Home About us Editorial board Ahead of print Current issue Archives Submit article Instructions Subscribe Search Contacts Login 
  • Users Online: 1176
  • Home
  • Print this page
  • Email this page


 
 Table of Contents  
ORIGINAL ARTICLE
Year : 2015  |  Volume : 27  |  Issue : 2  |  Page : 183-188

Mandibulo-osseous predictors of osteoporosis: A double-blind study on the correlation and comparison of mental index with bone mineral density in post-menopausal women


1 Department of Oral Medicine and Radiology, Panineeya Mahavidhyalaya Institute of Dental Sciences and Research Centre, Hyderabad, Telangana, India
2 Department of Oral Medicine and Radiology, Sri Sai College of Dental Surgery, Vikarabad, Telangana, India
3 Department of Pediatric and Preventive Dentistry, G Pulla Reddy Dental College and Hospital, Kurnool, Andhra Pradesh, India
4 Department of Oral and Maxillofacial Pathology, Government Dental College and Hospital, Hyderabad, India

Date of Submission25-Oct-2014
Date of Acceptance17-Oct-2015
Date of Web Publication21-Nov-2015

Correspondence Address:
Shefali Waghray
86, Gruhalaxmi Colony, Vikrampuri, Secunderabad - 500 015, Telangana
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0972-1363.170134

Rights and Permissions
   Abstract 

Introduction: Osteoporosis is a metabolic bone disease characterized by microarchitectural deterioration in bone tissue leading to fractures, and is essentially a preventable disease when detected in the early stages. Novel methods for early identification of osteoporosis can have a great impact in combating this otherwise progressive disease. Aims: The present study was conducted with the objectives of evaluating the precision of a radiomorphometric index [mental index (MI)] measured on a panoramic radiograph in early diagnosis of osteoporosis and finding its correlation with bone mineral density (BMD) measured by digital X-ray radiogrammetry method. Materials and Methods: The study consisted of 71 women who were in natural menopause. The MI was calculated by two investigators, with each investigator recording two sets of measurements. The BMD was assessed and the T-score was obtained by digital X-ray radiogrammetry method. Based on the T-score obtained, the patients were divided into three study groups of normal (n = 24), osteopenic (n = 30), and osteoporotic (n = 17). The values obtained were tabulated for statistical analysis. Results: In the present study, it was found that there was a statistically significant difference in the mean scores of MI among normal, osteopenic, and osteoporotic subjects. Normal subjects had significantly higher MI (P < 0.001) than the osteopenic subjects and, similarly, the osteopenic subjects had significantly higher MI (P < 0.001) than the osteoporotic subjects. The inter- and intra-investigator variability was found to be low. Conclusion: Based on the results of the present study, it was concluded that a simple radiomorphometric index (MI) which is relatively easier to measure on a panoramic radiograph can be an indicator of osteoporosis and may aid in early detection and treatment planning of one of the most prevalent metabolic bone diseases.

Keywords: Digital radiogrammetry, mental index, osteoporosis, panoramic radiograph


How to cite this article:
Waghray S, Velpula N, Dara BG, Duddu MK, Narayen V, Allam NS. Mandibulo-osseous predictors of osteoporosis: A double-blind study on the correlation and comparison of mental index with bone mineral density in post-menopausal women. J Indian Acad Oral Med Radiol 2015;27:183-8

How to cite this URL:
Waghray S, Velpula N, Dara BG, Duddu MK, Narayen V, Allam NS. Mandibulo-osseous predictors of osteoporosis: A double-blind study on the correlation and comparison of mental index with bone mineral density in post-menopausal women. J Indian Acad Oral Med Radiol [serial online] 2015 [cited 2021 Jul 29];27:183-8. Available from: https://www.jiaomr.in/text.asp?2015/27/2/183/170134


   Introduction Top


Osteoporosis is defined as a skeletal disorder characterized by low bone mass leading to enhanced bone fragility and consequent increase in fracture risk. [1] Human skeleton undergoes a continuous physiologic decrease in bone mass with advancing age. Women lose more mineralized bone than men, especially after menopause. With advancing disease, bone loss and fractures may ensue. Since the disease is preventable, diagnostic techniques which can identify osteoporosis are of major importance. Groen et al. were the first to suggest an association between osteoporosis and oral bone loss in the year 1960. [2] A number of investigators have stated the importance of a panoramic radiograph in the detection of progressive loss of alveolar bone as a manifestation of osteoporosis. [3],[4],[5] In the last four decades, various researchers have reported osteoporosis to be diagnosable through oral radiographs. In previous studies, it was reported that the radiographic trabecular pattern shows correlation with bone mineral density (BMD). [6],[7] But measurement of such a pattern on a radiograph is time consuming and difficult in a normal dental setup. Reproducibility of the radiomorphometric indices is of major importance in using them as screening tools for osteoporosis. This study focuses on the reliability of a simple parameter like cortical width measured along the mental foramen [mental index (MI)] in assessment of risk of osteoporosis. The aim of this study was to evaluate the usefulness of MI in screening for osteoporosis and to determine whether it correlates with the BMD determined by digital X-ray radiogrammetry (DXR) method.


