Visuospatial abilities and 3D-printed based learning.

PURPOSE: The use of 3D-printing in every field of medicine is expanding, notably as an educational tool. The aim of this study was to assess how visuospatial abilities (VSA) of students may impact learning helped with 3D-printed models. METHODS: Participants were undergraduate medical school students during their clinical rotation in oral and maxillofacial surgery in two French Universities. Students were included prospectively and consecutively from September 2021 to June 2023. First, a lecture about craniosynostosis was performed with the help of 3D-printed models of craniosynostotic skulls. Then, a mental rotation test (MRT) followed by a multiple-choice questions (MCQs) form about craniosynostosis presentations were submitted to the students. RESULTS: Forty undergraduate students were finally included. Median MRT score was 15 (10.75;21) and median score to the MCQs was 13 (11.75;14). There was a significantly weak correlation between the MRT-A score and the score to the MCQs (rs = 0.364; p = 0.022). A simple linear regression was calculated to predict the result to the MCQs on MRT-A score [ (F(1,39) = 281.248; p < 0.0001), with a R2 of 0.878 ]. CONCLUSION: This study showed that VSA has an impact on the recognition of complex clinical presentations, i.e. skulls with craniosynostosis. The correlation found between VSA and complex 3D shape recognition after learning aided with 3D-printed model is emphasizing the importance of VSA when using innovative technologies. Thus, VSA training should be envisioned during the curriculum.

Augmented reality in implantology: Virtual surgical checklist and augmented implant placement.

OBJECTIVES: Aim of the present study was to create a pedagogical checklist for implant surgical protocol with an augmented reality (AR) guided freehand surgery to inexperienced surgeons using a head mounted display (HMD) with tracking. METHODS: The anatomical model of a patient with two missing mandibular teeth requiring conventional single-tooth implants was selected. The computed tomography (CT) scans were extracted and imported into segmentation and implant planning software. A Patient-specific dental splint through an intermediate strut, supported 3D-printed QR code. A checklist was generated to guide surgical procedure. After tracking, the AR-HMD projects the virtual pre-surgical plan (inferior alveolar nerve (IAN), implant axis, implant location) onto the real 3D-printed anatomical models. The entire drilling sequence was based on the manufacturer's recommendations, on 3D-printed anatomical models. After the implant surgical procedure, CT of the 3D-printed models was performed to compare the actual and simulated implant placements. All procedures in the study were performed in accordance with the Declaration of Helsinki. RESULTS: In total, two implants were placed in a 3D-printed anatomical model of a female patient who required implant rehabilitation for dental agenesis at the second mandibular premolar positions (#35 and #45). Superimposition of the actual and simulated implants showed high concordance between them. CONCLUSION: AR in education offers crucial surgical information for novice surgeons in real time. However, the benefits provided by AR in clinical and educational implantology must be demonstrated in other studies involving a larger number of patients, surgeons and apprentices.

3D-printed model for gingival flap surgery simulation: Development and pilot test.

INTRODUCTION: To assess the feasibility of a realistic model for learning oral flaps using 3D printing technology. MATERIALS AND METHODS: A mould was designed to reproduce the mandibular gingival mucosa, and a mandibular model was created using a three-dimensional printer for training undergraduate students to perform gingival flaps. After a short interview about its use, the participants were asked to use the simulator and provide feedback using a 5-point Likert questionnaire. RESULTS: The 3D-printed oral surgery flap training model was practical and inexpensive. The model was very realistic, educational and useful for hands-on training. CONCLUSIONS: 3D printing technology offers new possibilities for training in dental treatments that are currently difficult to replicate. The use of this simulator for oral flap surgery was well-received and considered promising by the participants.

Inferior alveolar nerve repositioning surgical techniques and outcomes - a systematic review.

