Alaa Final.doc J Bagh College Dentistry Vol. 26(2), June 2014 Assessment of mandibular Oral Diagnosis 50 Assessment of mandibular radiomorphometric indices as predictors of osteoporosis in postmenopausal women (Cephalometric reconstructed computed tomographical study) Alaa S. Mahdi, B.D.S. (1) Lamia Al-Nakib, B.D.S., M.Sc. (2) ABSTRACT Background: Osteoporosis affects almost all of the bones in the female body; the most important one in the facial bone is mandible. Menopause is defined as an absence of the menses for one year. During this time, estrongen, progesterone and ovarian androgens production are diminished due to adult onset ovarian failure which leads to osteoporosis. This study aimed to evaluate the use of computed tomography mandibular morphometric indices for the assessment of pre and postmenopausal osteoporotic women. Subjects and material: This study conducted on 50 Iraqi females divided into 2 groups 20 -30years old as a control group and over50 years old as a study group attending Al-Karkh hospital, Department of Computed Tomography.(each group25 female). Information from each female was recorded and mentioned on a case sheet specially prepared. Data collected, when analysed, using SPSS version 13 program loaded on a computer machine. Results: All the measurements in this study( gonial angle in degree, antigonial angle in degree and depth in millimetre, mandibular and mental thickness in millimetre, bone mineral density in HU and mandibular cortex index),there were no statically significant differences between right and left side P-value <0.001. Gonial angle had statistically positive linear correlation with age in the study group P-value <0.001. Bone mineral density and mandibular and mental thickness had statically negative linear correlation with age. Antigonial angle increased as age increased till reach 180 degree in some cases and the depth decreased correlated to the age till reach zero mm in some cases P-value <0.001. Mandibular cortex index increased in bone irregularity related to increase in age. Conclusion: It was concluded that osteoporosis and osteoporosis risk in postmenopausal females could be detected by using CT scan through measuring certain mandibular radiomorphometric indices. (J Bagh Coll Dentistry 2014; 26(2): 50-57). الخالصة .من ضمن العظام عظام الوجھ والفكین خاصة عظمة الفك االسفل , تنخر العظام یؤثر على كل عظام االنثى ما بعد انقطاع الطمث , عدم انتظام الصفیحات العظمیھ التي تؤدي الى خشونة العظم وعدم انتظامھ في االشعھ, ترقرق الطبقھ السفلى الذقنیھوالخدیھ , رات تشمل اضمحالل العظم یتأثر ھذا العظم وضمن متغی .باعا درجھ تقریبا ومسافة اسفل الذقن تتغیر ت 180زیادة زاویة اسفل الذقن لتصل الى , تغیر زاویة عظمة الفك االسفل وزیادة درجتھا .سنھ النموذج البحثي 50سنھ والنموذج القیااسي فوق ال ) 30_20(امرأه عراقیھ وقسمت الى قسمین 50تمت ھذه الدراسھ على .والسریریھ من المریضھ وسجلت في ورقة تشخیص خاصھ خصصت لكل مریض قصدوا مستشفى الكرخ التعلیمي قسم االشعھوالمفراس الحلزوني اخذت المعلومات الطبیھ 13النسخھSPSS)(سوم بیانیھ باستعمال برنامج ربجمعت النتائج وحللت احصائیا بانھ ) وكثافة العظم والمقیاس السمكي الخدي, والخدیھ سمك العظم في المنطقة الذقنیھ,العمق الخدي , الزاویة الخدیھ , زاویة الفك االسفل(اوضحت النتائج لكل المتغیرات التي جمعت .لكل مریض لزاویة الفك االسفل تغیر بصورة طردیھ وعالقة موجبھ مع العمرلكل مریض) الیمنى والیسرى(الجھتین الیوجد اختالف بین .الذقني یتغیر بصوره عكسیھ وسالبھ مع زیادة العمر كثافة العظم والسمك الخدي .درجھ 180الخدیھ ل تقریبا مستوى الصفر في بعض الحاالت التي یصل فیھا الزاویھ درجھ في بعض الحالت اما العمق فیصل 180الخدیھ تتغیر بزیادة العمر لتصل تقریبا الزاویھ .بزیادة العمر الصنف الثاني والصنف الثالث) للعظم( المقیاس السمكي الخدي یزداد عدم انتظامھ لعمر ویمكن ان یشخص عن طریق مقایس معینة في الفك االسفل بسھولھ باستعمال اخیرا نتوصل بان ھشاشة العظام وخطر االصابھ بھا عند االناث ما بعد انقطاع الطمث یزداد بزیادة ا .