Further evidence for specific IFIH1 mutation as a cause of Singleton-Merten syndrome with phenotypic heterogeneity.

Singleton-Merten syndrome (MIM 182250) is an autosomal dominant inherited disorder characterized by early onset periodontitis, root resorption, osteopenia, osteoporosis, and aortic valve or thoracic aorta calcification. The disorder can have significant intrafamilial phenotypic variability. Here, we present a mother and daughter with Singleton-Merten syndrome harboring a previously described pathogenic missense mutation, c.2465G>A p.(Arg822Gln), in IFIH1 (interferon induced with helicase C domain 1), encoding MDA5 (Melanoma Differentiation-Associated protein 5). These data confirm the pathogenicity of IFIH1 c.2465G>A p.(Arg822Gln) for Singleton-Merten syndrome and affirm the striking phenotypic heterogeneity of this disorder. In addition, we expand the Singleton-Merten phenotype by adding severe systemic lupus erythematosus (SLE) to the clinical picture. Investigations of known SLE genes as well as a single nucleotide polymorphism suggested to be involved in development of SLE were normal.

Open reduction and internal fixation for intraarticular fracture of metacarpal head.

Intraarticular fracture of the metacarpophalangeal (MP) joint presents complex problems related to the sophisticated functional aspects of the hand. Injury to the metacarpal head may have a severe effect on hand function but few studies have investigated the management of this condition. In this study, we applied open reduction and internal fixation for the displaced fracture of the metacarpal head and report the clinical and radiographic outcomes of our experience. Thirteen patients (12 men, 1 woman; mean age 21 years) were included in this study, and medical records and radiographs were reviewed retrospectively. The average follow-up period was 12.5 months. Range of motion (ROM) and Disabilities of the Arm, Shoulder, and Hand (DASH) scores were analyzed, and functional results and serial radiographs were investigated for the maintenance of articular congruity and fracture union. The injured fingers were 5 long, 4 small, 2 ring, and 2 index. Five cases were fixed with K­wires, 5 cases with headless screws, and 3 cases with screw and K­wire. The average range of injured MP joint motion was 89°, total active range of motion (TAM) was 265°, and the average DASH score was 3.8 at the last follow-up. All patients showed fracture union on the radiographs and no patient showed significant articular surface incongruence or degenerative change. Open reduction and internal fixation of the metacarpal head fracture had favorable outcomes in our study. The authors suggest accurate reduction and stable fixation for better functional results in metacarpal head fractures.

Dynamic postures of the transverse metacarpal arch during typing.

The purpose of this paper is to describe the transverse metacarpal arch (TMA) during a dynamic typing task. Static/relaxed and dynamic typing TMA were collected from 36 right-handed females with musculoskeletal discomfort using a motion capture system. While the angle of right TMA static/relaxed posture (10.1° ± 5.5°) was significantly larger than the left (8.5° ± 5.6°) (P < .05), the right dynamic posture (10.6° ± 4.3°) was not significantly different from the left (10.3° ± 5.5°) (P = .66). Within both these mean scores, there was considerable individual variation, with some subjects demonstrating very flat TMA, and some very curved. The results indicate that TMA angular postures both for static/relaxed and dynamic typing are highly variable both between individuals and between individual hands.

Inflammatory pain in the rabbit: a new, efficient method for measuring mechanical hyperalgesia in the hind paw.

