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.

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.

Oral carcinoma cuniculatum, a rare variant of squamous cell carcinoma.

INTRODUCTION: Carcinoma cuniculatum (CC) is a rare variant of squamous cell carcinoma (SCC). Lack of awareness of this tumor and its difficult diagnosis delay management and complicate treatment. The aim of this study is to describe the clinical and histological features, predisposing factors, treatment and survival rate of oral carcinoma cuniculatum. MATERIAL & METHOD: All patients with histologically confirmed CC of the oral cavity treated between January 2013 and August 2022 in a specialized center were retrospectively included. Patients were identified using the database ADICAP ("Association pour le Développement de l'Informatique en Cytologie et Anatomie Pathologique"). Once identified, the charts were reviewed. RESULTS: Ten patients were included. CC lesions were mainly located in the mandibular or maxillary gingiva, while the 2 remaining lesions were located in the mobile tongue. The tumor showed local aggressiveness: mandibular or maxillary osteolysis was systematically found for gingival CC, while tongue lesions were classified cT3. Fifteen biopsies were performed in these 10 patients, histological diagnosis is difficult on a limited tissue sample. All patients underwent curative management with oncological excision surgery combined with neck lymph node dissection, and adjuvant radiotherapy (except one patient). DISCUSSION: The main problem is the difficulty of diagnosis when biopsies are performed, which leads to a significant delay in diagnosis compared with SCC. In the event of clinico-histological discordance after biopsy, CC should be considered.

Strip pharyngoplasty as a secondary functional surgery for persistent velopharyngeal insufficiency in cleft palate.

Despite a satisfactory primary repair, velopharyngeal insufficiency (VPI) may be a sequel of soft palate clefts, resulting in hypernasality and phonation disorders. In order to increase the function of the pharyngeal flap during a secondary pharyngoplasty, we have developed a strip pharyngoplasty technique involving the middle constrictor muscle of the pharynx. This article describes the successive steps of the intervention and discuss its indications, advantages and limitations. Strip pharyngoplasty as a secondary functional surgery for persistent VPI after primary cleft palate repair is an attractive surgical procedure, particularly adapted to cases with defective muscle contraction by providing a muscle contingent in addition to the mucosal flap.

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.

Contribution of FDG-PET in the diagnostic assessment of cervical lymph node metastasis in Oral Cavity Squamous Cell Carcinoma (OCSCC).

INTRODUCTION: The main objective of this study was to evaluate the contribution of FDG-PET in the diagnostic assessment of cervical lymph node metastasis in Oral Cavity Squamous Cell Carcinoma (OCSCC) and to advance a diagnostic threshold value for SUVmax in carcinomatous cervical lymph node. METHODS: 47 patients with OCSCC and suspicious cervical lymph node involvement (cN+) on FDG-PET were included in this retrospective study. The primary outcome was cervical lymph node SUVmax based on histological cervical metastatic disease (« gold standard ¼). RESULTS: Among the 77 cervical lymph nodes considered suspicious on patients' FDG-PET, 50 were really metastatic on histological examination. The lymph node SUVmax with metastatic involvement on histological examination was 4.6 ± 3.9 [2.6 - 23.7] versus 3.6 ± 1.2 [2 - 7.3] without carcinomatous involvement (p = 0.004). The lymph node size was not statistically significant according to metastatic disease (p = 0.28). DISCUSSION: A cervical lymph node SUVmax value of less than 2.6 on FDG-PET would suggest non-metastatic lymph node involvement. Supra Omohyoid Neck Dissection (SOHND) could therefore be performed in OCSCC when the SUVmax of the cervical lymph node is below this value in order to reduce the surgical morbidity of dissection of the lower internal jugular chain (Level IV).

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.

In Vitro and In Vivo Evaluation of a Bio-Inspired Adhesive for Bone Fixation.

Compared to metallic hardware, an effective bone adhesive can revolutionize the treatment of clinically challenging situations such as comminuted, articular, and pediatric fractures. The present study aims to develop such a bio-inspired bone adhesive, based upon a modified mineral-organic adhesive with tetracalcium phosphate (TTCP) and phosphoserine (OPS) by incorporating nanoparticles of polydopamine (nPDA). The optimal formulation, which was screened using in vitro instrumental tensile adhesion tests, was found to be 50%molTTCP/50%molOPS-2%wtnPDA with a liquid-to-powder ratio of 0.21 mL/g. This adhesive has a substantially stronger adhesive strength (1.0-1.6 MPa) to bovine cortical bone than the adhesive without nPDA (0.5-0.6 MPa). To simulate a clinical scenario of autograft fixation under low mechanical load, we presented the first in vivo model: a rat fibula glued to the tibia, on which the TTCP/OPS-nPDA adhesive (n = 7) was shown to be effective in stabilizing the graft without displacement (a clinical success rate of 86% and 71% at 5 and 12 weeks, respectively) compared to a sham control (0%). Significant coverage of newly formed bone was particularly observed on the surface of the adhesive, thanks to the osteoinductive property of nPDA. To conclude, the TTCP/OPS-nPDA adhesive fulfilled many clinical requirements for the bone fixation, and potentially could be functionalized via nPDA to offer more biological activities, e.g., anti-infection after antibiotic loading.

