What are the Characteristics of Oral Injuries Caused by Playground Equipment?

PURPOSE: Studies regarding oral injuries from playground equipment in children remain limited. This study aimed to clarify the characteristics of oral injury caused by playground equipment and identify associations with concomitant head injury. METHODS: Children treated between 2011 and 2021 at an oral surgery clinic for oral injuries from playground equipment were retrospectively investigated. The following factors were analyzed: demographic characteristics, mechanism of injury, type of equipment causing the injury, classification of oral injury, and whether the Department of Emergency and Critical Care Medicine was consulted regarding the head injury. The data collected were statistically analyzed using the Fisher-Freeman-Halton test with significance adopted at the 5% level. RESULTS: This study analyzed data from 82 children. Injuries were concentrated in age groups of 2 to 3 years (32.9%), 4 to 5 years (28.0%), and 6 to 7 years (25.6%). Regarding the mechanism of injury, falls were more common (89.0%) than impact/striking (11.0%). The type of equipment most frequently causing injury was slides (29.3%), followed by swings (23.2%) and iron bars (18.3%). Injuries were classified as soft tissue injury alone (56.1%) or tooth injury and/or jaw fracture (43.9%). Consultation with the Department of Emergency and Critical Care Medicine for head injury was uncommon (13.4%), and all consultations for brain injury diagnosed minor injuries. CONCLUSION: Oral injuries caused by playground equipment were frequent between 2 and 7 years old. The most common cause was falls, with most injuries caused by slides, swings, or iron bars. Approximately half of the oral injuries were soft tissue injuries only, while the other half were associated with tooth and/or jaw injuries. Department of Emergency and Critical Care Medicine consultations for head trauma were uncommon and consistently confirmed minor injuries.

Hybrid AI model for estimating the canopy photosynthesis of eggplants.

Modern models for estimating canopy photosynthetic rates (Ac) can be broadly classified into two categories, namely, process-based mechanistic models and artificial intelligence (AI) models, each category having unique strengths (i.e., process-based models have generalizability to a wide range of situations, and AI models can reproduce a complex process using data without prior knowledge about the underlying mechanism). To exploit the strengths of both categories of models, a novel "hybrid" canopy photosynthesis model that combines process-based models with an AI model was proposed. In the proposed hybrid model, process-based models for single-leaf photosynthesis and image analysis first transform raw inputs (environmental data and canopy images) into the single-leaf photosynthetic rate (AL) and effective leaf area index (Lc)), after which AL and Lc are fed into an artificial neural network (ANN) model to predict Ac. The hybrid model successfully predicted the diurnal cycles of Ac of an eggplant canopy even with a small training dataset and successfully reproduced a typical Ac response to changes in the CO2 concentration outside the range of the training data. The proposed hybrid AI model can provide an effective means to estimate Ac in actual crop fields, where obtaining a large amount of training data is difficult.

Immunohistochemical staining patterns of p53 predict the mutational status of TP53 in oral epithelial dysplasia.

Next-generation sequencing of oral squamous cell carcinoma (OSCC) has revealed TP53 as the most frequently mutated gene in OSCC mutually exclusive with human papillomavirus infection. Oral epithelial dysplasia (OED) is defined as a precancerous lesion of OSCC by the current World Health Organization (WHO) classification; therefore, it is assumed that TP53 mutations occur in early precancerous conditions such as OED. Here, we conducted an integrated analysis of TP53, including whole coding sequencing of TP53, FISH analysis of the 17p13.1 locus, and immunohistochemical analysis for p53 (p53-IHC), in 40 OED cases. We detected 20 mutations in 16 (40%) OED cases, and four cases, each harbored two mutations. FISH analysis revealed six of 24 cases (25%) had a deletion on 17p13.1, and four cases had concurrent TP53 mutations and 17p13.1 deletion (2-hit). Also, the increased frequency of TP53 mutations in higher degrees of OED implies acquisition of the mutation is a major event toward OSCC. p53-IHC revealed that overall cases could be categorized into four patterns that correlate well with the mutational status of TP53. Especially, two patterns, broad p53 expression type (pattern HI) and p53 null type (pattern LS), strongly correlated with a missense mutation and nonsense mutation, respectively. Furthermore, seven of the 40 cases progressed to SCC, and six of these seven cases presented pattern HI or LS. Therefore, patterns HI and LS have a high risk for malignant transformation if excisional treatment is not performed irrespective of the dysplasia grade. Although the current WHO classification mainly focuses on morphological criteria for the diagnosis of OED, interobserver discrepancy appears in some instances of the OED diagnosis. Our immunohistochemical analysis supports a more accurate pathological diagnosis for OED in cases of low dysplastic changes or of differential diagnosis with non-dysplastic lesions.

