The incremental contribution of mobile cone-beam computed tomography to the tool-lesion relationship during shape-sensing robotic-assisted bronchoscopy.

Introduction: This study aims to answer the question of whether adding mobile cone-beam computed tomography (mCBCT) imaging to shape-sensing robotic-assisted bronchoscopy (ssRAB) translates into a quantifiable improvement in the tool-lesion relationship. Methods: Data from 102 peripheral lung lesions with ≥2 sequential mCBCT orbital spins and from 436 lesions with 0-1 spins were prospectively captured and retrospectively analysed. The primary outcome was the tool-lesion relationship status across the first and the last mCBCT spins. Secondary outcomes included 1) the change in distance between the tip of the sampling tool and the centre of the lesion between the first and the last spins and 2) the per-lesion diagnostic yield. Results: Compared to lesions requiring 0-1 spins, lesions requiring ≥2 spins were smaller and had unfavourable bronchus sign and intra-operative sonographic view. On the first spin, 54 lesions (53%) were designated as non-tool-in-lesion (non-TIL) while 48 lesions (47%) were designated as TIL. Of the 54 initially non-TIL cases, 49 (90%) were converted to TIL status by the last spin. Overall, on the last spin, 96 out of 102 lesions (94%) were defined as TIL and six out of 102 lesions (6%) were defined as non-TIL (p<0.0001). The mean distance between the tool and the centre of the lesion decreased from 10.4 to 6.6 mm between the first and last spins (p<0.0001). The overall diagnostic yield was 77%. Conclusion: Targeting traditionally challenging lung lesions, intra-operative volumetric imaging allowed for the conversion of 90% of non-TIL status to TIL. Guidance with mCBCT resulted in a significant decrease in the distance between the tip of the needle to lesion centre.

Characterizing a learning curve for robotic-assisted bronchoscopy: Analysis of skills acquisition in a high-volume academic center.

OBJECTIVE: Shape-sensing robotic-assisted bronchoscopy is an emerging technology for the sampling of pulmonary lesions. We seek to characterize the shape-sensing robotic-assisted bronchoscopy learning curve at an academic center. METHODS: Shape-sensing robotic-assisted bronchoscopy procedures performed by 9 proceduralists at a single institution were analyzed. Cumulative sum analyses were performed to examine diagnostic sampling and procedure time over each operator's first 50 cases, with the acceptable yield threshold set to 73%. RESULTS: During the study period, 442 patients underwent sampling of 551 lesions. Each operator sampled 61 lesions (interquartile range, 60-63 lesions). Lesion size was 1.90 cm (interquartile range, 1.33-2.80 cm). The median procedure time for single-target cases decreased from 62 minutes during the first 10 cases to 39 minutes after case 40 (P < .001). The overall diagnostic yield was 72% (range, 58%-83%). Six of 9 operators achieved proficiency over the study period. An aggregated cumulative sum analysis of those who achieved competency demonstrated a steep improvement between lesions 1 and 21 and crossing of the competency threshold by lesion 25. Temporal analysis of yield-related lesion characteristics demonstrated that at approximately lesion 20, more challenging lesions were increasingly targeted, as evidenced by smaller target size, higher rates of unfavorable radial endobronchial ultrasound views, and a negative bronchus sign. CONCLUSIONS: Skills acquisition in shape-sensing robotic-assisted bronchoscopy is variable. Approximately half of proceduralists become facile with the technology within 25 lesions. After the initial learning phase, operators increasingly target lesions with more challenging features. Overall, these findings can inform certification and competency standards and provide new users with expectations related to performance over time.

Determinants of radiation exposure during mobile cone-beam CT-guided robotic-assisted bronchoscopy.