المفراس الحلزوني INTRODUCTION Osteoporosis affects all bones, including those of the facial skeleton. To date the facial bones have not drawn much attention due to the minimal probability of morbid fractures (1). There is scientific evidence that the decrease in bone mass due to osteoporosis also affect the mandible. Because of high costs and limited availability of DXA equipment it is worthwhile to look for alternative diagnostic techniques for osteoporosis (2,3). (1) M.Sc. Student, Department of Oral Diagnosis, College of Dentistry, University of Baghdad. (2) Assistant Professor, Department of Oral Diagnosis, College of Dentistry, University of Baghdad. Not everyone will get osteopenia or osteoporosis. However there are certain risk factors that can increase the likelihood that a person will have moderate to severe loss of bone mass, including the following (1, 2): • Gender: Women are a higher risk because they have less bone mass than men. Women also often experience a loss of bone mass after menopause. • Race: Asian and Caucasian women, especially those who are small-boned, are at highest risk. • Family history: Patients with a family history of low bone mass have a 50%-85% increased risk of developing osteoporosis. J Bagh College Dentistry Vol. 26(2), June 2014 Assessment of mandibular Oral Diagnosis 51 • Age: Most people (men and women) lose about .5% of bone mass every year after the age of 50. • Lifestyle choices: A poor diet with a lack of calcium and vitamin D, smoking, excessive use of alcohol or caffeine, and lack of exercise contribute to a loss of bone mass. • Other medical conditions: Hyperthyroidism, hyperparathyroidism, and Cushing's syndrome, can contribute to bone loss. Certain medications (such as prednisone or phenytoin) are known to cause bone loss as well (1). Considering that odontological patients are frequently referred for being submitted to panoramic radiography a widely available, low- cost method capable of demonstrating aging- related morphological alterations of the mandible, several indices, techniques for analysis and images processing have been researched in order to evaluate the applicability of this type of radiography for detecting bone mass loss. However, the results of these studies have been contradictory (4-6) In 2010 Huumonen, et al (5) found that the indices evaluated were reproducible; panoramic mandibular and mental indices presented the highest sensitivity in the detection of osteopenia/osteoporosis, however the panoramic mandibular index specificity was low. Although all the indices evaluated could identify low bone density, only the panoramic mandibular and mental indices could differentiate patients affected by osteopenia/osteoporosis. In the present study, normal reference measurements were used as the standard for the assessment of possible means of early detection of osteoporosis by radiographic examination, which is simple, and affordable by PATIENTS AND METHODS The sample included fifty (50) Iraqi female patients attending AL-Karkh Hospital Department of CT for different purposes from 6 Dec. 2012 till 1 Jul. 2013. The sample divided into two groups according to their age as following: 1st group: 25 subject with 20-30y as control group 2nd group: 25 subject with more than 50 ys as study group Exclusion criteria 1-Metabolic bone disease 2-Cancer with bone metastasis 3-Diabetes 4-Major renal impairment 5-Medication that affected bone metabolism other than estrogen 6-smoker Mandibular cortical thickness From CT viewer icons get sagittal view and scrolling the mouse to get the point that intersection of inferior border of mandible with line pass through the anterior border of the mandible. The thickness of the mandibular cortex was measured on the line perpendicular to the