What Are Possible Contributors to Associated Dental Injury in Mandibular Fractures?

PURPOSE: Among previous reports on dental injuries associated with mandibular fractures, there are few investigating the conditions under which dental injuries commonly occur. The aim of this study was to determine specific characteristics of mandibular fractures accompanied by dental injuries. METHODS: This retrospective cohort study included dentate patients with mandibular fractures treated at a tertiary trauma center between 2011 and 2019. The data were analyzed according to 2 outcome variables: patients with additional dental injuries and patients without. The predictor variables were patient age, sex, accident mechanism, number and location of mandibular fractures, and presence of submental lacerations. Odds ratios for the risk factors for dental injury were calculated in conjunction with descriptive statistics. Binary logistic regression analysis was also performed to identify the factors associated with dental injuries as dependent variables. RESULTS: Of 252 patients who had only mandibular fractures, 95 (37.7%) had associated dental injuries. In the group with dental injuries, 55.8% of mandibular fractures were caused by a fall (P = .003). Condyle fractures (77.9%) with dislocation (67.6%) and bilateral involvement (41.9%) were more common than in the group without dental injuries (P < .001). In patients with dental injuries, the incidence of 3 or more fractures (29.5%) was significantly higher than in the group without dental injuries. Dental injuries were more likely to occur in patients with concomitant submental lacerations (confidence interval (CI) 1.135-4.983, P = .02), and the risk of dental injury was significantly lower in the presence of angle fractures (CI 0.113-0.999, P = .045). CONCLUSIONS: A frontal impact involving the anterior part of the mandible is often associated with condyle and multiple mandibular fractures. This seems to be the typical mechanism for concomitant dental injuries. Submental laceration can be considered a prime sign of associated dental injuries.

Accidental oral bleeding in a dementia patient taking anticoagulants: A case report.

INTRODUCTION: Identifying the causes of accidental oral bleeding can be difficult in patients with dementia. The aim of this study was to highlight the effectiveness of multidisciplinary consultation, which proved extremely useful in investigating the cause of bleeding in this case. CASE PRESENTATION: An 86-year-old woman on anticoagulants who had been admitted to a geriatric facility experienced repeated oral bleeding of unknown cause, initially attributed to periodontitis. CONCLUSION: Along with anticoagulant use, a multidisciplinary consultation attributed the bleeding to the use of a spoon at mealtimes and possible scratching at the wound by the patient with her fingers.

Qualification of tumour mutational burden by targeted next-generation sequencing as a biomarker in hepatocellular carcinoma.

