Two methods of evaluating mandibular trabecular pattern in intraoral radiographs and the association to fragility fractures during a 47-year follow up.

In this longitudinal cohort study, we explored the association of fragility fractures to sparse trabecular bone pattern in intraoral radiographs using two methods, a visual and a semi-automated. Our aim was to study both sexes and to include younger age-groups, during a follow-up time of 47 years. The cohort consisted of 837 men and women aged 18-65 years, with intraoral radiographs from 1970-1971. The trabecular pattern was assessed in the mandibular premolar region with a visual and a semi-automated method. Data on fragility fractures were acquired from the Swedish National Patient Register for 47 years of follow-up time. Sparse trabecular pattern was found in 2.2% of the cohort using the visual method, and 18% were deemed at 'risk of osteoporosis' using the semi-automated method. A total of 132 individuals suffered at least one fragility fracture during the follow-up period. We found no significant association between fractures and sparse trabecular pattern using either method. This study shows that visual assessment, as a predictor of future fractures, may not be a suitable method for individuals of all ages and sexes. As for the semi-automated method, there is still very limited evidence for its fracture predictive ability.

Trabecular bone patterns as a fracture risk predictor: a systematic review.

BACKGROUND: The aim of this systematic review was to evaluate the assessment of trabecular bone patterns in dental radiographs, for fracture risk prediction, compared with the current diagnostic methods. METHODS: The PRISMA guidelines were followed. According to predefined inclusion criteria (PICO), literature searches were focussed on published studies with analyses of trabecular bone patterns on intraoral and/or in panoramic radiographs, compared with Dual X-ray Absorptiometry (DXA) and/or Fracture Risk Assessment Tool (FRAX), with the outcomes; fracture and/or sensitivity and specificity for osteoporosis prediction. The included studies were quality-assessed using the QUADAS-2 tool and the certainties of evidence was assessed using the GRADE approach. RESULTS: The literature searches identified 2913 articles, whereas three were found to meet the inclusion criteria. Two longitudinal cohort studies evaluated the use of trabecular bone patterns to predict bone fractures. In one of the studies, the relative risk of fracture was significantly higher for women with sparse bone pattern, identified by visual assessment of dental radiographs, and in the other study by digital software assessment. Visual assessment in the second study did not show significant results. The cross-sectional study of digital analyses of trabecular bone patterns in relation to osteoporosis reported a sensitivity of 0.70 and a specificity of 0.69. CONCLUSION: Based on low certainty of evidence, trabecular bone evaluation on dental radiographs may predict fractures in adults without a prior diagnosis of osteoporosis, and based on very low certainty of evidence, it is uncertain whether digital image analyses of trabecular bone can predict osteoporosis.

Mandibular cortical bone structure as risk indicator in fractured and non-fractured 80-year-old men and women.

OBJECTIVE: To investigate the association between mandibular cortex parameters and fracture in a group of 286 men and women, 79-80 years of age. STUDY DESIGN: In a cross-sectional study, the mandibular cortex was evaluated with Klemetti's index for cortical erosion. The cortical thickness was measured with a ruler adjusting for the magnification factor. The odds ratio (OR) for fracture when having a severely eroded cortex or a cortex thickness < 3 mm was calculated. RESULTS: A normal cortex was found in 65% of men, whereas only 7% had a severely eroded cortex. The OR for severely eroded cortex  as fracture risk predictor was significant (2.32; 95% CI 1.3-4.2), also when the female group was evaluated separately. A significant difference was found between the mean thickness for men (3.96 mm) and women (2.92 mm), respectively. The OR for cortical thickness < 3 mm was significant (2.00; 95% CI 1.1-3.6) in the total group, but not when men and women were evaluated separately. CONCLUSIONS: Among old women, the cortical parameters were significantly associated with prevalent fracture. In old men, other circumstances may be more important.

Predicting fractures using trabecular patterns on panoramic radiographs.

