Rabbit calvarial and mandibular critical-sized bone defects as an experimental model for the evaluation of craniofacial bone tissue regeneration.

INTRODUCTION: Many studies have aimed to investigate the regeneration potential of bone substitutes through animal models at different defect sites, where the bone healing mechanism varies due to developmental, structural and functional differences. This study aims to develop a rabbit model with two functionally different (non-load-bearing calvarias and load-bearing mandibular) critical-sized defects (CSD) in one rabbit. MATERIAL & METHOD: The comparison of the "gold standard" autograft to a sham (no graft) control was undertaken in order to validate this model; at the same time, a 3D-printed biphasic calcium phosphate scaffold was implanted to test its utility in the evaluation of new bone substitute materials. Twenty rabbits were selected with both a 10 mm calvaria defect and a 11 mm bicortical semi-cylindrical mandibular defect. The animals were euthanized at 4 and 12 weeks once surgery, microcomputed tomography and histological analysis had been performed. RESULTS: In the case of the calvaria, the results for the non-healing sham group compared with the healing of those that had undergone the autograft validated the CSD model. But the mandibular defect was not validated, due to the particularity of mandible high mechanical stress and infectious risk. DISCUSSION: This study showed for the first time that rabbits have a high tolerance for the bilateral double-site CSD model under consideration; and further studies are essential to modify and improve the design of mandibular CSD.

Ectopic third mandibular molar: evaluation of surgical practices and meta-analysis.

OBJECTIVES: To identify the preferred surgical approach (intra- or extra-oral) to remove an ectopic third mandibular molar (ETMM) according on its location and presence of an associated cyst or cutaneous fistula, and to determine the indications for a graft or osteosynthesis. MATERIALS AND METHODS: A surgical practice questionnaire was distributed to oral and maxillo-facial surgeons attending a National Congress of the French Society of Stomatology, Maxillo-facial and Oral Surgery. A systematic review of the literature and meta-analysis was carried on Pubmed, Cochrane, Embase and ScienceDirect databases using the MeSH terms: "Ectopic teeth", "Third molar", "Mandibular". One hundred and forty-three surgeons answered the questionnaire and the meta-analysis included 66 articles. RESULTS: From the questionnaire, the preferred surgical approach was intra-oral except when the ETMM was in the condyle, when it was extra-oral (69.5%; p < 0.001). In the meta-analysis, an extra-oral approach was only indicated when a cutaneous fistula was present (90% vs. 35.9%; p = 0.002), irrespective of ETMM location. In the questionnaire and meta-analysis, the presence of a cyst did not change the approach (p < 0.05). The indications for a graft or osteosynthesis were a condylar location (p < 0.001), while a cutaneous fistula decreased the indication (p = 0.04) and a cyst (p = 0.009) was only associated with a graft. CONCLUSIONS: The preferential approach was intra-oral, except when the ETMM was condylar or a cutaneous fistula was present when an extra-oral approach was preferred. Osteosynthesis or a graft were more likely when the ETMM was in the condyle. CLINICAL RELEVANCE: This study will help to orientate surgeons vis-à-vis ETMM treatment.

Orbitofrontal Reconstruction With a Three-Dimensional Titanium Patient-Specific Implant After Intraosseous Haemangioma Resection.

BACKGROUND: Intraosseous hemangiomas are rare benign tumors that can develop in the skull. Orbitofrontal localization is uncommon. The complexity of orbitofrontal anatomy results in difficult reconstruction following trauma or tumoral resection. CASE PRESENTATION: A 50-year-old woman with a right orbitofrontal intraosseous hemangioma was referred to our department. The authors decided to perform tumoral bone resection and orbitofrontal reconstruction using virtual surgical planning in collaboration with Materialize engineers (Materialise, Leuven, Belgium). Three cutting guides and a patient-specific 3-dimensional (3D) titanium implant were designed and manufactured in 3 weeks. Surgery was performed with a double surgical team composed of maxillofacial surgeons and neurosurgeons. No perioperative or post-operative complications occurred. Post-operatively, the patient was completely asymptomatic and clinical examination showed symmetrical and satisfactory facial morphology. CONCLUSION: Virtual surgical planning, design of patient-specific guides and manufacturing of implants make surgery easier and increase surgical precision. This technique is recommended for wide use in cases of oncological or complex trauma craniomaxillofacial reconstruction.

Virtual Surgery Planning and Three-Dimensional Printing Template for Osteotomy of the Zygoma to Correct Untreated Zygomaticomaxillary Complex Fracture.