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.

A Recurrent Orbital Hemorrhage in an Older Adult.

An adult patient in their 70s presented with unilateral painless proptosis and blurred vision of the right eye that resolved with corticosteroid treatment. Magnetic resonance imaging revealed a retrobulbar hemorrhage. Six months later, the hemorrhage and proptosis recurred, with incomplete resolution despite similar treatment. What would you do?

3D printing for orbital volume anatomical measurement.

PURPOSE: The aim was to develop a method for reproducible orbital volume (OV) measurement in vivo based on 3D printing. METHODS: Twelve orbits were obtained from dry skulls of the Human Anatomy Department of Lille University. Computer tomography (CT) slice images of these orbits were transformed into stereo-lithography (STL) format and 3D-printed. Bone openings were closed using either putty and cellophane after printing (3D-Orb-1) or at the printing stage in silico using MeshMixer (3D-Orb-2). The results were compared with those of the conventional water-filling method as a control group (Anat-Orb). RESULTS: The observers reported a mean orbital volume of 21.3 ± 2.1 cm3 for the open-skull method, 21.2 ± 2.4 cm3 for the non-sealed 3D-printing method, and 22.2 ± 2.0 cm3 for the closed-print method. Furthermore, the intraclass correlation coefficients (ICCs) showed excellent intra-rater agreement, i.e., an ICC of 0.994 for the first observer and 0.998 for the second, and excellent interobserver agreement (ICC: 0.969). The control and 3D-Orb-1 groups show excellent agreement (ICC: 0.972). The 3D-Orb-2 exhibits moderate agreement (ICC: 0.855) with the control and appears to overestimate orbital volume slightly. CONCLUSION: Our 3D-printing method provides a standardized and reproducible method for the measurement of orbital volume.

Radiographic volumetric risk factors for late enophthalmos prediction in orbital blow-out fractures: A retrospective study.

The aim of this study was to assess the correlation between volumetric risk factors, orbital volume (OV), orbital volume ratio (OVR), herniated volume (HV), and the newly described herniated volume ratio (HVR), with the occurrence of late enophthalmos. Patients presenting a unilateral unoperated blow-out fracture were retrospectively included. OV and HV were measured using planimetry on the initial CT scan images. OVR and HVR were then calculated. Enophthalmos was measured on the 2-month follow-up CT scan images. The population was divided into two groups according to their enophthalmos status. Correlations and multiple linear regression model were used. 17 patients out of 45 presented a late enophthalmos of 1 mm or more. There were significantly higher OVR (107 (3.76); p < 0.0001), HV (0.8 (0.47); p < 0.0001) and HVR (3.3 (1.82); p < 0.0001) in the enophthalmos group. A very strong linear correlation between enophthalmos and OVR (rs = 0.806), HV (rs = 0.948) and HVR (rs = 0.951) was found. Enophthalmos prediction using these volumetric parameters can help the surgeon's decision-making in orbital blow-out fractures in order to prevent late enophthalmos. Measurement is simple and reproducible. However, larger prospective studies are needed to confirm these results.

Effect of modified bilateral sagittal split osteotomy on inferior alveolar nerve neurosensory disturbance.

The aim of this study was to assess the occurrence of neurosensory disturbance of the inferior alveolar nerve (IAN) following modified mandibular bilateral sagittal split osteotomy (BSSO) that preserves the mandibular inferior border. All patients undergoing BSSO, associated or not with a Le Fort I osteotomy (performed by the same senior operator) between January 2018 and December 2019, were eligible. The modified BSSO consists of a modification of the technique described by Epker: the bony section of the buccal cortex stops 3-4 mm above the basal mandibular edge. While respecting the basilar border, sectioning is then performed up to the gonial angle where bicortical section is finally performed. Sensibility of the labial and chin area was evaluated immediately postoperatively, and at six months and two years of follow up. A total of 140 eligible patients underwent the modified BSSO between January 2018 and December 2019, and 72 were included. Hypoaesthesia was found in 81.9% of the patients (59/72 patients) at initial evaluation. It decreased to 45.8% (33/72 patients) at the six-month examination and to 12.5% (9/72 patients) at the last examination. Four bad splits were recorded. The modified BSSO preserves the inferior border of the mandible and maintains the IAN in the lingual fragment. There is no need to release the IAN, hence its manipulation is reduced and the incidence of IAN postoperative hypoaesthesia is also reduced.

Oral mucosal melanoma - A systematic review.

