Engineering Precise Interconnected Porosity in ß-Tricalcium Phosphate (ß-TCP) Matrices by Means of Top-Down Digital Light Processing.

This study evaluated the biocompatibility and accuracy of 3D-printed ß-tricalcium phosphate (ß-TCP) pure ceramic scaffolds. A specific shaping process associating a digital light processing (DLP) 3D printer and a heat treatment was developed to produce pure ß-TCP scaffolds leaving no polymer binder residue. The ß-TCP was characterised using X-ray diffraction, infrared spectroscopy and the detection of pollutants. The open porosity of produced matrices and their resorption were studied by hydrostatic weighing and calcium release measures. The biocompatibility of the printed matrices was evaluated by mean of osteoblast cultures. Finally, macroporous cubic matrices were produced. They were scanned using a micro-Computed Tomography scanner (micro-CT scan) and compared to their numeric models. The results demonstrated that DLP 3D printing with heat treatment produces pure ß-TCP matrices with enhanced biocompatibility. They also demonstrated the printing accuracy of our technique, associating top-down DLP with the sintering of green parts. Thus, this production process is promising and will enable us to explore complex phosphocalcic matrices with a special focus on the development of a functional vascular network.

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.

Primary Failure of Dental Eruption Due to Variants Parathyroid Hormone Receptor 1: Retrospective Study and Proposal of Guidelines Treatment.

OBJECTIVE: Primary failure of eruption is characterized by a nonsyndromic defect in tooth eruption in the absence of mechanical obstruction. It is correlated to rare heterozygous variants in the parathyroid hormone receptor 1 gene. The management of primary failure of eruption is complex because many therapies are ineffective. The present study aimed to compare the clinical outcomes of our patients with the findings reported in the literature, and to propose a treatment guideline based on the literature and our experience. METHODS: Retrospective study of patients affected by primary dental eruption failure in the department and analyse of the results and compare with those of the litterature. RESULTS: Twelve patients belonging to 5 families (9 males, 3 females; 13-52 y old) diagnosed and treated in the maxillofacial surgery and stomatology department of the Lille University Hospital were included. All patients showed posterior tooth involvement, and most patients showed bilateral defects. None of the affected teeth had coronal alveolar bone, whereas 6 patients showed root resorption in the affected teeth. Genetic analyses, performed on 11 patients, identified a parathyroid hormone receptor 1 disease-causing variant in 7 of them (63%). Multidisciplinary treatment was required to rehabilitate these patients. Orthodontic interventions, even at an early age, are difficult in affected teeth, which are often blocked or have internal resorption. Moreover, retention of these affected teeth during growth leads to dentoskeletal malocclusions, requiring difficult surgical management in the long term. Therefore, early extraction of these teeth is frequently recommended once the diagnosis has been confirmed. An implant-borne prosthetic rehabilitation can then be achieved at the end of growth after correction of the jaw discrepancy. In case of a late diagnosis, other surgical or noninvasive techniques may be used depending on the clinical situation. Distraction osteogenesis or segmental osteotomy could be discussed for patients with mild phenotypes. CONCLUSIONS: Early diagnosis of primary eruption defects is crucial to offer appropriate management as early as possible, and so to avoid late complicated treatments.

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 [...].

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.

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.

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.

Autogenous bone grafting with conventional implants vs zygomatic implants for atrophic maxillae: a retrospective study of the oral health-related quality of life.