OBJECTIVES: The observer score of the trabecular pattern on panoramic radiographs is known to be a strong predictor of bone fractures. The aim of this study was to enhance the predictive power of panoramic radiographs by means of texture analysis methods. MATERIAL AND METHODS: The study followed 304 postmenopausal women during 26 years. At the beginning of the study, panoramic radiographs were obtained. One observer assessed the trabecular pattern in the premolar region as dense, sparse, or alternating dense and sparse. In addition, on each radiograph, a region of interest was selected in the molar/premolar region and analyzed with texture analysis procedures. During 26 years of follow-up, 115 women suffered a fracture of the hip, spine, leg, or arm. Logistic regression was applied to test the predictive power of various variables with respect to fractures. RESULTS: Of all variables, the observer score of the trabecular pattern correlated strongest with the occurrence of fractures. By itself, the score yielded an ROC curve with an area of 0.80 under the curve. Combining the observer score with the texture analysis features increased the area under the ROC curve to 0.85. CONCLUSIONS: The trabecular pattern on panoramic radiographs provides a strong predictor of fractures, at least for postmenopausal women. The assessment by an observer combined with texture analysis procedures yields a predictive power that parallels best known predictions in literature. CLINICAL RELEVANCE: This study illustrates that panoramic radiographs are state of the art predictors of postcranial fractures.

FRAX and mandibular sparse trabeculation as fracture predictors: a longitudinal study from 1980 to 2002.

The fracture assessment tool (FRAX) is widely used for predicting fractures, but better methods are needed. The aim of this study was to determine whether visual assessments of mandibular trabecular bone could improve FRAX predictions. Three age-cohorts of women were examined twice - 499 women in 1980/1981 and 412 women in 1992/1993; 397 participated in both examinations. Information on 10-yr fracture events was available, and bone trabeculation was assessed in radiographs as 'dense', 'mixed', or 'sparse'. Fracture assessment tool values, without bone mineral density (BMD), were calculated twice. Both sparse trabeculation and FRAX >15% were associated with a twofold higher risk for future fracture in the younger group and with a three- to fourfold higher risk for future fracture in the older group. For those with both FRAX >15% and sparse trabeculation, the relative risk (RR) for a fracture in the next 10 yr was 5.9 (95% CI: 3.5-9.8) in the younger group and 22.7 (95% CI: 5.6-92) in the older group. If either FRAX >15% or sparse trabeculation was present, the RR was 2.6 (95% CI: 1.7-4.1) in the younger group and 15.7 (95% CI: 3.9-6.4) in the older group. We concluded that FRAX >15%, without BMD measurements, was an effective fracture predictor, and mandibular sparse trabeculation had a substantial additive effect. Together, FRAX plus mandibular sparse trabeculation predicts major osteoporotic fractures to approximately the same extent as does FRAX with BMD measurements.

From resistance to rescue--patients' shifting attitudes to antihypertensives: a qualitative study.

OBJECTIVE: The objective of this study was to gain a deeper knowledge and understanding of experiences of antihypertensive drug treatment. DESIGN: Interview study. SETTING: A primary health care centre in western Sweden. METHOD: Qualitative interviews and analyses through systematic text condensation described by Malterud. SUBJECTS: Ten informants in pharmacological treatment for high blood pressure (six men and four women). MAIN OUTCOME MEASURE: Experiences of hypertension drug treatment. RESULTS: The findings revealed a process starting with resistance to drug treatment related to lack of control, side effects, and unwanted awareness of impaired health. These negative feelings then changed into a positive desire for lifestyle changes caused by a fear of cardiovascular disease which in turn changed the attitude towards drugs into seeing them as a rescue remedy and something normal and this then evoked health care trust. CONCLUSION: Despite initial resistance to treatment, the experience of antihypertensive drug treatment became more positive with time. Confidence in the health care system is important for adherence to treatment. General practitioners have a key role in this regard.

Mandibular trabecular bone structure in adults with Crohn's disease.

