Tetsuya Yoda

Transverse maxillary deficiency (TMD) often causes severe crowding, posterior molar crossbite, and buccal corridors. In late adolescence, the maxillary midpalatal suture (MPS) forms an interdigitation that prevents MPS expansion by rapid palatal expansion. Surgically assisted rapid maxillary expansion (SARME) is sometimes performed in orthodontic patients beyond late adolescence with skeletal TMD to achieve a favorable maxillary width. In the present case, surgically assisted rapid maxillary expansion (SARME) with posterior alveolar osteotomy was performed to correct the TMD prior to two-jaw surgery. The skeletal open bite and mandibular prognathism were corrected by Le Fort I maxillary osteotomy and sagittal split ramus osteotomy, resulting in improved occlusal relationships and facial profiles. Three-dimensional analysis of dental casts showed selective lateral expansion of the maxillary molar region and an increased and stable palatal cross-sectional area, palatal width, and palatal volume during the retention period.

Introduction: This case report describes the multidisciplinary treatment of a patient with mandibular retrognathia and hyperdivergent skeletal pattern, condylar resorption, and severe obstructive sleep apnea (OSA). Case Presentation: A 42‐year‐old female patient presented with a chief complaint of mandibular retrognathia. The patient had no significant medical history, and her body mass index was 18.8. She had a +9.0 mm overjet and +1.0 mm overbite, and an Angle Class II molar relationship. Cephalometric analysis revealed SNA, SNB, and FMA of 76.0°, 67.5°, and 50.5°, respectively. Computed tomography (CT) images showed severe bilateral mandibular condylar head deformity due to resorption. Polysomnography revealed an apnea–hypopnea index (AHI) of 43.3, leading to a diagnosis of severe OSA. Correspondingly, continuous positive airway pressure (CPAP) therapy was started immediately. Management and Outcomes: After 19 months of preoperative orthodontic treatment with preadjusted edgewise appliances, Le Fort I osteotomy was performed to impact the maxilla by 3.0 mm at the anterior and 4.0 mm at the posterior nasal spine. The mandible was autorotated 8.6° counterclockwise, reducing ANB from +8.5° to +2.0°. A genioplasty was also performed. After 8 months of postoperative orthodontic treatment, the AHI decreased to 2.3, and CPAP therapy was discontinued due to significant improvement in respiratory function. CT images showed an increase in the upper airway volume after orthognathic surgery. No remarkable morphological changes were observed in the mandibular condylar head during orthodontic treatment. Favorable occlusion was maintained with no apparent relapse after 21 months of retention. Discussion: Unlike conventional maxillomandibular advancement for OSA, the surgical method described in this case study combines counterclockwise mandibular rotation and genioplasty to simultaneously improve respiratory function and craniofacial morphology in patients with hyperdivergent and Class II skeletal pattern accompanied by mandibular condylar head deformity.

Limited mouth opening is a characteristic of masticatory muscle tendon-aponeurosis hyperplasia (MMTAH). Although genetic involvement is suspected where familial onset is frequently observed, the genetic background of MMTAH is yet to be elucidated. In this study, we conducted whole genome sequencing of 10 patients with MMTAH and their family members when available. We also conducted RNA sequencing of normal temporal tendon (as disease region) and Achilles tendon (as control region) from commercially available pig samples. We identified 51 genes that had rare variants in patients with MMTAH and were highly expressed in the temporal tendons of pigs. Among the 51 genes, 37 genes have not been reported to be causative for human genetic diseases so far. As an implication of genetic involvement in the pathogenesis of MMTAH, 21 of these 37 genes were identified in two independent families. In particular, PCDH1 and BAIAP3 were identified in one affected individual in a family and consistently segregated in unrelated family, indicating they could be candidate causative genes of MMTAH. Our findings will help elucidate the genetic landscape of MMTAH and provide insights into future possibilities for tendon regeneration treatment.

Polyrotaxane is a supramolecular assembly consisting of multiple cyclic molecules threaded by a linear polymer. One of the unique properties of polyrotaxane is molecular mobility, cyclic molecules moving along the linear polymer. Molecular mobility of polyrotaxane surfaces affects cell spreading, differentiation, and other cell‐related aspects through changing subcellular localization of yes‐associated proteins (YAPs). Subcellular YAP localization is also related to cell senescence derived from oxidative stress, which is known to cause cancer, diabetes, and heart disease. Herein, the effects of polyrotaxane surface molecular mobility on subcellular YAP localization and cell senescence following H₂O₂‐induced oxidative stress are evaluated in human mesenchymal stem cells (HMSCs) cultured on polyrotaxane surfaces with different molecular mobilities. Oxidative stress promotes cytoplasmic YAP localization in HMSCs on high‐mobility polyrotaxane surfaces; however, low‐mobility polyrotaxane surfaces more effectively maintain nuclear YAP localization, exhibiting lower senescence‐associated β‐galactosidase activity and senescence‐related gene expression and DNA damage than that seen with the high‐mobility surfaces. These results suggest that the molecular mobility of polyrotaxane surfaces regulates subcellular YAP localization, thereby protecting HMSCs from oxidative stress‐induced cell senescence. Applying the molecular mobility of polyrotaxane surfaces to implantable scaffolds can provide insights into the prevention and treatment of diseases caused by oxidative stress.

Calcium pyrophosphate dihydrate (CPPD) deposition disease is a benign disorder characterized by acute gouty arthritis-like attacks and first reported by McCarty. CPPD deposition disease rarely occurs in the temporomandibular joint (TMJ), and although confirmation of positive birefringence by polarized light microscopy is important for diagnosis, it is not reliable because other crystals also show birefringence. We reported a case of CPPD deposition disease of the TMJ that was diagnosed by chemical analysis. A 47-year-old man with a chief complaint of persistent pain in the right TMJ and trismus was referred to our department in 2020. Radiographic examination revealed destruction of the head of the mandibular condyle and cranial base with a neoplastic lesion involving calcification tissue. We suspected CPPD deposition disease and performed enucleation of the white, chalky masses. Histopathologically, we confirmed crystal deposition with weak birefringence. SEM/EDS revealed that the light emitting parts of Ca and P corresponded with the bright part of the SEM image. Through X-ray diffraction, almost all peaks were confirmed to be CPPD-derived. Inductively coupled plasma atomic emission spectroscopy revealed a Ca/P ratio of nearly 1. These chemical analyses further support the histological diagnosis of CPPD deposition disease.

Hydrogels are promising materials in tissue engineering scaffolds for healing and regenerating damaged biological tissues. Previously, we developed supramolecular hydrogels using polyrotaxane (PRX), consisting of multiple cyclic molecules threaded by an axis polymer for modulating cellular responses. However, since hydrogels generally have a large amount of water, their adhesion to tissues is extremely weak. Herein, we designed a bilayered hydrogel with a PRX layer and a collagen layer (PRX/collagen hydrogel) to achieve rapid and strong adhesion to the target tissue. The PRX/collagen hydrogel was fabricated by polymerizing PRX crosslinkers in water with placement of a collagen sponge. The differences in components between the PRX and collagen layers were analyzed using Fourier transform infrared spectroscopy (FT-IR). After confirming that the fibroblasts adhered to both layers of the PRX/collagen hydrogels, the hydrogels were implanted subcutaneously in mice. The PRX hydrogel without collagen moved out of its placement site 24 h after implantation, whereas the bilayer hydrogel was perfectly adherent at the site. Together, these findings indicate that the bilayer structure generated using PRX and collagen may be a rational design for performing anisotropic adhesion.