INTRODUCTION: Autogenous bone grafting (ABG)-combined or not with Le Fort I osteotomy (LFIO)-and zygomatic implants (ZI) are two reliable techniques for the fixed rehabilitation of atrophic maxillae. ZI allow a reduced treatment duration with no need to graft, immediate loading and in principle less morbidity. The aim of this retrospective study was to compare these two protocols on oral health-related quality of life (OHRQoL). We also discussed implant and prosthetic survival rates, and biological complications. MATERIAL AND METHODS: All patients who benefited from ZI or ABG with conventional implants (CI) for a fixed maxillary rehabilitation, from November 2011 to April 2019, were included: 21 patients in the ABG group and 22 in the ZI group. OHRQoL was evaluated postoperatively by OHIP-14 questionnaire. RESULTS: OHIP-14 median scores were respectively 6.5 (interquartile range [IQR] 2.0-13.0) and 6.0 (IQR 3.0-10.0) without significant difference (p = 0.97). Implant/prosthetic survival rates were 97.9%/100% and 97.1%/95.5%. Biological complications rates were 33.3% and 36.4% without significant difference (p = 0.83). DISCUSSION: The type of surgery or prosthesis does not seem to affect final OHRQoL, implant and prosthetic survival rates or biological complications rates.

The inception of a hospital-based dental emergency department in a precarious region decreases the incidence of severe cellulitis of odontogenic origin.

INTRODUCTION: Although most localized odontogenic infections can be managed successfully without complications, some can cause extensive morbidity through the onset of cervicofacial cellulitis. The management of these more severe infections generally requires emergency treatment, including surgical treatment under general anesthesia, and prolonged length of hospital stay. MATERIAL & METHODS: In this work, we assessed the impact of the provision of a hospital-based dental emergency department on the regional incidence of severe odontogenic cellulitis in a socioeconomically precarious region. Monthly case rates of odontogenic cellulitis treated between January 2010 and December 2019 at the hospital-based dental emergency department of Lille Medical University Hospital were collected. RESULTS: The mean number of monthly severe odontogenic cellulitis cases treated under general anesthesia was significantly higher before than after the inception of the hospital-based dental emergency service [14.07 (5.83) vs 8.79 (4.42); p<0.0001]. Conversely, the monthly mean number of collected odontogenic cellulitis cases treated under local anesthesia was significantly lower before the emergency service was set up [22.42 (12.73) vs 43.32 (23.41); p<0.0001]. CONCLUSION: The provision of a hospital-based dental emergency department resulted in a decrease in severe dental infections in a region with high indices of socioeconomic precarity, morbidity and mortality. Greater accessibility to dental care allows for the rationalization of care through more precocious and fewer burdensome procedures.

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.

Implant repositioning with segmental osteotomy.

INTRODUCTION: The aim of this study is to assess a pioneering technique for atrophic premaxilla restoration. The objective is to reposition an implant reconstruction zone into a position both anatomically and physiologically suitable for occlusal function. Indeed, unlike the other few articles published on the correctional osteotomy of the implant in an inadequate situation, we have planned here an initially «unsuitable¼ insertion in order to benefit of the available bone mass. MATERIAL AND METHOD: 3 patients aged 14-20 years old (1 woman and 2 men) were operated on at the maxillo-facial department of Lille 2 University Hospital for partial implant-prosthetic rehabilitation on atrophic maxillary and/or mandibular sector. 13 implants were seated (85% in the maxilla) in the native bone then moved subsequently by segmental osteotomy. RESULTS: The patients were assessed both clinically and radiologically according to the functional and aesthetic criteria of implant-prosthetic restoration. Functionally, a biomechanically favourable implant/number of teeth ratio (80%) was achieved, with consistent occlusal relationships (centric positioning of the midline point and absence of crossbite) in 100% of cases. Aesthetically, the screw access hole is systematically non-apparent (100%) but has a prosthetically substituted reduced gingivo-alveolar architecture. DISCUSSION: These observations suggest that implant repositioning with segmental osteotomy allows for atrophic premaxilla restoration in implanted bone volume whatever the initial angulation. Peri-implant aesthetic difficulties are not specific to the technique suggested here but are quite common to all premaxilla reconstruction techniques. Lastly, this group of three patients is not enough to be conclusive, and a larger group would be necessary to validate this type of management.

Classification of pedicle ossification after maxillofacial reconstruction with bony free flap: An observational study.