BACKGROUND AND OBJECTIVE: Robotic-assisted bronchoscopy (RAB) is an emerging modality to sample pulmonary lesions. Cone-beam computed tomography (CBCT) can be incorporated into RAB. We investigated the magnitude and predictors of patient and staff radiation exposure during mobile CBCT-guided shape-sensing RAB. METHODS: Patient radiation dose was estimated by cumulative dose area product (cDAP) and cumulative reference air kerma (cRAK). Staff equivalent dose was calculated based on isokerma maps and a phantom simulation. Patient, lesion and procedure-related factors associated with higher radiation doses were identified by logistic regression models. RESULTS: A total of 198 RAB cases were included in the analysis. The median patient cDAP and cRAK were 10.86 Gy cm2 (IQR: 4.62-20.84) and 76.20 mGy (IQR: 38.96-148.38), respectively. Among staff members, the bronchoscopist was exposed to the highest median equivalent dose of 1.48 µSv (IQR: 0.85-2.69). Both patient and staff radiation doses increased with the number of CBCT spins and targeted lesions (p < 0.001 for all comparisons). Patient obesity, negative bronchus sign, lesion size <2.0 cm and inadequate sampling by on-site evaluation were associated with a higher patient dose, while patient obesity and inadequate sampling by on-site evaluation were associated with a higher bronchoscopist equivalent dose. CONCLUSION: The magnitude of patient and staff radiation exposure during CBCT-RAB is aligned with safety thresholds recommended by regulatory authorities. Factors associated with a higher radiation exposure during CBCT-RAB can be identified pre-operatively and solicit procedural optimization by reinforcing radiation protective measures. Future studies are needed to confirm these findings across multiple institutions and practices.

A Prospective Study on Deep Inspiration Breath Hold Thoracic Radiation Therapy Guided by Bronchoscopically Implanted Electromagnetic Transponders.

BACKGROUND: Electromagnetic transponders bronchoscopically implanted near the tumor can be used to monitor deep inspiration breath hold (DIBH) for thoracic radiation therapy (RT). The feasibility and safety of this approach require further study. METHODS: We enrolled patients with primary lung cancer or lung metastases. Three transponders were implanted near the tumor, followed by simulation with DIBH, free breathing, and 4D-CT as backup. The initial gating window for treatment was ±5 mm; in a second cohort, the window was incrementally reduced to determine the smallest feasible gating window. The primary endpoint was feasibility, defined as completion of RT using transponder-guided DIBH. Patients were followed for assessment of transponder- and RT-related toxicity. RESULTS: We enrolled 48 patients (35 with primary lung cancer and 13 with lung metastases). The median distance of transponders to tumor was 1.6 cm (IQR 0.6-2.8 cm). RT delivery ranged from 3 to 35 fractions. Transponder-guided DIBH was feasible in all but two patients (96% feasible), where it failed because the distance between the transponders and the antenna was >19 cm. Among the remaining 46 patients, 6 were treated prone to keep the transponders within 19 cm of the antenna, and 40 were treated supine. The smallest feasible gating window was identified as ±3 mm. Thirty-nine (85%) patients completed one year of follow-up. Toxicities at least possibly related to transponders or the implantation procedure were grade 2 in six patients (six incidences, cough and hemoptysis), grade 3 in three patients (five incidences, cough, dyspnea, pneumonia, and supraventricular tachycardia), and grade 4 pneumonia in one patient (occurring a few days after implantation but recovered fully and completed RT). Toxicities at least possibly related to RT were grade 2 in 18 patients (41 incidences, most commonly cough, fatigue, and pneumonitis) and grade 3 in four patients (seven incidences, most commonly pneumonia), and no patients had grade 4 or higher toxicity. CONCLUSIONS: Bronchoscopically implanted electromagnetic transponder-guided DIBH lung RT is feasible and safe, allowing for precise tumor targeting and reduced normal tissue exposure. Transponder-antenna distance was the most common challenge due to a limited antenna range, which could sometimes be circumvented by prone positioning.

Feasibility of shape-sensing robotic-assisted bronchoscopy for biomarker identification in patients with thoracic malignancies.

