Assessment of a New Medical Device (PirifixTM) for Positioning and Maintaining the Upper Dental Arch during Le Fort I Osteotomy.

INTRODUCTION: Several medical devices (MDs) are used to assist surgeons in positioning the upper dental arch (UDA) during Le Fort I osteotomies (LFIOs). Some only allow holding, others only positioning. This study aimed to assess the accuracy of a new MD (PirifixTM) coupling these two functions during LFIO on 3D-printed models. MATERIALS AND METHODS: DICOM data were selected from patients who underwent surgical planning for LFIO between 27 July 2020 and 1 December 2022. Their anatomy was reproduced after segmentation, planning, and stereolithography in two models. Each model was assigned to one of two surgical groups: the control group (positioning by occlusal splint) and the PirifixTM group. Each patient's model was planned with the objective of horizontalizing and recentering the UDA. After positioning, models were digitalized using Einscan Pro 2X and compared to the planned model with CloudCompare. The statistical analysis was performed using the Wilcoxon Mann-Whitney test. The result was considered significant if the p-value was less than 0.05. RESULTS: Twenty-one patients were selected. Forty-two anatomical models were 3D-printed. The mean difference compared to the planned and corrected positions was 0.69 mm for the control group and 0.84 mm for the PirifixTM group (p = 0.036). CONCLUSION: PirifixTM may be a new alternative to available MDs. Further investigations are needed to describe the relationship between the device and facial soft tissues.

Are 3D-printed anatomical models of the ear effective for teaching anatomy? A comparative pilot study versus cadaveric models.

PURPOSE: Despite the combination of chalkboard lectures and cadaveric models, the ear remains a complex anatomical structure that is difficult for medical students to grasp. The aim of this study was to evaluate the contribution of a 3D-printed ear model for educating undergraduate medical students by comparing it with a conventional cadaveric model. METHODS: Models of the ear comprising the outer ear, tympanic membrane, ossicles and inner ear were modeled and then 3D-printed at 6:1 and 10:1 scales based on cadaveric dissection and CT, cone-beam CT and micro/nano CT scans. Cadaveric models included two partially dissected dry temporal bones and ossicles. Twenty-four 3rd year medical students were given separate access to cadaveric models (n = 12) or 3D-printed models (n = 12). A pre-test and two post-tests were carried out to assess knowledge (n = 24). A satisfaction questionnaire focusing solely on the 3D-printed model, comprising 17 items assessed on a 5-point Likert scale, was completed by all study participants. A 5-point Likert scale questionnaire comprising four items (realism, color, quality and satisfaction with the 3D-printed ear model) was given to three expert anatomy Professors. RESULTS: The test scores on the first post-test were higher for the students who had used the 3D-printed models (p < 0.05). Overall satisfaction among the students and the experts was very high, averaging 4.7 on a 5-point Likert-type satisfaction scale. CONCLUSION: This study highlights the overall pedagogical value of a 3D-printed model for learning ear anatomy.

Persistent myogenic temporomandibular disorders: Are navigation-guided botulinum toxin-A injections into the lateral pterygoid muscles effective?

BACKGROUND: Botulinum toxin has proven effective in treating persistent myogenous temporomandibular disorders (M-TMDs) unresponsive to conservative therapies. While the usual injection sites are the masseter and temporalis muscles, the deeper lateral pterygoid muscle (LPM) is often overlooked due to its difficulty of access and the risk of local complications. This study aims to evaluate the effectiveness of botulinum toxin-A injections (BTX-A) in the LPM with MR-guided navigation of patients with persistent M-TMDs. METHODS: This retrospective study enrolled 34 patients suffering from M-TMDs despite conservative therapies with a total of 51 injection sessions. All of them were treated by BTX-A injections in the LPM using MR-guided navigation, masseter and temporalis with clinical guidance. The effectiveness of the treatment was evaluated with measures of maximum pain-intensity scores of breakthrough and background pain, maximal interincisal mouth opening (MIO), and the presence of joint sounds. The assessment was conducted before injections, and subsequently, at 1 and 3 months postoperatively. Adverse events and perception of improvement with the treatment were also reported for each injection sessions. RESULTS: BTX-A injections in the LPM significantly improved pain scores intensity with a reduction of 65 % and 49 % respectively at the 1- and 3-month follow-ups, with peak effectiveness at 1 month. This study showed also a statistically significant improvement in mean MIO at 3 months post-injection and a decrease in joint sounds with persistence in 9,7 % of cases at 3-month follow-up compared to 41,2 % at baseline. No significant adverse events were observed. Patients treated with BTX-A injections in the LPM had a subjective complete improvement in their perception of treatment efficacy in 63 % of cases at the end of the follow-up period. CONCLUSIONS: This study reports clinical experience on the use of MR-guided navigation to perform accurate, reliable, and safe BTX-A injections in the LPM. Although our results appear to be encouraging regarding symptom improvement of patients suffering from persistent M-TMDs, this approach may not be feasible as a primary standard procedure for managing M-TMDs. Further research is necessary to explore potential reproducible, safe, and cost-effective alternatives to enhance the accessibility of the LPM in clinical practice.