OBJECTIVES: Crohn's disease (CD) is associated with reduced bone mineral density. The main objective of the present study was to assess the mandibular trabecular bone quality and to compare our findings with those among sex- and age-matched controls. Furthermore, background variables known to be significant for bone density were compared. MATERIALS AND METHODS: Intraoral radiographs of 49 Crohn's patients (23-61 years old) and 49 age- and sex-matched controls were evaluated. Mandibular trabecular pattern was classified as either sparse, mixed dense plus sparse, or dense. Furthermore, two computer-based methods analyzed the transitions from trabecula to intertrabecular spaces and the size and number of these spaces. Differences in continuous background variables were tested with Student's two-sample t test and ordinal variables with Mann-Whitney U test or Kruskal-Wallis nonparametric tests. RESULTS: All three methods to evaluate bone structure seen on dental radiographs showed significantly sparser trabeculation in Crohn's patients than in the control group. The Crohn's patients were heavier, more often smokers, and more frequently had mothers who developed fragility fractures. Furthermore, the Crohn's patients, especially smokers, had a significantly higher fracture rate than the matched control group but no significant relationship was found between trabeculation pattern and fracture. CONCLUSIONS: The results of this investigations indicated that trabecular bone is significantly sparser in subjects with Crohn's disease compared to a matched control group. CLINICAL RELEVANCE: An early identification of CD patients with sparse trabeculation and appropriate advice concerning nutrition and exercise may lead to less fractures and medication in the future.

Mandibular trabecular bone as fracture indicator in 80-year-old men and women.

The objective of the present study was to compare assessments of the mandibular bone as fracture risk indicators for 277 men and women. The mandibular trabecular bone was evaluated in periapical radiographs, using a visual index, as dense, mixed dense and sparse, or sparse. Bone texture was analysed using a computer-based method in which the number of transitions from trabeculae to intertrabecular spaces was calculated. The sum of the sizes and intensities of the spaces between the trabeculae was calculated using Jaw-X software. Women had a statistically significantly greater number of fractures and a higher frequency of sparse mandibular bone. The OR for having suffered a fracture with visually sparse trabecular bone was highest for the male group (OR = 5.55) and lowest for the female group (OR = 3.35). For bone texture as an indicator of previous fracture, the OR was significant for the female group (OR = 2.61) but not for the male group, whereas the Jaw-X calculations did not differentiate between fractured and non-fractured groups. In conclusion, all bone-quality assessments showed that women had a higher incidence of sparse trabecular bone than did men. Only the methods of visual assessment and trabecular texture were significantly correlated with previous bone fractures.

The experience of disagreement between students and supervisors in PhD education: a qualitative study.

BACKGROUND: PhD supervision is mostly individual and disagreement between supervisors and PhD students is a seldom-discussed topic at universities. The present study aimed to describe the experience of disagreement between PhD students and supervisors. METHODS: Nine supervisors and seven PhD students from Sweden and England were interviewed using a video recorder. The recorded material was analysed using inductive content analysis. RESULTS: Disagreements in PhD education can be described with the overarching theme: the nature of the disagreements changes over time. Five categories emerged to describe the variations of the experiences: involvement in important decisions, supervisors not being up-to-date, dubious advice from supervisors, mediating between supervisors, and interpersonal relationships. CONCLUSIONS: There is a gradual shift in competence where PhD students may excel supervisors in subject knowledge. Early disagreements may indicate immaturity of the student while disagreements later may indicate that the student is maturing making their own decisions. Consequently, disagreements may need to be addressed differently depending on when they occur. Addressing them inappropriately might slow the progressions and result in higher attrition rate among PhD students. The five categories may be elements in future PhD supervisor training programs and should be further evaluated for their importance and impact on PhD education.

Does mandibular bone structure predict subsequent height loss? A longitudinal cohort study of women in Gothenburg, Sweden.

