Traffic Cameras-An Effective and Sustainable Method of Reducing Traffic and Airborne Particles During Arthroplasty Surgery.

BACKGROUND: Traffic in the operating room (OR) create turbulence and contaminates air by bacterial shedding. Therefore, we examined: (1) if the number and duration of door openings were associated with increased particles during arthroplasty surgery; (2) if traffic cameras installed in the operating room were an effective intervention to decrease traffic and particles during arthroplasty surgery; and (3) the effectiveness of traffic camera over time. METHODS: Fifty cases were included between November 3, 2021, and June 22, 2022, with 25 cases in each group. Two particle counters were used to count particles sized 0.5 to 10 µm. One counter was positioned within the sterile field, and another between the OR doors. Two door counters were mounted to count door openings. For the intervention, traffic cameras were mounted facing each door and took snapshots with door openings. RESULTS: The number of door openings/minute was 30% less in the Intervention group (P < .001). The Intervention group had significantly lower particles by 26 to 43% in the operative field (0.5 µm, P = .01; 0.7 µm, P = .008; 1 µm, P = .007; 2.5 µm, P = .006; 5 µm, P = .01; and 10 µm, P = .01). The particles between the OR doors were decreased by 2 to 42% in the Intervention group and the difference was significant for (0.5 µm, P = 0.03; 0.7 µm, P = .02; and 1 µm, P = .03). The decrease in door openings and particles were sustained over the study period. CONCLUSION: The use of traffic cameras was an effective and sustainable method to limit OR traffic and door openings, which resulted in a reduction in particles in the operating room.

Evaluating femoral graft placement using three-dimensional magnetic resonance imaging in the reconstruction of the anterior cruciate ligament via independent or transtibial drilling techniques: a retrospective cohort study.

PURPOSE: Anterior cruciate ligament (ACL) reconstruction is a common surgical procedure, yet failure still largely occurs due to nonanatomically positioned grafts. The purpose of this study was to retrospectively evaluate patients with torn ACLs before and after reconstruction via 3D MRI and thereby assess the accuracy of graft position on the femoral condyle. METHODS: Forty-one patients with unilateral ACL tears were recruited. Each patient underwent 3D MRI of both knees before and after surgery. The location of the reconstructed femoral footprint relative to the patient's native footprint was compared. RESULTS: Native ACL anatomical location of the native ACL had a significant impact on graft position. Native ACLs that were previously more anterior yielded grafts that were more posterior (3.70 ± 1.22 mm, P = 0.00018), and native ACL that were previously more proximal yielded grafts that were more distal (3.25 ± 1.09 mm, P = 0.0042). Surgeons using an independent drilling method positioned 76.2% posteriorly relative to the native location, with a mean 0.1 ± 2.8 mm proximal (P = 0.8362) and 1.8 ± 3.0 mm posterior (P = 0.0165). Surgeons using a transtibial method positioned 75% proximal relative to the native location, with a mean 2.2 ± 3.0 mm proximal (P = 0.0042) and 0.2 ± 2.6 mm posterior (P = 0.8007). These two techniques showed a significant difference in magnitude in the distal-proximal axis (P = 0.0332). CONCLUSION: The femoral footprint position differed between the native and reconstructed ACLs, suggesting that ACL reconstructions are not accurate. Rather, they are converging to a normative reference point that is neither anatomical nor isometric.

Using citizen science data to assess the population genetic structure of the common yellowjacket wasp, Vespula vulgaris.

Monitoring insect genetic diversity and population structure has never been more important to manage the biodiversity crisis. Citizen science has become an increasingly popular tool to gather ecological data affordably across a wide range of spatial and temporal scales. To date, most insect-related citizen science initiatives have focused on occurrence and abundance data. Here, we show that poorly preserved insect samples collected by citizen scientists can yield population genetic information, providing new insights into population connectivity, genetic diversity and dispersal behaviour of little-studied insects. We analysed social wasps collected by participants of the Big Wasp Survey, a citizen science project that aims to map the diversity and distributions of vespine wasps in the UK. Although Vespula vulgaris is a notorious invasive species around the world, it remains poorly studied in its native range. We used these data to assess the population genetic structure of the common yellowjacket V. vulgaris at different spatial scales. We found a single, panmictic population across the UK with little evidence of population genetic structuring; the only possible limit to gene flow is the Irish sea, resulting in significant differentiation between the Northern Ireland and mainland UK populations. Our results suggest that queens disperse considerable distances from their natal nests to found new nests, resulting in high rates of gene flow and thus little differentiation across the landscape. Citizen science data has made it feasible to perform this study, and we hope that it will encourage future projects to adopt similar practices in insect population monitoring.