   Materials and Methods Top


Seventy-one women living in Hyderabad who were in natural menopause with no known systemic conditions were randomly chosen for the study. The study was approved by the local ethics committee and informed consent was obtained from each subject. Inclusion criterion for the study was women over 60 years of age in natural menopause. Subjects on medications such as glucocorticoids, anticonvulsants, gonadotropin releasing hormone, excessive thyroxin doses, lithium, and calcium supplements were excluded from the study. With the intention of blinding the study, four oral radiologists were recruited as volunteers and were assigned as two observers and two investigators. The personal details and past medical history, along with time elapsed since menopause were recorded and maintained by Observer I. The subjects were coded and the information about the subjects was blinded to both the investigators in order to eliminate information bias. Hand-wrist and panoramic radiographs were taken. All the radiographs were taken following a standardized patient positioning and imaging technique on the Planmeca Proline EC 2002 machine by the same investigator each time (Investigator I). The panoramic image was standardized by correctly determining the patient position, head alignment, and the same investigator took all the radiographs each time. The density and contrast were further assessed by the investigators and any radiographs which were not in the standard range of quality were excluded from the study. After exposure, the image processing and archiving was done using the DurrVistaScan workstation and digital images were obtained.

Calculation of the radiomorphometric MI

All measurements were made in millimeters on the digital image with the inbuilt linear measurement scale in the DurrDBSWIN Vista software (version 3.2). Two sets of measurements were recorded by two investigators in a duration of 1 week for the evaluation of intra-investigator and inter-investigator reliability. When the mental foramen was visible bilaterally, the measurements were made bilaterally and their mean was used as the exposure measure in the analysis. When only one mental foramen was visible, the measurements were done only on that side. The inferior edge of the mental foramen was located and a line parallel to the long axis of the mandible and tangential to the inferior border of the mandible was drawn. A line perpendicular to this tangent intersecting the inferior border of the mental foramen was constructed. The cortical width for the MI was measured along this line. MI was calculated as the width of the cortex along the line perpendicular to the tangent intersecting the inferior border of the mental foramen [Figure 1] and [Figure 2].
Figure 1: Calculation of mental index (MI) along the perpendicular drawn from the inferior border of the mental foramina to the inferior border of the mandible (h)

Click here to view
Figure 2: Cropped panoramic radiograph showing the MI measurements along the mandibular cortex

Click here to view


Calculation of the BMD

The BMD was calculated using the DXR method. The cortical thickness of the three middle metacarpal bones in the hand was measured in a digital X-ray image by a computer using the Pronsco X-posure system software and BMD was expressed as T-score [the number of standard deviations (SD) above or below the mean BMD values for a young healthy adult] and Z-score (the number of SD above or below the mean BMD values for a population of the same age and gender). Based on the 1994 World Health Organization (WHO) report, [8] the subjects were divided as normal (T-score −1 and above), osteopenic (T-score lower than −1 and greater than −2.5), and osteoporotic (T-score of −2.5 or lower) [Figure 3]. Unblinding of the study was done and all the readings obtained from Investigator I and Investigator II were tabulated for statistical analysis.
Figure 3: Sample distribution among the study groups

Click here to view



   Results Top


Two sets of readings of MI obtained by the two investigators were tabulated and the average obtained. A magnification factor of 20%, as specified by the manufacturer of the panoramic machine (Planmeca Proline EC 2002), was subtracted from the averages obtained. The final readings of MI, along with the T-score, obtained for normal, osteopenic, and osteoporotic subjects were distributed among the samples [Figure 3]. The statistical analysis was done using SPSS version 14. A P-value of <0.05 was set to be statistically significant. The results were tabulated and graphs obtained. All the values obtained were in millimeters. Mean scores of MI among the three groups of normal, osteopenic, and osteoporotic were obtained and their standard deviations were calculated. Comparison of means between all the groups was done using analysis of variance (ANOVA) followed by post-hoc Tukey's honest significant difference (HSD) test [Table 1]. A correlation of the MI values was done with the study groups using the Pearson correlation coefficient analysis [Table 2].
Table 1: Comparison of mean MI among the study groups