INTRODUCTION: Maxillofacial reconstruction with bony free flap is a classical technique. However, pedicle ossification after such reconstruction is a misunderstood complication that is rarely reported in the literature. It is usually manifested as trismus, neck pain, and hard swelling, but it is predominantly asymptomatic and, thus, mainly incidentally discovered at a later stage. The aim of our study is to propose a classification for pedicle ossification based on both radiological features and vascular calcification progression. We also describe a case of metachronous ossification after two fibula free flap procedures. MATERIAL & METHODS: Our observational study includes all patients from our unit who underwent maxillofacial reconstruction with bony free flap from 2003 to 2018. We collected all cases of pedicle ossifications identified during the follow-up and described the radiological status of each one to categorise them in different groups and propose a classification scheme for the same. RESULTS: Radiological and histological analysis showed a progressive three-step evolution of pedicle ossification, starting from the media, progressing into the lumen, and then reaching completion in the extravascular region. The final stage was observed in all symptomatic patients. CONCLUSION: Pedicle ossification is a progressive process that passes through three successive histological stages that may be associated with factors such as smooth muscle cell phenotype modification [1]. This complication may lead to more severe clinical symptoms and may require surgery for removal of the calcification.

Biological factors predicting the length of hospital stay in odontogenic cellulitis.

OBJECTIVE: The purpose of this study was to assess whether common biological factors are correlated with a longer hospital stay. STUDY DESIGN: All patients having odontogenic cellulitis, treated from January 2019 to December 2019 at Lille University Hospital, and requiring surgical drainage under general anesthesia, were included, retrospectively. Data, such as length of hospital stay and biological factors, namely, C-reactive protein (CRP) level, Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score, and bacterial samples were collected. RESULTS: Significant moderate-strong correlations were found between postoperative length of stay and patients' LRINEC score (rs = 0.556) and presurgical CRP level (rs = 0.579). There was a significant moderate correlation between postoperative length of stay and presurgical procalcitonin level (rs = 0.451), and a weak correlation between postoperative length of stay and presurgical white blood cell count (rs = 0.282). Linear regression verified CRP as an independent predictor of length of hospital stay, showing a significant linear relationship between them (p < 0.0001). A significant regression equation was found (F(1,65) = 27.089; p = 0.0001), with an R2 of 0.294. CONCLUSION: In this study, CRP was the key biological predictor of length of hospital stay. STATEMENT OF CLINICAL RELEVANCE: The ability to predict length of hospital stay and identify patients requiring intensive care management, using simple and inexpensive biological parameters (such as CRP), will enable more cost-effective care and efficient hospital bed management.

A Systematic Review of Rat Models With Temporomandibular Osteoarthritis Suitable for the Study of Emerging Prolonged Intra-Articular Drug Delivery Systems.

PURPOSE: Development of minimally invasive therapies for temporomandibular joint osteoarthritis (TMJOA) has focused on drug intra-articular injections to avoid the systemic adverse effects experienced when these substances are administered orally. Therefore, we performed a systematic review to answer the question "Which method of induction of a TMJOA-related pain model in rats leads to prolonged painful symptoms, allowing the best assessment of a sustained drug delivery system?" MATERIALS AND METHODS: Following the PRISMA guidelines, we searched MEDLINE for papers published from 1994 to July 2020 on a TMJ arthritis model using rats. We identified the means of pain induction and of nociception assessment. We assessed protocol bias using an adaptation of the QUADAS-2 tool. Animal selection, the reference standard method of pain assessment, applicability of a statistical assessment, and flow and timing were assessed. RESULTS: Of the 59 full papers we reviewed, 41 performed no pain assessment after the first 7 days following induction of the TMJ-related pain model. We eventually identified 18 long-term TMJOA-related pain models. Pain was induced by injection of toxic substances, most commonly Freund's complete adjuvant (50 µg per 50 µl), formalin at various concentrations, or monosodium iodoacetate (0,5 mg per 50 µl), into the TMJ, or by physical methods. Few studies reported data on pain after 21 days of follow-up. Heterogeneity of induction methods, pain assessment methods, and flow and timing biases precluded a meta-analysis. CONCLUSIONS: Given that pain is 1 of the main symptoms of TMJOA, experimental study protocols should include long-term pain assessment.