The discovery of novel analgesic compounds that target some receptors can be challenging due to species differences in ligand pharmacology. If a putative analgesic compound has markedly lower affinity for rodent versus other mammalian orthologs of a receptor, the evaluation of antinociceptive efficacy in non-rodent species becomes necessary. Here, we describe a new, efficient method for measuring inflammation-associated nociception in conscious rabbits. An electronic von Frey device is used, consisting of a rigid plastic tip connected to a force transducer in a hand-held probe. The plastic tip is applied to the plantar surface of a hind paw with increasing force until a withdrawal response is observed. The maximum force (g) tolerated by the rabbit (i.e., withdrawal threshold) is recorded. In young, conscious rabbits (500-700 g), baseline hind paw withdrawal thresholds typically fell within the 60-80 g range. Three hours after injection of the inflammatory agent carrageenan (3%, 200 microL, intra-plantar), withdrawal thresholds dropped by approximately 30-40 g, indicating the presence of punctate mechanical hyperalgesia. The development of hyperalgesia was dose dependently prevented by the NSAID indomethacin (ED50=2.56 mg/kg, p.o.) or the bradykinin B2 receptor peptide antagonist HOE 140 (intra-paw administration). An established hyperalgesia was dose dependently reversed by morphine sulfate (ED50=0.096 mg/kg, s.c.) or the bradykinin B1 receptor peptide antagonist [des-Arg10, Leu9]-kallidin (ED50=0.45 mg/kg, s.c.). Rabbits treated with the novel B(1) receptor small molecule antagonist compound A also showed dose-dependent reversal of hyperalgesia (ED50=20.19 mg/kg, s.c.) and analysis of plasma samples taken from these rabbits showed that, unlike other rabbit pain models, the current method permits the evaluation of pharmacokinetic-pharmacodynamic (PK-PD) relationships (compound A plasma EC50=402.6 nM). We conclude that the Electrovonfrey method can be used in rabbits with inflammatory pain to generate reliable dose- and plasma concentration-effect curves for different classes of analgesics.

The effectiveness of physical therapies for patients with base of thumb osteoarthritis: Systematic review and meta-analysis.

BACKGROUND: Trapeziometacarpal osteoarthritis (known as base of thumb OA) is a common condition causing pain and disability worldwide. OBJECTIVE: The purpose of this review was to evaluate the effectiveness of multimodal and unimodal physical therapies for base of thumb osteoarthritis (OA) compared with usual care, placebo or sham interventions. DESIGN: Systematic review and meta-analysis. METHOD: We searched MEDLINE (PubMed), CINAHL, Embase, AMED, PEDro, Cochrane Database of Systematic Review, Cochrane Register of Controlled Trials (CENTRAL) from inception to May 2017. Randomized controlled trials involving adults comparing physical therapy treatment for base of thumb OA with an inactive control (placebo or sham treatment) and reported pain, strength or functional outcomes were included. Meta-analyses were performed where possible. Methodological risk of bias was assessed with the Cochrane Risk of Bias tool. RESULTS: Five papers with low risk of bias were included. Meta-analyses of mean differences (MD) with 95% confidence intervals (95% CI), were calculated for between-group differences in point estimates at 4 weeks post-intervention. Multimodal and unimodal physical therapies resulted in clinically worthwhile improvements in pain intensity (MD 2.9 [95% CI 2.8 to 3.0]; MD 3.1 [95% CI 2.5 to 3.8] on a 0-10 scale, respectively). Hand function improved following unimodal treatments (MD 6.8 points [95% CI 1.7 to 11.9)] on a 0-100 scale) and after a multimodal treatment (MD 20.5 (95%CI -0.7 to 41.7). CONCLUSIONS: High quality evidence shows unimodal and multimodal physical therapy treatments can result in clinically worthwhile improvements in pain and function for patients with base of thumb OA.

Modeling of biodynamic responses distributed at the fingers and the palm of the human hand-arm system.

The objective of this study is to develop analytical models for simulating driving-point biodynamic responses distributed at the fingers and palm of the hand under vibration along the forearm direction (z(h)-axis). Two different clamp-like model structures are formulated to analyze the distributed responses at the fingers-handle and palm-handle interfaces, as opposed to the single driving point invariably considered in the reported models. The parameters of the proposed four- and five degrees-of-freedom models are identified through minimization of an rms error function of the model and measured responses under different hand actions, namely, fingers pull, push only, grip only, and combined push and grip. The results show that the responses predicted from both models agree reasonably well with the measured data in terms of distributed as well total impedance magnitude and phase. The variations in the identified model parameters under different hand actions are further discussed in view of the biological system behavior. The proposed models are considered to serve as useful tools for design and assessment of vibration isolation methods, and for developing a hand-arm simulator for vibration analysis of power tools.