Inferior alveolar nerve (IAN) lateralization (IANL) or transposition (IANT) are both techniques allowing for dental implant placement in posterior atrophic mandibles. The aim of this study was to systematically review the implant survival rate and the complications associated with IAN reposition techniques with simultaneous implant placement in atrophic posterior mandibles. This systematic review was conducted following PRISMA guidelines (Preferred Reporting Items for Systematic review and Meta-Analysis). The review was designed to answer the following PICO question: Is IAN repositioning (I) a safe and efficient technique (O) to treat patient looking for fixed dental rehabilitation of an atrophic posterior mandible (P). Thirty-three articles were reviewed, including a total of 899 patients, and approximately 950 IAN repositioning procedures. Dental implant survival rate ranged between 86.95% and 100% with a mean dental survival rate of 90.16%. Among the 269 patients who underwent IANT, there were 93% immediate neurosensory disturbance, and 15% persistent neurosensory disturbance. Among the 350 patients who underwent IANL, there were 93% immediate neurosensory disturbance, and 6% persistent neurosensory disturbance. IANT and IANL are reliable techniques allowing safe dental implant placement in atrophic posterior mandible with high patient satisfaction. IANL seems to cause less persistent neurosensory disturbances compared to IANT. The level of evidence is poor due to the high number of bias present in the included studies. IAN neurosensory disturbance assessment should be better homogenized in order to increase comparability.

Craniofacial fibrous dysplasia: Systematic review of facial management.

Craniofacial fibrous dysplasia (CFD) may be associated with major cosmetic or functional consequences. However, management recommendations for CFD are currently unavailable. Therefore, this systematic literature review aimed to review the existing approaches for CFD management and propose a management algorithm. The focus question was "What are the different options for CFD treatment and their complication rates?" The MEDLINE database was searched, and 33 articles evaluating a total of 1154 patients were reviewed. The bias assessment showed that 20 of the 33 studies had a high or intermediate risk of bias, mainly because of retrospective data collection and small patient numbers. Radical surgery showed a lower recurrence rate than debulking, but its use should be weighed against the morbidity caused by the reconstruction performed in this technique. Orbital decompression using a radical technique or debulking is effective in cases showing exophthalmos or dystopia. Surveillance is a viable option for asymptomatic and/or non-progressive lesions. In cases showing optic nerve compression, prophylactic decompression should be avoided, and decompression should be performed only when patients show diminished visual acuity or visual field defect. Although bisphosphonates have shown efficacy in pain management, their posology requires further discussion. A management algorithm is presented.

Robotic calvarial bone sampling.

The aim of this study was to assess the feasibility of complex unicortical calvarial harvesting by using the Cold Ablation Robot-Guided Laser Osteotome (CARLO® primo+). A cadaveric study was performed with a progressive complexity of the bone harvesting. This preliminary study on the cadaveric cranial vault area examined the tracking precision, the strategies, settings and durations of harvesting, the accuracy of the unicortical bone cutting, and the risk of dura exposition. All sampling was realised with no more difficulty than that experienced during the standard procedure. No bicortical cutting occurred during CARLO® primo + robot-guided laser cutting. During the second sampling, dura was partially exposed due to improper angulation of the curved osteotome during harvesting. Complex unicortical calvarial harvesting using robot-guided laser appears to be feasible and safe. In the future, robotic approaches will probably replace current surgical techniques using cutting guides and help reduce intraoperative inaccuracies due to the human factor.

Management of postoperative outcomes of polytetrafluoroethylene membranes in alveolar ridge reconstruction: a systematic review.

Guided bone regeneration (GBR) is a validated technique with satisfactory outcomes during 30 years of follow-up. The use of polytetrafluoroethylene (PTFE) membrane for vertical augmentation has been studied extensively. However, studies have reported exposure rates of up to 31%, there is no consensus on the management of postoperative exposure. The objective of this study was to propose a management approach for postoperative exposure of polytetrafluoroethylene (PTFE) membranes in alveolar ridge reconstruction. MATERIAL AND METHOD: An electronic search in PubMed Central's and additional electronic databases was performed. The search strategy was limited to human studies, full-text English or French articles published from 1990 until april 2023. The extracted data included defect location, membrane type, biomaterials, time to postoperative exposure, and Fontana classification stage. Protocol bias assessment was performed using an adaptation of the QUADAS-2 tool. This review has been registered on PROSPERO (ID: CRD42023445497). RESULTS: A total of 43 articles were found to be eligible, and 11 of these met the predefined inclusion and exclusion criteria. Based on the results of this systematic review, an algorithm for the management of PTFE membrane exposure is proposed. CONCLUSION: Postoperative membrane exposure is not a determining factor for the success of bone grafting. In cases with postoperative complications, the majority of cases still achieved adequate implant-prosthetic rehabilitation. Lastly, this series of 11 articles was insufficient to draw conclusions regarding good practice recommendations. A larger series is required to validate the specific management approaches.

