Evaluating the reproducibility and validity of maximal mouth opening measurement techniques.

OBJECTIVES: A limitation of the maximal mouth opening (MMO) is a frequent complication of oral (cancer) surgery. The measurement between the right central incisors is considered the golden standard for assessing MMO, although it has been noted to overestimate MMO in edentulous patients. This study aims to evaluate the reproducibility and validity of four MMO techniques and to determine the extent to which they are dependent on the remaining dentition. MATERIALS AND METHODS: Four methods for capturing the MMO were recorded in consecutive patients with mixed dentition. The degree of agreement between the different measurement methods was compared using Bland-Altman plots. To investigate the reproducibility of each method, intersession, interobserver and intraobserver reliability were calculated for measurements performed by two clinicians across two sessions. Two subgroups were created based on dentition: (A) cases missing at least one right central incisor, and (B) patients with both right central incisors present. RESULTS: All but one intraclass correlation coefficient (ICC) demonstrated excellent reproducibility (ICC > .9). The highest ICC values were found for the intraoral MMO(iMMO) and corrected intraoral MMO(ciMMO) method. A significant relationship between the MMO in both subgroups was identified only for the intraoral Range of Motion (iROM) method (p=.010*). CONCLUSION: The findings suggest that the current golden standard for measuring MMO does not adequately account for the absence of the right central incisor(s). Two of the proposed methods, which include corrections for missing incisors, should be incorporated into future clinical trials on MMO.

Surgical management of a temporal meningoencephalocele with a patient-specific combined craniofossa prosthesis: illustrative case.

BACKGROUND: Meningoencephaloceles can originate through any defect in the cranial bones, including the skull base. They can be completely asymptomatic or present with typical symptoms such as headaches, seizures, or meningitis. OBSERVATIONS: The authors present the case of a 54-year-old female who presented with right-sided ear and temporomandibular joint (TMJ) pain. Computed tomography showed a large lytic lesion of the squamous part of the temporal bone with cortical bone destruction, extending to the mandibular fossa. Magnetic resonance imaging demonstrated a temporal bone meningoencephalocele. The patient underwent resection, dural repair, and multilayer reconstruction with a patient-specific three-dimensional-printed titanium combined craniofossa prosthesis. LESSONS: To the authors' knowledge, this is the first case report of TMJ pain associated with a temporal meningoencephalocele. The exact location and extension of the lesion determine the surgical approach and need for reconstruction in temporal bone meningoencephaloceles. In cases of destruction of the mandibular fossa, a patient-specific combined craniofossa prosthesis is recommended to reconstruct the bone defect. https://thejns.org/doi/10.3171/CASE24132.

Virtual reconstruction of orbital defects using Gaussian process morphable models.

PURPOSE: The conventional method to reconstruct the bone level for orbital defects, which is based on mirroring and manual adaptation, is time-consuming and the accuracy highly depends on the expertise of the clinical engineer. The aim of this study is to propose and evaluate an automated reconstruction method utilizing a Gaussian process morphable model (GPMM). METHODS: Sixty-five Computed Tomography (CT) scans of healthy midfaces were used to create a GPMM that can model shape variations of the orbital region. Parameter optimization was performed by evaluating several quantitative metrics inspired on the shape modeling literature, e.g. generalization and specificity. The reconstruction error was estimated by reconstructing artificial defects created in orbits from fifteen CT scans that were not included in the GPMM. The developed algorithms utilize the existing framework of Gaussian process morphable models, as implemented in the Scalismo software. RESULTS: By evaluating the proposed quality metrics, adequate parameters are chosen for non-rigid registration and reconstruction. The resulting median reconstruction error using the GPMM was lower (0.35 ± 0.16 mm) compared to the mirroring method (0.52 ± 0.18 mm). In addition, the GPMM-based reconstruction is automated and can be applied to large bilateral defects with a median reconstruction error of 0.39 ± 0.11 mm. CONCLUSION: The GPMM-based reconstruction proves to be less time-consuming and more accurate than reconstruction by mirroring. Further validation through clinical studies on patients with orbital defects is warranted. Nevertheless, the results underscore the potential of GPMM-based reconstruction as a promising alternative for designing patient-specific implants.

Bridging the knowledge-Practice gap: Insights from a survey of Belgian dental professionals on diagnosis and supportive oral cancer treatment in comparison with international guidelines.