inferior border of the mandibular cortex at the intersection with the tangent line. The measurement was done for both sides. Mental Cortex Thickness From the icons CT viewer sagittal view could be obtained the reading taken in slices passing through mental foramen The thickness of the cortex at mental area will be measured on the line perpendicular to the parallel lines drown in upper and lower borders of inferior border of the mandible at the middle of the mental foramen (full cortex thickness) Scrolling the mouse to get opposite side and same technique was repeated to measure the mental cortex thickness of other side. Figure 1: Mental cortical thickness Gonial angle From sagittal view this angle readied by drown two lines the 1st with the inferior border of the mandible the 2nd from the outer border of the ramus. J Bagh College Dentistry Vol. 26(2), June 2014 Assessment of mandibular Oral Diagnosis 52 Figure 2: Gonial angle Antigonial depth and angle From sagittal view : a. Two lines parallel to the antigonial region that interseted at the deepest point of the antigonial notch. b. Antigonial depth was measured as the distance along perpendicular line from the deepest point of the notch concavity to a tangent through the inferior border of the mandible. Bone minerial density value BMD were recorded in the mental and gonial areas at full thickness of the cortical bone in Hounsfield unit Figure 3: Bone density in mental area in HU Mandibular cortex index Klemettis classification for osteoporosis: Class I: Smooth & even endosteal margin in inferior cortex on one or both sides Class II: Semilunar defect on one or both sides Class III: Heavy resorptive or porosity sign on one or both sides This result obtained by change the windowing contrast from modified to bony shadow to see any defect in cortical bone that may appear in one or both sides. RESULTS Assessment of menopausal effect The mean of gonial angle was significantly higher among post-menopausal cases (121.9) degree comparing with control (114.4) degree in (Table.1) Menopausal on average increases gonial angle by mean of 7.5 degree than antigonial angle that was 3 degrees which indicated for moderate strong effect more than antigonial angle about twice time in revealing the menopausal effect (Cohen’s d=0.55). The result was obviously but the differences failed to reach the level of statistically significance. Mandibular cortex index (MCI) The median MCI was significantly higher percentage among post-menopausal cases (class II) was 44%compare to control sample as shown in (table 2) The linear correlation between outcome measurements among cases only According to the table 3, one can determine the relation between the variables strong weak or moderate 0-0.2 =very weak 0.21-0.4=weak 0.41-0.7=moderate strong 0.71-0.9=strong 0.91-1=very strong The bone mineral density in gonial area had statistically significant strong positive (direct) linear correlation with bone density in mental area. r=728 (p<0.001) From table (3) mandibular and mental cortex thickness had moderate strong positive linear correlation r=0.6 p<0.001 Gonial and antigonial angle had statistically non significant very weak correlation r=0.269 p=0.06NS J Bagh College Dentistry Vol. 26(2), June 2014 Assessment of mandibular Oral Diagnosis 53 Figure 4: Relation between bone mineral density-gonia and mental area Association between MCI and other variable among cases The mean gonial angle was Lowest in class I MCI (117 degree) increasing to 122.1 degree in class II MCI cases to reach its highest mean 126.5 degree among class III MCI cases. (Table 4) R=0.516 p<0.001 the difference among mean in goinal angle were statistically significant and moderate strong positive linear correlation between GA and MCI. From table5 