The effect of preemptive and/or postoperative ibuprofen therapy for orthodontic pain.

The control of pain during orthodontic treatment is of vital interest to both clinicians and patients. Surprisingly, there has been limited research into the control of orthodontic pain, and there is no standard of care for controlling this discomfort. The purpose of this study was to compare the effectiveness of preemptive ibuprofen therapy, postoperative ibuprofen therapy, and a combination of the 2 therapies. Forty-one orthodontic patients aged 9 years 3 months to 16 years 11 months who were to undergo separator placement were enrolled in this prospective study. Patients were randomly assigned to 1 of 3 experimental conditions: (1) 400 mg ibuprofen taken orally 1 hour before separator placement and 400 mg ibuprofen taken orally 6 hours after the initial dose, (2) 400 mg ibuprofen taken orally 1 hour before separator placement and a lactose capsule taken orally 6 hours after the initial dose, or (3) a lactose capsule taken orally 1 hour before separator placement and 400 mg ibuprofen taken 6 hours after the initial placebo. The results revealed that preemptive ibuprofen therapy significantly decreased pain that was experienced 2 hours after separator placement and at bedtime. Beginning on day 2, there was a trend for patients who had taken both preemptive and postoperative ibuprofen doses to have lower pain scores compared with the other 2 groups. In conclusion, these data indicate that ibuprofen taken 60 minutes before separator placement alleviates pain at 2 hours and at bedtime after treatment. Further study with the use of additional postoperative doses is warranted.

Alveolar process fractal dimension and postcranial bone density.

OBJECTIVES: Our goal was to determine whether the radiographic fractal dimension of the maxillary and mandibular alveolar processes is related to bone density of the alveolar processes, spine, hip, and radius in healthy women. STUDY DESIGN: Thirty-seven dentate healthy white women aged 20 to 78 years underwent assessment of systemic and alveolar process bone. After a periodontal examination, D-speed vertical bite-wing and periapical radiographs with aluminum step wedges and a density correction algorithm were used to make alveolar process fractal dimension and density calculations within regions of interest that avoided crestal bone and intrabony defects. Anteroposterior (L1-L4) and lateral (L2-L4) lumbar spine, total hip, and total wrist densities were determined by means of dual energy x-ray absorptiometry. RESULTS: Correlation analysis revealed significant relationships between maxillary alveolar process fractal dimension and maxillary alveolar process density (r = 0.47, P < or =.01), mandibular alveolar process density (r = 0.48, P < or =.01), and mandibular alveolar process fractal dimension (r = 0.44, P < or =.05); and between mandibular alveolar process fractal dimension and maxillary alveolar process density (r = 0.54, P < or =.01) and mandibular alveolar process density (r = 0.58, P < or =.001). No significant relationships were found between the maxillary alveolar process or the mandibular alveolar process fractal dimension and the density of any postcranial regions. CONCLUSIONS: In healthy women, the alveolar process radiographic fractal dimension is significantly related to the alveolar process density but is not related to the density of the spine, hip, or radius.

An evaluation of preoperative ibuprofen for treatment of pain associated with orthodontic separator placement.

Patients undergoing orthodontic treatment can experience significant levels of pain. This study assessed the effectiveness of preoperative ibuprofen in reducing the incidence and the severity of pain after orthodontic separator placement. Sixty-three adolescent patients (mean age, 13 years) were included in this randomized, double-blind, placebo-controlled, prospective study. Patients were randomly assigned to 1 of 3 experimental conditions: (1) 400 mg of ibuprofen taken orally 1 hour before separator placement and a lactose placebo taken orally immediately after the appointment, (2) a lactose placebo taken orally 1 hour before separator placement and 400 mg of ibuprofen taken orally immediately after the appointment, or (3) a lactose placebo taken orally 1 hour before separator placement and again immediately after the appointment. The patient's level of discomfort was assessed with a visual analog scale at 2, 6, and 24 hours, as well as at 2, 3, and 7 days after placement of the orthodontic separators. An analysis of variance and Duncan's multiple range test revealed that 2 hours after their orthodontic appointment the patients who had taken ibuprofen 1 hour before separator placement had significantly less pain with chewing than did the patients who received either ibuprofen postoperatively or a placebo. Additional measures suggest a trend for less pain for this group of patients. These results support the use of pretreatment ibuprofen for patients requiring analgesics for orthodontic discomfort. Future study of the use of preemptive analgesics in orthodontics is warranted.