Clinical Inquiry: Does knuckle popping lead to arthritis?

Habitual knuckle popping, or cracking (over the course of several decades) isn't associated with clinical or radiographic evidence of osteoarthritis.

Up-regulation of site-specific remodeling without accumulation of microcracking and loss of osteocytes.

Functional adaptation of bone normally protects the skeleton from fracture during daily activity. Accumulation of microcracking and loss of osteocytes have been implicated in the regulation and initiation of targeted (reparative) remodeling of bone and, in certain situations, the development of fatigue or stress fracture. We performed a histologic study of the dorsal cortex of the mid-diaphysis of the third metacarpal (Mc-III) bone of Thoroughbred racehorses after bones were bulk-stained in basic fuchsin and transverse calcified sections were prepared. The Thoroughbred racehorse is an extreme athlete whose Mc-III bone experiences particularly high cyclic strains during training and racing. A group of non-athletic horses was also included in the experiment. The following variables were quantified: activation frequency (Ac.f); bone formation rate (BFR); resorption space density (Rs.N/T.Ar); microcrack density (Cr.Dn); microcrack mean length (Cr.Le); microcrack surface density (Cr.S.Dn); osteocyte density (Ot.N/T.Ar; Ot.N/B.Ar); and bone volume fraction (B.Ar/T.Ar). Ac.f and BFR were estimated using a mathematical algorithm. Using confocal microscopy, bones were examined for fine microcracks, diffuse matrix injury, and disruption of the osteocyte syncytium. Low values for Cr.Dn (#/mm2) were found in both groups (0.022+/-0.008 and 0.013+/-0.006 for racing Thoroughbreds and non-athletic horses, respectively). There was no significant relationship between Cr.Dn and Ot.N/T.Ar; Ot.N/B.Ar, B.Ar/T.Ar, and Ot.N/T.Ar; Ot.N/B.Ar, and remodeling (Ac.f, Rs.N/T.Ar) and Ot.N/T.Ar; Ot.N/B.Ar. Intense remodeling of the Mc-III dorsal cortex was found in the racing Thoroughbreds (Ac.f 12.8+/-7.4 #/mm2/year; BFR 31.5+/-15.6%; Rs.N/T.Ar 0.19+/-0.09 #/mm2) and was significantly increased compared with non-athletic horses. Overall, remodeling was weakly correlated with Cr.Dn (r2=0.15, P<0.05). Subtle matrix injury, not detectable by bright-field microscopy, was particularly evident adjacent to resorption spaces in Thoroughbred bone. In non-athletic horses, disruption of the dendritic cell processes of osteocytes associated with cement lines and interstitial fragments was more evident. Taken together, these findings suggest that site-specific (targeted) induction of remodeling during functional adaptation of bone in a high-strain skeletal site is not dependent on accumulation of microcracking or loss of osteocytes. We hypothesize that athleticism can directly influence bone turnover in this extreme athlete through pathways that do not involve classical linear microcracks.

[Study of bone mass in Turner syndrome]. / Estudio de la masa ósea en el síndrome de Turner.

