Quantitative evaluation of maxillary alveolar cortical bone thickness and density using computed tomography imaging.

INTRODUCTION: Primary stability is essential to the success of orthodontic mini-implants (OMIs) and heavily depends on the mechanical retention between OMIs and their supporting bone. Alveolar cortical bone commonly serves as the supporting bone for OMIs during treatment. The purposes of this study were to characterize alveolar cortical bone thickness and density in the maxilla and to explore patient factors that may significantly affect these bone properties. METHODS: Sixty medical computed tomography scans of the maxilla were analyzed from a selected sample of patients seen at the Radiology Department of Boston Children's Hospital. Interradicular alveolar bone thickness and density were measured at 2, 4, 6, and 8 mm from the buccal and palatal alveolar bone crests using the Synapse 3D software (version 4.1; FUJIFILM Medical Systems USA, Stamford, Conn). Analyses were conducted with STATA /1C (version 12.0 for Windows; StataCorp, College Station, Tex) using multivariate mixed-effects regression models and paired t tests. RESULTS: Mean age and body mass index of the study sample were 17.88 years and 22.94 kg/m2, respectively. Cortical bone density and thickness significantly increased from the coronal (2 mm) to the apical (8 mm) regions of the alveolar bone (P <0.05). At 8 mm from the alveolar crest, interradicular buccal cortical bone was thickest (1 mm) and densest (1395 Hounsfield units) between the first and second molars. On the palatal side, the thickest bone (1.15 mm) was found between the canine and first premolar; it was similarly densest (1406 Hounsfield units) between the first premolar and canine, and between the first premolar and second premolar interradicular bones. On average, palatal cortical bone was thicker and denser compared with buccal; this difference was statistically significant (P <0.01) in the anterior and middle maxilla, with the anterior maxillary region showing the greatest difference. Female subjects have significantly denser bone compared with male subjects; however, sex is not significantly associated with bone thickness. Body mass index and age are positively associated with bone thickness and density. Radiologic absence of bone was more commonly seen in the anterior maxilla. CONCLUSIONS: Alveolar bone properties vary in the maxilla in patterns that could guide clinicians in selecting sites best suited for placement of OMIs.

Clinical trial of a farnesyltransferase inhibitor in children with Hutchinson-Gilford progeria syndrome.

Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare, fatal, segmental premature aging syndrome caused by a mutation in LMNA that produces the farnesylated aberrant lamin A protein, progerin. This multisystem disorder causes failure to thrive and accelerated atherosclerosis leading to early death. Farnesyltransferase inhibitors have ameliorated disease phenotypes in preclinical studies. Twenty-five patients with HGPS received the farnesyltransferase inhibitor lonafarnib for a minimum of 2 y. Primary outcome success was predefined as a 50% increase over pretherapy in estimated annual rate of weight gain, or change from pretherapy weight loss to statistically significant on-study weight gain. Nine patients experienced a ≥50% increase, six experienced a ≥50% decrease, and 10 remained stable with respect to rate of weight gain. Secondary outcomes included decreases in arterial pulse wave velocity and carotid artery echodensity and increases in skeletal rigidity and sensorineural hearing within patient subgroups. All patients improved in one or more of these outcomes. Results from this clinical treatment trial for children with HGPS provide preliminary evidence that lonafarnib may improve vascular stiffness, bone structure, and audiological status.

Serum citrulline as a biomarker of gastrointestinal function during hematopoietic cell transplantation in children.

OBJECTIVES: We sought to determine whether serum citrulline (CIT), an amino acid produced by small bowel enterocytes, was associated with clinical and biochemical markers of gastrointestinal function in children undergoing hematopoietic cell transplantation (HCT). METHODS: We conducted a multicenter, prospective cohort study of 26 children to define time-related changes in serum CIT during the course of HCT. Markers of gastrointestinal function including oral energy intake, emesis, stool volume, presence of graft-versus-host disease (GVHD), oral mucositis severity, and cytokine and neurohormone levels were measured. Weekly serum CIT concentrations were obtained from 10 days prior until 30 days after HCT. RESULTS: Mean baseline CIT concentration was 22.7 µmol/L (95% confidence interval [CI] 17.7-27.6) on day -10, which decreased to a nadir of 7.5 µmol/L (95% CI 3.1-18.0, P = 0.017) on day 8 following HCT before returning to baseline by day 30. After adjustment for IL-6 level (1.0% lower CIT per 10% increase in interleukin-6, P = 0.004), presence of acute GVHD (27% lower CIT, P = 0.025), and oral energy intake (2.1% lower CIT per 10% decrease in energy intake, P = 0.018), the nadir shifted to day 10, when mean CIT concentration was lower in patients with severe oral mucositis (6.7 µmol/L, 95% CI 3.4-13.1) than in those without severe mucositis (11.9 µmol/L, 95% CI 5.8-24.4, P = 0.003). Change in CIT was not correlated with stool volume, C-reactive protein, tumor necrosis factor-α, leptin, or ghrelin. CONCLUSIONS: In children undergoing HCT, serum CIT correlates with measures of gastrointestinal function (oral mucositis severity, dietary intake, acute GVHD) and may reflect mucosal injury to the gastrointestinal tract.