BACKGROUND & AIMS: Tumour mutational burden (TMB) predicts improved response and survival to immunotherapy. In this pilot study, we optimized targeted next-generation sequencing (tNGS) to estimate TMB in hepatocellular carcinoma (HCC). METHODS: We sequenced 48 non-paired samples (21 fresh-frozen [FF] and 27 paraffin-embedded [FFPE]), among which 11 FFPE samples were pretreated with uracil-DNA glycosylase (UDG). Thirty samples satisfied post-sequencing quality control. High/low TMB was defined by median number of mutations/Mb (Mut/Mb), across different minimum allele frequency (MAF) thresholds (≥0.05, ≥0.1 and ≥0.2). RESULTS: Eligible patients (n = 29) were cirrhotic (84%) with TNM stage I-II HCC (75%). FFPE samples had higher TMB (median 958.39 vs 2.51 Mut/Mb, P < .0001), estimated deamination counts (median 1335.50 vs 0, P < .0001) and C > T transitions at CpG sites (median 60.3% vs 9.1%, P = .002) compared to FF. UDG-treated samples had lower TMB (median 4019.92 vs 353 Mut/Mb, P = .041) and deamination counts (median 6393.5 vs 328.5, P = .041) vs untreated FFPE. At 0.2 MAF threshold with UDG treatment, median TMB was 5.48 (range 1.68-16.07) and did not correlate with salient pathologic features of HCC, including survival. CONCLUSION: While tNGS on fresh HCC samples appears to be the optimal source of tumour DNA, the low median TMB values observed may limit the role of TMB as a predictor of response to immunotherapy in HCC.

Diverticulum in buccal mucosa: A rare sac-like oral pouch.

OBJECTIVE: This article describes a rare case of oral diverticulum. BACKGROUND: Diverticulum represents a sac-like protrusion of the gastrointestinal tract, commonly arising in the colon wall of elder individuals. Zenker's diverticulum can also occur in the pharyngeal mucosa. However, oral diverticulum appears rare. MATERIAL AND METHOD: The patient was an 88-year-old man with dementia living in a geriatric facility. A dental hygienist incidentally identified a small pouch containing stagnant food residue in the left buccal mucosa during oral hygiene procedures. RESULTS: The small pouch with stagnant food residue was identified as a diverticulum. CONCLUSION: Diverticula may be identified from the stagnation of food residue. Dental specialists who practice oral hygiene should be aware of diverticula as a differential diagnosis.

Effects of loss of consciousness on maxillofacial fractures in simple falls.

BACKGROUND/AIMS: Loss of consciousness while falling is reported to increase the risk of more severe injury. However, few studies of maxillofacial injuries have been reported. The aim of this study was to investigate the effects of loss of consciousness on maxillofacial fractures in falls on a level surface (simple falls). MATERIAL AND METHODS: Patients with maxillofacial fractures caused by simple falls were subdivided into two categories: patients who fell without loss of consciousness and patients who fell with loss of consciousness, according to the Guidelines for the Diagnosis and Management of Syncope (version 2009). The severity of the injuries was compared between these two groups. RESULTS: In 413 patients with maxillofacial fractures, 58 cases were falls without loss of consciousness, and 44 cases were falls with loss of consciousness. In falls with loss of consciousness, 54.5% were reflex syncope, followed by syncope due to orthostatic hypotension (15.9%), epilepsy (15.9%), and cardiac syncope (9.1%). The average number of fracture lines in the mandible was significantly lower in falls without loss of consciousness (1.53 ± 0.7) than in falls with loss of consciousness (2.00 ± 1.00) (P = 0.045). The average Facial Injury Severity Scale score was lower in falls without loss of consciousness (2.24 ± 1.20) than in falls with loss of consciousness (2.68 ± 1.39). Fractures of other parts of the body were significantly more common in falls without loss of consciousness (22.2%) than in falls with loss of consciousness (9.1%) (P = 0.0135). CONCLUSIONS: Patients with loss of consciousness and maxillofacial fractures due to simple falls showed a tendency to sustain more severe maxillofacial injuries than those without loss of consciousness.

Adult-onset Still's disease initially thought to be an odontogenic infection: A case report.

OBJECTIVE: To present a case of Adult-onset Still's disease (AOSD) initially suspected to be odontogenic inflammation. BACKGROUND: Adult-onset Still's disease is a rare, complex autoinflammatory disease and a known cause of fever of unknown origin. MATERIALS AND METHODS: The patient had both a fever and dental pain. Following meticulous examination, the patient was diagnosed with AOSD. CONCLUSION: Clinicians should keep in mind that a patient such as AOSD may visit their clinics.

