Reginald W. Taylor

Evaluation of Preemptive Valdecoxib Therapy on Initial Archwire Placement Discomfort in Adults

The purpose of this randomized, double-blinded, placebo-controlled prospective clinical trial was to compare the efficacy of preemptive and postoperative administration of valdecoxib in reducing discomfort caused by initial archwire placement in adults. A total of 56 orthodontic patients aged 18-54 years who were to begin treatment were randomly assigned to one of three groups: (1) placebo, (2) those who received preemptive valdecoxib 40 mg at least 30 minutes before initial archwire placement, or (3) those who received postoperative valdecoxib 40 mg two hours after initial archwire placement. Patients in the active treatment groups also received continuous valdecoxib therapy for an additional 48 hours. Discomfort levels were recorded on a visual analog scale at zero, two, six, 24, and 48 hours after initial archwire placement. At baseline, no significant differences were detected between the three groups. In the preemptive valdecoxib group, there was no significant increase (P > .05) in discomfort from baseline at any time point. The placebo and postoperative valdecoxib groups showed significant (P < .05) increases in discomfort after six hours, with the peak discomfort at 24 hours. The postoperative group showed a tendency toward decreased discomfort over time, but the changes were not significantly different from the placebo or the preemptive group. Preemptive analgesia with nonsteroidal anti-inflammatory drugs may be an approach to prevent discomfort associated with initial archwire placement in healthy adults.

Transverse dentoalveolar changes after slow maxillary expansion

INTRODUCTION In this study, we evaluated the transverse dentoalveolar changes in the maxillary first molar region after early treatment with the quad-helix appliance. METHODS Seventy-three consecutive patients (39 boys, 34 girls) who had phase 1 quad-helix treatment were evaluated with cone-beam computed tomography scans taken before phase 1 (mean age, 9.2 years) and phase 2 (mean age, 11.9 years) treatments. Buccal bone thickness, buccal cortical plate thickness, lingual bone thickness, alveolar width, palatal width, and intermolar width were measured by using standardized orientations. RESULTS Slow palatal expansion with the quad-helix decreased buccal bone thickness (1.6 mm ± 0.8), and increased lingual bone thickness (1.6 mm ± 1.3) and alveolar width (0.5 mm ± 1.0). Intermolar widths and palatal widths increased 6.5 mm ± 2.9 and 3.9 mm ± 1.8, respectively. At the beginning of phase 2, approximately one third of the patients showed little or no buccal cortical plate on at least 1 side. Patients retained with the Hawley demonstrated some relapse tendencies; patients without retention had the greatest relapse tendencies. CONCLUSIONS Early treatment with the quad-helix appliance proved to be highly effective in increasing intermolar, palatal, and alveolar widths. The teeth moved through the alveolus, leading to substantial decreases in buccal bone thickness and increases in lingual bone thickness.

Bony adaptation after expansion with light-to-moderate continuous forces

INTRODUCTION The purpose of this study was to evaluate the biologic response of dentoalveolar bone to archwire expansion with light-to-moderate continuous forces. METHODS With a split-mouth experimental design, the maxillary right second premolars of 7 adult male dogs were expanded for 9 weeks using passive self-ligating brackets (Damon Q; Ormco, Orange, Calif) and 2 sequential archwires (0.016 × 0.022-in copper-nickel-titanium alloy, followed by 0.019 × 0.025-in copper-nickel-titanium alloy). Intraoral and radiographic measurements were made to evaluate tooth movements and tipping associated with expansion; archwire forces were measured using a force gauge. Microcomputed tomography was used to compare buccal bone height, total tooth height, total root height, and buccal bone thickness. Bone formation was evaluated histologically using tetracycline and calcein fluorescent labels and hematoxylin and eosin stains. RESULTS Buccal expansion was produced by forces between 73 and 178 g. Compared with the control side, which showed no tooth movement, the experimental second premolars were expanded by 3.5 ± 0.9 mm and tipped by 15.8°. Buccal bone thickness was significantly thinner (about 0.2 mm) in the coronal aspects and significantly thicker (about 0.9 mm) in the apical aspects over the mesial roots. The tipping and expansion significantly (P <0.05) reduced buccal bone height (ie, caused dehiscences) at the mesial (about 2.9 mm) and distal (about 1.2 mm) roots. Bony apposition occurred on the trailing edges of tooth movement and on the leading edges of the second premolar apices. The axial microcomputed tomography slices indicated, and the bone histomorphometry and histology demonstrated, newly laid-down bone on the periosteal side of the buccal cortical surfaces. Ordered osteoblast aggregation was also evident on the periosteal surfaces of buccal bone, just cervical to the apparent center of rotation of the tooth. Tooth and root heights showed no significant differences between the experimental and control second premolars. CONCLUSIONS Buccal expansion with light-to-moderate continuous forces produced 3.5 mm of tooth movement, uncontrolled tipping, and bone dehiscence, but no root resorption. Bone formation on the periosteal surfaces of cortical bone indicates that apposition is possible on the leading edge of tooth movements.

