Assessing temperature-based adaptation limits to climate change of temperate perennial fruit crops

Temperate perennial fruit and nut trees play varying roles in world food diversity-providing edible oils and micronutrient, energy, and protein dense foods. In addition, perennials reuse significant amounts of biomass each year providing a unique resilience. But they also have a unique sensitivity to seasonal temperatures, requiring a period of dormancy for successful growing season production. This paper takes a global view of five temperate tree fruit crops-apples, cherries, almonds, olives, and grapes-and assesses the effects of future temperature changes on thermal suitability. It uses climate data from five earth system models for two CMIP6 climate scenarios and temperature-related indices of stress to indicate potential future areas where crops cannot be grown and highlight potential new suitable regions. The loss of currently suitable areas and new additions in new locations varies by scenario. In the southern hemisphere (SH), end-century (2081-2100) suitable areas under the SSP 5-8.5 scenario decline by more than 40% compared to a recent historical period (1991-2010). In the northern hemisphere (NH) suitability increases by 20% to almost 60%. With SSP1-2.6, however, the changes are much smaller with SH area declining by about 25% and NH increasing by about 10%. The results suggest substantial restructuring of global production for these crops. Essentially, climate change shifts temperature-suitable locations toward higher latitudes. In the SH, most of the historically suitable areas were already at the southern end of the landmass limiting opportunities for adaptation. If breeding efforts can bring chilling requirements for the major cultivars closer to that currently seen in some cultivars, suitable areas at the end of the century are greater, but higher summer temperatures offset the extent. The high value of fruit crops provides adaptation opportunities such as cultivar selection, canopy cooling using sprinklers, shade netting, and precision irrigation.

Enhanced recovery after surgery (ERAS®) society guidelines for gynecologic oncology: Addressing implementation challenges - 2023 update

BACKGROUND

Despite evidence supporting its use, many Enhanced Recovery After Surgery (ERAS) recommendations remain poorly adhered to and barriers to ERAS implementation persist. In this second updated ERAS® Society guideline, a consensus for optimal perioperative care in gynecologic oncology surgery is presented, with a specific emphasis on implementation challenges.

METHODS

Based on the gaps identified by clinician stakeholder groups, nine implementation challenge topics were prioritized for review. A database search of publications using Embase and PubMed was performed (2018-2023). Studies on each topic were selected with emphasis on meta-analyses, randomized controlled trials, and large prospective cohort studies. These studies were then reviewed and graded by an international panel according to the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system.

RESULTS

All recommendations on ERAS implementation challenge topics are based on best available evidence. The level of evidence for each item is presented accordingly.

CONCLUSIONS

The updated evidence base and recommendations for stakeholder derived ERAS implementation challenges in gynecologic oncology are presented by the ERAS® Society in this consensus review.

Adjuvant Radiotherapy in Stage II Endometrial Cancer: Selective De-intensification of Adjuvant Treatment

AIMS

Risk stratification, including nodal assessment, allows for selective de-intensification of adjuvant radiotherapy in stage II endometrial cancer. Patterns of treatment and clinical outcomes, including the use of reduced volume 'mini-pelvis' radiotherapy fields, were evaluated in a population-based study.

MATERIALS AND METHODS

All patients diagnosed with pathological stage II endometrial cancer between 2000 and 2014, and received adjuvant radiotherapy in a regional healthcare jurisdiction were reviewed. Registry data were supplemented by a comprehensive review of patient demographics, disease characteristics and treatment details. The Charlson Comorbidity Score was calculated. Survival and recurrence data were analysed.

RESULTS

In total, 264 patients met the inclusion criteria. Most patients had endometrioid histology (83%); 41% of patients had International Federation of Gynecologists and Obstetricians grade 1 disease. Half (49%) had surgical nodal evaluation; 11% received chemotherapy. Most patients (59%) were treated with full pelvic radiotherapy fields ± brachytherapy. Seventeen per cent of patients received mini-pelvis radiotherapy ± brachytherapy, whereas 24% received brachytherapy alone. Five-year recurrence-free survival was 87% for the entire cohort, with no significant difference by adjuvant radiotherapy approach. Only one patient receiving mini-pelvis radiotherapy ± brachytherapy recurred in the pelvis but outside of the mini-pelvis field. Recorded late toxicity rates were highest for full pelvis radiotherapy + brachytherapy.