Antibiotic Prescribing Patterns Among Dental Professionals In Massachusetts.

Purpose: The purposes of this study were to investigate prescribing patterns of antibiotics for the management of common pediatric oral infections, and to and identify the independent predictors of antibiotic preference across different groups of dental practitioners in Massachusetts, USA. Methods: A cross-sectional survey assessed antibiotic prescribing practices of general dentists, pediatric dentists, endodontists, and oral surgeons based on a series of clinical scenarios where antibiotic coverage may be warranted. Results: The appropriate therapeutic management of patients with facial cellulitis occurred across all clinical groups. Endodontists were least likely to prescribe antibiotics for patients with irreversible pulpitis, and those with pulpal necrosis with associated parulis. Seventy-four percent of respondents prescribed antibiotics for patients suffering from pericoronitis and trismus. Conclusion: With the exception of the management of facial cellulitis, adherence to published guidelines for the prescription of antibiotics is low. Specifically, antibiotics are being prescribed too often for patients with tooth pain or localized abscesses and infrequently when the systemic spread of infection is less obvious, such as with trismus but no fever. Universally promulgated guidelines formulated by professional bodies may lead to improved adherence and a reduction in negative outcomes resulting from the overprescription of antibiotics.

Oral health and bone density in adolescents and young women with anorexia nervosa.

PURPOSE: To evaluate the dental and periodontal health of adolescents and young women with restrictive anorexia nervosa (AN), and relationship between bone mineral density (BMD) assessed by dual energy Xray absorptiometry (DXA) and dental radiographs. STUDY DESIGN: Twenty-three young women, median age 17.6 years (range 14.4-27.2), were studied within three months of entering a clinical trial. DXA BMD measurements were obtained and subjects underwent a comprehensive dental examination, including panoramic and bitewing dental radiographs. Three observers assessed mandibular cortical width (MCW) in the mental foramen region on panoramic radiographs. RESULTS: Dental findings included very good to excellent oral hygiene. Gingival recession was evident in 10 participants (43%). Dental erosion was not seen and the mean decayed missing or filled teeth (DMFT) was 8.6. There was a weak positive correlation between BMD by DXA and MCW on radiographs. CONCLUSIONS: We report dental manifestations associated with restrictive AN, and the association between bone assessments by DXA and dental radiographs in this patient group. Despite subnormal DXA measurements in most patients, essentially all adolescents had a normal dental examination. Dental providers should be cognizant of the fact that many patients with eating disorders may not display the "classic" findings reported in the literature.

Microbiome at sites of gingival recession in children with Hutchinson-Gilford progeria syndrome.

BACKGROUND: Hutchinson-Gilford progeria syndrome (HGPS) is a rare premature aging disorder with significant oral and dental abnormalities. Clinical symptoms include various features of accelerated aging such as alopecia, loss of subcutaneous fat, bone abnormalities, and premature cardiovascular disease. In addition, children with HGPS have been observed to suffer from generalized gingival recession. Whether periodontal manifestations associated with this syndrome are the results of changes in the oral flora is unknown. The present study aimed to identify the microbial composition of subgingival sites with gingival recession in children with HGPS. METHODS: Nine children with HGPS were enrolled in this study. Plaque samples were collected from teeth with gingival recession. DNA samples were analyzed using the Human Oral Microbe Identification Microarray (HOMIM). Microbial profiles from HGPS children were compared with microbial profiles of controls from healthy individuals (n = 9) and patients with periodontal disease (n = 9). RESULTS: Comparison of microbial compositions of HGPS samples with periodontal health samples demonstrated significant differences for two bacterial taxa; Porphyromonas catoniae and Prevotella oulora were present in children with HGPS, but not normal controls. There were statistically significant differences of 20 bacterial taxa between HGPS and periodontal disease groups. CONCLUSIONS: Typical periodontal pathogens were not present at sites with gingival recession in HGPS children. The microbial compositions of sites of gingival recession and attachment loss in HGPS were generally more similar to those of periodontal health than periodontal disease. Species other than typical periodontal pathogens may be involved in this recession.