Jacob Disease, Osteochondroma of the Coronoid Process, Coronoid Process Hyperplasia or Langenbeck Disease: The Big Jumble. Comment on Raccampo et al. Jacob's Disease: Case Series, Extensive Literature Review and Classification Proposal. J. Clin. Med. 2023, 12, 938.

We read the article by Raccampo et al., about Jacob disease and their ambiguous definition of the condition [...].

Surgical treatment outcomes of solitary fibrous tumors in the head and neck: A retrospective study.

The aim of this study was to better characterize head and neck solitary fibrous tumors (SFTs) and to evaluate surgical treatment. This retrospective study included patients who presented with head and neck SFTs. Clinical, radiological, and histological information and data regarding the treatments performed were collected. The risk of locoregional and distant metastases was calculated, and for orbital SFTs a specific classification was used. Overall, 34 patients were included. The majority of the SFTs were found in the oral cavity (n = 10), followed by the neck region (n = 8). The mean time to recurrence was 67.4 months. All patients underwent primary surgical resection. Recurrence was observed in five patients with a low risk of locoregional recurrence and distant metastasis. The treatment of choice is complete resection. Recurrence seems to be highly correlated with positive surgical margins. The safety margin should be increased when removing the lesion, and long-term follow-up should be performed.

Efficacy of Intra-Articular Injection of Botulinum Toxin Type A (IncobotulinumtoxinA) in Temporomandibular Joint Osteoarthritis: A Three-Arm Controlled Trial in Rats.

Temporomandibular disorders (TMD) are complex pathologies responsible for chronic orofacial pain. Intramuscular injection of botulinum toxin A (BoNT/A) has shown effectiveness in knee and shoulder osteoarthritis, as well as in some TMDs such as masticatory myofascial pain, but its use remains controversial. This study aimed to evaluate the effect of intra-articular BoNT/A injection in an animal model of temporomandibular joint osteoarthritis. A rat model of temporomandibular osteoarthritis was used to compare the effects of intra-articular injection of BoNT/A, placebo (saline), and hyaluronic acid (HA). Efficacy was compared by pain assessment (head withdrawal test), histological analysis, and imaging performed in each group at different time points until day 30. Compared with the rats receiving placebo, those receiving intra-articular BoNT/A and HA had a significant decrease in pain at day 14. The analgesic effect of BoNT/A was evident as early as day 7, and lasted until day 21. Histological and radiographic analyses showed decrease in joint inflammation in the BoNT/A and HA groups. The osteoarthritis histological score at day 30 was significantly lower in the BoNT/A group than in the other two groups (p = 0.016). Intra-articular injection of BoNT/A appeared to reduce pain and inflammation in experimentally induced temporomandibular osteoarthritis in rats.

Is panoramic radiography adequate for diagnosing coronoid process hyperplasia? A case series.

INTRODUCTION: The objective of this study was to compare the length ratios obtained on panoramic radiography and computed tomography (CT) to verify whether the former is adequate for diagnosing coronoid process hyperplasia. METHODS: A case series of patients with coronoid process hyperplasia was investigated. Length ratios between the coronoid process and condyle were measured on panoramic radiographs by using the Levandoski method and on CT scans by using the methods described by Tavassol et al. and Stopa et al. The mean length ratios obtained using the three measurement methods were compared. RESULTS: The mean length ratio measured with the Levandoski method was significantly lower than that measured with the method described by Stopa et al. (1.09 [0.09] vs. 1.21 [0.09]; P = 0.0001) and lower than that measured with the method described by Tavassol et al. (1.09 [0.09] vs. 1.34 [0.44]; P = 0.013). CONCLUSION: Panoramic measurement of the coronoid process by using the Levandoski method tended to underestimate the length ratio, emphasizing the importance of using a scanographic measurement method at the slightest doubt to confirm the diagnosis of coronoid process hyperplasia.