The relationship between the density of the alveolar processes and that of post-cranial bone.

Skeletal mass declines in all populations with age, and the literature suggests that changes in oral bone may be linked to the status of the post-cranial (systemic) skeleton. However, there is a lack of information defining the relationship between alveolar process bone and the post-cranial skeleton in healthy individuals. The purpose of this study was to determine: (1) if the bone densities of the maxillary and mandibular alveolar processes are related to the bone density of the spine, hip, or radius in healthy women; and (2) if the alveolar process densities decline with age. Forty-one dentate Caucasian women aged 20 to 78 years underwent assessment of post-cranial (systemic) and alveolar process bone. D-speed vertical bitewing and periapical radiographs incorporating aluminum stepwedges, controlled exposure and processing conditions, and a density correction algorithm were used to make alveolar process density assessments with regions of interest (ROIs) apical to crestal bone and intrabony defects. Anteroposterior lumbar (L1 to L4) and lateral lumbar (L2 to L4) spine, total hip (and subregions), and radius bone densities were determined by dual-energy x-ray absorptiometry (DEXA). Correlation analysis revealed significant relationships between maxillary alveolar process bone density and the density of the mandibular alveolar process (r = 0.57, p < or = 0.001), anteroposterior lumbar spine (r = 0.53, p < or = 0.001), lateral lumbar spine (r = 0.52, p < or = 0.001), total hip (r = 0.39, p = 0.01), total radius (r = 0.39, p = 0.01), and age (r = -0.38, p = 0.01). A two-tailed t test comparison revealed significantly greater maxillary alveolar process bone density in women younger than 50 years of age than in those 50 and older (p < or = 0.01). We conclude that the density of maxillary alveolar process bone is significantly related to the density of the mandibular alveolar process, lumbar spine, hip, and radius in healthy women and that maxillary alveolar process bone density declines with age.

Evaluation of profile esthetic change with mandibular advancement surgery.

Our purpose was to investigate the impact of mandibular advancement surgery on profile esthetics and to attempt to define guidelines that could be of value to the clinician in predicting profile esthetic change. The sample consisted of 34 patients who had been treated with a combination of orthodontics and mandibular advancement surgery without genioplasty. Initial (pretreatment) and final (posttreatment) cephalometric radiographs of each patient were used to produce silhouette images and to quantify skeletal changes that occurred with surgery. The images were displayed randomly to lay persons and orthodontic residents who were asked to score the esthetics of each profile. On average, after mandibular advancement surgery, B point moved forward 5.0 mm (SD = 2.6 mm) and downward 4.7 mm (SD = 3.1 mm), and the ANB angle decreased 3.0 degrees (SD = 1.6 degrees ) Graphical analysis and results of paired t tests revealed that for patients with an initial ANB angle >/= 6 degrees, a consistent improvement in profile esthetics was seen following surgery (P

Mandibular bone density and fractal dimension in rabbits with induced osteoporosis.

OBJECTIVE: Our goal in this investigation was to examine the mandibular bone density and radiographic textural changes and the relationship between mandibular and spinal bone mineral density in an osteoporotic rabbit model. STUDY DESIGN: Three adult female New Zealand white rabbits in each of 4 groups received daily injections of cortisone acetate at a dosage of 0.0 (control), 3.0, 7.5, or 15.0 mg/kg for 4 weeks. The rabbits were then killed, and the mandible and spine of each animal were removed. Digital radiographs (70 kVp, 10 mA, 8 impulses) of the hemimandibles and spines were made. Lateral and anteroposterior bone densities of the lumbar spine (L2) were calculated, and average mandibular interdental bone density, fractal dimension, and gradient values were calculated. RESULTS: Correlation analysis revealed that cumulative steroid dose was strongly related to mandibular bone density (r = -0.80, P <.01), moderately related to mandibular fractal dimension (r = -0.61, P <. 05), and moderately related to anteroposterior lumbar spine density (r = -0.64, P <.05). Moderate correlations were found between mandibular interdental bone density and spinal density (r = 0.56, P <.05), but mandibular fractal dimension was not related to spinal density. CONCLUSIONS: In osteoporotic female rabbits, mandibular bone mineral density decreases in relation to spinal density and cumulative steroid dose. Mandibular fractal dimension decreases with cumulative steroid dose but is not significantly related to either mandibular density or spinal density.