Click here to view
Table 2: Correlation of MI with bone mineral density scores (T-score) within groups using Pearson correlation

Click here to view


Comparison of MI and BMD

The MI scores were compared with the BMD scores. It was found that in 24 subjects showing normal BMD, the MI ranged from 2.32 to 4.74 with a mean of 3.97. In 30 osteopenic subjects, the MI ranged from 2.48 to 4.86 with a mean of 3.35. In the 17 osteoporotic subjects, the MI ranged from 0.78 to 3.5 with a mean of 2.13. Post-hoc test revealed that normal subjects had a significantly higher MI (P < 0.001) than osteopenic and osteoporotic subjects and, similarly, osteopenic subjects had a significantly higher MI (P < 0.001) than osteoporotic subjects [Figure 4].
Figure 4: Comparison of mental index (MI) among groups, where the vertical axis represents mean MI and the horizontal axis represents the T-score

Click here to view


Correlation of MI with the BMD scores within groups

Correlation of MI was done with the study groups using the Pearson correlation coefficient. It was found that there was a significant (P = 0.01) moderate to strong (MI) correlation at 0.01 level (two-tailed) with the study groups. Within each group also, it was found that MI was moderately correlating with BMD scores in osteopenic (P = 0.05) and osteoporotic (P = 0.05) patients. Hence, the results show that as the BMD increased from osteoporotic to normal, the radiographic measurements also increased [Table 2].

Reliability of MI

In measuring the MI, the intra-investigator reliability ranged from 0.980 to 0.988 and the inter-investigator reliability ranged from 0.964 to 0.980. A strong correlation was found between the measurements of each investigator and the measurements of the two investigators [Table 3].
Table 3: Inter- and intra-examiner reliability of MI measurements

Click here to view



   Discussion Top


Osteoporosis is characterized by decrease in BMD and microarchitectural deterioration in bone tissue leading to fractures. An osteoporotic fracture is a fracture of bone caused due to compromised bone strength, and commonly occurs in the vertebral bodies and distal radius, both sites composed predominantly of medullary bone. [1] According to the US National Osteoporosis Foundation (NOF), bone deterioration is greater in women, especially postmenopausal women, compared to men. Women in their eighth decade have a 10 times greater risk of being osteoporotic than women in their fifth decade. [8] In women, the risk of developing osteoporotic fractures after the age of 50 years is estimated to be 40-50%, similar to that of coronary heart disease. It has been reported that only one-third of the patients surviving a hip fracture regain their original level of function. [9] The debilitating effects of osteoporosis may have dramatic outcomes in terms of morbidity, mortality, and cost of health care. It was found that post-menopausal women receiving anti-resorptive drugs obtain a 5-10% increase in BMD which reduces the risk of osteoporotic fractures. [10] Hence, there is a pressing need to establish effective strategies for early diagnosis of osteoporosis. Various methods have been employed to determine the BMD, which include dual-energy X-ray absorptiometry (DXA and DEXA), quantitative computed tomography (QCT), qualitative ultrasound (QUS), single-photon absorptiometry (SPA), dual-photon absorptiometry (DPA), DXR, and single-energy X-ray absorptiometry (SEXA). DXR is a highly precise BMD measure in which the cortical thickness of the three middle metacarpal bones in the hand is measured in a digital X-ray image and is converted to the forearm BMD through a geometrical operation. Because of its high precision, DXR is the technique of choice used to measure small changes in BMD that occur over time, and hence is more effective in monitoring changes that occur naturally on aging. [11]

In a dental setting, a panoramic radiograph is commonly taken. Hence, it will be very useful if this radiograph can hint the possibility of the patient being osteoporotic. Although a review of literature has revealed studies indicating that a panoramic radiograph may be one of the tools that can be used to identify individuals with low BMD and high risk of osteoporotic fracture, [12],[13],[14],[15] the present study focuses on the use of a simple radiomorphometric index (MI) measured on a panoramic image which is easy to calculate and can be done on a routine basis. The study was double blinded and the aforementioned index was calculated and compared in normal, osteopenic, and osteoporotic subjects. To curtail intrinsic errors and observer variability, the present study involved two sets of readings calculated by two different investigators. Inter- and intra-investigator reliability was assessed using the intra-class correlation coefficients. A strong correlation was found between the measurements of each investigator and the measurements of the two investigators. This was in accordance to the results of a study conducted by Yaşşar and Akgünlüü, [16] in which a strong correlation was found in the intra-examiner measurements. However, inter-examiner reliability was not assessed for the same.