Five- to 12-Year Outcomes of a Short, Tapered, Highly Porous, Proximally Coated Cementless Femoral Stem.

BACKGROUND: Short cementless stems in total hip arthroplasty have gained increasing popularity, yet on-going studies of many of these implants are lacking. The aim of this study was to evaluate the minimum 5 year clinical and radiological results of a short, highly porous, single-tapered-wedge cementless femoral implant. METHODS: A retrospective study of 281 hips in 256 patients who had a minimum 5-year follow-up and underwent primary total hip arthroplasty between 2010 and 2016 were evaluated. Clinical and radiological results, complications, and the presence of postoperative thigh pain were evaluated. RESULTS: The mean follow-up was 8 years (range, 5 to 12 years). Clinically, patients had significant improvement in the average patient-related outcome scores postoperatively (Harris hip score: pre 47 versus post 95, University of California Los Angeles activity scale: pre 4 versus post 6, Western Ontario and McMaster Universities Arthritis Index: pre 51 versus post 3, Short Form (SF)-12 physical component summary : pre 32 versus post 52, Short Form-12 mental component summary: pre 49 versus post 55 (P < .001)). Radiographic signs of ingrowth were present in all hips. There were three patients (1.1%) who developed transient thigh pain postoperatively, all of which resolved with nonoperative management. CONCLUSION: This study provides the longest follow-up of this short, highly porous, single-tapered-wedge cementless femoral stem in the literature. This short, single-wedge stem with its highly porous coating demonstrated reproducible bone ingrowth in all patients and significant functional improvement with a very low rate of transient thigh pain.

Local tissue concentrations of cefazolin during total joint arthroplasty: a systematic review.

BACKGROUND: Periprosthetic joint infections (PJI) following joint arthroplasty are now the leading cause of reoperation and are associated with serious morbidity to the patient, often requiring several staged operations and a prolonged course of parenteral antibiotics. Prophylactic administration of intravenous antibiotics before skin incision is arguably the most important measure to prevent PJI; however, the dose effectiveness of cefazolin in target tissue is not well known. We aimed to identify parameters affecting local tissue concentration (LTC) of cefazolin. METHODS: We performed a literature search using the following keywords: "orthopaedics," "orthopedic," "arthroplasty" and "cefazolin." We included studies that measured LTC of cefazolin from samples obtained during either a total knee or total hip arthroplasty. RESULTS: Of the 332 records screened, we included 10 studies that described LTC of cefazolin. The included studies evaluated dosing (n = 7), procedure type (n = 3), body mass index (n = 1) and tourniquet utilization (n = 1). CONCLUSION: Few studies have measured LTC levels of antibiotics (or levels of cefazolin) to validate current recommendations for antibiotic prophylaxis in orthopedic surgery. With infection as the leading reason for early reoperation or revision surgery, the parameters affecting LTC during orthopedic procedures need to be further assessed.

Episode-of-care costs of total hip arthroplasty: day surgery versus same-day admission.

BACKGROUND: Although day surgery (DS) total hip arthroplasty (THA) has good patient satisfaction and a good safety profile, accurate episode-of-care cost (EOCC) calculations for this procedure compared to standard same-day admission (SDA) THA are not well known. We determined the EOCCs for patients who underwent THA, comparing DS and SDA pathways. METHODS: We evaluated the EOCCs for consecutive patients who underwent DS or SDA THA for osteoarthritis or osteonecrosis performed by a single surgeon at 1 academic centre from July 2018 to January 2020. Patient demographic and clinical data were recorded, as were preoperative diagnosis, type of anesthesia, type of implant used, surgical time and estimated blood loss. We determined direct and indirect costs from time of arrival at the presurgical unit to hospital discharge. We determined the EOCCs using an ABC method. RESULTS: The study included 50 patients who underwent THA (25 DS, 25 SDA). The mean length of stay in the SDA group was 45.1 (standard deviation [SD] 21.4) hours. Differences were observed between the 2 groups in mean age, mean Charlson Comorbidity Index score, surgical technique and mean surgical time (p ≤ 0.001). The mean total EOCC for SDA THA was $10 911 (SD $706.12, range $9944.07-$12 871.95), compared to $9672 (SD $546.55, range $8838.30-$11 058.07) for DS THA, a difference of 11.4%, mostly attributable to hospital resources such as laboratory tests, radiologic studies and cost of the surgical admission. CONCLUSION: Day surgery THA is cost-effective in selected patient populations. With the savings identified in this study, every 10 additional DS THA procedures would save sufficient resources to perform an additional THA operation.