BACKGROUND: Several risk factors for loss of height with increasing age have been identified. OBJECTIVE: To investigate if mandibular bone structure predicts future height loss in middle-aged and elderly Swedish women. DESIGN: Prospective cohort study with longitudinally measured heights, radiographical assessments of the cortical bone using Klemetti's Index (normal, moderate or severely eroded cortex) and classification of the trabecular bone using an index proposed by Lindh et al (sparse, mixed or dense trabeculation). No intervention was performed. SETTING: Gothenburg, Sweden. PARTICIPANTS: A population-based sample of 937 Swedish women born in 1914, 1922 and 1930 was recruited. At the baseline examination, the ages were 38, 46 and 54 years. All had undergone a dental examination with panoramic radiographs of the mandible, and a general examination including height measurements on at least two occasions. MAIN OUTCOME MEASURE: Height loss was calculated over three periods 12-13 years (1968-1980, 1980-1992, 1992-2005). MAIN RESULTS: Mean annual height loss measures were 0.075 cm/year, 0.08 cm/year and 0.18 cm/year over the three observation intervals, corresponding to absolute decreases of 0.9 cm, 1.0 cm and 2.4 cm. Cortical erosion in 1968, 1980 and 1992 significantly predicted height loss 12 years later. Sparse trabeculation in 1968, 1980 and 1992 also predicted significant shrinkage over 12 or 13 years. Multivariable regression analyses adjusting for baseline covariates such as height, birth year, physical activity, smoking, body mass index and education yielded consistent findings except for cortical erosion 1968-1980. CONCLUSION: Mandibular bone structure characteristics such as severe cortical erosion and sparse trabeculation may serve as early risk factors for height loss. Since most individuals visit their dentist at least every 2 years and radiographs are taken, a collaboration between dentists and physicians may open opportunities for predicting future risk of height loss.

Assessment of trabecular pattern on periapical and panoramic radiographs: a pilot study.

OBJECTIVE: This methodological study aimed to determine whether the mandibular trabecular bone assessment from panoramic radiographs, using a visual index, corresponds to the evaluation obtained from periapical radiographs. MATERIAL AND METHODS: A panoramic radiograph and corresponding periapical radiographs of the region of the lower premolars and molars were collected from each of 32 patients (mean age 18.5 +/- 5.5 years). Two calibrated observers assessed randomly the interdental sites between the first molar and second premolar and between the two premolars on all the radiographs using a visual index. Evaluations were repeated with an interval of 60 days. The results of the repeated evaluations were used to assess intra- and inter-observer agreements, employing Kappa statistics. Spearman's correlation was used to determine the association between assessments of panoramic and periapical radiographs. RESULTS: In total, 79 interdental sites were evaluated on the panoramic and periapical radiographs. The visual analysis of periapical radiographs revealed intra-observer agreements of 0.88 for observer 1 and 0.93 for observer 2, and an inter-observer agreement of 0.82. The intra-observer agreement for panoramic radiographs was 0.79 and 0.83 for observers 1 and 2, respectively, and the inter-observer agreement was 0.79. A substantial correlation was found between periapical and panoramic radiographs (rho = 0.737, p = 0.001). CONCLUSIONS: Although panoramic radiographs are less reliable than periapical radiographs, they can be used for assessment of the trabecular bone pattern with the aid of a visual index. Training on the method is recommended to obtain results with a high reproducibility.

Changing trabecular patterns in panoramic radiographs of Swedish women during 25 years of follow-up.

OBJECTIVES: The radiographic trabecular pattern on dental radiographs may be used to predict fractures. The aim of this study was to analyze longitudinal changes in the mandibles of 145 females between 1980 and 2005. METHODS: Panoramic radiographs were obtained in 1980 and 2005. On 290 radiographs, regions of interest (ROIs) were selected in the ramus, angle and body. In all ROIs, the orientation was measured in 36 directions with the line frequency deviation method. The effects of ageing were analyzed for the fracture and the non-fracture groups separately. RESULTS: During the follow-up, 61 females suffered fractures of the hip, wrist, spine, leg or arm. The fracture and non-fracture groups displayed dissimilar age changes in each investigated ROI. All significant changes pertained to increasing values of line frequency deviation. With increasing age, the trabecular network in the mandible lost details and the trabeculae became more aligned in their main direction. In the "ramus", the alignment was to the 110-120˚ axis, parallel to the posterior and anterior ramus border. In the "angle", the alignment was to the 135-150˚ axis, parallel to the oblique line, and in the "body" ROI to the 150-175˚ direction, approximately parallel to the occlusal plane and inferior cortex. CONCLUSION: Most changes were consistent with the notion that the bone aged less severely in the non-fracture group. In the fracture group, the findings indicate that bone loss leads to redistribution of the remaining bone tissue in such a way that the trabeculae are accentuated perpendicular to the principal loading.