Oral mucosal melanoma (OMM) is the subject of few studies, resulting in a lack of understanding. The aim of this study is to review the current literature on OMM. The term searched was "oral mucosal melanoma" between 01/01/2000 and 03/15/2021 in the PubMed Database (MEDLINE). Patients presenting with OMM and treated in our center between January 2009 and January 2020 were included in a case series. Demographics, location, risk factors, genetic mutations, treatment performed, and overall survival (OS) rates were evaluated. The PubMed database search yielded a total of 513 results, thirty-eight articles were finally included, which amounted to 2230 cases of OMM. 13 patients were included in the case series. A male-to-female ratio of 1.28:1.00 was found with a mean age at first diagnosis of 58.2 years old. Hard palate (1060 cases) and then gingiva (794 cases) were the two main locations. No risk factors could be identified. OMM were staged III or IV at diagnosis. Mutations were described as such: KIT in 14.6% of cases, BRAF in 7%, and NRAS in 5.6%. Treatment protocols varied but radical surgery was the cornerstone treatment associated with adjuvant therapies. Immunotherapy has not been evaluated for OMM. OS rates were 43.4% at 3 years, 33.1% at 5 year and 15.4% at 10 years. OMM show distinct features from cutaneous melanoma (CM): typical locations, no identified risk factors, different mutations profile, worse prognosis with advanced stage at diagnosis. Targeted therapies are still underused compared to CM.

Three-Dimensional Printing Model Enhances Craniofacial Trauma Teaching by Improving Morphologic and Biomechanical Understanding: A Randomized Controlled Study.

BACKGROUND: Teaching about craniofacial traumas is challenging given the complexity of the craniofacial anatomy and the necessity for good spatial representation skills. To solve these problems, three-dimensional printing seems to be an appropriate educative material. In this study, the authors conducted a randomized controlled trial. The authors' main objective was to compare the performance of the undergraduate medical students in an examination based on the teaching support: three-dimensionally printed models versus two-dimensional pictures. METHODS: All participants were randomly assigned to one of two groups using a random number table: the three-dimensionally-printed support group (three-dimensional group) or the two-dimensionally-displayed support group (two-dimensional group). All participants completed a multiple-choice question evaluation questionnaire on facial traumatology (first, a zygomatic bone fracture; then, a double mandible fracture). Sex and potential confounding factors were evaluated. RESULTS: Four hundred thirty-two fifth-year undergraduate medical students were enrolled in this study. Two hundred six students were allocated to the three-dimensional group, and 226 were allocated to the two-dimensional group. The three-dimensionally printed model was considered to be a better teaching material compared with two-dimensional support. The global mean score was 2.36 in the three-dimensional group versus 1.99 in the two-dimensional group (p = 0.008). Regarding teaching of biomechanical aspects, three-dimensionally-printed models provide better understanding (p = 0.015). Participants in both groups exhibited similar previous student educational achievements and visuospatial skills. CONCLUSIONS: This prospective, randomized, controlled educational trial demonstrated that incorporation of three-dimensionally-printed models improves medical students' understanding. This trial reinforces previous studies highlighting academic benefits in using three-dimensionally-printed models mostly in the field of understanding complex structures.

Impacted lower third molar relationship with mandibular angle fracture complications.

INTRODUCTION: Mandibular angle fractures are very common and are associated with the highest risk of complications. The aim of this study is to evaluate the correlation between impacted lower third molar and mandibular angle fracture complications. MATERIAL AND METHODS: All patients presenting with a mandibular angle fracture and at least 2 months follow up were retrospectively included. The following complications were recorded: post-traumatic malocclusion, mouth opening limitation, inferior alveolar nerve hypoesthesia, infection, delayed union, hardware loosening. The patients were divided in two groups: impacted lower third molar or erupted/absent lower third molar. RESULTS: A total of 68 patients were included, lower third molar was impacted in 36 cases and erupted/absent in 32 cases. 40 complications were recorded in 27 patients at 2 months. No statistically significant difference could be found about malocclusion, mouth opening limitation and inferior alveolar nerve hypoesthesia. A lower rate of persistent inferior alveolar nerve hypoesthesia (p = 0.0557) in patients with impacted lower third molar (19.4%) was observed compared to patients without impacted lower third molar (40.6%). There was no occurrence of delayed union and hardware loosening in impacted lower third molar group, whereas 5 delayed unions and 4 hardware loosening were recorded in erupted/absent lower third molar group. Finally, the rate of patients with at least one of the 6 complications is significantly higher in the erupted/absent lower third molar group (17/32, 53.1%) than in the impacted lower third molar group (10/36, 27.8%), p = 0.033. DISCUSSION: The risk of overall complication is decreased when lower third molar is impacted in mandibular angle fracture. This supports the idea of a role of the impacted lower third molar in fracture reduction and stability.