OBJECTIVES: To evaluate bone mass in patients with Turner syndrome by measuring metacarpal cortical thickness and bone diameter before and after treatment with oxandrolone, growth hormone (GH) and estrogens. PATIENTS AND METHODS: We studied 42 girls with Turner syndrome divided into the following groups: group I: 31 patients aged between 3 and 15 years who were not treated before the study; group II: 15 patients treated with GH at start ages of between 5.2-14.8 years; group III: 17 patients treated with oxandrolone at start ages of between 5.3 and 15.2 years; group IV: 17 patients treated with estrogens and divided in different subgroups: IVa: seven patients treated with GH and estrogens at start ages of between 6.1 and 12.9 years; IVb: five patients treated with oxandrolone and estrogens at start ages of between 13.4 and 17.4 years, and IVc: five patients treated with oxandrolone, GH and estrogens at start ages of between 10.3 and 16.1 years. Bone mass was evaluated by a radiogrammetric method that measures the cortical thickness and bone diameter of three metacarpal bones with a magnifying glass. The results are expressed in SD according to Spanish longitudinal reference standards (Andrea Prader Center of Growth and Development) from 0.5 to 9 years of age and to Swiss standards from the age of 10 years onwards. Statistical significance was set at p < 0.05. RESULTS: Group I (spontaneous development): cortical development was below the mean and was significantly diminished at the ages of 9, 13 and 14 years; bone diameter was decreased in relation to controls throughout the study period; group II (impact of GH treatment): cortical thickness showed a nonsignificant increase of 0.6 SD from baseline to years 3-4 of treatment and diameter increased by 0.5 SD from baseline to year 4 of treatment; group III (impact of oxandrolone): cortical thickness increased from -0.8 SD before treatment to 0.0 SD at years 2 and 3 of treatment; bone diameter increased from -1.5 SD at baseline to -1 SD at 3 years of treatment; group IV (impact of treatment with estrogens); IVa: cortical thickness and bone diameter increased; IVb: cortical thickness increased but bone diameter was unchanged; IVc: both cortical thickness and bone diameter increased. CONCLUSIONS: The results of this study show that cortical thickness and bone diameter are decreased in untreated girls with Turner syndrome; cortical thickness was significantly decreased at the ages of 9, 13 and 14 years, while bone diameter was diminished at all ages, suggesting the presence of osteopenia in these patients. GH treatment produced a nonsignificant increase in cortical thickness and bone diameter. Oxandrolone treatment showed a positive effect on bone mass during the first few years of therapy. Because of the small number of patients, conclusions cannot be reached on the effectiveness of estrogens.

Investigation of the effect of conservative interventions in thumb carpometacarpal osteoarthritis: systematic review and meta-analysis.

PURPOSE: The purpose of this study was to conduct a current review of randomized controlled trials regarding the effect of conservative interventions on pain and function in people with thumb carpometacarpal (CMC) osteoarthritis (OA), perform a meta-analysis of the findings and summarize current knowledge. METHOD: Data were obtained from MEDLINE, CINAHL, Embase, PEDro and CENTRAL databases from their inception to May 2014. Reference lists of relevant literature reviews were also searched. All published randomized trials without restrictions to time of publication or language were considered for inclusion. Study subjects were symptomatic adults with thumb CMC OA. Two reviewers independently selected studies, conducted quality assessment and extracted results. Data were pooled in a meta-analysis, when possible, using a random-effects model. Quality of the body evidence was assessed using GRADE approach. RESULTS: Sixteen RCTs involving 1145 participants met the inclusion criteria. Twelve were of high quality (PEDro score > 6). We found moderate quality evidence that manual therapy and therapeutic exercise combined with manual therapy improve pain in thumb CMC OA at short- and intermediate-term follow-up, and from low to moderate quality evidences that magneto therapy improves pain and function at short-term follow-up. Orthoses (splints) were found to improve function at long-term follow-up and pinch strength at short-term follow-up. Finally, we found from very low to low-quality evidence that other conservative interventions provide no significant improvement in pain and in function at short- and long-term follow-up. CONCLUSIONS: Some of the commonly performed conservative interventions performed in therapy have evidence to support their use to improve hand function and decrease hand pain. Additional research is required to determine the efficacy of other therapeutic interventions that are performed with patients with thumb CMC OA. IMPLICATIONS FOR REHABILITATION: Manual therapy and exercise are an effective means of improving pain and function at short-term follow-up by patients with thumb CMC OA. Magneto therapy, manual therapy, manual therapy and exercise and Orthoses (splints) were found to have clinically significant results. Very few of the included studies showed a clinically significant effect size in favor of treatment.

