designated the post-pubertal growth stage. Each dental and skeletal maturation stage were separately evaluated by two board certified radiologists (PN, SJ).

Table 1. Definitions of tooth development stages according to the Demirjian classification (Demirjian et al., 1973).

Table 2. Definitions of skeletal maturity indicators (SMIs) according to the Fishman classification (Fishman, 1982).

Statistical analysis

The data were analyzed using SPSS Statistics for Windows, version 26.0 (IBM Inc., Chicago, IL, USA) by another author (PD). Descriptive statistics were reported as mean, standard deviation, minimum and maximum of samples grouped by the three SMI periods for males and females. Spearman’s rank correlation coefficients between dental development using the Demirjian classification and skeletal maturation using the Fishman method for males and females were separately analyzed with a significance level of 0.01. Forty panoramic radiographs and 40 hand-wrist radiographs were randomly reassessed for intra-observer agreement one month after the first assessment by the same radiologist who was blinded for each assessment. In addition, 40 radiographs were evaluated between two radiologists for inter-observer agreement, and Cohen’s Kappa value was used to indicate the level of agreement.

RESULTS

The distribution of the study subjects according to the SMIs categorized into three periods as pre-peak (SMI 1-4), peak (SMI 5-7), and post-peak (SMI 8-11) is presented in Table 3. The mean chronological ages for each period of skeletal maturity were consistently older in male subjects. The mean chronological age of the male group was older than the female group by approximately 1.18 years (range, 1.04 years through 1.31 years). The reproducibility of all assessments was found to be almost perfect with high values. Cohen’s Kappa values of intra-observer agreement were 0.940 for the SMI and 0.898-0.913 for the tooth assessment. The inter-observer agreement was found to be 0.850 for the SMI and 0.814-0.874 for tooth assessment (Table 4).

The relationships between the skeletal maturity stages from the hand-wrist radiographs and tooth development of the four mandibular teeth (33, 34, 35, and 37) are shown in Table 5. The Spearman correlation coefficients ranged from 0.577 to 0.728 for male subjects and from 0.551 to 0.684 for female subjects. Tooth 37 was found to have the highest correlation in both sexes (0.728 [males] and 0.684 [females], P < 0.01). Tooth 33 was found to have the lowest correlation in both sexes (0.557 [males] and 0.551 [females], P < 0.01).

The percentage distributions for the relationship between the Demirjian et al. classification of individual teeth in the three SMI periods are shown in Tables 6-11. In the pre-peak period (SMI 1-4) in male subjects (Table 6), teeth 33, 34, and 35 had the highest percentages in stage G, which were 74.07%, 68.52%, and 75.93%, respectively. However, tooth 37 had the highest percentage in stage F (57.41%). In female subjects (Table 7), teeth 33, 34, and 35 had the highest percentages in stage F, which were 65.00%, 75.00%, and 80.00%, respectively. However, no obvious tooth development stage for tooth 37 was determined, which had a percentage distribution greater than 50%.

In the peak period (SMI 5-7) in male subjects (Table 8), teeth 33, 35, and 37 had the highest percentages in stage G, which were 72.29%, 59.04%, and 65.06%. However, tooth 34 had the highest percentage in stage H (62.65%). In female subjects (Table 9), tooth 33 had the highest percentage in stage H (50.00%).

In the post-peak period (SMI 8-11) in male subjects (Table 10), teeth 33, 34, and 35 had the highest percentages in stage H, which were 70.00%, 95.00%, and 80.00%. However, tooth 37 had the highest percentage in stage G (55.00%). In female subjects (Table 11), teeth 33, 34, and 35 had the highest percentages in stage H, which were 77.78%, 69.84%, and 52.38%.

Table 3. Descriptive statistics of the samples grouped by skeletal maturity indicators (SMIs).

Table 4. Cohen’s Kappa values of skeletal maturation using the Fishman method and dental development using the Demirjian classification.

Table 5. Spearman correlation coefficients between dental and skeletal maturation stages for males and females.

Note: ** Correlation is significant at the 0.01 level

Table 6. Percentage distribution of the Demirjian classification of individual teeth at SMI stages 1-4 for males.

Table 7. Percentage distribution of the Demirjian classification of individual teeth at SMI stages 1-4 for females.

Table 8. Percentage distribution of the Demirjia classification of individual teeth at SMI stages 5-7 for males.

Table 9. Percentage distribution of the Demirjian classification of individual teeth at SMI stages 5-7 for females.

Table 10. Percentage distribution of the Demirjian classification of individual teeth at SMI stages 8-11 for males.

Table 11. Percentage distribution of the Demirjian classification of individual teeth at SMI stages 8-11 for females.

DISCUSSION

Panoramic radiographs are routinely used in dental practice because they clearly reveal the crown and root structures of teeth (Proffit et al., 2018). This imaging modality also offers a comprehensive view of the dental arches and is particularly useful in screening, diagnosing, and treatment planning in clinical dental practice. However, panoramic radiographs do not provide information regarding the overall skeletal growth status of an individual, which is a critical factor in orthodontic treatment timing, especially for interventions that rely on growth modification (Krailassiri et al., 2002).