Acquisition of mutans streptococci and caries prevalence in pediatric sickle cell anemia patients receiving long-term antibiotic therapy.

PURPOSE: The purpose of this study was to: (1) evaluate the prevalence of mutans streptococci (MS) and dental caries in sickle cell anemia (SCA) patients receiving long-term prophylactic penicillin therapy; and (2) determine changes in MS colonization and dental caries upon discontinuing the antibiotic. METHODS: Sixty subjects with SCA and 60 age- and race-matched control subjects participated in this study. The SCA subjects were divided into 2 separate age groups: (1) group 1 subjects were under 6 years of age and received penicillin twice a day; and (2) group 2 subjects were 6 to 12 years old and received no daily prophylactic antibiotics, although up to age 6 they had received daily penicillin before it was discontinued. DMFS/dmfs scores for all subjects were obtained through a comprehensive dental examination including bitewing radiographs. Stimulated salivary samples to assess MS levels were obtained on all subjects. Data on medical, dental, fluoride, and dietary history were obtained on all patients through a written parental questionnaire. RESULTS: No group 1 patients had positive cultures for MS. In contrast, 70% of marched controls cultured positively for MS (P<.01). The DMFS/dmfs score for group 1 was 0.21 vs 5.1 for the control group (P<.01). Differences in surfaces affected were also noted, with no group 1 patients having interproximal lesions compared to 47% of control subjects having these lesions (P<.01). Group 2 also had significantly lower levels of MS than matched controls (47% vs 97%, P<.01), although there was no statistically significant difference in caries prevalence or surfaces involved. CONCLUSIONS: These findings demonstrate that long-term penicillin prophylaxis in SCA patients likely prevents the acquisition of MS, resulting in significantly lower caries rates in these patients. This benefit occurs only during active administration of the drug, however, and only delays the acquisition of MS.

Cross sectional: normal maximal incisal opening and associations with physical variables in children.

PURPOSE: The purpose of this investigation was to establish a normal range of maximal incisal opening (MIO) in children, and the correlation between MIO with age, height, weight, gender, race, and molar relationship. METHODS: Calibrated examiners used the TheraBite Range of Motion (ROM) scale to obtain two MIO readings from 500 enrolled subjects, accounting for overbite or open bite. The subject's height, weight, molar relationship, age, gender, and race were recorded. Subjects were stratified according to age, and mean MIO ± standard deviation for each age group was determined. RESULTS: Mean MIO was positively correlated with age (P<.001), height (P<.001), weight (P<.001), and race (P<.001). However, height became insignificant in the multivariable regression model. On average, MIO of African-Americans was 3.66 mm larger than Whites (P<.001), and MIO of Hispanics/Latinos was 2.52mm greater than Whites (P<.001). There was no statistically significant association with left or right molar relationships (P=.07, P=.26 respectively) or gender (P=.58). CONCLUSIONS: TheraBite ROM scale is a practical tool to clinically measure MIO. MIO mimics somatic growth, peaking at age 12-13 years for females and 14-15 years for males. African-Americans and Hispanics/Latinos have a greater mean MIO than Whites. The established norms will be useful in diagnosis and treatment.

Effect of titrated parenteral nutrition on body composition after allogeneic hematopoietic stem cell transplantation in children: a double-blind, randomized, multicenter trial.

BACKGROUND: Children undergoing hematopoietic stem cell transplantation (HSCT) often require parenteral nutrition (PN) to optimize caloric intake. Standard approaches to nutritional supplementation provide 130-150% of estimated energy expenditure, but resting energy expenditure (REE) may be lower than expected after HSCT. Provision of PN exceeding energy needs may lead to overfeeding and associated complications. OBJECTIVE: We conducted a blinded, randomized, controlled, multicenter trial in children undergoing HSCT to determine the effect on body composition of 2 different approaches of nutrition support: standard amounts of energy from PN (130-150% of REE) compared with PN titrated to match measured REE. DESIGN: Twenty-six children undergoing HSCT were randomly assigned to standard or titrated PN. Energy intake was monitored until day 30 after HSCT. Body-composition and anthropometric measures were obtained through day 100. The primary outcome variable was percentage body fat (%BF) measured by dual energy X-ray absorptiometry. RESULTS: The estimated change in %BF from baseline to day 30 was 1.2 ± 0.5% in the standard group and 0.1 ± 0.5% in the experimental group, but the overall time course of %BF did not differ significantly by treatment (P = 0.39 for time × treatment interaction). A profound loss of lean body mass (LBM) occurred in both groups during the intervention period and persisted through day 100. CONCLUSIONS: Parenteral energy intake titrated to energy expenditure does not result in a lower accumulation of BF than does standard energy intake. Neither titrated nor standard PN regimens during HSCT preserve LBM. Alternative approaches to preserve LBM are needed. This trial is registered at clinicaltrials.gov as 00115258.