Strip and Cka negatively regulate JNK signalling during Drosophila spermatogenesis.

One fundamental property of a stem cell niche is the exchange of molecular signals between its component cells. Niche models, such as the Drosophila melanogaster testis, have been instrumental in identifying and studying the conserved genetic factors that contribute to niche molecular signalling. Here, we identify jam packed (jam), an allele of Striatin interacting protein (Strip), which is a core member of the highly conserved Striatin-interacting phosphatase and kinase (STRIPAK) complex. In the developing Drosophila testis, Strip cell-autonomously regulates the differentiation and morphology of the somatic lineage, and non-cell-autonomously regulates the proliferation and differentiation of the germline lineage. Mechanistically, Strip acts in the somatic lineage with its STRIPAK partner, Connector of kinase to AP-1 (Cka), where they negatively regulate the Jun N-terminal kinase (JNK) signalling pathway. Our study reveals a novel role for Strip/Cka in JNK pathway regulation during spermatogenesis within the developing Drosophila testis.

Trends in Morbidity, Mortality, and Cost of Hospitalizations Associated With Infectious Disease Sequelae of the Opioid Epidemic.

BACKGROUND: Increases in fatal drug poisonings and hepatitis C infections associated with the opioid epidemic are relatively well defined, because passive surveillance systems for these conditions exist. Less described is the association between the opioid epidemic and skin, soft-tissue, and venous infections (SSTVIs), endocarditis, sepsis, and osteomyelitis. METHODS: Michigan hospitalizations between 2016 and 2018 that included an International Classification of Diseases, Tenth Revision, Clinical Modification, code indicating substance use were examined for codes indicative of infectious conditions associated with injecting drugs. Trends in these hospitalizations were examined, as were demographic characteristics, discharge disposition, payer, and cost data. RESULTS: Among hospitalized patients with a substance use diagnosis code, endocarditis, osteomyelitis, sepsis, and SSTVI hospitalizations increased by 33%, 35%, 24%, and 12%, respectively between 2016 and 2018. During this time frame, 1257 patients died or were discharged to hospice. All SSTVI hospitalizations resulted in >$1.3 billion in healthcare costs. Public insurance accounted for more than two-thirds of all hospitalization costs. CONCLUSIONS: This study describes a method for performing surveillance for infection-related sequelae of injection drug use. Endocarditis, osteomyelitis, sepsis, and SSTVI hospitalizations have increased year over year between 2016 and 2018. These hospitalizations result in significant morbidity, mortality, and healthcare costs and should be a focus of future surveillance and prevention efforts.

Phenotypic Plasticity of Nest-Mate Recognition Cues in Formica exsecta Ants.

It is well established that many ant species have evolved qualitatively distinct species-specific chemical profile that are stable over large geographical distances. Within these species profiles quantitative variations in the chemical profile allows distinct colony-specific odours to arise (chemotypes) that are shared by all colony members. This help maintains social cohesion, including defence of their colonies against all intruders, including con-specifics. How these colony -level chemotypes are maintained among nest-mates has long been debated. The two main theories are; each ant is able to biochemically adjust its chemical profile to 'match' that of its nest-mates and or the queen, or all nest-mates share their individually generated chemical profile via trophollaxis resulting in an average nest-mate profile. This 'mixing' idea is better known as the Gestalt model. Unfortunately, it has been very difficult to experimentally test these two ideas in a single experimental design. However, it is now possible using the ant Formica exsecta because the compounds used in nest-mate recognition compounds are known. We demonstrate that workers adjust their profile to 'match' the dominant chemical profile within that colony, hence maintaining the colony-specific chemotype and indicates that a 'gestalt' mechanism, i.e. profile mixing, plays no or only a minor role.

Thirty-Day Major and Minor Complications Following Total Hip Arthroplasty-A Comparison of the Direct Anterior, Lateral, and Posterior Approaches.