Functional factors associated with continuous eruption of maxillary incisors in adulthood: A 10-year prospective cohort study.

PURPOSE: To investigate whether functional factors estimated by the masseter muscle thickness (MMT) and the maximum occlusal force (MOF), were associated with the amount of continuous eruption of maxillary incisors in adults. MATERIALS AND METHODS: Dental casts were taken twice in 24 adult female patients during a 10-year prospective cohort study. At the first appointment, ultrasonographic measures of the MMT and MOF were recorded. The casts were scanned into a digital model and measurements of the eruption and clinical crown lengthening (CL) of the maxillary incisors were calculated after superimpositions on the palatal region. Univariate and multivariate mixed effect regression models were used to assess the single and joint role of functional factors, with presence or absence of occlusal contacts and CL on incisor eruption. RESULTS: By using the linear mixed effects regression model, we observed that both the MMT and MOF were correlated with the maxillary incisor eruption. In particular, the thicker the masseter or the stronger the occlusal force, the lower the amount of eruption. Using a backward multivariable mixed effects model, the incisor eruption was correlated with the MMT combined with presence or absence of contacts and clinical CL. The amount of tooth eruption (0.32 mm on average) was positively associated with CL (0.29 mm on average); therefore, the greater the CL (gingival recession), the greater the amount of tooth eruption. The presence of occlusion contact between the maxillary incisors and their mandibular antagonists was found as an inhibitor of eruption in the multivariate model. CONCLUSIONS: The functional capacity of masticatory muscles, as estimated by the MMT, plays a role in the amount of maxillary incisor eruption. The stronger the masticatory muscles, the lower the amount of eruption.

The rise and fall of the alveolar process: Dependency of teeth and metabolic aspects.

The alveolar bone has a unique capacity to follow the teeth's movements. It is formed around erupting teeth and their periodontal ligaments: the more the teeth have erupted, the larger the alveolar process. Throughout life the teeth erupt and migrate in an occlusal and mesial direction to compensate for attrition, an evolutionary trait. After tooth extraction, the alveolar process is resorbed to varying degrees. The mandibular alveolar bone mirrors skeletal bone condition. Due to fast bone turnover (which is the fastest in the whole skeleton), low bone mass and increased fracture risk may first be seen here. If a periapical radiograph of the mandibular premolars shows a dense trabeculation with well-mineralized trabeculae and small intertrabecular spaces, it is a reliable sign of normal skeletal bone density (BMD) and low skeletal fracture risk, whereas a sparse trabecular pattern indicates osteopenia and high fracture risk. The bone turnover rate in the mandible is twice that of the maxilla, and may, hypothetically, play a role in the development of osteonecrosis of the jaw (ONJ), which has been found mainly in the mandibular alveolar process?

Evaluation of clinical and radiographic indices as predictors of osteoporotic fractures: a 10-year longitudinal study.

OBJECTIVES: The aim of the study was to evaluate 2 radiographic and 3 clinical indices as predictors of future osteoporotic fractures. STUDY DESIGN: In a prospective, longitudinal study with a 10-year fracture follow-up, the 2 radiographic indices mandibular cortical erosion (normal, mild/moderate erosion, and severe erosion of the inferior cortex) and cortex thickness were assessed using panoramic radiographs of 411 women, age 62 to 78 years. The clinical indices were the fracture assessment tool FRAX, the osteoporosis index of risk (OSIRIS), and the osteoporosis self-assessment tool (OST). RESULTS: The relative risks (RRs) for future fracture were significant for FRAX greater than 15%, 4.1 (95% confidence interval [CI] 2.4-7.2), and for severely eroded cortices, 1.7 (95% CI 1.1-2.8). Cortical thickness less than 3 mm, OSIRIS, and OST were not significant fracture predictors (RR 1.1, 1.4, and 1.5, respectively). For the 5 tested fracture predictors, Fisher's exact test gave the following P values for differences between fracture and nonfracture groups: FRAX <.001, cortical erosion 0.023, OST 0.078, OSIRIS 0.206, and cortical thickness 0.678. The area under the curve was 0.69 for FRAX less than 15%, 0.58 for cortical erosion, and 0.52 for cortical thickness. Adding OSIRIS and OST did not change the area under the curve significantly. CONCLUSIONS: FRAX and severely eroded cortices predicted fracture but cortical thickness, OSIRIS, and OST did not.