OBJECTIVE: Molecular diagnostic assays require samples with high nucleic acid content to generate reliable data. Similarly, programmed death-ligand 1 (PD-L1) immunohistochemistry (IHC) requires samples with adequate tumor content. We investigated whether shape-sensing robotic-assisted bronchoscopy (ssRAB) provides adequate samples for molecular and predictive testing. METHODS: We retrospectively identified diagnostic samples from a prospectively collected database. Pathologic reports were reviewed to assess adequacy of samples for molecular testing and feasibility of PD-L1 IHC. Tumor cellularity was quantified by an independent pathologist using paraffin-embedded sections. Univariable and multivariable linear regression models were constructed to assess associations between lesion- and procedure-related variables and tumor cellularity. RESULTS: In total, 128 samples were analyzed: 104 primary lung cancers and 24 metastatic lesions. On initial pathologic assessment, ssRAB samples were deemed to be adequate for molecular testing in 84% of cases; on independent review of cellular blocks, median tumor cellularity was 60% (interquartile range, 25%-80%). Hybrid capture-based next-generation sequencing was successful for 25 of 26 samples (96%), polymerase chain reaction-based molecular testing (Idylla; Biocartis) was successful for 49 of 52 samples (94%), and PD-L1 IHC was successful for 61 of 67 samples (91%). Carcinoid and small cell carcinoma histologic subtype and adequacy on rapid on-site evaluation were associated with higher tumor cellularity. CONCLUSIONS: The ssRAB platform provided adequate tissue for next-generation sequencing, polymerase chain reaction-based molecular testing, and PD-L1 IHC in >80% of cases. Tumor histology and adequacy on intraoperative cytologic assessment might be associated with sample quality and suitability for downstream assays.

Brief Report: Chylothorax and Chylous Ascites During RET Tyrosine Kinase Inhibitor Therapy.

INTRODUCTION: Spontaneous chylous effusions are rare; however, they have been observed by independent investigators in patients treated with RET tyrosine kinase inhibitors (TKIs). METHODS: This multicenter, retrospective study evaluated the frequency of chylous effusions in patients treated with RET TKIs. Clinicopathologic features and management of patients with chylous effusions were evaluated. RESULTS: A pan-cancer cohort of 7517 patients treated with one or more multikinase inhibitor or selective RET TKI and a selective TKI cohort of 96 patients treated with selpercatinib or pralsetinib were analyzed. Chylous effusions were most common with selpercatinib (7%), followed by agerafenib (4%), cabozantinib (0.3%), and lenvatinib (0.02%); none were observed with pralsetinib. Overall, 12 patients had chylothorax, five had chylous ascites, and five had both. Time from TKI initiation to diagnosis ranged from 0.5 to 50 months. Median fluid triglyceride level was lower in chylothoraces than in chylous ascites (397 mg/dL [interquartile range: 304-4000] versus 3786 mg/dL [interquartile range: 842-6596], p = 0.035). Malignant cells were present in 13% (3 of 22) of effusions. Chyle leak was not identified by lymphangiography. After initial drainage, 76% of patients with chylothorax and 80% with chylous ascites required additional interventions. Selpercatinib dose reduction and discontinuation rates in those with chylous effusions were 47% and 0%, respectively. Median time from diagnosis to disease progression was not reached (95% confidence interval: 14.5-undefined); median time from diagnosis to TKI discontinuation was 11.4 months (95% confidence interval: 8.2-14.9). CONCLUSIONS: Chylous effusions can emerge during treatment with selected RET TKIs. Recognition of this side effect is key to prevent potential misattribution of worsening effusions to progressive malignancy.

Four-Dimensional Computed Tomography-Based Correlation of Respiratory Motion of Lung Tumors With Implanted Fiducials and an External Surrogate.

PURPOSE: Our purpose was to assess the suitability of airway-implanted internal fiducial markers and an external surrogate of respiratory motion for motion management during radiation therapy of lung tumors. METHODS AND MATERIALS: We analyzed 4-dimensional computed tomography scans acquired during radiation therapy simulation for 28 patients with lung tumors who had anchored fiducial markers bronchoscopically implanted inside small airways in or near the tumor in a prospective trial. We used a linear mixed model to build population-based correlative models of tumor and surrogate motion. The first 24 of the 28 patients were used to build correlative models, and 4 of the 28 consecutive patients were excluded and used as an internal validation cohort. Of the 24 patients from the model building cohort, all were used for the models based on the internal fiducial. The external surrogate was completely visualized in 11 patients from the model building cohort, so only those were used for the models based on the external surrogate. Furthermore, we determined the predicted residual error sum of squares for our correlative models, which may serve as benchmarks for future research. RESULTS: The motion of the internal fiducials was significantly associated with the tumor motion in the anterior-posterior (P < .0001) and superior-inferior (SI) directions (P < .0001). We also observed a strong correlation of the external surrogate anterior-posterior motion to the tumor dominant SI motion (P < .0001). In the validation cohort, the internal fiducial SI motion was the only reliable predictor of lung tumor motion. CONCLUSIONS: The internal fiducials appear to be more reliable predictors of lung tumor motion than the external surrogate. The suitability of such airway-implanted internal fiducial markers for advanced motion management techniques should be further investigated. Although the external surrogate seems to be less reliable, its wide availability and noninvasive application support its clinical utility, albeit the greater uncertainty will need to be compensated for.