In contrast, hand-wrist radiographs have been widely recognized for their accuracy in assessing skeletal maturity and predicting the timing of the pubertal growth spurt (Grave and Brown, 1976). However, the routine use of hand-wrist radiographs in orthodontic practice is limited due to concerns of radiation exposure in addition to the routine panoramic radiographs (Flores-Mir et al., 2004). If a strong correlation can be established between panoramic radiographs and hand-wrist radiographs, panoramic radiographs may serve as a screening tool to estimate skeletal growth phases. A strong correlation would reduce the need for additional hand-wrist radiographs until the timing of the peak growth period is suspected.

The Demirjian tooth development method is a radiographic analysis that is widely used to evaluate tooth development stages. This method focuses on crown and root formation and is categorized into eight stages from A to H based on the morphological progression of each tooth (Demirjian et al., 1973). The method emphasizes the visibility of enamel, dentin, and root structures rather than solely relying on absolute tooth size. The Demirjian tooth development method demonstrates strong intra- and inter-observer reliability, which makes it a valuable method to assess dental growth. Its consistency in dental staging reinforces its role as a standard technique in pediatric dentistry and forensic sciences (Liversidge et al., 2003; Jayaraman et al., 2013).

The Fishman SMIs consist of 11 sequential stages based on epiphyseal and metaphyseal changes in specific bones of the hand and wrist. These include the middle phalanx, distal phalanx, radius, and ulnar sesamoid. The method requires only a hand-wrist radiograph, which makes it practical, fast, and non-invasive. It is especially beneficial for orthodontists who need to determine the timing for jaw growth modification treatments (Baccetti et al., 2005). To evaluate the correlation between tooth development and skeletal maturity, Fishman skeletal maturity can be reclassified into three periods of growth status: pre-peak (SMI 1-4), peak (SMI 5-7), and post-peak (SMI 8-11) (Fishman, 1987; Upalananda et al., 2024). SMI 5-7 aligns with the peak pubertal growth spurt, which is critical for orthodontic interventions such as growth modification (Flores-Mir et al., 2004). 

Our findings revealed that male subjects consistently exhibited higher mean chronological ages across all skeletal maturity stages, being on average approximately 1.18 years older than their female counterparts (Table 3). These results align with those of Chertkow who examined the correlation between the early appearance of the ulnar sesamoid and tooth mineralization in a study in South Africa (Chertkow, 1980). Chertkow’s research similarly found that males demonstrated a significantly more advanced pattern of tooth calcification. Based on these observations, it is recommended that tooth mineralization be assessed separately for males and females in relation to skeletal maturation stages.

Our study confirmed a significant correlation between dental and skeletal maturation stages with tooth 37, which demonstrated the strongest association in both males (0.728) and females (0.684) (Table 5). This finding is in line with a previous study (Uysal et al., 2004) that explored the relationship between tooth mineralization stages and skeletal maturity indicators.

In the present study, distinct patterns were observed in males across different growth periods. During the pre-peak period, most teeth, which included teeth 33, 34, and 35, were found in Demirjian stage G, while tooth 37 was typically in stage F. As subjects transitioned into the peak period, tooth 37 progressed to stage G along with teeth 33 and 35, while tooth 34 advanced further into stage H. In the post-peak period, teeth 33, 34, and 35 reached stage H, whereas tooth 37 remained in stage G. These findings suggest that tooth 34 and tooth 37 serve as useful indicators for identifying the transition from pre-peak to peak period. Specifically, the combination of tooth 34 in stage G and tooth 37 in stage F may indicate the optimal timing for growth modification. In contrast, the presence of teeth 33, 34, and 35 in stage H, along with tooth 37 in stage G, may reflect a post-peak period, which suggests that growth-based treatment options may be less effective, and alternative approaches should be considered.

In females, the patterns were less clearly defined. During the pre-peak period, teeth 33, 34, and 35 were generally found in stage F, while in the post-peak period, they had progressed to stage H. However, in the peak period, increased variability was observed and no consistent stage pattern could be clearly established except the changing of teeth 33 and 34 from stage F to stage G or H. This suggests that, in females, relying solely on dental calcification stages may be insufficient to accurately identify the pubertal growth spurt, and additional skeletal or hormonal markers may be necessary to precisely determine the peak period.

CONCLUSION

In males, tooth 34 and tooth 37 demonstrated the potential to be reliable indicators to identify the transition from the pre-peak growth period to the peak growth period. Specifically, when tooth 34 is at stage G and tooth 37 is at stage F, this combination suggests that the individual is entering the peak growth period, which indicates the optimal time for orthodontic treatment planning. In contrast, among females the pre-peak and post-peak periods are relatively distinguishable; however, the peak period itself shows considerable variability and overlap that makes it challenging to pinpoint with certainty. Therefore, in female subjects, additional diagnostic methods may be necessary to accurately identify the peak growth period for clinical decision-making.