In the present study, it was found that there was a statistically significant difference in the mean scores of MI among normal, osteopenic, and osteoporotic subjects. Normal subjects had significantly higher MI (P < 0.001) than the osteopenic ones and, similarly, the osteopenic subjects had significantly higher MI than the osteoporotic subjects. This was in accordance with the finding of Devlin and Horner. [14] In a recent Turkish study conducted by Gulsahi et al., [17] it was found that the values of MI were significantly lower in increased age group, and they proposed that an MI value of less than 3 mm may be seen as high risk for osteoporosis indicating the need for further advanced osteoporosis investigations. In the present study, a similar finding was observed wherein the MI in osteoporotic subjects was in the range of 0.78-3.5 with a mean of 2.13. Although the conclusion was supported by the large sample size used, the limitation was that no data was collected on age, gender, medical status, and bone densitometry. The advantage of the present study was that data were collected based on age, gender, medical status, and bone dosimetry. Furthermore, the present study was double blinded, wherein two investigators and two observers were used to curtail bias and intrinsic errors, thereby having a high reliability of the index. Bone dosimetry method employed in the present study is a highly precise method and a technique of choice used to measure small changes in BMD that occur over time. [11]

Obtaining better results is easier when gross changes like width of the inferior border, length of the teeth, etc., are measured than measuring parameters like the morphology of the superior border of the inferior cortex, which depends on the visual perception and entails high examiner variability. Reproducibility of an index is of utmost importance in using it for the assessment of osteoporosis. Hence, our study involved the MI, which is more reproducible in a dental setting. Dutra et al.[18] stressed on the efficacy of MI over other indices as the status of the mandibular dentition does not influence this index. In another study conducted by Bras et al.[19] in the University of Amsterdam, the authors reported that a relatively constant thickness of cortical bone at the mandibular angle following adolescent growth and the decrease in cortical thickness in post-menopausal women suggested that the cortical thickness may be useful as a parameter in determining metabolic bone loss. In a similar type of study conducted by Kribbs [20] in the University of Washington, mandibular measurements were compared with the measurements of bone mass in the spine and the wrist. Mandibular bone mass was not significantly affected with increase in age, but mandibular bone mass significantly correlated with skeletal bone mass and cortical thickness decreased with age. Correlational analysis in the present study showed that within each group, MI was moderately correlating with BMD scores in osteopenic patients and osteoporotic patients (P = 0.05). Hence, it was found that as BMD increased from osteoporotic to normal, the value of MI also increased. This was in conjunction with the findings of studies conducted by Khojastehpour et al.[21]

Limitations

Although the study included a highly reproducible index, the reliability of other known indices like Panoramic Mandibular Index (PMI), Gonial Index (GI), and Body Mass Index (BMI) was not assessed in the present study. Furthermore, a larger sample size on a wider stretch of population would aid in determining a cut-off value of the cortical width (MI) to find the stage of osteoporosis in post-menopausal women. This would add momentum to the research in this area and explain why variations in values occurred in some demographic regions.


   Conclusion Top


The present study compared the diagnostic information obtained from MI calculated on a panoramic image with the BMD in the assessment of osteoporosis and concluded that there was a statistically significant decrease in the cortical width (MI) in the study groups from normal to osteoporotic. The inter- and intra-investigator variability was low. Furthermore, MI correlated significantly with BMD scores. The authors conclude that MI is a simple and reliable radiomorphometric index which can possibly prove as a predictor of osteoporosis in undiagnosed cases, thereby helping in early treatment planning and effective management of the disease.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
   References Top

1.
Johari Khatoonabad M, Aghamohammadzade N, Taghilu H, Esmaeili F, Jabbari Khamnei H. Relationship among panoramic radiography findings, biochemical markers of bone turnover and hip BMD in the diagnosis of postmenopausal osteoporosis. Iran J Radiol 2011;8:23-8.  Back to cited text no. 1
    
2.
Groen JJ, Duyvensz F, Halsted JA. Diffuse alveolar atrophy of the jaw (non-inflamatory form of paradental disease) and pre-senile osteoporosis. Gerontol Clin (Basel) 1960;2:68-86.  Back to cited text no. 2
    
3.
Jagelaviciene E, Krasauskiene A, Zalinkevicius R, Kubilius R, Vaitkeviciene I. The relationship between the calcaneal bone mineral density and the mental index in post-menopausal females. Dentomaxillofac Radiol 2013;42:20120050.  Back to cited text no. 3
    