Current Concepts of the Carpal Boss: Pathophysiology, Symptoms, Clinical or Imaging Diagnosis, and Management.

The carpal boss reflects an osseous protuberance at the level of the dorsal base of the second or third metacarpal, variably present in the general population. There are numerous theories as to the etiology of the bony excrescence; however, the exact cause remains uncertain. The abnormality can result in dorsal wrist pain and swelling. The diagnosis is typically established based on clinical examination and imaging, including radiography, ultrasound, nuclear medicine, computed tomography, and magnetic resonance imaging. We review the proposed theories of how the carpal boss develops, explain the clinical manifestations, demonstrate the imaging appearance, and address treatment strategies.

Long term clinical outcome of dental implants placed in a patient with Singleton-Merten syndrome.

PATIENTS: Singleton-Merten syndrome is an extremely rare autosomal dominant condition with less than 10 reported cases in the literature. It is characterized by abnormal aortic calcifications and dental abnormalities. The goal of this case report is to discuss the abnormal oral clinical features and the modified treatment protocol that was used in order to achieve osseointegration of dental implants in a patient having abnormal bone density and bone turnover associated with Singleton-Merten Syndrome. DISCUSSION: Following extraction of the remaining teeth, titanium implants (Friadent GmbH, Mannheim, Germany and Straumann(®), Basel, Switzerland) were placed in the upper and lower jaw of the patient. The upper jaw which was treated with dental implants, received a bar supported implant retained prosthesis and the lower jaw an implant retained telescopic prosthesis. The patient was regularly followed up for the past 13 years during which, clinical and radiological evaluation of osseointegration was undertaken. All the loaded implants showed clinical and radiographic evidence of osseointegration. With a follow up of 13 years after insertion of the first implant, the patient reported functioning well with no complications. CONCLUSION: The treatment with dental implants in the extremely rare Singleton-Merten syndrome patients is a reasonable treatment option to rehabilitate maxillofacial aesthetics and establish normal function of the jaws.

Macrophage colony stimulating factor restores in vivo bone resorption in the op/op osteopetrotic mouse.

The op/op variant of murine osteopetrosis is a recessive mutation characterized by impaired bone resorption due to lack of osteoclasts. Cultured osteoblasts and fibroblasts from this mutant do not secrete M-CSF activity and resident macrophages are absent in bone marrow. This failure has been related to a mutation within the M-CSF coding region. We report now that the administration of recombinant human M-CSF (rhM-CSF) corrects in vivo the impaired bone resorption in this animal. The treatment restores the bone marrow cavity virtually absent in the op/op animal and induces the appearance of resorbing osteoclasts and of resident bone marrow macrophages. This proves that the deficiency of M-CSF is the cause of the op/op bone disorder and that this cytokine is directly or indirectly necessary for physiological osteoclastogenesis, the resulting bone resorption and for the establishment of bone marrow hemopoiesis.

Metacarpal bone loss in middle-aged women: "horse racing" in a 9-year population based follow-up study.

Differences in the rate of metacarpal bone loss were evaluated in a 9 year population based follow-up study among 799 women initially aged 45-64 years, using initial and follow-up radiographs of the hands. Metacarpal bone loss started around the age of 50 years and was present in more than 95% of the women. The average annual rate of loss was approximately 1% of the initial value. The prevalence of osteopenia increased from 5% for women aged 45-49 years, up to 68% for women aged 70-76. The rate of bone loss was not similar for each individual. Regression analyses of rate of change-in-RCA on initial level of RCA indicated the presence of a consistent subgroup of fast bone losers. However, osteopenia at follow-up was more accurately predicted from initial bone density than from differences in the rate of loss.

Stiff and strong compressive properties are associated with brittle post-yield behavior in equine compact bone material.