Differences in craniofacial and dental characteristics of adolescent Mexican Americans and European Americans

INTRODUCTION The purpose of this study was to compare the soft-tissue profiles of matched Class I adolescent European Americans and Mexican Americans. The secondary aim was to explain profile differences based on group differences in soft-tissue thickness, skeletal morphology, dental position, and tooth size. METHODS The study pertained to 207 untreated Class I adolescents, including 93 Mexican Americans and 114 European Americans. Lateral cephalometric and model analyses were performed to quantify morphologic differences. Two-way analyses of variance were used to evaluate ethnicity, sex, and their interaction. RESULTS Mexican Americans had significantly (P <0.05) greater lip protrusion and facial convexity than did European Americans. Mexican Americans had smaller craniofacial dimensions and larger teeth, resulting in maxillary and mandibular dentoalveolar protrusion. Mexican Americans also had thicker soft tissues and greater maxillary skeletal prognathism than European Americans. The combination of thicker soft tissues, maxillary skeletal prognathism, and dentoalveolar protrusion explained the protrusive lips of Mexican Americans. The greater facial convexity of Mexican Americans was due primarily to maxillary prognathism and mandibular hyperdivergence. Sex differences pertained primarily to size; the linear dimensions of the boys were consistently and significantly larger than those of the girls. CONCLUSIONS European American normative data and treatment objectives do not apply to Mexican Americans. Knowledge of the soft-tissue, skeletal morphology, and dental position differences should be applied when planning treatment for Mexican American patients.

Effect of force on alveolar bone surrounding miniscrew implants: a 3-dimensional microcomputed tomography study.

INTRODUCTION The primary aim of this study was to better understand how bone adapts to forces applied to miniscrew implants. A secondary aim was to determine whether the direction of force applied to miniscrew implants has an effect on bone surrounding the miniscrew implants. METHODS A randomized split-mouth design, applied to 6 skeletally mature male foxhound dogs, was used to compare miniscrew implants loaded for 9 weeks with 200 or 600 g to unloaded control miniscrew implants. By using microcomputed tomography, with an isotropic resolution of 6 μm, bone volume fractions (bone volume/total volume) were calculated for bone around the entire miniscrew implant surface. Bone volume fractions were calculated for bone 6 to 24, 24 to 42, and 42 to 60 μm from the miniscrew implant surface. For each loaded miniscrew implant, the bone volume fraction was also calculated for 2 compression and 2 noncompression zones. RESULTS The 6 to 24-μm layer showed a significantly lower (P <0.05) bone volume fraction than did the 24 to 42-μm and the 42 to 60-μm layers, which were not significantly different. The bone volume fractions of cortical bone surrounding the apical aspects of the unloaded miniscrew implants were significantly greater (P <0.05) than the bone volume fractions of cortical bone surrounding the loaded miniscrew implants. In contrast, the bone volume fractions of noncortical bone surrounding loaded miniscrew implants were significantly greater (P <0.05) than the bone volume fractions of bone surrounding the unloaded miniscrew implants. Miniscrew implants loaded with 200 g showed significantly greater (P <0.05) amounts of noncortical bone volume fractions than did miniscrew implants loaded with 600 g. With both 200 and 600 g, zones under compression had significantly greater bone volume fractions than did the noncompression zones. CONCLUSIONS The application of force, the amount of force applied, and the direction of force all have significant effects on the amounts of bone produced around miniscrew implants.