Can bronchoscopically implanted anchored electromagnetic transponders be used to monitor tumor position and lung inflation during deep inspiration breath-hold lung radiotherapy?

PURPOSE: To evaluate the efficacy of using bronchoscopically implanted anchored electromagnetic transponders (EMTs) as surrogates for 1) tumor position and 2) repeatability of lung inflation during deep-inspiration breath-hold (DIBH) lung radiotherapy. METHODS: Forty-one patients treated with either hypofractionated (HF) or conventional (CF) lung radiotherapy on an IRB-approved prospective protocol using coached DIBH were evaluated for this study. Three anchored EMTs were bronchoscopically implanted into small airways near or within the tumor. DIBH treatment was gated by tracking the EMT positions. Breath-hold cone-beam-CTs (CBCTs) were acquired prior to every HF treatment or weekly for CF patients. Retrospectively, rigid registrations between each CBCT and the breath-hold planning CT were performed to match to 1) spine, 2) EMTs and 3) tumor. Absolute differences in registration between EMTs and spine were analyzed to determine surrogacy of EMTs for lung inflation. Differences in registration between EMTs and the tumor were analyzed to determine surrogacy of EMTs for tumor position. The stability of the EMTs was evaluated by analyzing the difference between inter-EMT displacements recorded at treatment from that of the plan for the CF patients, as well as the geometric residual (GR) recorded at the time of treatment. RESULTS: A total of 219 CBCTs were analyzed. The average differences between EMT centroid and spine registration among all CBCTs were 0.45±0.42 cm, 0.29±0.28 cm, and 0.18±0.15 cm in superior-inferior (SI), anterior-posterior (AP) and lateral directions, respectively. Only 59% of CBCTs had differences in registration < 0.5 cm for EMT centroid compared to spine, indicating that lung inflation is not reproducible from simulation to treatment. The average differences between EMT centroid and tumor registration among all CBCTs were 0.13±0.13 cm, 0.14±0.13 cm and 0.12±0.12 cm in SI, AP and lateral directions, respectively. Ninety-five percent of CBCTs resulted in a < 0.5 cm change between EMT centroid and tumor registration, indicating that EMT positions correspond well with tumor position during treatments. Six out of the seven recorded CF patients had average differences in inter-EMT displacements ≤0.26 cm and average GR ≤0.22 cm, indicating that the EMTs are stable throughout treatment. CONCLUSIONS: Bronchoscopically implanted anchored EMTs are good surrogates for tumor position and are reliable for maintaining tumor position when tracked during DIBH treatment, as long as the tumor size and shape are stable. Large differences in registration between EMTs and spine for many treatments suggest that lung inflation achieved at simulation is often not reproduced.

Shape-Sensing Robotic-Assisted Bronchoscopy in the Diagnosis of Pulmonary Parenchymal Lesions.