3D printing as a pedagogical tool for teaching normal human anatomy: a systematic review.

BACKGROUND: Three-dimensional-printed anatomical models (3DPAMs) appear to be a relevant tool due to their educational value and their feasibility. The objectives of this review were to describe and analyse the methods utilised for creating 3DPAMs used in teaching human anatomy and for evaluating its pedagogical contribution. METHODS: An electronic search was conducted on PubMed using the following terms: education, school, learning, teaching, learn, teach, educational, three-dimensional, 3D, 3-dimensional, printing, printed, print, anatomy, anatomical, anatomically, and anatomic. Data retrieved included study characteristics, model design, morphological evaluation, educational performance, advantages, and disadvantages. RESULTS: Of the 68 articles selected, the cephalic region was the most studied (33 articles); 51 articles mentioned bone printing. In 47 articles, the 3DPAM was designed from CT scans. Five printing processes were listed. Plastic and its derivatives were used in 48 studies. The cost per design ranged from 1.25 USD to 2800 USD. Thirty-seven studies compared 3DPAM to a reference model. Thirty-three articles investigated educational performance. The main advantages were visual and haptic qualities, effectiveness for teaching, reproducibility, customizability and manipulability, time savings, integration of functional anatomy, better mental rotation ability, knowledge retention, and educator/student satisfaction. The main disadvantages were related to the design: consistency, lack of detail or transparency, overly bright colours, long printing time, and high cost. CONCLUSION: This systematic review demonstrates that 3DPAMs are feasible at a low cost and effective for teaching anatomy. More realistic models require access to more expensive 3D printing technologies and substantially longer design time, which would greatly increase the overall cost. Choosing an appropriate image acquisition modality is key. From a pedagogical viewpoint, 3DPAMs are effective tools for teaching anatomy, positively impacting the learning outcomes and satisfaction level. The pedagogical effectiveness of 3DPAMs seems to be best when they reproduce complex anatomical areas, and they are used by students early in their medical studies.

Hybrid workflow for custom-made medical devices: A case report about nasal reconstruction.

Specialist industries usually develop custom-made medical devices outside a medical structure at the request of a healthcare professional. Access to 3D-printing technology with dedicated softwares in hospitals allow surgeons to perform virtual surgery leading to safer and more precise surgery. The authors present the hybrid workflow that combined the skills of surgeons, engineers and manufacturers to create titanium custom-made cutting guide and implants to reconstruct the nasal bone after the resection of an intraosseous hemangioma. This process aimed to optimize pre-operative planning, to improve precision, to predict the esthetic results of reconstruction. Moreover, it leads to a reduction of manufacturing time and the overall costs of surgery and to achieve genuine custom-made care.

CT-guided microwave ablation of osteoid osteoma: Long-term outcome in 28 patients.

PURPOSE: The purpose of this study was to assess the long-term efficacy of CT-guided microwave ablation (MWA) in the treatment of osteoid osteoma. Secondary objectives were to assess early outcome and side-effects of MWA. MATERIALS AND METHODS: Twenty-eight consecutive patients (18 men, 10 women) with a median age of 19.5 years (IQR: 16, 25.5) with a total of 28 non-spinal osteoid osteoma treated by CT-guided MWA were retrospectively included. The ablations were performed with a median power and duration of 60 Watt and 1 min 30 s, respectively. Pain referred to osteoid osteoma was assessed at predefined time points using a 0-10 numeric rating scale. At one month, contrast-enhanced follow-up MRI was performed to evaluate the nidus vascularization and the volume of necrosis induced by MWA. Clinical success was defined by the absence of osteoid osteoma-related pain, and technical success was defined by the presence of necrosis of the nidus on the one-month post-MWA MRI. RESULTS: Long term success rate was 93% (26/28) after a follow-up of 55.5 months (IQR: 25.75, 74.5) and technical success rate was 96 % (25/26). One late failure was observed after a patient had been declared cured at one month but the formal proof of a late recurrence of osteoid osteoma could not be brought. Three minor complications were reported including mild reversible superficial radial nerve injury with a skin burn (grade 2) in one patient and moderate skin burn only in two patients. CONCLUSION: Our results suggest that CT-guided MWA is an effective option for a minimally-invasive treatment of osteoid osteoma with a low rate of complication and no late recurrence.

