Mathieu Gass

Dr. Mathieu Gass

orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 July 2019 in Journal of Cranio-Maxillofacial Surgery
Verified
Journal Article
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MFMarc Anton Fuessinger
Marc Anton Fuessinger
SSSteffen Schwarz
Steffen Schwarz
JNJoerg Neubauer
Joerg Neubauer
CCCarl-Peter Cornelius
Carl-Peter Cornelius
MGMathieu Gass
Mathieu Gass
SSStefan Schlager
Stefan Schlager

17 October 2021 in Journal of Anatomy
Verified
Journal Article
Open access
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MGMathieu Gass
Mathieu Gass
MFMarc Anton Fuessinger
Marc Anton Fuessinger
MMMarc Metzger
Marc Metzger
SSSteffen Schwarz
Steffen Schwarz
JBJohannes Daniel Bähr
Johannes Daniel Bähr
SSStefan Schlager
Stefan Schlager
Purpose: The current standard in reconstructing defects of the orbital floor, by using the concept of mirroring, is time‐consuming and ignores the natural asymmetry of the skull. By using a statistical shape model (SSM), the reconstruction can be automatized and improved in accuracy. The present study aims to show the possibilities of the virtual reconstruction of artificial defects of the orbital floor using an SSM and its potentials for clinical implementation.Methods: Based on 131 unaffected CT scans of the midface, an SSM was created which contained the shape variability of the orbital floor. Nineteen midface CT scans, that were not included in the SSM, were manually segmented to establish ground truth (control group). Then artificial defects of larger and smaller sizes were created and reconstructed using SSM (Group I) and the gold standard of mirroring (Group II). Eventually, a comparison to the surface of the manual segmentation (control group) was performed.Results: The proposed method of reconstruction using an SSM leads to more precise reconstruction results, compared with the conventional method of mirroring. Whereas mirroring led to the reconstruction errors of 0.7 mm for small defects and 0.73 mm for large defects, reconstruction using SSM led to deviations of 0.26 mm (small defect) and, respectively, 0.34 mm (large defect).Conclusions: The presented approach is an effective and accurate method for reconstructing the orbital floor. In connection with modern computer‐aided design and manufacturing, individual patient‐specific implants could be produced according to SSM‐based reconstructions and could replace current methods using manual bending techniques. By acknowledging the natural asymmetry of the human skull, the SSM‐based approach achieves higher accuracy in reconstructing injured orbits.

20 October 2021 in Head & Face Medicine
Verified
Journal Article
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MFMarc Anton Fuessinger
Marc Anton Fuessinger
SSSteffen Schwarz
Steffen Schwarz
MGMathieu Gass
Mathieu Gass
PPPhilipp Poxleitner
Philipp Poxleitner
LBLeonard Simon Brandenburg
Leonard Simon Brandenburg
MMMarc Metzger
Marc Metzger
Background: Complex bilateral midface fractures necessitate a surgically challenging procedure to preserve or restore the occlusion and the sensitive eye area. In this case control study, we aim to show the potential of a statistical shape model (SSM) for measuring the quality of the midface reconstruction, compared to the estimated preoperative situation. Methods: An individualized SSM was postoperatively registered on 19 reconstructed complex bilateral midface fractures. Using this SSM, the distances from the simulated preoperative situation to the postoperative positions of the fracture segments were calculated. The fracture lines for Le Fort II, Le Fort III, and NOE fractures were chosen as reference points for the distance measurements. Results: The SSM could be registered on all 19 complex bilateral midface fractures. All analyzed fractures showed a dorsal impaction (negative values) of the midface. Le Fort II fractures showed deviation values of –0.98 ± 4.6 mm, Le Fort III fractures showed values of –3.68 ± 3.6 mm, NOE type 2 fractures showed values of –0.25 ± 4.6 mm, and NOE type 1 fractures showed values of –0.25 ± 4.6 mm. Conclusions: The SSM can be used to measure the quality of the achieved reduction of complex bilateral midface fractures based on the estimated preoperative situation. Trial registration: DRKS00009719.