Continuous eruption of maxillary teeth and changes in clinical crown length: A 10-year longitudinal study in adult women.

BACKGROUND: Continuous physiologic eruption of teeth may become a main aesthetic issue for implants inserted in the maxillary anterior region. PURPOSE: To study maxillary tooth vertical changes during a 10 years period by 3-dimensional superimposition of digital dental casts. MATERIAL AND METHODS: Alginate impressions were taken at both baseline and at the 10-year follow-up in a sample of 24 adult Swedish women (average age of 48 years at T0). The upper arch plaster casts were digitized with a 3-dimensional scanner and then superimposed on the palate and the palatal rugae. Occlusal and gingival anatomic structures were digitized for each upper tooth from first molar to first molar. The vertical changes of these structures gave an indication of tooth extrusion and apical or coronal displacement of the gingival margin. RESULTS: A trend was found for eruption in the anterior region (+0.3 mm on average) while a slight extrusion if not any was found in the first molars and premolars area. Vertical displacement of the gingival margin showed also a positive trend from first molars to incisors. Negative average values, corresponding clinically to gingival recession, were found on first molars (-0.36 mm) and premolars (-0.15 mm), while no displacement was detected in the anteriors. Clinical crown lengths increased in all teeth and it is mainly due to gingival recession for first molars and premolars, while for the incisors the eruption is coupled to a slight equivalent gingival coronal migration. CONCLUSIONS: During a 10-year period, continuous eruption takes place in female adult subjects, especially in the upper incisors area while gingival recession occurred in first molars and premolars area leading to crown length elongation. Implant placement in the anterior area of the maxilla may have an aesthetic impact even in mature adults due to the continuous eruption of the adjacent teeth.

Changes in the radiographic characteristics of the mandibular alveolar process in dentate women with varying bone mineral density: a 5-year prospective study.

The association between skeletal bone mineral density (BMD) and mandibular alveolar bone mass has been reported to be rather weak, probably due to local functional factors. Many new investigations are therefore focused on assessing the mandibular bone structure. No long-term structural alterations have been reported in human mandibular bone with the exception of alveolar crest changes related to periodontal disease. The aim of this prospective study was to investigate dentate women to see if possible alterations in the radiographic characteristics of the mandibular alveolar bone are related to changes in BMD. The BMD of 131 women (initial age 22-75 years) was determined in the distal forearm with dual energy X-ray absorptiometry on two occasions separated by an interval of 5 years. Mandibular alveolar bone mass (MABM) was assessed both by the optical density and by the grey-level value on digitized, calibrated, periapical radiographs. The radiographic alveolar bone structure was evaluated with a visual index [Lindh C, Petersson A, Rohlin M. Assessment of the trabecular pattern before endosseous implant treatment: diagnostic outcome of periapical radiography in the mandible. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1996;82:335-43. ] and digitally by the alveolar bone texture. MABM decreased significantly during the 5-year period. Changes in MABM, evaluated by the mean grey-level value of a bone segment between the premolars, were correlated to changes in skeletal BMD (r = 0.33, P < 0.001). Changes in MABM, evaluated by the optical density, did not correlate to changes in skeletal BMD. The overall trabecular pattern did not change during the study period, but small changes in the bone texture were measured. The changes in the bone texture were correlated with BMD change (r = 0.39, P < 0.001). We conclude that changes in the mandibular alveolar bone do reflect changes in the skeletal BMD, and these may be estimated on periapical radiographs by changes in their grey-level value and their texture.

Alveolar bone loss in osteoporosis: a loaded and cellular affair?