Role of the radiologist in the diagnosis and management of the two forms of hepatic echinococcosis.

Echinococcosis is a parasitic disease caused by two zoonotic tapeworms (cestodes) of the Echinocococcus genus. It can be classified as either alveolar or cystic echinococcosis. Although the two forms differ significantly in terms of imaging findings, they share similarities in terms of management and treatment. In parallel to medical treatment with albendazole (ABZ), and surgery, historically used in these diseases, various imaging-guided interventional procedures have recently emerged (drainage, stenting, or Puncture, aspiration, injection, and reaspiration (PAIR)). These options open up a new range of therapeutic options. As in oncology, multidisciplinary consultation meetings now play a major role in adapted management and patient care in hepatic echinococcosis. Consequently, diagnostic imaging and interventional expertise have brought radiologists to the fore as important members of these multidisciplinary team. The radiologist will need to evaluate parasite activity in both forms of the disease, to guide the choice of the appropriate therapy from among medical treatment, interventional radiology procedures and/or surgical treatment. Knowledge of the specific complications of the two forms of echinococcosis will also help radiologists to discuss the appropriate treatment and management. The aim of this review is to describe the core knowledge that what a radiologist should possess to actively participate in multidisciplinary meetings about hepatic echinococcosis. We discuss the role of imaging, from diagnosis to treatment, in alveolar (AE) and cystic echinococcosis (CE), respectively.

Kodama-XUUB: an informative classification for alveolar echinococcosis hepatic lesions on magnetic resonance imaging.

OBJECTIVE: To propose a modification of the Kodama classification to classify type III lesions of alveolar echinococcosis (AE) that do not have microcysts. MATERIALS AND METHODS: 200 magnetic resonance imaging (MRI) images of AE liver lesions from four endemic regions of the world were classified according to Kodama, distinguishing within type III those with microcysts from those without. Each center included 50 MRIs of patients with unoperated AA liver lesions. The first 50 cases were classified by a first reader in the presence of four second-line readers from each region. Then each second-line reader classified his or her 50 cases. RESULTS: In all centers, type III lesions were predominant: 58% of the total lesions and 23% of them were without microcysts. The average age of the patients was 47 years. In China, the patients were on average younger and the lesions larger. German patients had more lesions within the liver. Type I and II lesions, synonymous with earlier diagnosis, were more common in Europe. CONCLUSION: The Kodama classification needed to be modified because of the existence of a significant proportion of unclassifiable lesions. This is especially true since the presence of microcysts is an informative element of parasite activity. Therefore, this study proposes a Kodama-XUUB classification with type IIIa lesions having microcysts and type IIIb lesions not having microcysts.

TITLE: Kodama-XUUB : une classification informative des lésions hépatiques de l'échinococcose alvéolaire à l'Imagerie par Résonance Magnétique. ABSTRACT: Objectif : Proposer une modification de la classification de Kodama permettant de classer les lésions de type III qui ne présentent pas de microkystes. Matériels et Méthodes : 200 IRM de lésions hépatiques d'EA en provenance de quatre régions d'endémie dans le monde ont été classées selon Kodama, en distinguant au sein du type III celles qui présentaient des microkystes de celle qui n'en présentaient pas. Chaque centre a inclus 50 IRM de patients avec lésions hépatiques d'EA non opérées. Les 50 premiers cas ont été classés par un premier lecteur en présence des quatre seconds lecteurs issus de chacune des régions. Puis chaque second lecteur a classé ses 50 cas. Résultats : Dans tous les centres, les lésions de type III étaient largement prédominantes : 58 % du total des lésions et 23 % d'entre elles ne présentaient pas de microkystes. La moyenne d'âge des patients était de 47 ans. En Chine, les patients étaient en moyenne plus jeunes et les lésions plus larges. Les patients allemands présentaient plus de lésions au sein du foie. Les lésions de type I et II, synonymes de diagnostic plus précoce étaient plus fréquentes en Europe. Conclusion : La classification de Kodama nécessitait d'être modifiée du fait de l'existence d'une proportion non négligeable de lésions non classifiables. Ce d'autant que la présence de microkystes est un élément informatif de l'activité du parasite. C'est pourquoi cette étude propose une classification Kodama-XUUB avec un type IIIa de lésions avec microkystes et un type IIIb sans microkystes.