the relation between MCI and bone mineral density in both mental and gonial area the mean decreased with class increased (1729.1 to 1426.2 to 947.1) that were mental area while in gonial (1511.1 to 1421.6 to 930.4) so there was moderate strong correlation between bone density and MCI Effect of age on outcome measurement among cases After classifying the study group into three groups with ten class interval 50-59and 60-69 and 70-73. Gonial angle and antigonial angle and depth: The mean of gonial angle increase with ages increased 117.2 to 124.7 to 131.5 There was strong correlation between gonial angle and increasing age, gonial angle had a statistically significant strong linear correlation with age p<0.001 as shown in (table 6). Mental and mandibular thickness The mean of mental thickness was decreased with age increased from 3.7mm in 1st age class to 3.1mm in the second class, to 2.1mm in 3rd age class and strong correlation r=0.71 p<0.001 as shown in (table 7). The mandibular thickness also decreased with aged class from2.4mm to 2.1mm to 1.6mm the mandibular thickness had weak correlation with age r=0.43 p<0.001. So the mental thickness had stronger correlation with age than mandibular thickness depending on r value. Mandibular cortex index: The median in 1stclass (50-59y) was class I. In the 2nd class (60-69y) was class II, while in the 3rd class (70-73y) was class III. That indication for increasing bone change with age and strong correlation r=0.672 p<0.001in (table 8) Table1: Difference between cases and control group for gonial angle and antigonial angle size and depth Variables Controls (young adult females) Cases (post-menopausal age female) P Mean difference Cohen's d Gonial angle 0.007 7.5 0.55 Range (112 - 140) (110 - 136) Mean 114.4 121.9 SD 17.89 7.23 SE 2.53 1.02 N 50 50 Anti-gonial angle size 0.09[NS] 3.0 0.34 Range (153 - 180) (152 - 180) Mean 169.9 172.9 SD 9.92 7.51 SE 1.4 1.06 N 50 50 Anti-gonial depth 0.26[NS] -0.1 -0.22 Range (0 - 1.2) (0 - 1.2) Mean 0.6 0.5 SD 0.46 0.43 SE 0.07 0.06 N 50 50 J Bagh College Dentistry Vol. 26(2), June 2014 Assessment of mandibular Oral Diagnosis 54 Table 2: Mandibular cortex index (MCI) in control group and cases Study group Controls (young adult females) Cases (post-menopausal age female) Mandibular cortical index N % N % Class-1 50 100.0 14 28.0 Class-2 0 0.0 22 44.0 Class-3 0 0.0 14 28.0 Total 50 100.0 50 100.0 P (Mann-Whitney) < 0.001 Table 3: Relation between variables in cases (postmenopausal) only. Gonial angle Anti-gonial angle Anti-gonial depth Bone mineral density- mental Bone mineral density- Gonia Mental cortical thickness Anti-gonial angle r=0.269 P=0.06[NS] Anti-gonial depth r=-0.164 P=0.26[NS] r=-0.872 P<0.001 Bone mineral density-mental r=-0.642 P<0.001 r=-0.303 P=0.033 r=0.165 P=0.25[NS] Bone mineral density-Gonia r=-0.537 P<0.001 r=-0.287 P=0.043 r=0.308 P=0.03 r=0.728 P<0.001 Mental cortical thickness r=-0.519 P<0.001 r=-0.039 P=0.79[NS] r=-0.058 P=0.69[NS] r=0.692 P<0.001 r=0.486 P<0.001 Mandibular cortical thickness r=-0.368 P=0.008 r=-0.403 P=0.004 r=0.403 P=0.004 r=0.523 P<0.001 r=0.476 P<0.001 r=0.626 P<0.001 Table 4: Relation of MCI in postmenopausal to gonial angle and antigonial angle and depth. Variables Mandibular cortical index Class I Class II Class III P Gonial angle 0.001 Range (110 - 126) (110 - 130) (114 - 136) Mean 117 122.1 126.5 SD 4.84 7.33 6.2 SE 1.29 1.56 1.66 N 14 22 14 r=0.516 P<0.001 Anti-gonial angle 0.01 Range (160 - 180) (152 - 180) (163 - 180) Mean 174.7 169.5 176.5 SD 7.96 7.2 5.26 SE 2.13 1.54 1.41 N 14 22 14 r=0.043 P=0.77[NS] Anti-gonial depth 0.014 Range (0 - 1.2) (0 - 1.2) (0 - 0.8) Mean 0.3 0.7 0.4 SD 0.52 0.35 0.35 SE 0.14 0.07 0.09 N 14 22 14 r=0.018 P=0.9[NS] J Bagh College Dentistry Vol. 26(2), June 2014 