Geometric and densitometric standardization of intraoral radiography through use of a modified XCP system.

OBJECTIVE: The purposes of this study were to examine the density correction afforded by curve-fitting algorithms and to investigate whether the device we developed significantly improves the reliability of longitudinal alveolar process bone radiographic density measurements. STUDY DESIGN: Stepwedges were radiographed over a range of impulse settings, and curve-fitting algorithms were fitted to sets of step images on each digitized film. Differences between the actual thicknesses of an alternate set of steps and their corresponding thickness estimates were calculated. Next, clinicians made periapical radiographs from interproximal bony sites on a dry skull using our imaging device. Differences in bone densities between corresponding regions of interest taken 1 week apart were calculated. RESULTS: Analysis of variance and Duncan's Multiple Range test demonstrated that piecewise linear, third-degree polynomial, and fourth-degree polynomial curves provided significantly better estimates of stepwedge thickness than did sigmoid or first degree polynomial-curves (P < .05) and that the differences between repeat bone density measurements made with density correction were significantly less than those made without density correction (P < .05). CONCLUSIONS: Piecewise linear, third-degree polynomial, and fourth-degree polynomial curve-fitting algorithms provided the best densitometric correction. The use of our imaging device increased the reliability of longitudinal bone density measurements.

Prediction of mandibular growth rotation: assessment of the Skieller, Björk, and Linde-Hansen method.

The purpose of this investigation was to assess the method proposed by Skieller, Björk, and Linde-Hansen in 1984 to predict mandibular growth rotation. Our sample consisted of 40 randomly selected, untreated, adolescent subjects representative of the patient population generally encountered in orthodontic practice. The four independent variables identified in the Skieller study as having the highest predictive value (mandibular inclination, intermolar angle, shape of the lower border of the mandible, and inclination of the symphysis) were identified on initial lateral cephalograms. The proposed regression equations were applied and predicted mandibular rotations obtained. Final lateral cephalograms made 6 years after the initial profile radiographs were superimposed and actual mandibular rotation recorded. The observed and predicted rotations were compared and regression analyses performed to determine the amount of variability in observed values accounted for by the four variables individually and in combination. Only 5.6% of the variability in mandibular growth rotation could be accounted for using the four variables individually. Only 9% of the variability could be accounted for with a combination of the variables. In addition, we performed a Monte Carlo analysis, which mirrored the Skieller analysis but used random numbers instead of actual cephalometric data, to determine if the Skieller results may simply have capitalized on chance. Using the same forward stepwise selection procedure with a rejection level of P >.1, we found after 5000 simulations that a mean of 84% and a median of 94% of mandibular growth rotation variability could be accounted for using meaningless data in the Skieller analysis. This result was comparable to the Skieller value of 86%. In conclusion, information derived from pretreatment lateral cephalograms using the Skieller, Björk, and Linde-Hansen method does not permit clinically useful predictions to be made in a general population relative to the direction of future mandibular growth rotation.

Fractal dimension in radiographic analysis of alveolar process bone.