CONCLUSION

Risk stratification in a real-world setting allowed for selective de-intensification of adjuvant radiation with equivalent outcomes for stage II endometrial cancer. Mini-pelvis radiotherapy combined with brachytherapy is effective in highly selected patients, with the potential to decrease toxicity without compromising local control. Brachytherapy should be considered in low-risk stage II patients.

Somatic yolk sac differentiation in tumors of the gynecologic tract: A report of two cases and review of the literature

•Somatic yolk sac tumor differentiation associated with malignant neoplasms is uncommon and associated with poor outcome.•In the gynecologic tract, somatic yolk sac differentiation most often arises in postmenopausal patients.•Somatic yolk sac differentiation shares driver mutations with and likely differentiates from the corresponding carcinoma.•This is the first report of somatic yolk sac differentiation in the gynecologic tract from a non-epithelial malignancy.

Impacts of heat stress on global cattle production during the 21st century: a modelling study

BACKGROUND

Heat stress in animals is one of the major climate change impacts on domesticated livestock raised in both intensive and extensive production systems. At temperatures higher than an animal's thermoneutral zone, heat stress can affect liveweight gain, milk yield, and fertility. Animal welfare may also be negatively affected by heat stress even in the absence of effects on productivity, at least in the short term.

METHODS

We estimated the comparative statics change in the value of cattle milk and meat production from heat stress-induced losses at the global level, using climate scenario outputs for the middle (2045) and end of the century (2085). The loss estimates are based on bioenergetic equations that relate changes in dry matter intake (DMI) to both cold and hot, humid weather. DMI changes were estimated using CMIP6 climate data and linked to a global dataset containing information on livestock production systems, animal numbers, and region-specific and system-specific animal diets. Changes in DMI were converted to changes in milk and meat production and valued using early 20th century world prices (ie, constant 2005 US dollars).

FINDINGS

For a high greenhouse-gas emission scenario (SSP5-8.5), production losses from heat stress were estimated to amount to $39·94 billion (95% CI 34·39-45·49 billion) per year by the end of the century, or 9·8% of the value of production of meat and milk from cattle in 2005. For a low emission scenario (SSP1-2.6), the value of production losses was $14·89 billion (12·62-16·95 billion) per year, or 3·7% of 2005 value. In both scenarios, losses in most tropical regions were projected to be far greater than they were in temperate regions.

INTERPRETATION

Our results highlight the potential magnitude and extent of the adaptation efforts that will be necessary to combat the effects of increasing heat stress on cattle production during this century if food security challenges are to be minimised. Adaptations include switching to more heat-tolerant breeds and provision of shade, ventilation, and cooling systems.

FUNDING

CGIAR Trust Fund and bilateral donors.

Impacts of heat stress on global cattle production during the 21st century: a modelling study

BACKGROUND

Heat stress in animals is one of the major climate change impacts on domesticated livestock raised in both intensive and extensive production systems. At temperatures higher than an animal's thermoneutral zone, heat stress can affect liveweight gain, milk yield, and fertility. Animal welfare may also be negatively affected by heat stress even in the absence of effects on productivity, at least in the short term.

METHODS

We estimated the comparative statics change in the value of cattle milk and meat production from heat stress-induced losses at the global level, using climate scenario outputs for the middle (2045) and end of the century (2085). The loss estimates are based on bioenergetic equations that relate changes in dry matter intake (DMI) to both cold and hot, humid weather. DMI changes were estimated using CMIP6 climate data and linked to a global dataset containing information on livestock production systems, animal numbers, and region-specific and system-specific animal diets. Changes in DMI were converted to changes in milk and meat production and valued using early 20th century world prices (ie, constant 2005 US dollars).

FINDINGS

For a high greenhouse-gas emission scenario (SSP5-8.5), production losses from heat stress were estimated to amount to $39·94 billion (95% CI 34·39-45·49 billion) per year by the end of the century, or 9·8% of the value of production of meat and milk from cattle in 2005. For a low emission scenario (SSP1-2.6), the value of production losses was $14·89 billion (12·62-16·95 billion) per year, or 3·7% of 2005 value. In both scenarios, losses in most tropical regions were projected to be far greater than they were in temperate regions.