BACKGROUND: The choice of surgical approach during total hip arthroplasty (THA) remains highly controversial. The aim of the present study was to compare 30-day major and minor complications, following primary THA between the direct anterior, lateral, and posterior approaches. METHODS: Our hospital performs primary THAs using all 3 aforementioned approaches based on surgeon preference. Patients who underwent primary THA from August 2010 to August 2017 were identified using our institution's total joint registry, and their data were combined with prospectively collected data from the National Surgical Quality Improvement Program database (which evaluates a random sample of approximately 20% of all surgical patients in our hospital). Baseline characteristics, operative variables, and postoperative complications were then compared between the three groups. RESULTS: The analysis comprised 1967 primary THAs (1913 patients), whereby 56%, 29%, and 15% were performed through a posterior, lateral, and direct anterior approach, respectively. Thirty-day major and minor complications occurred in 3.9% and 9.4% of surgeries, respectively. After adjusting for baseline patient characteristics, there was no significant difference in major or minor perioperative complications between the 3 approaches. CONCLUSIONS: This study compared perioperative complications between the 3 most commonly used approaches for THA utilizing a synthesis of our institutional total joint registry and high-quality National Surgical Quality Improvement Program data. Thirty-day major and minor complications were similar regardless of the surgical approach employed, which may help surgeons and patients simplify the multiple considerations taken into account when deciding on surgical approach for primary THA. LEVEL OF EVIDENCE: Therapeutic, Level III.

Smoking Cessation Before and After Total Joint Arthroplasty-An Uphill Battle.

BACKGROUND: Patients actively smoking at the time of primary total joint arthroplasty (TJA) are at increased risk of perioperative complications. Employing strategies for smoking cessation has therefore become routine. A potential benefit of cessation in anticipation of TJA may be long-term cessation. However, success rates and the longevity of successful smoking cessation attempts before TJA have yet to be presented. METHODS: Our institution's total joint registry documents self-reported smoking status. As such, all patients who underwent TJA from 2007 to 2018 were identified and grouped as nonsmokers, smokers (regularly smoking within 1 year before surgery), and former smokers (those who quit smoking within 1 year before surgery). Thereafter, postoperative smoking status was assessed with special attention to former smokers to see who remained smoke-free. RESULTS: From the 28,758 primary TJAs identified, 91.3% (26,244) were nonsmokers, 7.3% (2109) were smokers, and 1.4% (405) had quit smoking before surgery. Among former smokers, 86% were abstinent 1 year postoperatively but only 45% were still abstinent 8 years postoperatively. Conversely, 7% of smokers at the time of surgery eventually quit and 6% of prior nonsmokers started smoking over the same time period. CONCLUSION: Despite concerted efforts to help patients stop smoking before TJA, 7.3% remain smokers. Among those who are successful, less than half (45%) remain smoke-free after surgery. Compared to current smokers, however, patients who managed to quit before surgery are more likely to remain smoke-free after surgery. These findings demonstrate the tremendous challenge smoking represents in contemporary TJA practices. LEVEL OF EVIDENCE: Therapeutic level III.

Cotinine Testing Improves Smoking Cessation Before Total Joint Arthroplasty.

BACKGROUND: Patients who are actively smoking at the time of primary total joint arthroplasty (TJA) are at an increased risk of perioperative complications. Serum cotinine testing is a sensitive and specific method to verify abstinence from smoking and may therefore improve a patient's chance of smoking cessation. The primary purpose of this study was to assess whether cotinine testing improves the self-reported quit rate among smokers before TJA. METHODS: Our hospital performs a high volume of TJAs and documents smoking status at each clinic visit (at 6-month intervals), as well as at the time of surgery through an institutional total joint registry. As part of a retrospective analysis, this information was used to identify all self-reported smokers (regularly cigarette smoking within 1 year of TJA) who underwent unilateral TJA from 2007 to 2018. The cohort had a mean age of 66 years, 55% were female, and the mean body mass index was 31 kg/m2. Patients whose serum cotinine was obtained within 1 month before surgery were then separated from the cohort and compared to the smokers who did not undergo cotinine testing. RESULTS: Of the 28,758 primary TJAs identified, 8.8% (2514) were smokers. Serum cotinine testing was obtained on 103 of these patients. The abstinence rate (by means of self-reporting) before surgery significantly improved from 15.8% to 28.2% in the untested vs cotinine-tested groups, respectively (P = .005). Among all patients who underwent cotinine testing, 77% were negative (abstinent) and an additional 15% had cotinine levels between 3 and 8 ng/mL representing passive tobacco exposure. Among patients who stated they had quit smoking, 15% still had positive cotinine tests. CONCLUSION: Smoking cessation remains a major challenge in contemporary TJA practices despite a concerted effort to help patients quit. Our findings suggest that cotinine testing significantly improves the self-reported quit rates of smokers before surgery and helps identify the 15% who falsely report abstinence to ensure appropriate counseling of inherent risks. LEVEL OF EVIDENCE: Therapeutic level III.