Untreated zygomaticomaxillary complex fractures may lead to aesthetical and functional sequelae needing secondary surgical correction. A 31-year-old male was addressed to our department for right enophthalmos and loss of cheek projection 3 months after facial trauma. Restauration of facial symmetry can be achieved by repositioning of the zygomaticomaxillary complex by osteotomies. To achieve good functional and aesthetical results, the reduction needs to be accurate. This is the main difficulty in delayed cases as there are less anatomical landmarks due to initial trauma and bone remodeling. Nowadays, in France, thanks to good care access, very few patients are not treated within the first two weeks after trauma; thus, surgeons have little experience on secondary reduction. It has been reported that navigation-guided surgery and use of stereolithographic models improve results. In small centers, access to both technologies and induced over-cost may limit their use. With the ease to access a 3D printer, small centers have to develop innovative, simple ways to offer comparative results. In the case presented, surgery planning and plate modeling were achieved using an office-based three-dimensional printed model. To reduce the cost, free open source software has been used. In this case, facial symmetry has been restored and post-operative computed tomography scan shows good stability. This simple, cost effective technique, is applicable in most centers equipped with a 3D printer and ensures a good and reproductive result even when this surgery is not routinely done.

Impairments in Food Oral Processing in Patients Treated for Tongue Cancer.

Patients surgically treated for oral cancer are affected by several underestimated deglutition disorders risk factors. This study aims to characterize the level of these food oral processing (FOP) impairments in a group of patients treated by surgery for tongue cancer. Twenty-seven consecutive patients surgically treated for tongue cancer were evaluated concerning their chewing capacity (Mastication-test), and responded to questions concerning their capacity to bite, chew and manipulate food with their tongue, and their quality of life. According to the Mastication-test, 16 patients suffered total FOP incapacities (TI group), characterized by high tumor stage, invasive carcinological surgery and necessity of reconstructive surgery; 12 patients were partially or not impaired (PI/NI-group). Tongue movement score and number of dental units were lower in the TI group than in the PI/NI-group. Subjective FOP criteria were clearly impaired in the TI group and correlated with a poor oral health-related quality of life. One year after surgery, there is a decrease in BMI for TI group patients while the PI group patients had a significant increase in BMI. All patients surgically treated for oral cancer suffered FOP impairments, but not with the same severity. Totally impaired subjects are at higher risk from long-term malnutrition. Functional evaluation of FOP should form part of the post-operative follow-up for all patients suffering from tongue cancer, using a quick combined evaluation of chewing efficiency, oral health quality of life and nutritional status.

Efficacy of pentoxifylline-tocopherol-clodronate in mandibular osteoradionecrosis.

OBJECTIVES/HYPOTHESIS: PENTOCLO treatment, associating pentoxifylline, tocopherol, and clodronate, resolves radiation-induced fibrosis. The main aim of the present study was to prospectively assess efficacy in mandibular osteoradionecrosis (ORN). STUDY DESIGN: Prospective cohort study. METHODS: Twenty-seven patients with mandibular ORN were included in the Pentoclauvergne Study between January 2014 and February 2016. After an initial 28-day phase of antibiotic, antifungal, and corticosteroid therapy, they received the PENTOCLO association daily until cure or a maximum of 24 months. The main assessment criterion was exposed bone area (EBA); secondary criteria comprised the Subjective, objective, management, and analytic (SOMA) score. RESULTS: Under PENTOCLO, EBA decreased by 28% at 2 months, 55% at 6 months, and 92% at 24 months; the SOMA score decreased by 23%, 38%, and 50%, respectively. A complete treatment course cured 76.5% of patients at a mean 9.6 months. CONCLUSIONS: PENTOCLO is a simple, well-tolerated, and effective treatment for mandibular ORN. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:E559-E566, 2020.

Reconstruction of a Large Posttraumatic Mandibular Defect Using Bone Tissue Engineering With Fresh-Frozen Humeral Allograft Seeded With Autologous Bone Marrow Aspirate and Vascularized With a Radial Forearm Flap.

