Prognostic Factors of Mandibular Osteoradionecrosis Including Accurate Colocalization of Avulsions and Dosimetric Dental Mapping Software, a Case-control Study.

PURPOSE: Osteoradionecrosis (ORN) of the mandible remains a significant complication in the intensity modulated radiation therapy (IMRT) era. Dental dose cannot be predicted from heterogeneous IMRT dose distributions; mandibular dose metrics cannot guide dentist avulsion decisions in high-risk ORN situations. Using a mapping tool to report dental root dose, avulsions, and ORN sites, we re-examined ORN risk factors in a case-control study. METHODS AND MATERIALS: From 2008 to 2019, 897 consecutive patients with oral cavity/oropharynx or unknown primary cancer undergoing IMRT were analyzed to identify ORN cases. These were matched (1 ORN/2 controls) retrospectively for tumor location, surgery, and tobacco consumption in a monocentric case-control study. Univariate and multivariate analyses integrated ORN factors and accurate dental dose data (grouped into 4 mandibular sectors). Generalizability was investigated in a simulated population database. RESULTS: A total of 171 patients were included. The median follow-up was 5.2 and 4.5 years in the ORN and control groups, respectively. The median time to ORN was 12 months. In univariate analysis, post-IMRT avulsions at the ORN site (hazard ratio [HR] = 3.6; 95% confidence interval [CI] = 1.5-8.9; P = .005), tumor laterality (HR, 4.4; 95% CI, = 1.4-14, P = .01), mean mandibular dose (HR, 1.1; 95% CI, = 1.01-1.1; P = .018) and mean dose to the ORN site (HR, 1.1; 95% CI, = 1.1-1.2; P < .001) correlated with higher ORN risk. In multivariate analysis, mean dose to the ORN site (HR, 1.1; 95% CI, = 1.1-1.2; P < .001) and post-IMRT avulsions at the ORN site (HR, 4.6; 95% CI, = 1.5-14.7; P = .009) were associated with ORN. For each increase in gray in dental dose, the ORN risk increased by 12%. Simulations confirmed study observations. CONCLUSIONS: Dental dose and avulsions are associated with ORN, with a 12% increase in risk with each additional gray. Accurate dose information can help dentists in their decisions after IMRT.

Prosthetic rehabilitation in patients with jaw reconstruction by fibula free flap: A systematic review.

This systematic review aimed to evaluate the dental prosthetic rehabilitation (DPR) in patients after jaw reconstruction with fibula free flap. Four databases were searched from January 2000 to January 2023. Of the 2507 studies identified, 36 observational studies were included. Cancer was the most common surgical indications for jawbone resection with 58.3 % of cases followed by benign tumours which representing 24 %. The DPR rate was estimated at 51.6 % across the studies (ranging from 38 % to 55 % depending on the benign or malignant nature of the tumors). Implant-supported prostheses represented 58.9 % of cases of which 66.9 % were fixed and 33.1 % were implant-stabilized overdentures. Virtual surgical planning (VSP) was used in 20 % of studies and aimed to improve the position of the grafted fibula, quality, and aesthetics of DPR and to decrease ischemia and the operating time. One in two authors performed DPR 12 months after jaw reconstruction. If implant survival rate reached 93 % in non-irradiated fibula, it fell to 38 %, 55 %, and 77 % if implantation occurred in the 12, 17, and 24 months after radiotherapy, respectively. Various parameters should be better investigated in further studies including the typology of the prostheses (implant-supported vs removable), the use of VSP, and the optimal time for DPR taking into account the characteristics of the tumor, the size of bone defect, and the need for external irradiation therapy.

Long-term vertical stability of horseshoe osteotomy for the correction of large vertical excess of the maxilla, a retrospective assessment in 15 patients.