OBJECTIVES: This in vitro study examined radiographic fractal dimension changes in alveolar process bone during simulated osteoporosis. STUDY DESIGN: Ten specimens of human maxillary alveolar process bone were progressively decalcified, and the percentage of calcium lost at each decalcification stage was quantified. Four radiographs of each specimen, together with an aluminum step-wedge, were exposed at 70 kVp at each stage. The test set of 560 radiographs was digitized, identical bony regions of interest were selected from the density-corrected images of each specimen, the regions were digitally filtered to reduce film-grain noise, and fractal dimension was computed on a line-to-line basis. Correlation analysis quantified the relationship between calcium loss and fractal dimension change. Analysis of variance and Duncan's multiple range test determined whether a difference existed in fractal dimension computed from images at x-ray beam angulations of -5, 0, and +5 degrees. RESULTS: A strong correlation (average r = -0.94, p < or = 0.0037) was found between generalized demineralization and decreasing fractal dimension. In every bone sample fractal dimension changed significantly (p < or = 0.0189) with angular change. CONCLUSIONS: Radiographic fractal dimension holds promise for detecting simulated osteoporosis in the maxilla under ideal conditions, but the sensitivity of fractal dimension to small x-ray beam angular change renders its clinical application questionable.

Detection of simulated osteoporosis in maxillae using radiographic texture analysis.

An effective mass screening tool for detecting osteoporosis is currently lacking. Alveolar bone, routinely examined during periodic dental examinations, may provide a window into the status of systemic bone density. The primary objective of this investigation was to compare the performance of various textural features, computed from dental radiographs, in detecting early simulated osteoporosis of alveolar bone. Five specimens of human maxillary alveolar bone were progressively decalcified and the percentage calcium lost at each decalcification stage quantified. Two radiographs of each specimen, together with an aluminum stepwedge, were exposed at 70 kVp at each stage. The test set of 140 radiographs was digitized, identical bony regions of interest selected from the density-corrected images of each specimen, the regions digitally filtered to reduce film-grain noise, and textural features computed on a line-to-line basis. Correlation analysis identified a set of features whose changes consistently exhibited a moderate-to-strong linear association with bone mineral loss over a wide range of decalcification. Repeated measures analysis of variance was subsequently applied to this set to measure the minimal decalcification that could be detected by each feature under optimal conditions of x-ray beam angulation (0 degrees) and suboptimal conditions (+/- 5 degrees). The best performing features were mean intensity, gradient, Laws' texture energy measures, and fractal dimension which detected 5.7% bone decalcification at optimal beam angulation and 9.4-12.6% at suboptimal angulation.

Performance of filters for noise reduction in maxillary alveolar bone imaging.

Film-grain noise degrades image detail, hinders detection of subtle radiographic bone changes, and could thwart attempts to use dental radiographs of alveolar bone to detect osteoporosis. The purpose of this investigation was to quantify and compare the performance of various 1- and 2-D spatial and frequency domain filters in suppressing this noise. Estimates of noise-free bone profiles (scan lines) from each of five maxillary interdental areas were made by superimposing and averaging 16 identically exposed and digitized radiographs. The average mean absolute error and mean-squared error between the 80 initially noisy images and their respective noise-free profiles were calculated to provide an estimate of initial noise. Filter performance was measured as the change in these values after filtering the noisy images. Frequency domain analysis revealed that bone signal power spectra dominated at frequencies less than 2-3 cycles/mm and that some form of low-pass filtering would be applicable. The 2-D Butterworth low-pass filter provided the best performance, removing 57% of the film-grain noise when measured by mean absolute error, and over 80% when measured by mean-squared error. Surprisingly, the Lee, Lp mean, geometric mean, binomial, median, and simple neighborhood averaging filters offered comparable levels of performance.

Detection of simulated osteoporosis in human anterior maxillary alveolar bone with digital subtraction.

The purpose of this in vitro study was to examine radiographic changes in human anterior maxillary alveolar bone during simulated osteoporosis (decalcification) and to determine the minimal amount of generalized decalcifications that can be detected under optimal radiographic conditions with the use of digital subtraction. Five samples of human anterior maxillary alveolus were progressively decalcified at timed intervals with 0.1 N hydrochloric acid solutions, and the percentage of calcium lost during each interval was quantified with calcium assays. Sets of four radiographs were exposed at 70 kVp initially and after each decalcification interval. The radiographs were digitized and digitally filtered, and bone profiles (scan lines) were generated between selected points on lead markers. To further reduce corrupting film-grain noise each set of four profiles were superimposed and averaged on a pixel-by-pixel basis. The averaged profile from each stage of decalcification was subtracted from the averaged initial profile on a pixel-by-pixel basis, and the mean profile intensity change for each decalcification stage calculated. Statistical analysis was performed with repeated measures analysis of variance. Results indicate that generalized decalcification less than or equal to 5.3% was detected in all samples of human anterior maxillae with the use of digital subtraction.