4.
Devlin H, Karayianni K, Mitsea A, Jacobs R, Lindh C, van der Stelt P, et al. Diagnosing osteoporosis by using dental panoramic radiographs: The OSTEODENT project. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;104:821-8.  Back to cited text no. 4
    
5.
Taguchi A, Sugino N, Miki M, Kozai Y, Mochizuki N, Osanai H, et al. Detecting young Japanese adults with undetected low skeletal bone density using panoramic radiographs. Dentomaxillofac Radiol 2011;40:154-9.  Back to cited text no. 5
    
6.
Lee BD, White SC. Age and trabecular features of alveolar bone associated with osteoporosis. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2005;100:92-8.  Back to cited text no. 6
    
7.
Faber TD, Yoon DC, Service SK, White SC. Fourier and wavelet analyses of dental radiographs detect trabecular changes in osteoporosis. Bone 2004;35:403-11.  Back to cited text no. 7
    
8.
WHO. Assessment of fracture risk and its applications in screening for postmenopausal osteoporosis. WHO Technical Report Series. Geneva: WHO; 1994. p. 1-10.  Back to cited text no. 8
    
9.
Chrischilles EA, Butler CD, Davis CS, Wallace RB. A model of lifetime osteoporosis impact. Arch Intern Med 1991;151:2026-32.  Back to cited text no. 9
    
10.
Cummings SR, Karpf DB, Harris F, Genant HK, Ensurd K, LaCroix AZ, et al. Improvement in spine bone mineral density and reduction in risk of vertebral fractures during treatment with antiresorptive drugs. Am J Med 2002;112:281-9.  Back to cited text no. 10
    
11.
Rosholm A, Hyldstrup L, Backsgaard L, Grunkin M, Thodberg HH. Estimation of bone mineral density by digital X-ray radiogrammetry: Theoretical background and clinical testing. Osteoporos Int 2001;12:961-9.  Back to cited text no. 11
    
12.
Hastar E, Yilmaz HH, Orhan H. Evaluation of mental index, mandibular cortical index and panoramic mandibular index on dental panoramic radiographs in the elderly. Eur J Dent 2011;5:60-7.  Back to cited text no. 12
    
13.
Govindraju P, Chandra P. Radiomorphometric indices of the mandible - An indicator of osteoporosis. J Clin Diagn Res 2014;8:195-8.  Back to cited text no. 13
    
14.
Devlin H, Horner K. Mandibular radiomorphometric indices in the diagnosis of reduced skeletal bone mineral density. Osteoporos Int 2002;13:373-8.  Back to cited text no. 14
    
15.
Balcikonyte E, Balciuniene I, Alekna V. Panoramic radiographs in assessment of bone mineral density. Stomatol Baltic Dental Maxillofac J 2004;6:17-9.  Back to cited text no. 15
    
16.
Yaºar F, Akgünlü F. The difference in panoramic mandibular indices and fractal dimension between patients with and without spinal osteoporosis. Dentomaxillofac Radiol 2006;35:1-9.  Back to cited text no. 16
    
17.
Gulsahi A, Yüzügüllü B, Imirzalioglu P, Genç Y. Assessment of panoramic radiomorphometric indices in Turkish patients of different age groups, gender and dental status. Dentomaxillofac Radiol 2008;37:288-92.  Back to cited text no. 17
    
18.
Dutra V, Yang J, Devlin H, Susin C. Radiomorphometric indices and their relation to gender, age and dental status. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2005;99:479-84.  Back to cited text no. 18
    
19.
Bras J, van Ooij CP, Abraham-Inpijn L, Kusen GJ, Wilmink JM. Radiographic interpretation of the mandibular angular cortex: A diagnostic tool in metabolic bone loss. Part I. Normal state. Oral Surg Oral Med Oral Pathol 1982;53:541-5.  Back to cited text no. 19
    
20.
Kribbs PJ. Comparison of mandibular bone in normal and osteoporotic women. J Prosthet Dent 1990;63:218-22.  Back to cited text no. 20
    
21.
Khojastehpour L, Shahidi SH, Barghan S, Aflaki EL. Efficacy of panoramic mandibular index in diagnosing osteoporosis in women. J Dent 2009;6:11-5.  Back to cited text no. 21
    


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4]
 
 
    Tables

  [Table 1], [Table 2], [Table 3]



 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

   Abstract Materials and Me... Results Discussion Conclusion Introduction Article Figures Article Tables
  In this article
 References

 Article Access Statistics
    Viewed946    
    Printed21    
    Emailed0    
    PDF Downloaded249    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]