20 December 2021 in Journal of Clinical Medicine
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Journal Article
Open access
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MFMarc Anton Fuessinger
Marc Anton Fuessinger
MGMathieu Gass
Mathieu Gass
CWCaroline Wölm
Caroline Wölm
CCCarl-Peter Cornelius
Carl-Peter Cornelius
RZRuediger M. Zimmerer
Ruediger M. Zimmerer
MMMarc Metzger
Marc Metzger
Purpose: The known preformed osteosynthesis plates for the midface are helpful tools for a precise and fast fixation of repositioned fractures. The purpose of the current study is to analyze the precision of newly developed prototypes of preformed osteosynthesis plates for the mandible. Methods: Four newly designed preformed osteosynthesis plates, generated by a statistical shape model based on 115 CT scans, were virtually analyzed. The used plates were designed for symphyseal, parasymphyseal, angle, and condyle fractures. Each type of plate has three different sizes. For analysis, the shortest distance between the plate and the bone surface was measured, and the sum of the plate-to-bone distances over the whole surface was calculated. Results: A distance between plate and bone of less than 1.5 mm was defined as sufficient fitting. The plate for symphyseal fractures showed good fitting in 90% of the cases for size M, and in 84% for size L. For parasymphyseal fractures, size S fits in 80%, size M in 68%, and size L in 65% of the cases. Angle fractures with their specific plate show good fitting for size S in 53%, size M in 60%, and size L in 47%. The preformed plate for the condyle part fits for size S in 75%, for size M in 85%, and for size L in 74% of the cases. Conclusion: The newly developed mandible plates show sufficient clinical fitting to ensure adequate fracture reduction and fixation.

Verified
Journal Article
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CSChristian Ingo Schwer
Christian Ingo Schwer
TRTeresa Roth
Teresa Roth
MGMathieu Gass
Mathieu Gass
RRRené Marcel Rothweiler
René Marcel Rothweiler
TLTorsten Loop
Torsten Loop
JKJohannes Kalbhenn
Johannes Kalbhenn
Background: Bimaxillary orthognathic surgery bears the risk of severe postoperative airway complications. There are no clear recommendations for immediate postoperative follow-up and monitoring. Objective: to identify potential risk factors for prolonged mechanical ventilation and delayed extubation in patients undergoing bimaxillary orthognathic surgery. Methods: The data of all consecutive patients undergoing bimaxillary surgery between May 2012 and October 2019 were analyzed in a single-center retrospective cohort study. The clinical data were evaluated regarding baseline characteristics and potential factors linked with delayed extubation. Results: A total of 195 patients were included; 54.9% were female, and the median age was 23 years (IQR 5). The median body mass index was 23.1 (IQR 8). Nine patients (4.6%) were of American Society of Anesthesiologists Physical Status Classification System III or higher. The median duration of mechanical ventilation in the intensive care unit was 280 min (IQR, 526 min). Multivariable analysis revealed that premedication with benzodiazepines (odds ratio (OR) 2.60, 95% confidence interval (0.99; 6.81)), the male sex (OR 2.43, 95% confidence interval (1.10; 5.36)), and the duration of surgery (OR 1.54, 95% confidence interval (1.07; 2.23)) were associated with prolonged mechanical ventilation. By contrast, total intravenous anesthesia was associated with shorter ventilation time (OR 0.19, 95% confidence interval (0.09; 0.43)). Conclusion: premedication with benzodiazepines, the male sex, and the duration of surgery might be considered to be independent risk factors for delayed extubation in patients undergoing bimaxillary surgery.

28 May 2025 in Diagnostics
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Journal Article
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Ioanna KalaitsidouIoanna Kalaitsidou
Ioanna Kalaitsidou
MGMathieu Gass
Mathieu Gass
Dimitris TatsisDimitris Tatsis
Dimitris Tatsis
SKSherin Khalil
Sherin Khalil
CSChristian Schedeit
Christian Schedeit
BSBenoit Schaller
Benoit Schaller
Background: Trismus, or restricted mouth opening, can present significant challenges in oral and maxillofacial surgery and trigger substantial functional and psychosocial disabilities. Intra-articular causes, such as temporomandibular joint ankylosis and arthritis, are thoroughly described; however, extra-articular pathologies like neoplastic, traumatic, infectious, and fibrotic conditions of adjacent soft and hard tissues are less frequently reported and present distinct diagnostic complexities and therapeutic hurdles. This retrospective study aims to investigate the difficulties encountered in diagnosis and surgical interventions associated with rare extra-articular causes of trismus. Material and Methods: This article describes five rare causes of extra-articular trismus. The cases range from benign pathologies like coronoid hyperplasia and osteomas to more complex diagnoses of myositis ossificans, external auditory canal abscess, and chronic osteomyelitis. A thorough diagnostic workup was performed for each patient, and specific surgical interventions were administered based on their pathology. Results: All five patients showed significant improvements in mouth opening after surgery. Diagnostic accuracy was ensured with advanced imaging modalities and innovative surgical techniques, and adequate postoperative care translated the favorable outcome. Conclusions: Although based on individual case descriptions, this study emphasizes the potential importance of early diagnosis, a multidisciplinary approach, and individualized treatment planning in managing rare extra-articular causes of trismus. These cases suggest a basis for a more organized system for the timely identification and treatment of such conditions. Additional research is needed to improve diagnostic accuracy, optimize surgical management, and develop evidence-based aftercare treatment to improve patient care and quality of life.