BACKGROUND: The landscape of guided bronchoscopy for the sampling of pulmonary parenchymal lesions is evolving rapidly. Shape-sensing robotic-assisted bronchoscopy (ssRAB) recently was introduced as means to allow successful sampling of traditionally challenging lesions. RESEARCH QUESTION: What are the feasibility, diagnostic yield, determinants of diagnostic sampling, and safety of ssRAB in patients with pulmonary lesions? STUDY DESIGN AND METHODS: Data from 131 consecutive ssRAB procedures performed at a US-based cancer center between October 2019 and July 2020 were captured prospectively and analyzed retrospectively. Definitions of diagnostic procedures were based on prior standards. Associations of procedure- and lesion-related factors with diagnostic yield were examined by univariate and multivariate generalized linear mixed models. RESULTS: A total of 159 pulmonary lesions were targeted during 131 ssRAB procedures. The median lesion size was 1.8 cm, 59.1% of lesions were in the upper lobe, and 66.7% of lesions were beyond a sixth-generation airway. The navigational success rate was 98.7%. The overall diagnostic yield was 81.7%. Lesion size of ≥ 1.8 cm and central location were associated significantly with a diagnostic procedure in the univariate analysis. In the multivariate model, lesions of ≥ 1.8 cm were more likely to be diagnostic compared with lesions < 1.8 cm, after adjusting for lung centrality (OR, 12.22; 95% CI, 1.66-90.10). The sensitivity and negative predictive value of ssRAB for primary thoracic malignancies were 79.8% and 72.4%, respectively. The overall complication rate was 3.0%, and the pneumothorax rate was 1.5%. INTERPRETATION: This study was the first to provide comprehensive evidence regarding the usefulness and diagnostic yield of ssRAB in the sampling of pulmonary parenchymal lesions. ssRAB may represent a significant advancement in the ability to access and sample successfully traditionally challenging pulmonary lesions via the bronchoscopic approach, while maintaining a superb safety profile. Lesion size seems to remain the major predictor of a diagnostic procedure.

An evolving role for endobronchial ultrasonography in the intensive care unit.

Endobronchial ultrasound (EBUS) bronchoscopy is an established minimally-invasive modality for visualization, characterization, and guidance of sampling of paratracheal and parabronchial structures and tissues. In the intensive care unit (ICU), rapidly obtaining an accurate diagnosis is paramount to the management of critically ill patients. In some instances, diagnosing and confirming terminal illness in a critically ill patient provides needed closure for patients and their loved ones. Currently available data on feasibility, safety, and yield of EBUS bronchoscopy in critically ill patients is based on single center experiences. These data suggest that in select ICU patients convex and radial probe-EBUS bronchoscopy can serve as useful tools in the evaluation of mediastinal lymphadenopathy, central airway obstruction, pulmonary embolism, and peripheral lung lesions. Barriers to the use of EBUS bronchoscopy in the ICU include: (I) requirement for dedicated equipment, prolonged procedure time, and bronchoscopy team expertise that may not be available; (II) applicability to a limited number of patients and conditions in the ICU; and (III) technical difficulty related to the relatively large outer diameter of the convex probe-EBUS bronchoscope and an increased risk for adverse cardiopulmonary consequences due to intermittent obstruction of the artificial airway. While the prospects for EBUS bronchoscopy in critically ill patients appear promising, judicious patient selection in combination with bronchoscopy team expertise are of utmost importance when considering performance of EBUS bronchoscopy in the ICU setting.

COVID-19 Impact on Interventional Pulmonology Training.

Background: The impact of the coronavirus disease (COVID-19) pandemic extends beyond the realms of patient care and healthcare resource use to include medical education; however, the repercussions of COVID-19 on the quality of training and trainee perceptions have yet to be explored. Objective: The purpose of this study was to determine the degree of interventional pulmonology (IP) fellows' involvement in the care of COVID-19 and its impact on fellows' clinical education, procedure skills, and postgraduation employment search. Methods: An internet-based survey was validated and distributed among IP fellows in North American fellowship training programs. Results: Of 40 eligible fellows, 38 (95%) completed the survey. A majority of fellows (76%) reported involvement in the care of patients with COVID-19. Fellows training in the Northeast United States reported involvement in the care of a higher number of patients with COVID-19 than in other regions (median, 30 [interquartile range, 20-50] vs. 10 [5-13], respectively; P < 0.01). Fifty-two percent of fellows reported redeployment outside IP during COVID-19, mostly into intensive care units. IP procedure volume decreased by 21% during COVID-19 compared with pre-COVID-19 volume. This decrease was mainly accounted for by a reduction in bronchoscopies. A majority of fellows (82%) reported retainment of outpatient clinics during COVID-19 with the transition from face-to-face to telehealth-predominant format. Continuation of academic and research activities during COVID-19 was reported by 86% and 82% of fellows, respectively. After graduation, all fellows reported having secured employment positions. Conclusion: Although IP fellows were extensively involved in the care of patients with COVID-19, most IP programs retained educational activities through the COVID-19 outbreak. The impact of the decrease in procedure volume on trainee competency would be best addressed individually within each training program. These data may assist in focusing efforts regarding the education of medical trainees during the current and future healthcare crises.