INTRODUCTION: Vertical stability after a Le Fort I (LF1) osteotomy with substantial upward movement can be compromised by the position and the volume of the inferior turbinate. A horseshoe (HS) osteotomy represents then an alternative as it preserves the hard palate and the intranasal volume. The aim of this study was to assess the vertical stability of the maxilla after HS osteotomy. MATERIALS AND METHODS: Patients who underwent a HS osteotomy for the correction of long-face syndrome were retrospectively analyzed. The vertical stability was assessed on lateral cephalograms performed preoperatively (T0), immediately postoperatively (T1), and at the last follow-up (T2) by studying points C (the distal cusp of the first maxillary molar), point P (the prosthion, the lowest edge of the maxillary alveolus of the central incisor), and point I (the upper central incisor edge) in a coordinate system. Postoperative complications and aesthetics of the smile were also investigated. RESULTS: Fifteen patients were included (7 females, 8 males, mean age 25.5 ± 9.8 yeras). The mean impaction ranged from 5 mm on point P to 6.1 mm on point C, with a maximal movement of 9.5 mm. A non-significant relapse of 0.8 ± 1.7, 0.6 ± 0.8, and 0.5 ± 1.8 mm was observed after a mean 20.7 months on point C, P, and I respectively. Smile parameters were significantly improved by the procedure, mainly regarding the correction of the gum smile. CONCLUSION: HS osteotomy represents a good alternative to total LF1 osteotomy for substantial maxillary upward movement in long face syndrome deformities.

Reconstruction techniques of the orbit after Brown class III maxillectomy: A systematic review.

This systematic review aimed to evaluate the surgical techniques used for orbital floor reconstruction after Brown class III maxillectomy for cancer. Three databases were searched from January 1990 to January 2022. Of the 614 studies identified, 20 were retained after eligibility assessment. The surgical techniques were classified into four groups: free bone flaps (A), alloplastic implants (B), bone grafts (C), and soft-tissue reconstructions (D). Ectropion and diplopia concerned 42.6% and 6.6% of the patients, respectively. Soft tissue reconstruction was more likely to cause ectropion (17/27), followed by the reconstruction techniques of group B (34/79), group C (26/70), and group A (1/7). Postoperative enophthalmos was identified in 18 patients (9.6%), mostly in group D (5/35), followed by groups B (8/68), A (3/33), and C (2/52). Free bone flaps and alloplastic implants represent good reconstructive options in terms of postoperative ocular parameters.

A case report of condyle metastasis and a review of the literature.

Metastasis of the oral cavity is a rare condition and should be investigated for a primary tumor in the lungs, breast, kidney and prostate. Involvement of the mandibular condyle frequently mimics TMJ dysfunction with pain, swelling and limitation of mouth opening. We report the case of atypic TMJ dislocation as an inaugural sign of condyle metastasis. We also discuss the diagnostic approach by a brief review of the literature.

Donor site sequelae and patient satisfaction after head and neck reconstruction with a radial forearm free flap.

PURPOSE: Radial forearm free flap (RFFF) being a workhorse flap in head and neck reconstruction, we investigated its donor site delayed consequences. METHODS: Multicentric case series evaluating 189 patients who underwent RFFF for carcinologic reasons at least 6 months before. Patients and surgeon's appreciation regarding the aesthetic and functional consequences of the flap harvest on their daily life were evaluated by questionnaires using likert scales. Medical data were collected from patients' charts retrospectively. RESULTS: Thirty percent of patients had at least one sequelae. Experiencing a graft necrosis did not worsen long-term results. Cosmetic satisfaction was significantly worst for women, according to patients' and surgeons' opinion. For 81% and 92% patients, respectively, the flap harvest had no impact on daily life nor sport practice. Ratio between the benefits of reconstruction and the sequelae at the donor site was judged "excellent" for 77% patients. CONCLUSIONS: Although objectively important, RFFF morbidity has little impact in head and neck cancer patient's life.

Postimplantation radiation therapy in head and neck cancer patients: Literature review.

There is no recommendation regarding the timing for implant surgery in patients with head and neck cancer (HNC) who require postoperative radiation therapy (RT). This systematic review focused on the literature about the outcomes of implants placed during ablative surgery in patients with HNC who underwent postoperative RT. Implants placed after radiation therapy and implants placed in reconstructed jaws were excluded. Four comparative studies involving 755 native mandible primary implants were analyzed. The survival rate with postimplantation RT was 89.6% vs 98.6% in patients with no additional radiation. The overall success of implant-retained overdenture in patients with RT performed postimplantation was 67.4% vs 93.1% in patients with implant surgery that was carried out 1 year after the completion of radiation therapy. Only five cases of osteoradionecrosis (ORN) of the jaw were reported. The outcomes for implant survival rates appear to be positive for irradiated implants.