Oral lacerations during motocross: A case report.

Motocross is a high-risk sport that can cause serious injuries including oral injuries. However, mouthguard use is not mandatory in motocross. This report describes a case of an oral laceration with exposure of bilateral inferior alveolar nerves as a result of a motocross accident in which the patient was not wearing a mouthguard.

Acute exacerbation of chronic disseminated intravascular coagulation associated with thoracoabdominal aortic aneurysm after tooth extraction.

OBJECTIVE: To present a rare case of persistent bleeding from the tooth extraction socket in a patient with chronic disseminated intravascular coagulation (DIC). BACKGROUND: Acute exacerbation of chronic DIC occurs by various trigger factors. CLINICAL REPORT: The patient's chronic DIC in association with thoracoabdominal aortic aneurysm was activated by tooth extraction, resulting in persistent bleeding from the socket. CONCLUSION: Patients with chronic DIC may have persistent bleeding following tooth extraction.

Huntington's disease with severe neck infection.

OBJECTIVE: To present a case of Huntington's disease (HD) with severe neck infection. BACKGROUND: Huntington's disease (HD) is a progressive neurodegenerative genetic disorder and is often accompanied by dysphagia. MATERIALS AND METHODS: The patient was a 64-year-old man with HD. The severe neck infection was considered as one of the symptoms of HD. CONCLUSION: Clinicians should remember that patients with HD are apt to delay dental consultation, resulting in serious oral infections.

Second-generation total synthesis of aplyronine A featuring Ni/Cr-mediated coupling reactions.

Second-generation total synthesis of aplyronine A, a potent antitumor marine macrolide, was achieved using Ni/Cr-mediated coupling reactions as key steps. The overall yield of the second-generation synthetic pathway of aplyronine A was 1.4%, obtained in 38 steps based on the longest linear sequence. Compared to our first-generation synthetic pathway of aplyronine A, the second-generation synthesis greatly improved both the yield and number of steps. In particular, we improved the stereoselectivity in the construction of the C13 stereogenic center and the C14-C15 (E)-trisubstituted double bond using the asymmetric Ni/Cr-mediated coupling reaction. Furthermore, we established efficient reaction conditions for the asymmetric Ni/Cr-mediated coupling reaction between the C21-C28 segment and C29-C34 segment. Thus, this coupling reaction proceeded with an equimolar ratio of each segment.

Do maxillary dentures protect the skull base from penetration injury?

Key Clinical Message: Foreign bodies penetrating from the oral cavity can damage surrounding tissues. This case is considered an extremely rare and fortunate instance in which a maxillary denture appeared to weaken the external force and change the direction of the scissors, preventing damage to vital organs. Abstract: The patient was a 73-year-old man. While on a ladder pruning a plant, he accidentally fell. The gardening scissors passed through the maxillary sinus from the maxillary alveolus and penetrated below the zygomatic arch. At the time of injury, the patient was wearing a metal-frame denture on the maxilla, and contact between the cutting edge and the denture was speculated to have weakened the piercing force of the blade and changed the direction of the cutting edge. This extremely rare case demonstrates how a maxillary denture could reduce the severity of a penetrating injury caused by scissors.

Molar luxations caused by holding water taps. Report of five cases.

Luxation of a primary molar occurs rarely. Here, we describe five cases of primary molar luxation caused by holding a water tap pipe in the mouth during bathing. The patients were aged 16 to 19 months and the mandibular first primary molar was affected in all five cases. The second primary molar had not erupted. It is assumed that the flange of the pipe got stuck in the interdental space between the mandibular primary canine and first primary molar and the affected first molar was pushed out by force with the flange acting as a lever.

Off-stoichiometry and molybdenum substitution effects on elastic moduli of B1-type titanium carbide.