ACKNOWLEDGMENTS

The authors are grateful for support that was facilitated from the Dental Hospital, Faculty of Dentistry, Prince of Songkla University, Songkhla, Thailand.

AUTHOR CONTRIBUTIONS

Conceptualization: Pornpat Theerasopon, Pennipat Nabheerong and Phuwadon Duangto. Data acquisition: Chairat Charoemratrote, Pennipat Nabheerong and Suttiwat Jeamtrakool. Data analysis or interpretation: Pornpat Theerasopon, Phuwadon Duangto, Pennipat Nabheerong and Suttiwat Jeamtrakool. Drafting of the manuscript: Pornpat Theerasopon, Pennipat Nabheerong, Phuwadon Duangto and Chairat Charoemratrote. Critical revision of the manuscript: Pornpat Theerasopon and Pennipat Nabheerong. Approval of the final version of the manuscript: all authors.

CONFLICT OF INTEREST

The authors declare that they hold no competing interests.

REFERENCES

Baccetti, T., Franchi, L., and McNamara, J.A. 2005. The cervical vertebral maturation (CVM) method for the assessment of optimal treatment timing in dentofacial orthopedics. Seminars in Orthodontics. 11(3): 119-129.

Chertkow, S. 1980. Tooth mineralization as an indicator of the pubertal growth spurt. American Journal of Orthodontics and Dentofacial Orthopedics. 77(1): 79-91.

Demirjian, A., Goldstein, H., and Tanner, J.M. 1973. A new system of dental age assessment. Human Biology. 45(2): 211-227.

Fishman, L.S. 1982. Radiographic evaluation of skeletal maturation. A clinically oriented method based on hand-wrist films. Angle Orthodontist. 52(2): 88-112.

Fishman, L.S. 1987. Maturational patterns and prediction during adolescence. Angle Orthodontist. 57(3):178-193.

Flores-Mir, C., Nebbe, B., and Major, P.W. 2004. Use of skeletal maturation based on hand-wrist radiographic analysis as a predictor of facial growth: A systematic review. Angle Orthodontist. 74(1): 118-124.

Grave, K.C. and Brown, T. 1976. Skeletal ossification and the adolescent growth spurt. American Journal of Orthodontics and Dentofacial Orthopedics. 69(6): 611-619. 

Jayaraman, J., Wong, H.M., King, N.M., and Roberts, G.J. 2013. The French-Canadian data set of Demirjian for dental age estimation: A systematic review and meta-analysis. Journal of Forensic and Legal Medicine. 20(5): 373-381.

Krailassiri, S., Anuwongnukroh, N., and Dechkunakorn, S. 2002. Relationships between dental calcification stages and skeletal maturity indicators in Thai individuals. Angle Orthodontist. 72(2): 155-166.

Kumari, S., Sahu, A.K., Rajguru, J., Bishnoi, P., Garg, A.J., and Thakur, R. 2022. Age estimation by dental calcification stages and hand-wrist radiograph. Cureus. 14(9): e29045.

Liversidge, H.M., Lyons, F., and Hector, M.P. 2003. The accuracy of three methods of age estimation using radiographic measurements of developing teeth. Forensic Science International. 131(1): 22-29.

Proffit, W.R., Fields, H., Larson, B., and Sarver, D.M. 2018. Contemporary orthodontics, 6th ed. St Louis, Mo; Mosby Elsevier, Missouri.

Theerasopon, P. and Karnpanich, N. 2020. Growth assessment of maxilla and mandible for orthodontic treatment planning. Online Journal of Thai Association of Orthodontics. 10(1): 32-39.

Theerasopon, P., Woratanarat, W., Saiwong, N., Netprakon, N., Charoemratrote, C., and Duangto, P. 2024. Accuracy of age estimation method using dental radiographs of permanent mandibular second molars in a southern Thailand population. Natural and Life Sciences Communications. 23(3): e2024030.

Upalananda, W., Kanjanaprapas, A., and Thongudomporn, U. 2024. Skeletal growth status agreement in a group of Thai children and adolescents: A comparative analysis of Fishman's skeletal maturation and Baccetti's cervical vertebral maturation indices. Natural and Life Sciences Communications. 23(2): e2024025.

Uysal, T., Sari, Z., Ramoglu, S., and Basciftci, F. 2004. Relationships between dental and skeletal maturity in Turkish subjects. Angle Orthodontist. 74: 657-664.

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Supplementary Table 1. STROBE Statement—checklist of items that should be included in reports of observational studies.

*Give information separately for cases and controls in case-control studies and, if applicable, for exposed and unexposed groups in cohort and cross-sectional studies.

Note: An Explanation and Elaboration article discusses each checklist item and gives methodological background and published examples of transparent reporting. The STROBE checklist is best used in conjunction with this article (freely available on the Web sites of PLoS Medicine at http://www.plosmedicine.org/, Annals of Internal Medicine at http://www.annals.org/, and Epidemiology at http://www.epidem.com/). Information on the STROBE Initiative is available at www.strobe-statement.org.