Anatomo-sonographic identification of the longissimus capitis and splenius cervicis muscles: principles for possible application to ultrasound-guided botulinum toxin injections in cervical dystonia.

OBJECTIVE: The main objective of this study was to define and verify anatomo-sonographic landmarks for ultrasound-guided injection of botulinum toxin into the longissimus capitis (LC) and splenius cervicis (SC) muscles. METHODS AND RESULTS: After a preliminary work of anatomical description of the LC and SC muscles, we identified these muscles on two cadavers and then on a healthy volunteer using ultrasound and magnetic resonance imaging (MRI) to establish a radio-anatomical correlation. We defined an anatomo-sonographic landmark for the injection of each of these muscles. The correct positioning of vascular glue into the LC muscle and a metal clip into the SC muscle of a fresh cadaver as verified by dissection confirmed the utility of the selected landmarks. DISCUSSION: For the LC muscle, the intramuscular tendon of the cranial part of the muscle appears to be a reliable anatomical landmark. The ultrasound-guided injection can be performed within the cranial portion of the muscle, between the intra-muscular tendon and insertion into the mastoid process at dens of the axis level. For the SC muscle, the surface topographic landmarks of the spinous processes of the C4-C5 vertebrae and the muscle body of the levator scapulae muscle seem to be reliable landmarks. From these, the ultrasound-guided injection can be carried out laterally by transfixing the body of the levator scapulae. CONCLUSION: The study defined two cervical anatomo-sonographic landmarks for injecting the LC and SC muscles.

Intrahepatic manifestation and distant extrahepatic disease in alveolar echinococcosis: a multicenter cohort study.

BACKGROUND: The main endemic areas of alveolar echinococcosis (AE) are in central Europe and western China. The infiltration of intrahepatic vascular and bile ducts as well as extrahepatic disease can lead to complications and may increase morbidity in AE. PURPOSE: To evaluate the vascular/biliary involvement of hepatic alveolar echinococcosis (HAE) and distant extrahepatic disease at each of four locations in Germany, France, and China. MATERIAL AND METHODS: Contrast-enhanced abdominal magnetic resonance imaging (MRI) scans of patients with HAE, 200 in total, were evaluated by five examiners. AE liver lesions were classified according to Kodama's classification. Furthermore, distant extrahepatic manifestations were documented with additionally performed imaging modalities. Vascular/biliary involvement of hepatic manifestations as well as the presence of extrahepatic manifestations were correlated with the respective Kodama type of the liver lesion. RESULTS: Distant extrahepatic AE manifestations were significantly more frequent in China than in Europe (12/100 vs. 3/100; Fisher's exact test: P=0.0286). A significant relationship exists between presence of distant extrahepatic disease manifestation and size of the AE liver lesion (132.53 ± 48.65 vs. 92.49 ± 50.06; P = 0.0030). Vascular/biliary involvement is significantly more frequent in China than in Europe (86/100 vs. 65/100; χ2 = 11.92; P = 0.0006). Vascular/biliary involvement depends on lesion size (111.10 ± 47.44 vs. 47.36 ± 24.36; P<0.0001). Different types of AE liver lesions are associated with differences in vascular/biliary involvement and extrahepatic manifestations. CONCLUSION: Vascular/biliary involvement and presence of distant extrahepatic manifestations depend on size of the HAE lesions and are more frequently detected in China. Different MRI morphological patterns influence vascular/biliary involvement and the occurrence of distant extrahepatic manifestations.

Evaluation of intrahepatic manifestation and distant extrahepatic disease in alveolar echinococcosis.