INTERPRETATION

Our results highlight the potential magnitude and extent of the adaptation efforts that will be necessary to combat the effects of increasing heat stress on cattle production during this century if food security challenges are to be minimised. Adaptations include switching to more heat-tolerant breeds and provision of shade, ventilation, and cooling systems.

FUNDING

CGIAR Trust Fund and bilateral donors.

Three-dimensional evaluation of the transfer accuracy of a bracket jig fabricated using computer-aided design and manufacturing to the anterior dentition: An in vitro study

Objective

To evaluate the accuracy of a one-piece bracket jig system fabricated using computer-aided design and manufacturing (CAD/CAM) by employing three-dimensional (3D) digital superimposition.

Methods

This in vitro study included 226 anterior teeth selected from 20 patients undergoing orthodontic treatment. Bracket position errors from each of the 40 arches were analyzed quantitatively via 3D digital superimposition (best-fit algorithm) of the virtual bracket and actual bracket after indirect bonding, after accounting for possible variables that may affect accuracy, such as crowding and presence of the resin base.

Results

The device could transfer the bracket accurately to the desired position of the patient’s dentition within a clinically acceptable range of ± 0.05 mm and 2.0° for linear and angular measurements, respectively. The average linear measurements ranged from 0.029 to 0.101 mm. Among the angular measurements, rotation values showed the least deviation and ranged from 0.396° to 0.623°. Directional bias was pronounced in the vertical direction, and many brackets were bonded toward the occlusal surface. However, no statistical difference was found for the three angular measurement values (torque, angulation, and rotation) in any of the groups classified according to crowding. When the teeth were moderately crowded, the mesio-distal, bucco-lingual, and rotation measurement values were affected by the presence of the resin base.

Conclusions

The characteristics of the CAD/CAM one-piece jig system were demonstrated according to the influencing factors, and the transfer accuracy was verified to be within a clinically acceptable level for the indirect bracket bonding of anterior teeth.

Increases in extreme heat stress in domesticated livestock species during the twenty-first century

Anthropogenic climate change is expected to have major impacts on domesticated livestock, including increased heat stress in animals in both intensive and extensive livestock systems. We estimate the changes in the number of extreme heat stress days per year for animals raised outdoors that can be expected in the major domesticated animal species (cattle, sheep, goats, poultry, and pigs) across the globe during this century. We used the temperature humidity index as a proxy for heat stress, calculated using temperature and relative humidity data collated from an ensemble of CMIP6 climate model output for mid and end century. We estimate changes in the proportions of different livestock species that may be at increased risk of extreme heat stress under two contrasting greenhouse gas emission scenarios. Results are discussed in relation to changes in the suitability of different climate conditions for domesticated livestock during the current century. We find that by end century, extreme heat stress risk is projected to increase for all livestock species in many parts of the tropics and some of the temperate zones, and to become climatically more widespread, compared to 2000. Although adaptation options exist for both intensive and extensive livestock production systems, the increasing pervasiveness of extreme heat stress risk in the future will seriously challenge the viability of outdoor livestock keeping, particularly in the lower latitudes in lower and middle-income countries where the costs of adaptation may be challenging to address.

Geometry of anchoring miniscrew in the lateral palate that support a tissue bone borne maxillary expander affects neighboring root damage

Anchoring miniscrews used for a tissue bone borne maxillary expander (C-expander) can fail if they contact tooth roots or perforate the maxillary sinus. Cone beam computed tomography images were reviewed retrospectively to evaluate the geometric factors of miniscrew placement in the palate that contribute to root proximity (RP) and sinus perforation (SP), and to investigate the differences of miniscrew placement depth (PD) and placement angle (PA) among the groups in each variable from 340 anchoring miniscrews on 70 patients whose C-expanders showed sufficient stability after palatal expansion for orthodontic treatment. Two types of miniscrews were used: a self-tapping miniscrew with 1.8 mm-in-diameter, and a self-drilling miniscrew with 1.6 mm-in-diameter. While the self-tapping larger diameter miniscrew influenced root proximity significantly, the screw location and PD affected the rate of sinus perforation. PA was significantly different between the right and left sides of the palate. The results of this study confirmed that root proximity and sinus perforation of anchoring miniscrews in a tissue bone borne palatal expander occurred due to certain risk factors, even when the palates were expanded successfully. Knowledge of these factors can help the clinician place miniscrews with less risk of root proximity or sinus perforation.