OBJECTIVE: Early detection significantly improves the prognosis of oral cancer patients, contingent upon the knowledge of dental professionals. This study aimed to assess and compare the knowledge, practices and perceptions regarding oral cancer among dental professionals in Belgium. MATERIALS AND METHODS: A cross-sectional survey was distributed via Qualtrics to general dentists, dental specialists, dental hygienists, and oral and maxillofacial surgeons. The self-administered questionnaire comprised three sections: demographics (4 questions), knowledge (9 questions) and clinical practices (19 questions) related to oral cancer detection and treatment. Descriptive statistics were employed for data analysis, with Chi-square tests assessing responses by specialization, gender, years of experience and number of oral cancer patients treated. RESULTS: A total of 262 questionnaires were completed, with the majority of respondents being general dentists (61%) followed by dental specialists (25%), oral hygienists (8%) and oral and maxillofacial surgeons (6%). 70% of the respondents reported treating fewer than four oral cancer patients throughout their careers. 5 out of the 9 knowledge questions achieved over 50% correct responses, with an average correct answer rate of 54%. Oral and maxillofacial surgeons and dental professionals who have treated more than four oral cancer patients, demonstrated significantly higher scores on multiple knowledge questions. Responses to clinically oriented questions showed less diversity across professions, and generally aligning with guidelines from professional oncological societies. CONCLUSION: This survey highlights the need for enhanced education on oral cancer among Belgian dental professionals. Knowledge levels were notably higher among more experienced respondents. The development and implementation of comprehensive guidelines tailored to dentists and oral hygienists for oral cancer prevention and patient care are warranted to optimize clinical practice standards.

CD4+ T cell activation distinguishes response to anti-PD-L1+anti-CTLA4 therapy from anti-PD-L1 monotherapy.

Cancer patients often receive a combination of antibodies targeting programmed death-ligand 1 (PD-L1) and cytotoxic T lymphocyte antigen-4 (CTLA4). We conducted a window-of-opportunity study in head and neck squamous cell carcinoma (HNSCC) to examine the contribution of anti-CTLA4 to anti-PD-L1 therapy. Single-cell profiling of on- versus pre-treatment biopsies identified T cell expansion as an early response marker. In tumors, anti-PD-L1 triggered the expansion of mostly CD8+ T cells, whereas combination therapy expanded both CD4+ and CD8+ T cells. Such CD4+ T cells exhibited an activated T helper 1 (Th1) phenotype. CD4+ and CD8+ T cells co-localized with and were surrounded by dendritic cells expressing T cell homing factors or antibody-producing plasma cells. T cell receptor tracing suggests that anti-CTLA4, but not anti-PD-L1, triggers the trafficking of CD4+ naive/central-memory T cells from tumor-draining lymph nodes (tdLNs), via blood, to the tumor wherein T cells acquire a Th1 phenotype. Thus, CD4+ T cell activation and recruitment from tdLNs are hallmarks of early response to anti-PD-L1 plus anti-CTLA4 in HNSCC.

OrthoCalc: The six degrees of freedom measurement workflow of rotational and displacement changes for maxilla positioning evaluation.

BACKGROUND: This study is undertaken to establish the accuracy and reliability of OrthoCalc, a 3D application designed for the evaluation of maxillary positioning. METHODS: We registered target virtual planned models, maxillary models from pre-operative and post-operative CT scans, and post-operative intra-oral scans to a common reference system, allowing for digital evaluation. To assess rotational changes, we introduced a novel measurement method based on virtual cuboid models. Displacement errors were calculated based on proposed registration matrices. We also compared OrthoCalc to established commercial medical software as a benchmark. RESULTS: Statistical significance calculated showed no significant differences between OrthoCalc and commercial software. the biggest error of 0.04 degree in rotation change was found in the yaw. A maximum displacement change of 0.75 mm was found in the X direction. CONCLUSIONS: Our study validates OrthoCalc as a precise and reliable tool for assessing maxillary position changes with six degrees of freedom in orthognathic surgery, endorsing its clinical utility.

Exploring long-term responses to immune checkpoint inhibitors in recurrent and metastatic head and neck squamous cell carcinoma.

OBJECTIVES: Immune checkpoint inhibitors (ICI) have introduced a new era in the treatment of recurrent and/or metastatic head and neck squamous cell carcinoma (R/M HNSCC). Optimal duration for ICI therapy is still unclear and the long-term outcomes and toxicity in patients responding to these therapies warrant further exploration. This study attempts to identify the clinical and biological determinants of a durable response and evaluate outcomes following ICI treatment discontinuation. MATERIALS AND METHODS: A retrospective review of 181 patients treated with ICI for R/M HNSCC was conducted. Long-term responders were defined as patients who sustained disease control at least two years after initiating ICI therapy. We compared clinical and biological characteristics associated with these long-term responders against the broader treatment population. RESULTS: 10 % of R/M HNSCC patients treated with ICIs demonstrated a durable long-term response. Only three relapses (16 %) occurred after discontinuing ICI treatment in this subset, with a median follow-up of 52 months. Upon retreatment with ICI, two attained a documented response. Extended ICI response was observed even with < 2 years of treatment. 74 % of long-term responders experienced immune-related adverse events (irAEs), 37 % of which severe irAEs. Hypothyroidism was the most frequently reported irAEs. The predictive potential of systemic inflammation indices for clinical response appears to be limited. CONCLUSIONS: ICI present an optimistic avenue for HNSCC patients, offering substantial long-term responses. The study suggests that a two-year treatment could be optimal and irAEs, although common, are typically mild.