Novel Bronchoscopic Management of Airway Bleeding With Absorbable Gelatin and Thrombin Slurry.

BACKGROUND: Airway bleeding, either spontaneous or as a result of bronchoscopy, is associated with significant morbidity and mortality. Multiple bronchoscopic techniques are available to achieve complete hemostasis or as a bridge to definitive therapies. METHODS: We report our experience on the feasibility of endobronchial instillation of an absorbable gelatin and thrombin slurry (GTS) for the treatment of spontaneous hemoptysis and procedure-related bleeding. RESULTS: We identified 13 cases in which GTS was used for endobronchial hemostasis when standard bronchoscopic measures like cold saline, epinephrine, and in some cases balloon occlusion were not successful. GTS was delivered through the working channel of the bronchoscope in 10 cases and through the distal port of a bronchial blocker in the remaining 3 cases. Median age was 69 years (range, 52 to 79 y). Eight cases corresponded to spontaneous hemoptysis and 5 cases to diagnostic or therapeutic procedures. Bleeding was considered severe in 9 (70%) cases. All but 1 case were associated with malignancy. Hemostasis was achieved in 10 (77%) cases by using standard measures in addition to GTS. No patient adverse events at 30 days or damage to the equipment were identified. CONCLUSIONS: Bronchoscopic instillation of an absorbable GTS is feasible and may be used in cases of spontaneous or procedure-related bleeding in addition to conventional measures. It can be delivered through the working channel of the bronchoscope or through the distal port available in some bronchial blockers. Controlled studies are necessary to determine the safety and efficacy of this novel technique.

MI Paste Plus to prevent demineralization in orthodontic patients: a prospective randomized controlled trial.

INTRODUCTION: Enamel demineralization is a problem in orthodontics. Fluoride is partially effective in addressing this problem, but additional treatment options are needed. The objective of this prospective randomized controlled trial was to determine the effectiveness of a new product, MI Paste Plus (GC America, Alsip, Ill), in the prevention or reduction of white spot lesions in orthodontic patients. METHODS: Sixty patients who were undergoing routine orthodontic treatment were recruited for this prospective randomized clinical trial. A double-blind method of randomization was used to determine whether each patient received the MI Paste Plus or a placebo paste (Tom's of Maine, Salisbury, United Kingdom). Each patient was asked to administer the paste by using a fluoride tray for a minimum of 3 to 5 minutes each day at night after brushing. Photographic records obtained in a light-controlled environment were used to record the presence or absence of white spot lesions in both groups. The enamel decalcification index was used to determine the number of white spot lesions per surface at each time interval. Patients were followed at 4-week intervals for 3 months. A scoring system from 0 to 6 was used to determine the level of caries or cavitations. This system was also used for each tooth at each time interval. RESULTS: Fifty patients (26 using MI Paste Plus, 24 using the placebo paste) completed the study. The enamel decalcification index scores for all surfaces were 271 and 135 at the start of treatment and 126 and 258 at the end of treatment for the MI Paste Plus and placebo paste groups, respectively. The enamel decalcification index scores in the MI Paste Plus group reduced by 53.5%, whereas the placebo group increased by 91.1% during the study period. A 3-way analysis of variance (ANOVA) was done for the average enamel decalcification index scores. The surface type, the product/time interactions, and the product/surface interactions of the mean enamel decalcification index scores were significant (P <0.05). CONCLUSIONS: MI Paste Plus helped prevent the development of new white spot lesions during orthodontic treatment and decreased the number of white spot lesions already present. The placebo paste had no preventive action on white spot development during orthodontic treatment; the number of lesions actually increased. MI Paste Plus reduced white spots on the gingival surfaces; the placebo paste had the opposite effect. The incisal surface effect on the mean enamel decalcification index scores over time and between products was highly significant. The incisal enamel decalcification index scores were consistently higher than those for the other surfaces (mesial, distal, and gingival).

Cone beam computed tomography analysis of dentoalveolar changes immediately after maxillary expansion.