Quantitative cone-beam computed tomography evaluation of hard and soft tissue thicknesses in the midpalatal suture region to facilitate orthodontic mini-implant placement

Objective

To identify the most favorable sites that optimize the initial stability and survival rate of orthodontic mini-implants, this study measured hard and soft tissue thicknesses in the median and paramedian regions of the palate using cone-beam computed tomography (CBCT) and determined possible sexand age-related differences in these thicknesses.

Methods

The study sample comprised CBCT images of 189 healthy subjects. The sample was divided into four groups according to age. A grid area was set for the measurement of hard and soft tissue thicknesses in the palate. Vertical lines were marked at intervals of 0, 1.5, and 3.0 mm lateral to the midpalatal suture, while horizontal lines were marked at 2-mm intervals up to 24 mm from the posterior margin of the incisive foramen. Measurements were made at 65 points of intersection between the horizontal and vertical lines.

Results

The palatal hard tissue thickness decreased from the anterior to the posterior region, with a decrease in the medial-to-lateral direction in the middle and posterior regions. While the soft tissue was rather thick around the lateral aspects of the palatal arch, it formed a constant layer that was only 1-2-mm thick throughout the palate. Statistically significant differences were observed according to sex and age.

Conclusions

The anterolateral palate as well as the midpalatal suture seem to be the most favorable sites for insertion of orthodontic mini-implants. The thickness of the palate differed by age and sex; these differences should be considered while planning the placement of orthodontic mini-implants.

Treatment outcomes of various force applications in growing patients with skeletal Class III malocclusion

OBJECTIVES

To evaluate skeletal, dentoalveolar, and soft tissue changes between intraoral light force application and extraoral heavy force application in growing patients with skeletal Class III malocclusion.

MATERIALS AND

Methods: A retrospective study was conducted with pretreatment and posttreatment lateral cephalometric data from 50 subjects with skeletal Class III malocclusion. In the first group (15 boys, 10 girls; 8.67 ± 2.13 years old), each subject wore a biocreative horseshoe appliance (CHS) with two Class III elastics that exerted a force of 200 g. In the second group (13 boys, 12 girls; 8.96 ± 1.82 years old), each subject wore a Petit-type facemask and a lingual arch with hooks fixed to the maxillary arch with a total force of 700 g. Both groups of patients were instructed to wear the appliance approximately 14 hours a day, and 22 linear measurements and 8 angular measurements were evaluated. Changes of measurements from each group were compared by paired t-tests, considering a 5% significance level.

RESULTS

Forward growth of the maxilla, improvement of the maxilla-mandible relationship, and upper incisor flaring were achieved in both groups without any statistically significant difference between them. Lateral cephalometric analysis also showed that U1 exposure, IMPA (Angle between mandibular plane and mandibular incisor axis), FMIA (Angle between FH plan and mandibular incisor axis), and L1-APog (Angle formed by the intersection of tooth axis of lower incisor and A-Pog line, Distance from lower incisor edge to A-Pog line) showed statistically significant differences. Lower incisors were inclined lingually in the CHS group.

CONCLUSIONS

During treatment of skeletal Class III malocclusion, the CHS with light Class III intermaxillary elastics therapy exhibits similar orthopedic changes to the maxillary complex and more dental changes to the lower anterior teeth compared with facemask therapy.

Effect of Different Head Hole Position on the Rotational Resistance and Stability of Orthodontic Miniscrews: A Three-Dimensional Finite Element Study

The orthodontic miniscrew is driven into bone in a clockwise direction. Counter-clockwise rotational force applied to the implanted miniscrew can degrade the stability. The purpose of this three-dimensional finite element study was to figure out the effect of shifting the miniscrew head hole position from the long axis. Two miniscrew models were developed, one with the head hole at the long axis and the other with an eccentric hole position. One degree of counter-clockwise rotation was applied to both groups, and the maximum Von-Mises stress and moment was measured under various wire insertion angles from −60° to +60°. All Von-Mises stress and moments increased with an increase in rotational angle or wire insertion angle. The increasing slope of moment in the eccentric hole group was significantly higher than that in the centric hole group. Although the maximum Von-Mises stress was higher in the eccentric hole group, the distribution of stress was not very different from the centric hole group. As the positive wire insertion angles generated a higher moment under a counter-clockwise rotational force, it is recommended to place the head hole considering the implanting direction of the miniscrew. Clinically, multidirectional and higher forces can be applied to the miniscrew with an eccentric head hole position.