Accuracy of surgical navigation for patient-specific reconstructions of orbital fractures: A systematic review and meta-analysis.

OBJECTIVE: This systematic review and meta-analysis aimed to review the recent literature on the technical accuracy of surgical navigation for patient-specific reconstruction of orbital fractures using a patient-specific implant, and to compare surgical navigation with conventional techniques. MATERIALS AND METHODS: A systematic literature search was conducted in PubMed (Medline), Embase, Web of Science, and Cochrane (Core Collection) databases on May 16, 2023. Literature comparing surgical navigation with a conventional method using postoperative three-dimensional computed tomography imaging was collected. Only articles that studied at least one of the following outcomes were included: technical accuracy (angular accuracy, linear accuracy, volumetric accuracy, and degree of enophthalmos), preoperative and perioperative times, need for revision, complications, and total cost of the intervention. MINORS criteria were used to evaluate the quality of the articles. RESULTS: After screening 3733 articles, 696 patients from 27 studies were included. A meta-analysis was conducted to evaluate volumetric accuracy and revision rates. Meta-analysis proved a significant better volumetric accuracy (0.93 cm3 ± 0.47 cm3) when surgical navigation was used compared with conventional surgery (2.17 cm3 ± 1.35 cm3). No meta-analysis of linear accuracy, angular accuracy, or enophthalmos was possible due to methodological heterogeneity. Surgical navigation had a revision rate of 4.9%, which was significantly lower than that of the conventional surgery (17%). Costs were increased when surgical navigation was used. CONCLUSION: Studies with higher MINORS scores demonstrated enhanced volumetric precision compared with traditional approaches. Surgical navigation has proven effective in reducing revision rates compared to conventional approaches, despite increased costs.

A 16-year retrospective study of vascular anomalies in the head and neck region.

Depending on the diagnostic modality, the classification of vascular anomalies varies and so does the nomenclature. The 'International Society for the Study of Vascular Anomalies' (ISSVA) is the most widely accepted classification in the literature and is mainly based on the radiologic and clinical presentation. The aim of this article is to review the clinical practice of diagnosis and treatment of vascular anomalies in the head and neck region in a university hospital, with special focus on the nomenclature. All patients with a vascular anomaly presenting to the department of oral and maxillofacial surgery were reviewed in a retrospective manner. Nomenclature, diagnostic process, lesion characteristics, treatment and outcome were examined. The lesions were (re)classified according to the ISSVA classification. A total of 185 patients were identified, of which 12.4% (n = 23) had a congenital anomaly. After reclassification, the most common lesions were venous malformations (n = 47, 25.4%), followed by lobular capillary hemangiomas (n = 17, 9.2%). A group of 39 anomalies could not be further specified. One hundred and one patients (54,6%) received treatment, of which 93 were treated surgically (92,1% of treated patients). Endovascular treatment was considered in 41 patients but applied in only eight. This strict selection led to a low a complication rate. We provide an overview of the clinical practice in the management of vascular anomalies in a university hospital. The histology report is a source of miscommunication because clinicians use the ISSVA classification, while pathologists use the WHO classification. Every professional involved should be aware of the differences in classification and nomenclature.

Maxillomandibular Reconstruction Using Insourced Virtual Surgical Planning and Homemade CAD/CAM: A Single-Center Evolution in 75 Patients.

BACKGROUND: Virtual surgical planning (VSP) and computer-aided design and manufacturing (CAD/CAM) of surgical guides and jigs have dramatically changed the predictability of bony reconstruction of the jaw. VSP craftsmanship can lead to precision and enables the surgeon to complement the donor bone osteotomies with bony resection of the jaw. In recent years, immediate dental rehabilitation has become an integral part of VSP. However, outsourced CAD/CAM technology is expensive and may not be an option for many institutions worldwide. METHODS: The authors present here a consecutive series of 75 maxillofacial reconstructions from 2015 to 2020. We established an insourced "in-house" protocol for VSP and "home-made" CAD/CAM for the reconstruction of maxilla-mandibular defects with fibula, iliac crest, and scapular angle flaps. All patient files were analyzed retrospectively, and relevant parameters influencing the reconstructive outcome were determined. RESULTS: The authors went from a fibula-based protocol toward the selection of optimal vascularized bone for immediate placement of osteointegrated implants. Bone flap survival was 94.7% after 4 months. The 3-year patient survival is 77.6%. The authors show the multiple steps required for the routine use of in-house CAD/CAM and report the related financial balance. CONCLUSIONS: Insourced VSP and CAD/CAM has evolved into a valuable strategy in maxillomandibular reconstruction that promotes accuracy and precision and allows for occlusion-based planning with quality-of-life and aesthetic outcomes as essential parts of the reconstruction even in high-level oral cancers. Further reductions in the hardware and software acquisition costs may lead to widespread implementation of this innovative technology. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.