BACKGROUND: The main endemic areas of alveolar echinococcosis (AE) are in Central Europe and Western China. Both the infiltration of intrahepatic vascular and bile duct structures as well as extrahepatic disease can lead to further complications and may increase morbidity in patients with AE. AIM: To evaluate vascular/biliary involvement in hepatic AE and its distant extrahepatic disease manifestations in an international collective was the aim. METHODS: Consecutively, five experienced examiners evaluated contrast-enhanced abdominal computed tomography (CT) scans for 200 patients with hepatic AE of each of four locations (n = 50) in Germany, France and China. Therefore, we retrospectively included the 50 most recent abdominal contrast-enhanced CT examinations at each center, performed because of hepatic AE from September 21, 2007 to March 21, 2018. AE liver lesions were classified according to the echinococcosis multilocularis Ulm classification for CT (EMUC-CT). Distant extrahepatic manifestations were documented either by whole body positron emission tomography-CT or with the addition of thoracic CT and cranial magnetic resonance imaging. Vascular/biliary involvement of the hepatic disease as well as the presence of distant extrahepatic manifestations were correlated with the EMUC-CT types of liver lesion. Statistical analysis was performed using SAS Version 9.4 (SAS Institute Inc., Cary, NC, United States). RESULTS: Distant extrahepatic AE manifestations were significantly more frequent in China than in Europe (P = 0.0091). A significant relationship was found between the presence of distant extrahepatic disease and AE liver lesion size (P = 0.0075). Vascular/biliary structures were involved by the liver lesions significantly more frequently in China than in Europe (P < 0.0001), and vascular/biliary involvement depended on lesion size. Different morphological types of AE liver lesions led to varying frequencies of vascular/biliary involvement and were associated with different frequencies of distant extrahepatic manifestations: Vascular/biliary involvement as a function of lesions primary morphology ranged from 5.88% of type IV liver lesions to 100% among type III lesions. Type IV differed significantly in these associations from types I, II, and III (P < 0.0001). With respect to extrahepatic disease, the primary morphology types IV and V of liver lesions were not associated with any case of distant extrahepatic disease. In contrast, distant extrahepatic manifestations in types I-III were found to varying degrees, with a maximum of 22% for type III. CONCLUSION: Different CT morphological patterns of hepatic AE lesions influence vascular/biliary involvement and the occurrence of distant extrahepatic manifestations. There are intercontinental differences regarding the characteristics of AE manifestation.

Hepatic alveolar echinococcosis: Comparative computed tomography study between two Chinese and two European centres.

The main endemic areas for alveolar echinococcosis (AE) are in Central Europe and Western China, and in >98% of cases, AE manifests in the liver. The aim of this work was to compare European and Chinese patient groups for number, size, and computed tomography (CT) appearance of hepatic AE lesions. A total of 200 CT scans of patients with hepatic AE were evaluated by four blinded, experienced radiologists from two European (Besancon, Ulm) and two Chinese centres (Xining, Urumqi). In addition to noting the number, size, and localisation of the lesions, the radiologists evaluated morphological appearance using the Echinococcus multilocularis Ulm Classification - CT scheme. Chinese patients were younger than European patients (36.8 ±â€¯13.2 vs. 63.5 ±â€¯17.7; p < 0.0001) and had significantly larger lesions (120.4 ±â€¯50.8 vs. 70.9 ±â€¯39.8; p < 0.0001). The morphological appearance of the lesions on CT differed significantly between the two groups (p < 0.05), as did the number of lesions (2.6 ±â€¯3.9 in European centres versus 3.8 ±â€¯5.0 in Chinese centres; p = 0.0062). Patient age and AE-related morphological manifestations differ between Europe and China, but the reasons for the differences are unknown.

AE hepatic lesions: correlation between calcifications at CT and FDG-PET/CT metabolic activity.

PURPOSE: To correlate the presence of calcifications in alveolar echinococcosis (AE) hepatic lesions to the metabolic activity in 18 fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT). METHODS: Our institutional review board approved this study. 61 patients (29 women, 32 men, aged from 15 to 86 years) were included in the study. Images of FDG-PET/CT were interpreted by two independent nuclear medicine physicians. AE hepatic lesions were classified as AE lesions with or without hypermetabolic activity. The presence of calcifications was assessed on unenhanced CT scans by two independent radiologists blinded with regard to the metabolic activity of the AE hepatic lesions. Every single calcification the size of which was < 3 mm and non-measurable calcifications which were forming areas with a powdery appearance were considered as microcalcifications. All other types of calcifications were reported as macrocalcifications. Statistical analysis was performed and p value < 0.05 was considered as statistically significant. RESULTS: Microcalcifications and macrocalcifications were present at CT in 95% (58/61) AE hepatic lesions and 43% (26/61) AE hepatic lesions, respectively. Hypermetabolic activity was present at FDG-PET/CT in 93% (57/61) AE hepatic lesions. 98% (56/57) of the AE hepatic lesions presenting with hypermetabolic activity at FDG-PET/CT showed microcalcifications at CT (p = 0.01) when only 40% (23/57) showed macrocalcifications at CT (p = 0.3). 100% (23/23) of the AE hepatic lesions with hypermetabolic activity at FDG-PET/CT and macrocalcifications at CT showed also microcalcifications at CT. CONCLUSIONS: Hypermetabolic activity of AE hepatic lesions at FDG-PET/CT is strongly correlated to the presence of microcalcifications at CT, independently of the presence of macrocalcifications.