Epidemiology, etiopathogenesis, and management of MRONJ: A European multicenter study.

INTRODUCTION: The purpose of this European multicenter study was to describe the general characteristics and risk factors of MRONJ lesions as well as their clinical diagnosis and management at different European Oral and Maxillofacial Surgery centers, in order to minimize selections biases and provide information about the epidemiology, etiopathogenesis, and the current trends in the treatment of MRONJ across Europe. MATERIALS AND METHODS: The following data were registered for each patient: gender; age at MRONJ diagnosis; past medical history; indication for antiresorptive or antiangiogenic therapy; type of antiresorptive medication; local risk factor for MRONJ; MRONJ Stage; anatomic location and symptoms; treatment; surgical complications; recurrence. RESULTS: A total of 537 patients (375 females, 162 males) with MRONJ were included. Statistically significant associations were found between patients with metastatic bone disease and recurrences (P < 0.0005) and between advanced MRONJ stages (stages 2 and 3) and recurrences (P < 0.005). Statistically significant associations were also found between male gender and recurrences (P < 0.05), and between MRONJ maxillary sites and recurrences (P < 0.0000005). CONCLUSIONS: A longer mean duration of antiresorptive medications before MRONJ onset was observed in patients affected by osteoporosis, whereas a shorter mean duration was observed in all metastatic bone cancer patients, and in particular in those affected by prostate cancer with bone metastases or multiple myeloma. Surgery plays an important role for the management of MRONJ lesions.

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.

Does Penicillin Allergy Increase the Risk of Surgical Site Infection after Orthognathic Surgery? A Multivariate Analysis.

This study aimed to demonstrate an association between the occurrence of surgical site infection (SSI) after orthognathic surgery and penicillin allergy and to assess whether other factors could be associated with the occurrence of SSI. A 10-year monocentric retrospective study was conducted to identify possible risk factors for SSI in orthognathic surgery. Bivariate analyses were performed using Fisher, Student, or Wilcoxon tests and multivariate analyses using logistic regression. Two hundred and sixty-six patients were included, and 3.5% had SSI. Bivariate analyses revealed a significant association between SSI and age at surgery (p = 0.01), penicillin allergy (p = 0.02), and postoperative antibiotic therapy by Clindamycin (Dalacine®) (p = 0.02). Multivariate analyses confirmed the association between the occurrence of SSI and treatment with Clindamycin (Dalacine®) or Clindamycin (Dalacine®) and Metronidazole (Flagyl®) postoperatively (p = 0.04). Antibiotic therapy with Clindamycin (Dalacine®) seems to be associated with a higher rate of SSI, and the mandible was the only site affected by SSI.

Wound of the Parotid Duct Following a Subcondylar Fracture.

Salivary gland and duct complications following surgical approaches to condylar fractures are well known, particularly in approaches requiring parotid tissue dissection. We report a rare case of a parotid duct wound caused by the fracture itself and due to a lateral displacement of the condylar fragment. Four days after the surgical management of a trifocal mandibular fracture (head fracture on the left side, laterally displaced condylar base and angular fracture on the right side) the patient presented with a fluctuating subcutaneous swelling in the right cheek, evoking a sialocele. The sialography showed a massive leak of iodinated contrast medium just in front of the parotid hilum, joining the subcutaneous undermining made during the approach and confirmed the diagnosis of a parotid duct wound. A pressure dressing was applied to the right mandibular angle for 2 weeks, allowing for complete remission. In conclusion, this unusual clinical case illustrates the fact that the parotid duct may be endangered in the event of condylar base fractures, not only by the surgical approach but also by the fracture itself, especially when there is severe lateral displacement.