Maxillary and mandibular bone mirror skeletal bone conditions. Bone remodeling happens at endosteal surfaces where the osteoclasts and osteoblasts are situated. More surfaces means more cells and remodeling. The bone turnover rate in the mandibular alveolar process is probably the fastest in the body; thus, the first signs of osteoporosis may be revealed here. Hormones, osteoporosis, and aging influence the alveolar process and the skeletal bones similarly, but differences in loading between loaded, half-loaded, and unloaded bones are important to consider. Bone mass is redistributed from one location to another where strength is needed. A sparse trabeculation in the mandibular premolar region (large intertrabecular spaces and thin trabeculae) is a reliable sign of osteopenia and a high skeletal fracture risk. Having dense trabeculation (small intertrabecular spaces and well-mineralized trabeculae) is generally advantageous to the individual because of the low fracture risk, but may imply some problems for the clinician.

Mandibular alveolar bone mass, structure and thickness in relation to skeletal bone density in dentate women.

The aim of this series of studies was to investigate the relationship between skeletal bone mineral density (BMD) and mandibular alveolar bone mass (MABM), structure, and thickness, as well as to evaluate the possible effect of local functional factors on MABM and alveolar thickness. A further aim was to elucidate whether longitudinal changes in mandibular radiographic characteristics and the bucco-lingual dimension of the alveolar process were related to alterations of BMD. BMD was measured in 160 dentate women using dual X-ray absorptiometry of the forearm. On periapical radiographs MABM was estimated using densitometry and the grey-level value. The alveolar bone structure was evaluated with a visual index and by examining the bone texture on periapical radiographs. The thickness of the masseter was assessed with ultrasound imaging to estimate the masticatory functional factor, and the bucco-lingual alveolar thickness was measured on casts. MABM and alveolar structure were significantly correlated to BMD. The best correlation was found between BMD and trabecular pattern evaluated with the visual index (r = 0.62, p < 0.001). The alveolar thickness was correlated to BMD, and to masseter thickness. MABM was influenced of age, the alveolar thickness, the number of occluding teeth, and the masseter muscle thickness but these factors had no effect on the trabecular structure. After five years, all measurements except the ultrasound imaging of the masseter muscle were repeated in 136 women. The mean BMD, MABM, and alveolar thickness decreased significantly during this period, whereas no significant change was found in the bone structure. In posterior region, the alterations in alveolar bone thickness, radiographic grey-level value, and bone texture were significantly correlated to the changes in BMD. In the anterior region, the alterations in alveolar thickness were not correlated with the changes in BMD. Furthermore, no correlation was found between alterations in MABM, estimated by densitometry, and changes in BMD. In conclusion, a significant relationship exists between BMD and mandibular alveolar bone mass, structure, and thickness. The local functional factors mainly influence MABM and the alveolar thickness in the molar region, whereas BMD influences the trabecular structure. Dense trabeculation is a strong indicator of high BMD, whereas sparse trabeculation predicts low bone mass. In peri- and postmenopausal women the alveolar shape in the premolar region can be used to predict BMD level. In the lower premolar region, the longitudinal alterations in BMD are related to longitudinal changes in grey-level value, bone texture and alveolar thickness. The decrease in bucco-lingual alveolar thickness may be due to periosteal resorption related to skeletal bone loss.

Five-year alveolar bone level changes in women of varying skeletal bone mineral density and bone trabeculation.

OBJECTIVES: To investigate alveolar bone level changes in women with varying skeletal bone mineral density (BMD) and bone trabeculation. STUDY DESIGN: In a prospective, longitudinal study of 128 women (22-75 years of age), BMD (dual x-ray absorptiometry), and periapical radiography were performed in 1996 and 2001. The mandibular trabecular bone was assessed as dense, mixed, or sparse. Mandibular alveolar bone level was measured with a Schei ruler and related to BMD (osteoporotic, osteopenic, or normal) and trabeculation. RESULTS: After 5 years, the total bone level score was significantly decreased (P = .001). No significant differences were found in the total bone level scores between the different BMD groups. The greatest decreased total bone level score in 1996 was found in the group with dense trabeculation (0.71 in the dense group vs. 0.31 in the nondense group, P = .005), and similarly in 2001 (0.75 in the dense group vs. 0.39 in the nondense group, P = .020). Five-year changes in the total bone level scores did not differ between trabeculation groups (P = .37). CONCLUSIONS: The small group of women with dense mandibular trabecular bone seems to suffer a greater decrease in alveolar bone height compared with other women, including women with osteoporosis.