INTRODUCTION: Currently, vascularized autologous bone transplantation is considered the gold standard for large mandibular continuity defect reconstruction. Donor site morbidity is a major concern. Therefore, bone tissue engineering (BTE) seems to be the ideal solution. Fresh-frozen bone allograft is the closest material to autologous bone. The purpose of this clinical report is to show a new technique of large mandibular continuity defect reconstruction using a fresh-frozen humeral allograft seeded with autologous iliac bone marrow aspirate and vascularized with a radial forearm flap. METHODS: A 33-year-old man presented with severe cranio-facial trauma resulting in several fractures of the facial skeleton including a comminuted mandibular fracture from left parasymphysis to left angle, which caused a large continuity defect. RESULTS: Result at 6 months was aesthetically and functionally satisfactory with osseointegration of the bone graft. DISCUSSION: The authors chose to use iliac bone marrow aspirate to seed the allograft scaffold since hematopoietic stem cells and mesenchymal stem cell are able to differentiate into osteoblasts, ease of harvest of the iliac crest and its low rate of morbidity. Contemporary biomaterials used for BTE are bioceramic but bone is still the better scaffold to engineer bone and only allografting avoids donor site morbidity. Vascularization is one of the main challenges of BTE; insertion of autologous vascular bundles from pedicle or free flaps is 1 solution. The authors chose the radial forearm flap since the pedicle is long and the authors did not need a great amount of soft tissue.

A new flap combination for reconstruction of lower nasal dorsum and supra-tip skin defects.

Repairing surgical defects of the nose is still challenging due to its tridimensional shape and its aesthetic concern. Difficulty in reconstructing nasal subunits lies in their contour, skin texture and limited availability of adjacent skin. For lower nasal dorsum and supra-tip regions, we design a new combined local flap as existing local flaps may give disappointing results. This combination flap was performed on two patients for reconstruction of the lower nasal dorsum area after basal cell carcinoma excision. Size of the excision ranged from 20 to 25 mm diameter and safe margins were obtained. The defects were reconstructed with a local flap that combined a rotation nasal flank flap and a V-Y advancement nasolabial flap. Excision and reconstruction were performed in a one-stage surgery under intravenous sedation and local anesthesia. There were no postoperative complications and no flap loss occurred. Aesthetic and functional results after 6 months postoperatively were satisfying without modification of nasal shape. This flap is reliable and offers interesting functional and aesthetic outcomes. It can be considered as a new reconstruction alternative for supra-tip and lower nasal dorsum skin defects performed in a one-stage procedure under local anesthesia.

Unilateral Condylar Hyperplasia: Is Reactivation After a Long Latency Period of Inactivity Plausible?

Unilateral condylar hyperplasia (UCH) is characterized by an overgrowth of the mandibular condyle responsible for a facial and dental asymmetry associated with temporomandibular joint function and maxillary growth consequences. The diagnosis is based on a body of clinical, radiological and histological arguments. A 38 years old woman with a reactivation of UCH after a latency period of 16 years following an orthognathic surgery performed for facial asymmetry normalization is presented. She was addressed to our department for a facial progressive asymmetry relapse and dental prosthetic consequences.The radiological images and the planar scintigraphy combined with single-photon emission computed tomography scans showed an active left unilateral condylar hyperplasia. A left proportional condylectomy was performed.The case presented highlights the possibility for the UCH to be reactivated after a long period of latency, leading to a relapse of the occlusal and facial disorders and so advocates the need for first condylectomy or at least a long-term follow-up if condylectomy is not performed as a first-line treatment.

Dental and Maxillofacial Signs in Leri-Weill Dyschondrosteosis.

One of the most common causes of short stature is a defect of the short stature homeobox-containing (SHOX) gene, which is located in pseudoautosomal region 1 on the distal end of the short arm of chromosomes Xp22.33 and Yp11.32. More than 300 different mutations in the SHOX gene responsible for short stature syndrome have been described. The phenotypic expression of SHOX haploinsufficiency is remarkably varied. The 3 typical clinical presentations, from least to most severe, are idiopathic short stature without skeletal malformations, Leri-Weill dyschondrosteosis (LWD), and Langer mesomelic dysplasia, which is believed to represent the homozygous form of LWD. Despite a higher prevalence in women, suggesting the potentiating action of high estrogen levels on the effects of SHOX deficiency, the syndrome was initially believed to have an autosomal pattern of inheritance. In reality, heterozygous SHOX mutations can be transferred from the Y to the X chromosome and vice versa. This phenomenon is called "the jumping SHOX gene" and corresponds to a pseudoautosomal dominant inheritance. LWD is characterized by mesomelic short stature and Madelung deformity defined by an upward and medial displacement of the radial joint surface, which restricts range of motion. Less specific dysmorphic signs associated with LWD, such as short hands and feet, scoliosis, or muscular hypertrophy, have been described. When reviewing the dental and maxillofacial signs, only limited and summary data (micrognathia and high arched palate) have been published in the literature. This report presents a case of LWD that highlights many other noteworthy dental and maxillofacial signs that are important to clearly identify and appropriately treat.

Postoperative Visual Loss: A Report of One Patient With Unilateral Blindness After Orthognathic Surgery.