Intraoperative imaging and navigation with mobile cone-beam CT in maxillofacial surgery.

INTRODUCTION: Intraoperative mobile Cone-Beam Computed Tomography (CBCT) trends to develop for the management of complex facial fractures. It allows a real-time imaging and surgical navigation. AIM: Through the presentation of two clinical cases, we aimed at presenting the procedure of intra-operative CBCT and new applications in maxillofacial surgery. RESULTS: A young patient with extended orbito-frontal fibrous dysplasia, and a child with the recurrence of a temporomandibular joint ankylosis secondary to mastoïditis, were operated using a intra-operative imaging control. In both cases, the intraoperative CBCT increased precision and safety of the bone resection. No surgical complication was noted and a good healing was obtained. CONCLUSION: Intraoperative CBCT raises the problems of radiation exposure and increased operating time. However, it represents a useful imaging tool and a navigation system in complex situations as osseous dysplasia and surgery of the temporo-mandibular joint.

Jaw osteosarcoma models in mice: first description.

BACKGROUND: Osteosarcoma (OS) is the most common cancer of bone. Jaw osteosarcoma (JOS) is rare and it differs from other OS in terms of the time of occurrence (two decades later) and better survival. The aim of our work was to develop and characterize specific mouse models of JOS. METHODS: Syngenic and xenogenic models of JOS were developed in mice using mouse (MOS-J) and human (HOS1544) osteosarcoma cell lines, respectively. An orthotopic patient-derived xenograft model (PDX) was also developed from a mandibular biopsy. These models were characterized at the histological and micro-CT imaging levels, as well as in terms of tumor growth and metastatic spread. RESULTS: Homogeneous tumor growth was observed in both the HOS1544 and the MOS-J JOS models by injection of 0.25 × 106 and 0.50 × 106 tumor cells, respectively, at perimandibular sites. Histological characterization of the tumors revealed features consistent with high grade conventional osteosarcoma, and the micro-CT analysis revealed both osteogenic and osteolytic lesions. Early metastasis was encountered at day 14 in the xenogenic model, while there were no metastatic lesions in the syngenic model and in the PDX models. CONCLUSION: We describe the first animal model of JOS and its potential use for therapeutic applications. This model needs to be compared with the usual long-bone osteosarcoma models to investigate potential differences in the bone microenvironment.

Postoperative morbidity of free flaps in head and neck cancer reconstruction: a report regarding 215 cases.

OBJECTIVES: The aim of this study was to identify the factors responsible for free flap failure, the surgical complications, and the non-oral feeding period in patients treated for an oral squamous cell carcinoma. MATERIALS AND METHODS: This multicentric study included 215 patients treated by tumour resection with immediate free flap reconstruction for an OSCC between 2010 and 2016. All of the patient medical files were reviewed and the data regarding the patient medical history, the tumour-related features, the surgical procedure, and the postoperative recovery were compiled. A statistical analysis with univariate and multivariate logistic regression was carried out. RESULTS: The free flap success rate was 94.4% in our series. A postoperative complication occurred in 101 patients (41%). Minor surgical complications were shown to increase the free flap failure rate (OR 3.32; p = 0.04). A major surgical complication was encountered in 48 patients (22.3%), and these were linked to minor surgical complications (OR 2.89; p = 0.004) and the use of a tracheostomy (OR 5.76, p = 0.002). Conversely, a medical history of high blood pressure had a protective effect (p = 0.04). The non-oral feeding rate at the end of the hospital stay was 28.4%, and it correlated with the tracheostomy (p = 0.002), as well as the major and the minor surgical complications (p = 0.04). CONCLUSION-CLINICAL RELEVANCE: Free flap reconstruction is a safe and reliable technique with head and neck cancer reconstruction. Postoperative care favouring early and safe oral-feeding, and avoiding a tracheostomy can reduce the incidence of surgical complications after OSCC reconstruction.