E-space preservation.

OBJECTIVE: To determine the relationship of E-space preservation with lingual holding arches to mandibular permanent second molar impaction. METHODS: Two hundred consecutively treated patients undergoing nonextraction treatment for incisor crowding were entered into the study. Lower incisor crowding was assessed by the Little Irregularity Index. Treatment involved E-space preservation via a passive lingual arch placed prior to exfoliation of the second primary molar. Panoramic and cephalometric radiographs were analyzed for any significant relationship of mandibular permanent second molar impaction relative to molar angulation, spacing, growth pattern, and skeletal relationships. RESULTS: Twenty-nine patients had at least one impacted second molar (14.5%). Of a possible 400 mandibular second molars, 34 were determined to be impacted (8.5%). Only the mandibular first molar-second molar angulation was found to be significant (P < .001). Pretreatment intermolar angulation of 24 degrees had a positive predictive value of 1. CONCLUSION: Impaction of permanent second mandibular molars in patients undergoing nonextraction via E-space preservation with a passive lingual arch is 10 to 20 times more prevalent than that observed in the general population. Risk of impaction is best predicted by the pretreatment intermolar angulation between first and second permanent mandibular molars.

A multi-center, randomized, controlled trial of parenteral nutrition titrated to resting energy expenditure in children undergoing hematopoietic stem cell transplantation ("PNTREE"): rationale and design.

BACKGROUND: Children undergoing hematopoietic stem cell transplantation (HSCT) frequently require prolonged courses of parenteral nutrition (PN) as a consequence of gastrointestinal dysfunction related to preparative chemotherapy and radiation. PN has been associated with shorter engraftment time and decreased mortality during HSCT, however, it is also linked with complications, including infections, liver disease, and metabolic disturbances. Some of these complications may be a result of providing PN in excess of nutrient requirements. We previously described significant reductions in resting energy expenditure (REE), as measured by indirect calorimetry, over the course of HSCT. We also documented a decline in mid-arm muscle area, suggesting depletion of muscle mass, while triceps skinfold, a marker of fat stores, was unchanged. These results suggested the need for further study of energy expenditure, body composition and nutritional intake in this group of high risk patients. DESIGN AND HYPOTHESIS: We hypothesize that changes in body composition affect REE during HSCT, and that standard nutritional support may lead to overfeeding. We are performing a randomized controlled trial of parenteral nutrition among children undergoing allogeneic HSCT. Subjects are randomized to receive PN designed to provide 100% of measured REE, or standard PN, i.e., 140% of estimated energy expenditure. The primary outcome variable is change in percent body fat. Secondary outcomes include glycemic control and frequency of infections, changes in REE and body composition. CONCLUSION: This study will provide unique and comprehensive nutritional data and its results will guide nutritional therapy for children undergoing HSCT and possibly other catabolic patients.

Proximal segment displacement in mandibular distraction osteogenesis.

Distraction osteogenesis has been advocated for treatment of the mandibular deformity in patients with hemifacial microsomia (HFM). During the active phase, the force of distraction pushes the distal segment of the mandible down, creating a distraction gap. Because of the abnormal temporomandibular joint anatomy in HFM patients, the proximal segment may not seat in the glenoid fossa and thus may be displaced with distraction. The purpose of this study was to determine the vector(s) of proximal segment movement during mandibular distraction using a semiburied device. Two investigators traced the immediate pre-and postdistraction panoramic radiographs of 12 HFM patients (mean age at operation = 8.4 years, mean distraction = 28 mm) who had mandibular distraction with a semiburied device. Radiographic analysis, based on a vertical maxillary reference line, measured change in condylar position with angular and linear measurements. Inter-rater reliability for the tracing and analysis was shown with a correlation coefficient between 0.89 and 0.99 for all measures. Based on the angular and linear measurements, 10 of the 12 patients had superior movement of the proximal segment with distraction. Sagittal movement of the proximal segment could not be judged adequately. This study was based on measurements made on panoramic radiographs. Direct measurements could not be made; thus, it was not possible to estimate proximal segment movement in millimeters or as a percentage of total movement. Further studies to document proximal segment movement using computed tomography scans may provide more quantitative data.