Assessment of mandibular Oral Diagnosis 55 Table 5: Relation between MCI and bone mineral density in postmenopausal females in mental and gonial area cases (post-menopausal age female) Variables Mandibular cortical index Class-1 Class-2 Class-3 P Bone mineral density-mental <0.001 Range (1320 - 1986) (1024 - 1860) (509 - 1699) Mean 1729.1 1426.2 947.1 SD 224.91 289.7 356.36 SE 60.11 61.76 95.24 N 14 22 14 r=-0.758 P<0.001 Bone mineral density-Gonial area <0.001 Range (1005 - 1946) (1054 - 1880) (505 - 1786) Mean 1511.1 1421.6 930.4 SD 363.23 288.35 390.91 SE 97.08 61.48 104.47 N 14 22 14 r=-0.544 P<0.001 Table 6: Relation of age with gonial angle, antigonial angle and depth. Variables Age (years) 50-59 60-69 70-73 P Gonial angle-Right <0.001 Range (110 - 127) (110 - 130) (128 - 136) Mean 117.2 124.7 131.5 SD 5.42 5.65 2.66 SE 1.11 1.26 1.09 N 24 20 6 r=0.747 P<0.001 Anti-gonial angle 0.03 Range (160 - 180) (152 - 180) (176 - 180) Mean 173.8 170.1 178.7 SD 7.36 7.67 1.63 SE 1.5 1.72 0.67 N 24 20 6 r=0.035 P=0.81[NS] Anti-gonial depth 0.017 Range (0 - 1.2) (0 - 1.2) (0 - 0.6) Mean 0.4 0.7 0.3 SD 0.49 0.31 0.29 SE 0.1 0.07 0.12 N 24 20 6 r=0.105 P=0.47[NS] J Bagh College Dentistry Vol. 26(2), June 2014 Assessment of mandibular Oral Diagnosis 56 Table 7: Relation between age and mandibular and mental thickness in postmenopausal female Variables Age (years) 50-59 60-69 70-73 P Mental cortical thickness (mm) <0.001 Range (3 - 4.3) (2 - 3.9) (1.9 - 2.2) Mean 3.7 3.1 2.1 SD 0.36 0.51 0.1 SE 0.07 0.11 0.04 N 24 20 6 r=-0.71 P<0.001 Mandibular cortical thickness (mm) <0.001 Range (1.8 - 3.5) (1.8 - 2.6) (1.5 - 1.9) Mean 2.4 2.1 1.6 SD 0.46 0.22 0.16 SE 0.09 0.05 0.07 N 24 20 6 r=-0.435 P=0.002 Table 8: Relation between age and MCI in post menaposaul female Variables Age (years) 50-59 60-69 70-73 Mandibular cortical index N % N % N % Class I 14 58.3 0 0.0 0 0.0 Class II 8 33.3 14 70.0 0 0.0 Class III 2 8.3 6 30.0 6 100.0 Total 24 100.0 20 100.0 6 100.0 P (Kruskal-Wallis) <0.001, r=0.672 P<0.001. DISCUSSION In this study the mandibular and mental cortex thickness was significantly lower among postmenopause when compared to premenopause study group and there was a statically highly significant inverse relation between menopausal and the mandibular and mental thickness with (P value <0.001) and this result indicate that the elderly age groups (postmenopausal has significantly lower thicknesses when compared to the younger age group(premenopausal)which emphasized the fact that it was an age related phenomena this finding is in agreement that found by others (12,13). As the human increased in age this angle will increased so the notch disappeared till reached near 180 degree due to many factors depended either male or female (14). In post menapousal female in this study this angle will reached large divergent level of angle to reached 180 degree that mean no notch or angle that agree with Shahabi et al. (15). Morphology of the mandible changes with age consequence of tooth loss which can be expressed as widening of the gonial angle shorting of the ramus and condylar height (16). Taguchi et al (17) found that multiple linear regression showed that the BMD was significantly decreased with age (16,17) which is similar to the present study. The association between the mandibular cortical thickness and bone mineral density was statistically significant even after adjustment for hormonal treatment, smoking, age at menopause, and body mass index (P = 0.04). In 2001, Shepherd (16) stated that bone loss is a closely age related phenomenon. Radio morphological change in the mandible either in cortical or trabecular bone is inversely correlation with age that agrees with our study and the result (18). 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