Evaluation of a multi-stage convolutional neural network-based fully automated landmark identification system using cone-beam computed tomographysynthesized posteroanterior cephalometric images

Objective

To evaluate the accuracy of a multi-stage convolutional neural network (CNN) model-based automated identification system for posteroanterior (PA) cephalometric landmarks.

Methods

The multi-stage CNN model was implemented with a personal computer. A total of 430 PA-cephalograms synthesized from cone-beam computed tomography scans (CBCT-PA) were selected as samples. Twenty-three landmarks used for Tweemac analysis were manually identified on all CBCT-PA images by a single examiner. Intra-examiner reproducibility was confirmed by repeating the identification on 85 randomly selected images, which were subsequently set as test data, with a two-week interval before training. For initial learning stage of the multi-stage CNN model, the data from 345 of 430 CBCT-PA images were used, after which the multi-stage CNN model was tested with previous 85 images. The first manual identification on these 85 images was set as a truth ground. The mean radial error (MRE) and successful detection rate (SDR) were calculated to evaluate the errors in manual identification and artificial intelligence (AI) prediction.

Results

The AI showed an average MRE of 2.23 ± 2.02 mm with an SDR of 60.88% for errors of 2 mm or lower. However, in a comparison of the repetitive task, the AI predicted landmarks at the same position, while the MRE for the repeated manual identification was 1.31 ± 0.94 mm.

Conclusions

Automated identification for CBCT-synthesized PA cephalometric landmarks did not sufficiently achieve the clinically favorable error range of less than 2 mm. However, AI landmark identification on PA cephalograms showed better consistency than manual identification.

Effect of Different Surface Designs on the Rotational Resistance and Stability of Orthodontic Miniscrews: A Three-Dimensional Finite Element Study

High orthodontic forces and various directions of applied forces can be associated with loosening of the screw anchorage in the bone. Screw designs have been modified to increase the stability of the miniscrews. This research evaluates the influence of three-designs on the stability of orthodontic miniscrews. A conventionally cylinder-type miniscrew design (Bio-Action screw, Jin-Biomed co., Bucheon, Korea) was set as a control, and three conditions were studied based on modifications of this control design. Condition-1 has narrowed threads in the upper part of the screw; Condition-2 has a notch at the middle part; and Condition-3 has the combination of Condition-1 and Condition-2. The moment required to unwind the miniscrew to five degrees is tested, and the moment generated at the cortical bone and the trabecular bone were calculated with finite element analysis. Compared to the control, all three conditions showed a higher moment required to unwind the miniscrew and a higher moment generated at the cortical bone. At the trabecular bone, condition-2 and -3 showed higher moment than the control, and condition-1 showed similar moment to the control. Condition-3 required a higher overall moment to unwind the miniscrew. These findings validate the design modifications used to increase the rotational resistance.

Evaluation of interradicular space, soft tissue, and hard tissue of the posterior palatal alveolar process for orthodontic mini-implant, using cone-beam computed tomography

INTRODUCTION

To investigate the anatomy of the posterior palatal alveolar process, which is often used for placement of the orthodontic mini-implant (OMI), and to suggest simple guidelines for safe placement of OMI.

METHODS

Cone-beam computed tomography (CBCT) scans of 60 patients (30 men, 30 women; age range, 18-39 years; average age, 25.8 years) was used to measure the palatal interradicular distance, the palatal bone thickness, and the palatal soft-tissue thickness. Measurements were performed on the area from the maxillary canine to the maxillary second molar based on the vertical distance apical from the cementoenamel junction. The CBCT data were analyzed by Bonferroni correction for multiple testing and the multivariable mixed linear model.

RESULTS

The palatal interradicular distance was the widest between the second premolar and the first molar and the narrowest between the first and second premolars. The palatal bone thickness at interdental sites was the thickest between the first and second premolars and the thinnest between the first and second molars. The interdental palatal soft-tissue thickness from the canine to the second premolar was thicker than any other area. There were minor measurement differences between genders and positive correlations between vertical distance from the cementoenamel junction plane and all of the parameters.