Our hypothesis was that post-yield mechanical behavior of compact bone material in compression, defined as the stress, strain, or energy absorbed between 0.2% strain-offset and the point of maximum stress, is correlated with material density, modulus, strength, histomorphometric evidence of remodeling, and post-failure gross specimen morphology. Post-yield behavior of compact bone material from the third metacarpal bone of 10 horses, ages 5 months to 20 years, was investigated using single-load compression-to-failure. The post-yield stress, strain, and absorbed energy were compared with the compressive elastic modulus, yield stress, ash density. post-failure macroscopic appearance of the specimen, and histologic evidence of remodeling. High values of elastic modulus, yield stress, and ash density were associated with low values of post-yield mechanical properties (stress, strain, and absorbed energy). Macroscopic post-failure morphology was associated with post-yield mechanical behavior, in that specimens displaying fractures were associated with lower post-yield mechanical properties, and that those without evidence of frank fracture were associated with higher post-yield mechanical properties. Microscopic evidence of remodeling activity was associated with high post-yield mechanical properties, but not with gross post-failure morphology. There was an abrupt change from relatively high values to extremely low values of post-yield mechanical properties at intermediate levels of ash density. This feature may serve as a functional tipper limit to the maximization of bone material stiffness and strength.

In vitro fatigue behavior of the equine third metacarpus: remodeling and microcrack damage analysis.

We studied remodeling and microcrack damage in specimens of Thoroughbred racehorse third metacarpal bone that had been subjected to monotonic or fatigue failure. We asked three questions. What effects does mechanical loading have on histologically observable microcrack damage? Are there regional variations in remodeling of the equine cannon bone, and do these variations correlate with mechanical properties? To what extent are remodeling and microcrack damage age-dependent? Machined beams from the medial, lateral, and dorsal cortices were loaded to fracture in four-point bending monotonically, or cyclically at a load initially producing 10,000 microstrain. Specimens were then bulk-stained in basic fuchsin, and cross sections were prepared from loaded and load-free regions of each beam. Current and past remodeling, porosity, and microcrack density and length were determined histomorphometrically. Strained and unstained microcracks were observed. Unstained cracks were associated with regions of woven bone and appeared to be damaged Sharpey's fibers. Their density (approximately 30/mm2) did not increase after failure, but their length (approximately 25 microns) did, especially near the surfaces of the beam. Stained cracks were wider and longer than unstained cracks and were located primarily near the fracture surface and on the compressed side of the beam. Stained cracks after failure were more numerous in those beams having a higher elastic modulus, a shorter fatigue life, or greater deformation at failure. The extent of past remodeling increased with age, especially in the medial region; the rate of current remodeling generally declined with age, but not in the dorsal region, which has the best fatigue resistance. In summary, while remodeling varied with age and region, its effects on bone structure did not appear to influence microdamage. Basic fuchsin staining of damage in fractured equine bone was independent of age and region and confined to near the fracture surfaces. Distributed microdamage consisted only of what appeared to be subtle disruptions of Sharpey's fibers.

Osteon pullout in the equine third metacarpal bone: effects of ex vivo fatigue.

An important concept in bone mechanics is that osteons influence mechanical properties in several ways, including contributing to toughness and fatigue strength by debonding from the interstitial matrix so as to "bridge" developing cracks. Observations of "pulled out" osteons on fracture surfaces are thought to be indicative of such behavior. We tested the hypothesis that osteon pullout varies with mode of loading (fatigue vs. monotonic), cortical region, elastic modulus, and fatigue life. Mid-diaphseal beams from the dorsal, medial, and lateral regions of the equine third metacarpal bone were fractured in four point bending by monotonic loading to failure under deflection control, with or without 10(5) cycles of previous fatigue loading producing 5000 microstrain (15-20% of the expected failure strain) on the first cycle; or sinusoidal fatigue loading to failure, under load or deflection control, with the initial cycle producing 10,000 microstrain (30-40% of the expected failure strain). Using scanning electron microscopy, percent fracture surface area exhibiting osteon pullout (%OP.Ar) was measured. Monotonically loaded specimens and the compression side of fatigue fracture surfaces exhibited no osteon pullout. In load-controlled fatigue, pullout was present on the tension side of fracture surfaces, was regionally dependent (occurring to a greater amount dorsally), and was correlated negatively with elastic modulus and positively with fatigue life. Regional variation in %OP.Ar was also significant for the pooled (load and deflection controlled) fatigue specimens. %OP.Ar was nearly significantly greater in deflection controlled fatigue specimens than in load-controlled specimens (p=0.059). The data suggest that tensile fatigue loading of cortical bone eventually introduces damage that results in osteonal debonding and pullout, which is also associated with increased fatigue life via mechanisms that are not yet clear.