INTRODUCTION: Blindness after orthognathic surgery may be the result of the surgical procedure itself or the consequence of factors induced by general anesthesia. However, the exact mechanism between is not known. The purpose of this article is to present a case of a postoperative visual loss after orthognathic surgery under general anesthesia concluding with a brief literature review about this topic. REPORT OF CASE: We report the case of a patient who suffered unilateral blindness with homolateral frontal paresthesia after orthognathic procedure in 2 steps. He presented intraoperative bradycardia with a potential undiagnosed hypertension, associated with significant blood loss and volume resuscitation by colloids and cristalloids.Postoperative examination concluded to posterior ischemic optic neuropathy. DISCUSSION AND CONCLUSION: By a systematic literature review, we discuss about surgical and anesthesic causes of postoperative visual loss, and particularly pathophysiology mechanism of posterior ischemic optic neuropathy. Some predisposition and risk factors have been identified and need to be taken into account.

Dental and Maxillofacial Signs in Aarskog Syndrome: A Review of 3 Siblings and the Literature.

PURPOSE: Dagfinn Aarksog first described faciodigitogenital syndrome in 1970. Its inheritance is X linked and autosomally recessive. Currently, the diagnosis of Aarskog-Scott syndrome (ASS) is based on clinical dysmorphologic findings and can be supported by genetic examination. REPORT OF CASES: This report describes 3 brothers already diagnosed with ASS who were referred for examination of oral and maxillofacial malformations associated with ASS. They presented classic features of ASS, such as digital and genital (shawl scrotum) anomalies. More specifically, in terms of orbitopalpebral malformations, they showed marked ptosis with hypertelorism and antimongoloid palpebral fissure that gave them the characteristic facies. Concerning their oral and maxillofacial malformations, they had dental and skeletal major discrepancies and some dental agenesia. DISCUSSION AND CONCLUSION: ASS is a rare X-linked syndrome composed of numerous morphologic facial, digital, and genital anomalies. The diagnosis is established genetically with the FGD1 mutation but there is no phenotypic and genotypic correlation with FGD1 mutations. Concerning maxillofacial malformations, maxillary and mandibular hypoplasia with jaw discrepancies can be found, as can teeth anomalies. It seems that these anomalies are widely underestimated.

Virtual Surgery Planning and Three-Dimensional Printing Template to Customize Bone Graft Toward Implant Insertion.

Premaxillary tooth loss and bone deficiency or atrophy often occur in facial trauma. Onlay bone graft and implants have so far been the best means of restoring function and esthetic appearance. Void space between the graft and the jaw bone, over projection and mucosal trauma can cause mucosal dehiscence, bone exposure, or resorption and can compromise implant survival. Virtual surgical planning using 3-dimensional printing technology has improved the efficiency of craniofacial surgery. The drawbacks of this technology are its cost and time-consuming preparation. However, the democratization of high-performance 3-dimensional printing and open-source software have enabled surgeons to master the procedure. The authors applied this innovative technology to customize bone graft for insertion of a premaxillary implant. It enabled us to custom-make the bone graft on the template and to perfectly embed the graft in the gap with a reduce operating time and a good osteointegration.

Retrospective evaluation of 211 patients with maxillofacial reconstruction using parietal bone graft for implants insertion.

PURPOSE: For a century, autologous bone grafts have been used in maxillofacial reconstruction. The ideal bone harvest site and grafting procedure remains a point of contention in regards to obtaining optimal long-term results with sufficient bone quantity and density without serious complications. More recently, confronted with growing patient requests and biomaterials development, maxillofacial surgeons and dentists have been considering these issues as they relate to pre-implant surgery. This study sought to evaluate implant success rate and complications following pre-implant surgery with parietal bone grafting. MATERIALS AND METHODS: A retrospective study was carried out on patients who underwent maxillofacial reconstruction of different sites (symphysis, mandibular corpus, maxillary sinus and premaxilla) for the purpose of implant insertion. RESULTS: 311 procedures in 211 patients were included. The implant osseointegration rate was around 95%. Clinical follow-up ranged from 10 months to 11 years. A secondary procedure was performed in 6.1% of cases and we noted no serious complications at the harvest site. DISCUSSION: With good revascularization and osseointegration of the graft, the use of parietal bone leads to an implant success rate similar to that seen in the literature. Moreover, the use of this material results in few infections and low bone resorption provided there is strict immobilization of the graft and no tension on the soft tissue sutures. CONCLUSION: Parietal bone grafts technique possess the required qualities for the success of implant surgery, offering results at least as interesting as others using autogenous bone and with no serious complications on donor site.