CONCLUSION

In this study, we evaluated the anatomy of the posterior palatal area using CBCT scans of adult patients. The data will provide guidelines to the clinicians before OMI placement in the posterior palatal alveolar process.

Computerized Assessment of Occlusion and Muscle Activity during Use of a Multilayer Clear Retainer: A Preliminary Study

The aim of this preliminary study was to evaluate the short-term changes of occlusal contacts and muscle activity after orthodontic treatment during the use of a multi-layer clear retainer. Evaluation was done with the T-scan and BioEMG systems. A total of 18 subjects were included, who were evaluated at three time intervals-T0 at debonding, T1 at one month after retainer delivery, and T2 at four months after retainer delivery. The T-scan and electromyography (EMG) data were recorded simultaneously. The T-scan system recorded the occlusion time, disclusion time and force distribution. The EMG waves were quantified by calculating the asymmetry index and activity index. The time variables changed but not significantly. Occlusal force decreased in the anterior dentition and increased in the posterior dentition during T0-T2. There was no clear evidence of a relationship between unbalanced occlusal forces and muscle activity. In most subjects, the temporalis anterior muscle was more dominant than the masseter muscle. From this preliminary computerized study, there were no significant changes in the state of the occlusion or muscle activity during the short-term retention period.

Automatic Cephalometric Landmark Identification System Based on the Multi-Stage Convolutional Neural Networks with CBCT Combination Images

This study was designed to develop and verify a fully automated cephalometry landmark identification system, based on multi-stage convolutional neural networks (CNNs) architecture, using a combination dataset. In this research, we trained and tested multi-stage CNNs with 430 lateral and 430 MIP lateral cephalograms synthesized by cone-beam computed tomography (CBCT) to make a combination dataset. Fifteen landmarks were manually and respectively identified by experienced examiner, at the preprocessing phase. The intra-examiner reliability was high (ICC = 0.99) in manual identification. The results of prediction of the system for average mean radial error (MRE) and standard deviation (SD) were 1.03 mm and 1.29 mm, respectively. In conclusion, different types of image data might be the one of factors that affect the prediction accuracy of a fully-automated landmark identification system, based on multi-stage CNNs.

Treatment of 2 impacted molars in a large dentigerous cyst (expansile cystic lesion) with combined orthodontic and surgical therapy

Nonmineralized cysts and cyst-like lesions that frequently occur in the mandible include ameloblastomas, odontogenic keratocysts, and dentigerous cysts. They have specific features of well-demarcated, unilocular, and radiolucent lesions that are often associated with tooth impaction. Although it rarely occurs, these cysts can become extremely large. Furthermore, cyst enlargement causes additional symptoms that can challenge the success of tooth recovery through orthodontic treatment. This clinical report presents the successful eruption of 2 impacted molars in a large dentigerous cyst treated with marsupialization and orthodontic traction using an orthodontic miniplate anchorage over a 4-year treatment period.

Validation in Alberta of an administrative data algorithm to identify cancer recurrence

Background

Readily available population-based data about cancer recurrence would improve surveillance and research for women of reproductive age.

Methods

We randomly selected 200 women from the Alberta Cancer Registry who had received a cancer diagnosis and who ever had a pregnancy between 2003 and 2012. Administrative data were obtained and linked. Several definitions of recurrence were assessed using various minimum lengths of time between the initial diagnosis date and subsequent diagnoses or treatments, or both. Chart review was used as a "gold standard" definition of recurrence.

Results

Chart review identified recurrences in 26 women. The definition that best captured "recurrence" was 2 or more cancer diagnosis codes 10 or more months from the diagnosis date [sensitivity: 80.8%; 95% confidence interval (ci): 60.7% to 93.5%; specificity: 81.0%; 95% ci: 74.4% to 86.6%; positive predictive value: 38.9%; 95% ci: 25.9% to 53.1%; negative predictive value: 96.6%; 95% ci: 92.2% to 98.9%; kappa = 0.42; 95% ci: 0.28 to 0.57].

Conclusions

Recurrence in reproductive-aged women can be captured with moderate validity using administrative data, but should be interpreted with caution.