Pulsed magnetic fields improve osteoblast activity during the repair of an experimental osseous defect.

The influence of pulsed low-frequency electromagnetic fields (PEMFs) on bone formation was investigated in studies of the healing process of transcortical holes, bored at the diaphyseal region of metacarpal bones of six adult horses, exposed for 30 days to PEMFs (28 G peak amplitude, 1.3 ms rise time, and 75 Hz repetition rate). A pair of Helmholtz coils, continuously powered by a pulse generator, was applied for 30 days to the left metacarpal bone, through which two holes, of equal diameter and depth, had been bored at the diaphyseal region. Two equal holes, bored at the same level in the right metacarpal and surrounded by an inactive pair of Helmholtz coils, were used as controls. All horses were given an intravenous injection of 25-30 mg/kg of tetracycline chloride on the 15th and again on the 25th day after the operation and were killed 5 days later. The histomorphometric analysis indicated that both the amount of bone formed during 30 days and the mineral apposition rate during 10 days (deduced from the interval between the two tetracycline labels) were significantly greater (p < 0.01 and p < 0.0001, respectively) in the PEMF-treated holes than in the controls. As did a previous investigation, these preliminary findings indicate that PEMFs at low frequency not only stimulate bone repair but also seem to improve the osteogenic phase of the healing process, at least in our experimental conditions.

Low metacarpal bone density, tooth loss, and periodontal disease in Japanese women.

The relationship between periodontitis and systemic bone mineral density in Japanese women is undetermined. We tested the hypothesis that periodontitis was more frequent in women with low metacarpal bone mineral density (m-BMD). Subjects were 190 Japanese women (89 premenopausal, 101 post-menopausal). Periodontal status was evaluated according to the Community Periodontal Index of Treatment Need (CPITN). M-BMD was measured by computed x-ray densitometry. The proportion of subjects with periodontitis (CPITN > or = 3) increased as m-BMD decreased in pre-menopausal (18.2%, 36.9%, and 66.6% in the normal, borderline, and very low m-BMD groups, p < 0.02) and post-menopausal women (41.5%, 54.8%, 60%, and 68.4% in the normal, borderline, low, and very low m-BMD groups, p < 0.05). Among post-menopausal women, those with very low m-BMD had fewer teeth present than women with normal m-BMD (19.9+/-7.2 vs. 25.1+/-4.1, p < 0.01). These results indicate that m-BMD loss is associated with periodontitis in Japanese women, and with tooth loss after menopause.

Distal metacarpal bone mineral density by dual energy X-ray absorptiometry (DEXA) scan. Methodological investigation and application in rheumatoid arthritis.

Dual energy X-ray absorptiometry scanning was performed along the axis of the third metacarpal bone of the non-dominant hand and including metacarpal bones 2, 3, 4 and 5. The Bone Mineral Density (BMD) was calculated for the distal 1/4 of each metacarpal bone. Ten patients with seropositive, erosive rheumatoid arthritis (RA) and 10 healthy, sex- and age-matched persons were investigated twice. The average BMD in RA patients was 73.6% of the value found in normals. The coefficient of variation on double determinations (in patients and controls) was 0.9-3.0%. We suggest that dual energy X-ray absorptiometry scanning with the scanning procedure proposed here may be an important instrument for the quantification of disease progression.