Osteonecrosis of the jaw induced by arsenic trioxide therapy in a leukemia patient: A rare case report and literature review

A patient suffering from acute promyelocytic leukemia (APL) was referred to the dental department before introduction of chemotherapy by all-trans retinoic acid and arsenic trioxide (ATO). A panoramic radiography showed his third upper maxillary left tooth included into the maxillary bone. The patient presented with a febrile episode. Consequently, the infectious gateway was researched. A left maxillary sinus migration of his third upper left tooth together with a bony sequestrum has been observed on a CT-scan. A surgery was then performed to remove the bony sequestrum and the tooth. The first hypothesis of tooth migration could be that the patient had an infection prior to introduction of chemotherapy. However, neither clinical or radiographic signs were observed during the initial check-up. The second hypothesis is that ATO caused osteonecrosis of the jaw (ONJ) induced the formation of a bony sequestrum associated to the tooth migration into the sinus. ONJ could be a potential adverse of ATO chemotherapy.

Morphological validation of a novel bi-material 3D-printed model of temporal bone for middle ear surgery education

Background

A new model of 3D-printed temporal bone with an innovative distinction between soft and hard tissues is described and presented in the present study. An original method is reported to quantify the model's ability to reproduce the complex anatomy of this region.

Methods

A CT-scan of temporal bone was segmented and prepared to obtain 3D files adapted to multi-material printing technique. A final product was obtained with two different resins differentiating hard from soft tissues. The reliability of the anatomy was evaluated by comparing the original CT-scan and the pre-processed files sent to the printer in a first step, and by quantifying the printing technique in a second step. Firstly, we evaluated the segmentation and mesh correction steps by segmenting each anatomical region in the CT-scan by two different other operators without mesh corrections, and by computing distances between the obtained geometries and the pre-processed ones. Secondly, we evaluated the printing technique by comparing the printed geometry imaged using µCT with the pre-processed one.

Results

The evaluation of the segmentation and mesh correction steps revealed that the distance between both geometries was globally less that one millimeter for each anatomical region and close to zero for regions such as temporal bone, semicircular canals or facial nerve. The evaluation of the printing technique revealed mismatches of 0.045±0.424 mm for soft and -0.093±0.240 mm for hard tissues between the initial prepared geometry and the actual printed model.

Conclusions

While other reported models for temporal bone are simpler and have only been validated subjectively, we objectively demonstrated in the present study that our novel artificial bi-material temporal bone is consistent with the anatomy and thus could be considered into ENT surgical education programs. The methodology used in this study is quantitative, inspired by engineer sciences, making it the first of its kind. The validity of the manufacturing process has also been verified and could, therefore, be extended to other specialties, emphasizing the importance of cross-disciplinary collaborations concerning new technologies.