Pre-implant and implant management of oligodontia patients: A 10-year retrospective study.

INTRODUCTION: the aim of this study was to report and assess the management and implant rehabilitation of oligodontia patients since its recognition in 2012 by french authorities in the nomenclature. MATERIAL AND METHODS: we conducted a retrospective study in the Maxillofacial Surgery and Stomatology Department of the Lille University Hospital between January 2012 and May 2022. Patients had to present an oligodontia recognized under the ALD31 in adulthood, and to have benefited from a pre-implant/implant surgical treatment in the unit. RESULTS: a total of 106 patients were included in the study. The mean number of agenesis was 12 per patient. The most missing teeth are the ones at the end of the series. After a pre-implant surgery phase including orthognathic surgery and/or bone grafting, 97 patients benefited from implant placements. The mean age for this phase was 19.38. A total of 688 implants were placed. The median number of implants placed was 6 per patient and 5 patients presented implant failures after or during the osseointegration phase (16 implants lost). The implant success rate was 97.6%. 78 patients benefited from rehabilitations by fixed implant-supported prostheses and 3 by implant-supported mandibular removable prostheses. DISCUSSION: The described care pathway seems to us adapted to the patients followed in our department, with good functional and esthetic results. It would be necessary to evaluate on a national scale to adapt the management process.

Comparison of chemical-induced temporomandibular osteoarthritis rat models (monosodium iodoacetate versus collagenase type II) for the study of prolonged drug delivery systems.

OBJECTIVE: To compare two agents that can induce a rat model of temporomandibular joint osteoarthritis (TMJOA) by chemical induction: monosodium iodoacetate (MIA) and collagenase type 2 (Col-2). We wished to ascertain the best agent for assessing drug-delivery systems (DDSs). METHOD: Male Wistar rats underwent intra-articular injection with MIA or Col-2. They were manipulated for 30 days. The head withdrawal threshold (HWT), immunohistological assessment, and positron emission tomography (PET) were used to evaluate the relevance of our models. RESULTS: For both the MIA and Col-2 groups, pain persisted for 30 days after injection. Change in the HWT showed that Col-2 elicited a strong action initially that decreased progressively. MIA had a constant action upon pain behavior. Histology of TMJ tissue from both groups showed progressive degradation of TMJ components. CONCLUSIONS: MIA and Col-2 induced orofacial pain by their local chemical action on TMJs. However, based on a prolonged and greater sustained effect on the pain threshold, persistent histological changes, and imaging results, MIA appeared to be more suitable for creation of a rat model of TMJOA for the study of DDSs.

ACTN3 genotype influences masseter muscle characteristics and self-reported bruxism.

OBJECTIVES: Main aim of the study was to explore the association between genetic polymorphisms in ACTN3 and bruxism. Secondary objectives included masseter muscle phenotypes assessment between bruxers and non-bruxers and according to genetic polymorphisms in ACTN3. MATERIALS AND METHODS: Fifty-four patients undergoing orthognathic surgery for correction of their malocclusion were enrolled. Self-reported bruxism and temporomandibular disorders status were preoperatively recorded. Saliva samples were used for ACTN3 genotyping. Masseter muscle samples were collected bilaterally at the time of orthognathic surgery to explore the muscle fiber characteristics. RESULTS: There were significant differences in genotypes for rs1815739 (R577X nonsense) (p = 0.001), rs1671064 (Q523R missense) (p = 0.005), and rs678397 (intronic variant) (p = 0.001) between bruxers and non-bruxers. Patients with self-reported bruxism presented a larger mean fiber area for types IIA (p = 0.035). The mean fiber areas in individuals with the wild-type CC genotype for rs1815739 (R577X) were significantly larger for type IIA fibers (1394.33 µm2 [572.77 µm2 ]) than in those with the TC and TT genotypes (832.61 µm2 [602.43 µm2 ] and 526.58 µm2 [432.21 µm2 ] [p = 0.014]). Similar results for Q523R missense and intronic variants. CONCLUSIONS: ACTN3 genotypes influence self-reported bruxism in patients with dentofacial deformity through specific masseter muscle fiber characteristics.