Detection of simulated osteoporosis in dog alveolar bone with the use of digital subtraction.

The purpose of this in vitro study was to examine radiographic changes in dog alveolar bone during simulated osteoporosis (decalcification) and to determine the minimal amount of generalized bone loss that can be detected under optimal radiographic conditions with the use of digital subtraction. Five samples of dog maxillary alveolus were progressively decalcified at timed intervals with 0.1 N hydrochloric acid solutions. The percentage of calcium lost during each interval was quantified with calcium assays. Sets of four radiographs from each sample were exposed at 30 kVp and 50 kVp initially and after each decalcification interval. The radiographs were digitized and bone profiles (scan lines) were generated between images of lead markers. To suppress contaminating image noise each set of four profiles were superimposed and averaged on a pixel-by-pixel basis. The averaged profile from each stage of decalcification was subtracted from the averaged initial profile on a pixel-by-pixel basis, the mean profile intensity change for each decalcification stage calculated, and this mean change compared to the initial mean intensity to yield the percentage mean profile intensity change for each sample for each decalcification stage. Statistical analysis was performed with repeated measures analysis of variance. Results indicate that generalized decalcification of less than 7.5% was detected in all samples of dog maxillae with exposures of 30 kVp and that generalized decalcification of less than 19% was detected with exposure of 50 kVp.

A three-dimensional system for planning orthognathic surgery. A case report.

Conventional records are often inadequate for planning correction of complex dentofacial deformities. A treatment planning system, consisting of computed tomographic-generated jaw models mounted on a special articulator, allows for presurgical decisions about the correctness of surgical movements or the need for alternative approaches.

Noise in D- and E-speed radiographic film.

The purpose of this investigation was to compare image noise in D- and E-speed radiographic film and to establish a basis for choosing a particular speed of film for study of trabecular changes in alveolar bone. Eleven D-speed and 11 E-speed radiographs were made at varying exposures and developed along with unexposed film of each type to produce uniform optical densities that range from approximately 0.05 to 2.5. Profiles (scan lines) were made of each film at a spatial resolution of 0.02 mm. Noise was quantified for each profile using three measures: the standard deviation of the profile pixel intensity, I(x), about the mean, I(x); the coefficient of variation of I(x) about I(x); and Wiener spectral analysis. Results indicate that the average magnitude of noise for D- and E-speed film over this range of optical densities exceeds 4% and 6%, respectively; the average noise content of E-speed film was 25% to 35% greater than D-speed; and noise energy of both films is concentrated at low spatial frequencies and low optical densities.

Maxillary alveolar bone imaging. Wiener filter design.

Optimal digital filter design is essential for noise suppression in the detection of subtle radiographic bony changes. The purpose of this study was to determine the signal (Ps) and noise (Pn) power spectra of sampled maxillary alveolar bone, to derive the optimal Wiener filter transfer function, H, from sets of Ps and Pn, and to quantify noise suppression through application of this filter. Sixteen standardized radiographs were made of five interproximal bony areas, each area from a separate dry human maxilla. The radiographs were digitized (0.02 mm/pixel resolution) and identical profiles (scan lines) generated between lead markers for each set of films. Ps was calculated from the averaged scan line of each set, Pn was calculated from the difference between the noisy images and the averaged scan line for each set, and an average maxillary H was calculated from the sets of Ps and Pn. Filtering of the 80 noisy sample radiographic profiles with H resulted in a 39% reduction in noise. Application of this digital filter should significantly improve detection of radiographic bony changes in the maxilla.

The effect of corticosteroid-induced osteoporosis on orthodontic tooth movement.