AIM: Rapid maxillary expansion (RME) splits the midpalatal suture to correct maxillary transverse discrepancies and increase the arch perimeter. The goal of this paper is to evaluate the immediate effects of RME with Hyrax appliances on the dentoalveolar complex using cone beam computed tomography (CBCT). METHODS: Twenty-eight patients (19 females and 9 males) requiring maxillary expansion therapy were included (mean age, 14.1 years; range, 13 to 20 years). CBCT images were taken at T1 (before maxillary expansion) and T2 (immediately after expansion) as part of clinical records. Maxillary arch width, posterior segment angulation, and buccal bone thickness at the level of the first premolar and first molar were evaluated. Paired t tests determined statistical significance (P < .05). RESULTS: The mean ± SD amount of expansion achieved was 4.7788 ± 2.8474 mm for the maxillary premolars and 4.6943 ± 3.2198 mm for the molars. Significant tipping of the palatal roots of the maxillary right and left premolars as well as that for the maxillary left molar was observed. When present, the thickness of the buccal plate decreased on all observed roots. CONCLUSION: There is a significant increase in interpremolar and intermolar distance with RME. The increase in root angulation suggests that the movement is more tipping than translation. The thickness of the buccal plate decreases immediately after RME. Therefore, the level of inflammation should be closely monitored to avoid periodontal destruction. There is a need to define standardized reference planes and comparable methodology to achieve compatible results among studies.

A Comparison of the Accuracy of Linear Measurements Obtained from Cone Beam Computerized Tomography Images and Digital Models.

The purpose of this study was to determine whether cone beam digital models are as accurate as OrthoCAD (Cadent, Inc, Carlstadt, NJ) digital models for the purposes of orthodontic diagnosis and treatment planning. Digital records of 30 subjects were retrospectively reviewed, and the digital models were obtained as OrthoCAD and InVivoDental (San Jose, CA) digital models. Seven parameters indicating linear measurements from predetermined landmarks were measured and analyzed. The analysis of variance and Bland and Altman Analysis were used to compare and evaluate measurements made from the study models generated from cone beam computed tomography (CBCT) and InVivoDental software. The mean difference between the maxillary InVivoDental models and the maxillary OrthoCAD models ranged from -0.57 to 0.44 mm. The analysis of variance for repeated measures (P < 0.001) was applied to all data obtained from the CBCT and OrthoCAD models. The results indicated a mean score of 35.12 and 35.12 mm, respectively. The mean difference of all values was -7.93 × 10-3 mm. The range of these values at the 95% confidence interval was -0.14 and 0.12 mm for the lower and upper limits, respectively. The results were not statistically significant for both groups. The Bland and Altman analysis was also applied to the data. In the maxilla, the results indicated that the mean difference between InVivoDental and OrthoCAD was -0.01 ± 1.24 mm. The range of the analysis indicated a spread of -2.40 mm and +2.40 mm. In the mandible, the results indicated that the mean difference between InVivoDental and OrthoCAD was -0.01 ± 1.21 mm. The range of the analysis indicated a spread of -2.36 mm and +2.37 mm. The results showed that the linear measurements obtained from CBCT image casts indicated a good level of accuracy when compared with OrthoCAD models. The accuracy was considered adequate for initial diagnosis and treatment planning in orthodontics.

3-D analysis of facial asymmetry in children with hip dysplasia.

OBJECTIVE: To determine whether facial asymmetry existed in patients with developmental dysplasia of the hip (DDH). MATERIALS AND METHODS: Subjects consisted of children between ages 5 and 10 years having DDH, and treated by the Von Rosen splint method. Three-dimensional (3-D) facial photographs were taken on all subjects using the 3dMDface system. Using RF6 PP2 software, anthropometric landmarks were plotted and used to calculate asymmetry based on 3-D coordinates in a reference framework. RESULTS: Of a total of 60 subjects with a mean age of 8 years (SD, 1.4 years), 30 had dysplasia of the left hip; 13, of the right; and 17 were bilateral. Twenty-seven subjects had upper face (UF) dominance values of 2 mm or more; of those, 26 were right-side dominant. Twenty-four subjects (40%) had a chin-point (CP) deviation of 2 mm or more; of those, 21 had right-side deviations. Statistically, UF and CP deviations were not significantly independent of each other (P > .05). Thirty percent of subjects had a posterior dental crossbite. CONCLUSIONS: The results indicate that facial asymmetry exists in patients with DDH.

Three-dimensional comparison of facial morphology in white populations in Budapest, Hungary, and Houston, Texas.