Efficacy of proportional condylectomy in a treatment protocol for unilateral condylar hyperplasia: A review of 73 cases.

INTRODUCTION: Unilateral condylar hyperplasia (UCH) is characterized by an excessive growth of a mandibular condyle, resulting in facial, and occlusal deformities. Scintigraphic hyperactivity usually triggers the need of condylectomy. Delaire has presented a protocol for the treatment of active or non-active UCH using systematically a proportional condylectomy, which could solve both aetiology and adaptive deformities. The aim of this study was to evaluate this protocol by clinical and radiographical analysis. MATERIALS AND METHODS: Seventy-three patients with UCH were included in this retrospective study, and divided by clinical and cephalometric analysis in vertical, or transversal forms of UCH according to Delaire's classification. All patients were treated with 'proportional condylectomy', any indicated orthognathic procedures, along with maxilla-mandibular elastic therapy, and rehabilitation. Architectural, aesthetical, occlusal, and functional features were evaluated using clinical, cephalometric, and photographic measurements both preoperatively, and at the end of the follow-up. RESULTS: A female predominance was observed (65.8%). Vertical forms were more represented than transversal forms (61.6% versus 38.4%). There was a significant improvement of the occlusal plane, the posterior vertical excess, the chin deviation and the soft-tissue features (p < 0.0001), regardless of the preoperative scintigraphic activity status (p < 0.0001). The occlusion, and temporo-mandibular joint (TMJ) functions was considered as normal in respectively 72.7%, and 93% of the patients. CONCLUSION: The results of this study have demonstrated that a protocol using a 'proportional condylectomy', any indicated orthognathic techniques, maxilla-mandibular elastic therapy, and rehabilitation, is a reliable option for treating UCH, regardless the activity status of the pathology.

European Maxillofacial Trauma (EURMAT) in children: a multicenter and prospective study.

OBJECTIVE: The aim of this study is to present and discuss the results of a European multicentre prospective study about pediatric maxillofacial trauma epidemiology during a year. STUDY DESIGN: The following data were recorded: gender, age, etiology, site of fracture, date of injury. Of the 3396 patients with maxillofacial fractures admitted within the study period, 114 (3.3%) were children aged 15 years and younger, with a male/female ratio of 2.6:1. Mean age was 10.9 years. Most patients (63%) were aged 11-15 years. RESULTS: The most frequent cause of injury was fall (36 patients). Sport injuries and assaults were almost limited to the oldest group, whereas falls were more uniformly distributed in the 3 groups. The most frequently observed fracture involved the mandible with 47 fractures. In particular, 18 condylar fractures were recorded, followed by 12 body fractures. CONCLUSIONS: Falls can be acknowledged as the most important cause of facial trauma during the first years of life. The high incidence of sport accidents after 10 years may be a reason to increase the use of mouthguards and other protective equipment. Finally, the mandible (and in particular the condyle) was confirmed as the most frequent fracture site.

IL-7 receptor blockade following T cell depletion promotes long-term allograft survival.

T cell depletion is commonly used in organ transplantation for immunosuppression; however, a restoration of T cell homeostasis following depletion leads to increased memory T cells, which may promote transplant rejection. The cytokine IL-7 is important for controlling lymphopoiesis under both normal and lymphopenic conditions. Here, we investigated whether blocking IL-7 signaling with a mAb that targets IL-7 receptor α (IL-7Rα) alone or following T cell depletion confers an advantage for allograft survival in murine transplant models. We found that IL-7R blockade alone induced indefinite pancreatic islet allograft survival if anti-IL-7R treatment was started 3 weeks before graft. IL-7R blockade following anti-CD4- and anti-CD8-mediated T cell depletion markedly prolonged skin allograft survival. Furthermore, IL-7 inhibition in combination with T cell depletion synergized with either CTLA-4Ig administration or suboptimal doses of tacrolimus to induce long-term skin graft acceptance in this stringent transplant model. Together, these therapies inhibited T cell reconstitution, decreased memory T cell numbers, increased the relative frequency of Tregs, and abrogated both cellular and humoral alloimmune responses. Our data suggest that IL-7R blockade following T cell depletion has potential as a robust, immunosuppressive therapy in transplantation.