Simultaneous Mandibular Anterior Segmental Osteotomy and Genioplasty: A Novel Technique.

The current standard approach to treat class II malocclusion is orthodontic preparation followed by a mandibular advancement through bilateral sagittal split osteotomy associated or not with a genioplasty. However, when a malocclusion with an important incisors' axis deviation is associated with a chin malposition, an alternative technique can be considered: simultaneous mandibular anterior segmental osteotomy and genioplasty. This technique is performed without a bony bridge between osteotomies. Care must be taken not to wound the lingual mucosa. If preserved, this technique is safe. The result is stable and predictable.

Surgical bone augmentation procedures for oral rehabilitation of patients with oligodontia: A review with a systematic approach.

Oligodontia is a developmental dental anomaly defined by the absence of 6 or more permanent teeth, excluding the third molars. We performed a review with a systematic approach and proposed a guideline for the choice of the bone augmentation surgery. The different bone augmentation technique terms were searched in the PubMed and Science Direct database. Clinical studies were eligible if they reported on pre-implant surgery in patients with oligodontia. The database search yielded 400 studies after duplicates removed. Thirty studies were finally included, involving 410 patients. Sixty-three sinus lifts were performed in 37 patients with no failure. Thirteen out of 33 patients with iliac bone transplantation and two out of 24 with parietal bone transplantation had resorption, one out of 4 patients who received allogeneic bone block had complete failure. Seventy-eight patients underwent guided bone regeneration, none had bone loss. No failure was found with the alveolar distraction osteogenesis technique. Four out of thirteen patients developed permanent hypoesthesia after inferior alveolar nerve transposition. The cumulative implant survival rate was 94.4% after bone augmentation procedures. Extensive edentulous areas should be grafted with parietal bone, as iliac grafts present a greater risk of resorption. Smaller edentulous areas should be treated by endobuccal harvesting or guided bone regeneration. Osteogenesis distraction and nerve transposition are effective surgeries for medium-to-large mandibular edentulous spaces. The implant survival rate is not significantly different between implants placed in grafted and nongrafted bone, the appropriate choice of bone augmentation technique can reduce the risk of peri­implant bone resorption.

Effectiveness of treatment by coronoidectomy and active rehabilitation in Langenbeck or Jacob diseases. A retrospective study of 20 cases.

BACKGROUND: The objective of this study was to evaluate the mouth opening (MO) in patients with Langenbeck or Jacob diseases after a multimodal treatment combining the coronoidectomy and a self or assisted postoperative rehabilitation. METHODS: This observational retrospective study included patients who had clinically impacted MO limitation. All patients underwent unilateral or bilateral coronoidectomy and then physical therapy for at least 3 months. MO measurements were compared between the preoperative time (M0), the immediate postoperative time (M1) and the last follow-up (M2). Other data regarding the surgical procedure and the postoperative rehabilitation were collected. RESULTS: Twenty patients were included. The MO was significantly improved from 19.15 ± 7.02 mm at M0 to 38.00 ± 7.62 mm at M1 (p = 0.0002). After a mean follow-up of 21.5 ± 40.5 months, the mean MO was 32.85 ± 5.69 mm (M2). All patients underwent coronoidectomy through an intraoral approach except for one patient who was given a combined extra-oral approach for a recurrent disease. Rehabilitation protocol included assisted physiotherapy and self-rehabilitation in 7 patients as well as just self-rehabilitation in 13 patients. No patient showed worsening or stagnation of MO. CONCLUSIONS: The multimodal treatment combining the surgical removal of the coronoid process and an active rehabilitation performed by the patient himself or assisted by a physiotherapist seems effective in Langenbeck or Jacob diseases.