INTRODUCTION: The aim of this study was to assess the use of 3-dimensional facial averages in determining facial morphologic differences in 2 white population groups. METHODS: Three-dimensional images were obtained in a reproducible and controlled environment from a commercially available stereo-photogrammetric camera capture system. The 3dMDface system (3dMD, Atlanta, Ga) photographed 200 subjects from 2 population groups (Budapest, Hungary, and Houston, Tex); each group included 50 men and 50 women, aged 18 to 30 years. Each face was obtained as a facial mesh and orientated along a triangulated axis. All faces were overlaid, one on top of the other, and a complex mathematical algorithm was used until an average composite face of 1 man and 1 woman was obtained for each subgroup (Hungarian men, Hungarian women, Texas men, and Texas women). These average facial composites were superimposed (men and women) based on a previously validated superimposition method, and the facial differences were quantified. RESULTS: Distinct facial differences were observed between the population groups. These differences could be seen in the nasal, malar, lips, and lower facial regions. In general, the mean facial differences were 0.55 +/- 0.60 mm between the Hungarian and Texas women, and 0.44 +/- 0.42 mm between the Hungarian and Texas men. The ranges of differences were -2.02 to 3.77 and -2.05 to 1.94 mm for the female and male pairings, respectively. CONCLUSIONS: Three-dimensional facial averages representing the facial soft-tissue morphology of adults can be used to assess diagnostic and treatment regimens for patients by population. Each population is different with respect to their soft-tissue structures, and traditional soft-tissue normative data (eg, white norms) should be altered and used for specific groups.

Force relaxation between latex and non-latex orthodontic elastics in simulated saliva solution.

UNLABELLED: The aim of this study was to compare the force relaxation between traditional latex elastics to different brands of non-latex elastics in a simulated saliva solution. The force relaxation of 6.35 mm (0.25 inch), 99 g (3.5 oz), non-colored latex elastics from Ormco Corp. and non-latex elastics from Phoenix Orthodontics, ClassOne Orthodontics, and Glenroe was tested. The elastics were stretched to 40 mm (1.57 inch) and the force produced by the elastics was then measured using a Mini 44 Instron machine. RESULTS: The latex elastics had an initial relaxation of 15 percent after 1 hour of incubation and maintained their reduced force after 24 hours of incubation. Non-latex elastics lost approximately 20 percent of their force after the first hour and continued to lose force after up to 24 hours of incubation resulting in as much as 48 percent force relaxation. CONCLUSION: Latex elastics should be used whenever possible; however, when non-latex elastics are warranted, the clinician should take into account their greater initial forces, significant force relaxation, and variability among brands.

Long-term treatment effectiveness of molding helmet therapy in the correction of posterior deformational plagiocephaly: a five-year follow-up.

OBJECTIVE: To evaluate the long-term effectiveness of helmet therapy in the correction of deformational plagiocephaly and to assess the early occlusal abnormalities seen in these patients. DESIGN: A prospective study with blinded measurements. PATIENTS: Twenty-eight patients with deformational plagiocephaly who were treated with molding helmet therapy with at least 5 years of follow-up. INTERVENTIONS: The average length of molding helmet treatment was 6.2 months. At the time of this follow-up evaluation, the mean interval since completing the molding helmet therapy was 5.6 years. MAIN OUTCOME MEASURES: Anthropometric measurements of cranial asymmetry included cranial vault asymmetry (CVA), orbitotragial depth asymmetry (OTDA), and cranial base asymmetry (CBA). A dental examination was also performed. RESULTS: At the completion of therapy, the most improvement was seen in the measurement of CBA, followed by CVA and OTDA. However, in evaluating the long-term stability of molding treatment, OTDA tended to continue improving after the initial treatment, while CBA and CVA appeared to regress, although none of the changes reached statistically significant levels. In dental measurements, all the dental midline and chin deviations were toward the unaffected side with respect to occipital deformation. CONCLUSION: This study demonstrated that helmet remodeling with the dynamic orthotic cranioplasty band is effective in the correction of cranial asymmetry, with some nonstatistically significant changes in long-term cranial vault symmetry. Dental observations indicated the possibility of occlusal abnormalities that may affect dental, especially orthodontic, diagnosis and treatment planning.