No Difference in Major Complication and Readmission Rates Following Simultaneous Bilateral vs Unilateral Total Hip Arthroplasty.

BACKGROUND: Simultaneous bilateral total hip arthroplasty (THA) is an attractive option for patients with osteoarthritis as it requires a single anesthetic and hospitalization. Nonetheless, serious concerns remain over the perioperative safety and rate of hospital readmission. The purpose of the present study was to compare the rate of 30-day major complications and hospital readmissions between patients undergoing simultaneous bilateral vs unilateral THA using the National Surgical Quality Improvement Program database. METHODS: The National Surgical Quality Improvement Program database was queried from 2011 to 2015 inclusively to identify all cases of elective, primary simultaneous bilateral THA and match them to a control group of unilateral THA cases. A multivariable regression analysis was then used to assess the relationship of simultaneous bilateral vs unilateral THA on major complications and readmissions. RESULTS: A total of 575 bilateral THA patients were matched to 2290 unilateral THA patients using a 4:1 ratio based on age, sex, and American Society of Anesthesiologists scores. Bilateral THA patients were more likely to undergo general anesthesia (77% vs 58.7%, P < .0001), required more postoperative transfusions (29.2% vs 15.9%, P < .0001) and were more often discharged to a rehabilitation facility rather than home (39.4% vs 20.8%, P < .0001). However, the adjusted odds of a major complication (odds ratio = 0.72, 95% confidence interval [0.41-1.24], P = .24) and 30-day readmission (odds ratio = 0.67, 95% confidence interval [0.38-1.19], P = .17) were similar between the 2 groups. CONCLUSION: Although patients who underwent simultaneous bilateral THA were more likely to be discharged to a rehabilitation facility and required significantly more perioperative transfusions compared to those undergoing unilateral THA, the odds of a 30-day major complication and readmission were similar between groups. LEVEL OF EVIDENCE: III.

The clinical impact of 18F-FDG PET/CT in extracranial pediatric germ cell tumors.

BACKGROUND: Extracranial germ cell tumors are an uncommon pediatric malignancy with limited information on the clinical impact of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the literature. OBJECTIVE: The purpose of this study was to evaluate and compare the clinical impact on management of 18F-FDG PET/CT with diagnostic computed tomography (CT) in pediatric extracranial germ cell tumor. MATERIALS AND METHODS: The list of 18F-FDG PET/CT performed for extracranial germ cell tumor between May 2007 and November 2015 was obtained from the nuclear medicine database. 18F-FDG PET/CT and concurrent diagnostic CT were obtained and independently reviewed. Additionally, the patients' charts were reviewed for duration of follow-up and biopsy when available. The impact of 18F-FDG PET/CT compared with diagnostic CT on staging and patient management was demonstrated by chart review, imaging findings and follow-up studies. RESULTS: During the study period, 9 children (5 males and 4 females; age range: 1.6-17 years, mode age: 14 years) had 11 18F-FDG PET/CT studies for the evaluation of germ cell tumor. Diagnostic CTs were available for comparison in 8 patients (10 18F-FDG PET/CT studies). The average interval between diagnostic CT and PET/CT was 7.2 days (range: 0-37 days). In total, five lesions concerning for active malignancy were identified on diagnostic CT while seven were identified on PET/CT. Overall, 18F-FDG PET/CT resulted in a change in management in 3 of the 9 patients (33%). CONCLUSION: 18F-FDG PET/CT had a significant impact on the management of pediatric germ cell tumors in this retrospective study. Continued multicenter studies are required secondary to the rarity of this tumor to demonstrate the benefit of 18F-FDG PET/CT in particular clinical scenarios.

Bifurcation analysis of single-cell gene expression data reveals epigenetic landscape.

We present single-cell clustering using bifurcation analysis (SCUBA), a novel computational method for extracting lineage relationships from single-cell gene expression data and modeling the dynamic changes associated with cell differentiation. SCUBA draws techniques from nonlinear dynamics and stochastic differential equation theories, providing a systematic framework for modeling complex processes involving multilineage specifications. By applying SCUBA to analyze two complementary, publicly available datasets we successfully reconstructed the cellular hierarchy during early development of mouse embryos, modeled the dynamic changes in gene expression patterns, and predicted the effects of perturbing key transcriptional regulators on inducing lineage biases. The results were robust with respect to experimental platform differences between RT-PCR and RNA sequencing. We selectively tested our predictions in Nanog mutants and found good agreement between SCUBA predictions and the experimental data. We further extended the utility of SCUBA by developing a method to reconstruct missing temporal-order information from a typical single-cell dataset. Analysis of a hematopoietic dataset suggests that our method is effective for reconstructing gene expression dynamics during human B-cell development. In summary, SCUBA provides a useful single-cell data analysis tool that is well-suited for the investigation of developmental processes.