Alveolar bone thickness and fenestration of incisors in untreated Korean patients with skeletal class III malocclusion: A retrospective 3-dimensional cone-beam computed tomography study

Purpose

The purpose of this study was to evaluate vertical bone loss and alveolar bone thickness in the maxillary and mandibular incisors of patients with skeletal class III malocclusion. This study also aimed to evaluate the periodontal condition of class III malocclusion patients who had not undergone orthodontic treatment.

Materials and Methods

The sample included cone-beam computed tomography scans of 24 Korean subjects (3 male and 21 female). Alveolar bone thickness (ABT), alveolar bone area (ABA), alveolar bone loss (ABL), and fenestration of the maxillary and mandibular incisors were measured using 3-dimensional imaging software.

Results

All incisors displayed an ABT of less than 1.0 mm from the labial surface to root level 7 (70% of the root length). A statistically significant difference was observed between the mandibular labial and lingual ABAs and between the maxillary labial and mandibular labial ABAs. The lingual ABA of the mandibular lateral incisors was larger than that of the mandibular central incisors. ABL was severe on the labial surface. A statistically significant difference was observed between the maxillary and mandibular labial ABL values(21.8% and 34.4%, respectively). Mandibular lingual ABL (27.6%) was significantly more severe than maxillary lingual ABL (18.3%) (P<0.05). Eighty-two fenestrations were found on the labial surfaces of the incisors, while only 2 fenestrations were observed on the lingual surfaces. Fenestrations were most commonly observed at root level 6.

Conclusion

Careful evaluation is needed before orthodontic treatment to avoid iatrogenic damage of periodontal support when treating patients with class III malocclusion.

Recommendations from the ERAS® Society for standards for the development of enhanced recovery after surgery guidelines

BACKGROUND

ERAS® Society guidelines are holistic, multidisciplinary tools designed to improve outcomes after surgery. The enhanced recovery after surgery (ERAS) approach was initially developed for colorectal surgery and has been implemented successfully across a large number of settings, resulting in improved patient outcomes. As the ERAS approach is increasingly being adopted worldwide and new guidelines are being generated for new populations, there is a need to define an ERAS® Society guideline and the methodology that should be followed in its development.

METHODS

The ERAS® Society recommended approach for developing new guidelines is based on the creation of multidisciplinary guideline development groups responsible for defining topics, planning the literature search, and assessing the quality of the evidence.

RESULTS

Clear definitions for the elements of an ERAS guideline involve multimodal and multidisciplinary approaches impacting on multiple patient outcomes. Recommended methodology for guideline development follows a rigorous approach with systematic identification and evaluation of evidence, and consensus-based development of recommendations. Guidelines should then be evaluated and reviewed regularly to ensure that the best and most up-to-date evidence is used consistently to support surgical patients.

CONCLUSION

There is a need for a standardized, evidence-informed approach to both the development of new ERAS® Society guidelines, and the adaptation and revision of existing guidelines.

Finite element study of controlling factors of anterior intrusion and torque during Temporary Skeletal Anchorage Device (TSAD) dependent en masse retraction without posterior appliances: Biocreative hybrid retractor (CH-retractor)

OBJECTIVES

To evaluate, using the finite element method (FEM), the factors that allow control of the anterior teeth during en masse retraction with the Biocreative hybrid retractor (CH-retractor) using different sizes of nickel-titanium (NiTi) archwires and various gable bends on the stainless-steel (SS) archwires.

MATERIALS AND METHODS

Using FEM, the anterior archwire section, engaged on the anterior dentition, was modeled in NiTi, and another assembly, the posterior guiding archwire, was modeled in SS. Two dimensions (0.016 × 0.022- and 0.017 × 0.025-inch NiTi) of the anterior archwires and different degrees (0°, 15°, 30°, 45°, and 60°) of the gable bends on the guiding wire were applied to the CH-retractor on the anterior segment to evaluate torque and intrusion with 100-g retraction force to TSADs. Finite element analysis permitted sophisticated analysis of anterior tooth displacement.

RESULTS

With a 0° gable bend all anterior teeth experienced extrusion. The canines showed a larger amount of extrusion than did the central and lateral incisors. With a gable bend of >15°, all anterior teeth exhibited intrusion. Bodily movement of the central incisor required a 30°∼45° gable bend when using anterior segments of 0.016 × 0.022-inch NiTi and 15°∼30° gable bend with the 0.017 × 0.025-inch NiTi.