Critical roles of periostin in the process of orthodontic tooth movement.

AIM The process of orthodontic tooth movement (OTM) involves multiple mechanisms of action including bone and extracellular matrix remodelling, although the role of periodontal ligament (PDL) in this process is largely unknown. Periostin, which is highly expressed in the PDL, is known to be responsible for mechanical stimulation in maintaining the integrity of periodontal tissues. We hypothesize that this protein plays an important role during OTM. MATERIAL AND METHODS By using spring in 4-week-old wild-type (WT) and periostin null mice, the rate of tooth movement and mineralization were evaluated. For the evaluation, double labelling, expression of sclerostin (SOST), number of TRAP-positive cells, and quality of collagen fibrils by Sirius red were analysed and compared between these two groups. RESULTS Our findings showed that the distance of the tooth movement and mineral deposition rates were significantly reduced in periostin null mice (P < 0.05), with a lack of expression changes in SOST as observed in the WT group. The arrangement, digestion, and integrity of collagen fibrils were impaired in periostin null mice. The number of osteoclasts reflected by expressions of TRAP (tartrate-resistant acid phosphatase) in the null mice was also significantly lower than the WT control (P < 0.05). CONCLUSION Periostin plays a stimulatory role in both SOST and TRAP responses to OTM in the compassion site, although it is not clear if this role is direct or indirect during orthodontic loading.

Effectiveness of a novel topical powder on the treatment of traumatic oral ulcers in orthodontic patients: A randomized controlled trial

OBJECTIVE To determine if 2-DeNT Oral Topical Powder is an effective treatment for traumatic oral ulcers. MATERIALS AND METHODS Of the 46 patients who were randomly allocated, 20 patients from the experimental group and 17 from the placebo control group completed the study. The patients, operators, and evaluators were all blinded. Patients applied the powder twice a day and completed a diary twice a day for 10 days. The diary was used to monitor the size of the lesions and pain levels (using a 10-cm visual analog scale). RESULTS By day 5, the ulcers in the experimental group had reduced in size by approximately 70%; and ulcers in the control group had reduced in size by 56%. The experimental-group ulcers were significantly (P < .05) smaller than the control-group ulcers from day 5 through day 9. Ulcers in the experimental group were completely resolved by day 8, whereas control-group ulcers were still present on day 10. Patients experienced a significant amount of stimulated pain until the night of day 2 in the experimental group and until the night of day 5 in the control group, but group differences in pain were not statistically significant. CONCLUSIONS The 2DeNT Oral Topical powder was more effective than the placebo powder at accelerating the healing of oral traumatic ulcers.

Retention of sealants during orthodontic treatment: An in vitro comparison of two etching protocols

OBJECTIVE To test the retention of smooth-surface sealants bonded with different etching protocols against toothbrushing and, secondarily, to characterize the type and location of sealant loss. MATERIALS AND METHODS Eighty-nine extracted human teeth were randomly assigned one of two etching protocols: 37% phosphoric acid etch (ETCH) or self-etching primer (SEP). Six specimens at a time were placed in a toothbrushing machine to simulate 4, 8, 12, and 24 months of toothbrush abrasion. Using black-light photographs of each specimen taken before and after brushing, four blinded coinvestigators determined new sealant loss, loss along the edge of an initial defect, and the location of sealant loss. RESULTS Overall, there were significantly (P < .05) more teeth with sealant loss in the SEP group (38.6%) than in the ETCH group (15.5%). New loss of sealant was significantly (P < .05) more likely in the SEP group (27.2%) than in the ETCH group (2.2%). Of the teeth with new loss of sealant, all (100%) had loss at the edge, and 23% had progressive loss. There was no significant group difference in sealant loss from initial defects. Of the teeth that showed enlargement of initial defects, 91% had loss at the edge and 91% had progressive loss. CONCLUSIONS Using SEP to apply facial sealants results in lower retention rates than using ETCH. The vast majority of sealant loss occurs at the edges. Loss of sealant due to enlargement of an initial defect is highly progressive over time.