Shorter Hospital Stay and Lower 30-Day Readmission After Unicondylar Knee Arthroplasty Compared to Total Knee Arthroplasty.

BACKGROUND: Reducing hospital stay and unplanned hospital readmission of arthroplasty patients has been a topic of recent interest. The aim of the present study was to query the National Surgical Quality Improvement Program database to compare the length of hospital stay (LOS) and the subsequent 30-day hospital readmission rates in patients undergoing primary unicondylar knee arthroplasty (UKA) and total knee arthroplasty (TKA). METHODS: We identified 1340 UKAs and 36,274 TKAs over a 2-year period (2011-2012). Patient demographics, comorbidities, LOS, 30-day postoperative complications, and readmission rates were compared between the groups. Multivariate regression analysis was used to determine the effect of procedure type on LOS and readmission rates. RESULTS: Unicondylar knee arthroplasty patients had a median LOS of 2 days compared to 3 days for TKAs (P < .001). The readmission rate in the TKA group was nearly double that of the UKA group (4.1% vs 2.2%) (P < .0001). Multivariate regression analysis identified that undergoing a UKA was predictive for a shorter LOS (coefficient -1 day) and was protective for 30-day readmission (odds ratio, 0.60; 95% confidence interval, 0.41-0.88). CONCLUSION: Patients undergoing UKA had a shorter LOS and a lower 30-day readmission rate compared to TKA patients. After adjusting for selected cofounders, we demonstrated that undergoing a UKA is a protective factor for 30-day readmission.

Simultaneous Bilateral Versus Unilateral Total Knee Arthroplasty: A Comparison of 30-Day Readmission Rates and Major Complications.

We queried the National Surgical Quality Improvement Program to compare the rate of 30-day readmissions and major complications between simultaneous bilateral and unilateral total knee arthroplasty (TKA). We identified 1771 patients who underwent simultaneous (same-day) bilateral TKA and matched them to a control group of 6790 patients who underwent unilateral TKA. The simultaneous bilateral TKA patients had longer surgery, were more commonly performed under general anesthesia, had a higher rate of postoperative transfusion, and a greater proportion of patients discharged to rehabilitation facilities. Simultaneous bilateral TKA has a low incidence of major complications and was not associated with more readmissions as compared to unilateral TKA (3.6% versus 3.5% respectively). Nonetheless, the odds of major complications was slightly higher following simultaneous bilateral TKA (OR=1.58).

Precision and accuracy of suggested maxillary and mandibular landmarks with cone-beam computed tomography for regional superimpositions: An in vitro study.

INTRODUCTION: Our objective was to identify and evaluate the accuracy and precision (intrarater and interrater reliabilities) of various anatomic landmarks for use in 3-dimensional maxillary and mandibular regional superimpositions. METHODS: We used cone-beam computed tomography reconstructions of 10 human dried skulls to locate 10 landmarks in the maxilla and the mandible. Precision and accuracy were assessed with intrarater and interrater readings. Three examiners located these landmarks in the cone-beam computed tomography images 3 times with readings scheduled at 1-week intervals. Three-dimensional coordinates were determined (x, y, and z coordinates), and the intraclass correlation coefficient was computed to determine intrarater and interrater reliabilities, as well as the mean error difference and confidence intervals for each measurement. RESULTS: Bilateral mental foramina, bilateral infraorbital foramina, anterior nasal spine, incisive canal, and nasion showed the highest precision and accuracy in both intrarater and interrater reliabilities. Subspinale and bilateral lingulae had the lowest precision and accuracy in both intrarater and interrater reliabilities. CONCLUSIONS: When choosing the most accurate and precise landmarks for 3-dimensional cephalometric analysis or plane-derived maxillary and mandibular superimpositions, bilateral mental and infraorbital foramina, landmarks in the anterior region of the maxilla, and nasion appeared to be the best options of the analyzed landmarks. Caution is needed when using subspinale and bilateral lingulae because of their higher mean errors in location.