CONCLUSIONS

With the CH-retractor, varying the size of the NiTi archwire and/or varying the amount of gable bend on the SS archwire affects control of the anterior teeth during en masse retraction without a posterior appliance.

Accuracy and reliability of the expected root position setup on clinical decision making of root position at midtreatment

INTRODUCTION

Accurate root position is imperative for successful orthodontic treatment that is stable and functional. Current methods to monitor root position are either inaccurate or use relatively high levels of radiation. A method to generate an expected root position (ERP) setup has been reported to have the potential to accurately evaluate root position with minimal radiation. The purpose of this study was to determine the accuracy and reliability of the clinical decisions made on root position using the ERP setup.

METHODS

This retrospective study included 10 subjects who had pretreatment and midtreatment cone-beam computed tomography (CBCT) scans and study models. An ERP setup was generated for all patients at midtreatment. Four examiners assessed both the CBCT scan and ERP setup and made clinical decisions regarding the root position with each method. Cohen's kappa was determined to assess intraoperator and intermethod reliability. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated to determine the accuracy of the ERP setup.

RESULTS

The kappa values for intraoperator reliability for both the CBCT scan and ERP setup fell within the 0.61-0.80 range. The kappa values for intermethod reliability between the CBCT scan and ERP setup fell within the 0.61-0.80 range for all tooth groups. The sensitivity of the ERP setup ranged from 0.72 to 0.90, specificity ranged from 0.89 to 0.97, positive predictive value ranged from 0.57 to 0.85, and negative predictive value ranged from 0.93 to 0.99.

CONCLUSIONS

This study demonstrated that the ERP setup, when compared with the gold standard CBCT scan, was accurate and reliable in making clinical decisions regarding root position at midtreatment.

Molar inclination and surrounding alveolar bone change relative to the design of bone-borne maxillary expanders: A CBCT study

OBJECTIVE

To evaluate the molar inclination and skeletal and alveolar bone changes when comparing tooth bone-borne (MSE) and tissue bone-borne type maxillary expanders (C-expander) using cone-beam computed tomography (CBCT) in late adolescence.

MATERIALS AND METHODS

A sample of 48 late-adolescent patients were divided into two groups according to the type of expander: MSE group (n = 24, age = 19.2 ± 5.9 years) and C-expander group (n = 24, age = 18.1 ± 4.5 years). CBCT scans were taken before treatment and 3 months after expansion. Transverse skeletal and dental expansion, alveolar inclination, tooth axis, buccal alveolar bone height, thickness, dehiscence, and fenestration were evaluated on the maxillary first molar. Paired t-test, independent t-test, Pearson's chi-square test, and Spearman correlation analysis were performed.

RESULTS

The MSE group produced greater dental expansion (P < .05), whereas skeletal expansion was similar in both groups (P = .859). The C expander group had more alveolar bone inclination change (P < .01), and the MSE group had more buccal tipping of the anchorage teeth (P < .01 or .001). Buccal alveolar bone height loss and thickness changes were greater in the MSE group (P < .01 or <.001). Formation of dehiscences was more frequent in the MSE group (P < .001), whereas for fenestrations, there were no significant differences between the two groups. Buccal bone height loss in the MSE group had a negative correlation with initial buccal bone thickness.

CONCLUSIONS

The incorporation of teeth into bone-borne expanders resulted in an increase in the severity of side effects. For patients in late adolescence, tissue bone-borne expanders offer comparable skeletal effects to tooth bone-borne expanders, with fewer dentoalveolar side effects.

The Biocreative Strategy. Part 6: Class III Treatment

Distalization of mandibular molars has always been one of the most challenging treatment objectives in clinical orthodontics, particularly in adult patients.(1) If the posterior space is sufficient and alveolar bone is available, however, lower molar distalization is a viable option in Class III nonextraction therapy. Several intraoral appliances have been introduced for this purpose, including the lip bumper,(2,3) a distal extension lingual arch,(4) the Jones Jig,(*5) the Franzulum appliance,(6) and the multiloop edgewise archwire (MEAW),(7) Today, molars can be moved distally using miniscrew anchorage, with no need for patient cooperation, to camouflage a Class III malocclusion or relieve crowding without premolar extractions.