The purpose of this research was to study the effect of corticosteroid-induced osteoporosis on orthodontic tooth movement and relapse. Sixteen 3-month-old New Zealand white rabbits were divided into four equal groups, two treatment and two control. All treatment rabbits were administered daily injections of 15 mg/kg cortisone acetate for 4 days before and during the experimental period. An orthodontic appliance delivering a mesial force of 4 ounces was placed on the maxillary left first molar of all animals. For all groups, measurements of active tooth movement were made after 4, 7, 11, and 14 days. For two of the groups, appliances were removed on day 14, and additional measurements of relapse were made through day 21. With the use of radiodensitometric readings of the humerus bone and histology of the maxilla, osteoporosis was demonstrated in the treatment animals. Mean incremental and cumulative active tooth movement was three to four times greater (p < 0.0001) in the treatment rabbits than in the controls. The treatment group in which relapse was measured demonstrated 100% relapse on day 18, whereas the control group relapsed at a much lesser rate through day 21 and never achieved 100% relapse. Histologic findings appeared to support tooth movement results. In conclusion, the results of this study indicate that rabbits subjected to corticosteroid-induced osteoporosis undergo significantly more rapid orthodontic tooth movement and subsequent relapse than control animals.

Comparison of digitized radiographic alveolar features between 20- and 70-year-old women. A preliminary study.

The purpose of this investigation was to determine whether a difference exists in four digital image features, extracted from standardized periapical radiographs of the maxillary alveolar bone, between younger and older women. These features included mean pixel intensity, I(x); pixel intensity variance, var I(x); mean absolute Fourier transform coefficient, magnitude of F(u); and mean spatial first moment of the absolute Fourier coefficients, M1. The interproximal bone between the maxillary canine and lateral incisor was analyzed in two groups of 10 younger and older women with mean ages of 24 and 74 years, respectively. I(x) was significantly less in the 70-year-old group than in the 20-year-old group (p = 0.01), as were magnitude of F(u) (p less than 0.05) and M1 (p less than 0.01). Var I(x) tended to be significantly less in the 70-year-old group (p = 0.06). We conclude that in women a measurable diminution in the magnitude of these four bony features comes with age.

Quantitative features of digitized radiographic bone profiles.

The purpose of this investigation was to examine the use of four image features in describing digitized radiographic bony scan lines, or profiles. These features include the mean pixel intensity, I (x); pixel intensity variance, var I (x); mean absolute Fourier transform coefficient, magnitude of F(u); and mean spatial first moment of the absolute Fourier coefficients, M1. In an animal model I (x) and M1 differed significantly while magnitude of F(u) tended to differ significantly between digitized radiographic profiles of osteoporotic (n = 6) and control (n = 6) rabbit humeri. Case examples illustrating the application of this technique to digitized radiographs of human interproximal alveolar bone are presented.

Periodontal force: a potential cause of relapse.

Relapse of aligned mandibular anterior teeth and the progressive collapse of the mandibular arch is a significant problem for orthodontists. However, identification of a specific cause of such relapse has proved elusive. The transseptal fiber system is thought to stabilize teeth against separating forces. It is hypothesized that this fiber system may actually maintain the contacts of approximating teeth in a state of compression, the long-term result of which could be contact slippage and collapse of the arch. The interproximal force (IPF) at the mandibular first molar-second premolar contact was investigated on the basis of previous studies with this representative contact. The IPF was measured in 10 subjects at six different widths of contact separation. By means of graphic plotting techniques, the IPF at zero separation was calculated to estimate the contact force when the molar and premolar were actually touching. The mean IPF at zero separation was found to be 36.7g (SE = 6.6g), and a t test confirmed the hypothesis that a state of compression between contacts exists (p less than 0.0001). After chewing, the mean IPF at zero separation was 57.2g (SE = 9.1g), and a paired t test revealed an increase in contact compression had resulted (p less than 0.01). It was concluded that the periodontium exerts a continuous force on the mandibular dentition and that this force acts to maintain the contacts of approximating teeth in a state of compression. This force is increased after occlusal loading and may help to explain long-term crowding of the mandibular anterior teeth, physiologic drifting of teeth, and maintenance of posterior dental contacts after interproximal wear.