B1-type MX ceramics are composed of transition metals (M) and C, N, and/or O (X) occupying the M and X sites, respectively, and having M-X nearest neighbor (NN) bonds and M-M and X-X next nearest neighbor (NNN) bonds. Substitution of the elements and the formation of structural vacancies in B1-type ceramics change the numbers and strengths of the bonds, leading to novel properties. The change in elastic modulus of off-stoichiometric TiC in equilibrium with a Ti-Mo solid solution phase was experimentally investigated based on the rule of mixtures from the Voigt model. The experimentally obtained values agreed well with the results of density functional theory calculations. The bulk modulus (K) of TiC increased from 205.6 to 239.2 GPa as the fraction of Ti sites occupied by Mo increased from 0.11 to 0.33, whereas the Young's modulus (E) and the shear modulus (G) remained nearly constant. On the other hand, all three elastic moduli decreased with increasing vacancy fraction at the C sites. These results suggest that the M-X bond strength should be the dominant factor in these moduli and the effect of M-M bond on K is greater than that of G and E.

Laugier-Hunziker Syndrome: A Rare Cause of Oral Mucosa Pigmentation.

Introduction: Various diseases cause pigmentation of the oral mucosa. Among them, however, Laugier-Hunziker syndrome is not well known to dentists. Laugier-Hunziker syndrome is a benign pigmentary disorder characterized by the unique expression of pigmentation of the mucosa, nails and skin. In this report, we present a rare case of Laugier-Hunziker syndrome that occurred in an elderly person. Case Presentation: The patient was an 84-year-old female resident of an elderly care facility. The institutional dental hygienist reported that she was concerned about the discoloration of the oral mucosa. On examination, she had pigmentation of her oral mucosa and nails. She had no history of any disease or medication that would cause pigmentation. Although this condition was initially unknown to us, a diagnosis of Laugier-Hunziker syndrome was made. Conclusion: We report a case of Laugier-Hunziker syndrome in an elderly woman, which is not a well-known condition among dental professionals. More knowledge about diseases that cause pigmentation of the oral mucosa would be helpful in dental practice, especially at external facilities.

Denture Clasp Injury of the Oral Mucosa.

Purpose: Clasp-penetrating oral injury caused by removable partial dentures is basically a minor injury but can also cause complications such as continuous bleeding. No systematic investigations of clasp injury have been undertaken. The aims of this study were to reveal the characteristics of clasp injury and estimate variables associated with clasp injury of the oral mucosa. Methods: This retrospective study used clasp injury as the outcome variable, with primary predictor variables of demographic characteristics, medical history, local characteristics, and denture design, including the site of the affected clasp. Denture type was examined according to the classification of Kennedy. Collected data were statistically analyzed using the χ2 test or Fisher's exact test and the level of significance adopted was 5%. Results: This report consists of 73 cases (36 men and 37 women), of which 31 cases had precise denture information. Among them, clasp injuries were more common with Class I (51.6%) and Class II (32.3%) dentures (p < .001). Premolar (64.5%) and canine clasps (32.3%) were significantly more frequently involved (p < .001). Conclusion: Clasp injury of the oral mucosa was significantly more common on the tongue, and mandibular free-end saddle dentures with premolar or canine clasps were the most notable risk factor for clasp-penetrating injury of the oral mucosa.

Endovascular coils mimicking accidental ingestion of a dental-related foreign body in radiographic imaging.

If a foreign body is seen on chest or abdominal radiographs, accidental aspiration or ingestion of a dental-related foreign body may be suspected. This report describes a case in which vascular embolization coils seen on radiography were suspected to represent a swallowed dental prosthesis. A 72-year-old man with a history of endovascular embolization of portosystemic shunt was admitted for mandibular fracture. On hospital day 2, a foreign body was noted on chest radiographs taken to confirm pleural effusion. No foreign body had been evident on radiographs of the same area the previous day. The foreign body was suspected to be a dental prosthesis, but intraoral examination ruled out this possibility, and the foreign body turned out to be metal coils used to embolize the shunt. Dentists and oral surgeons should be aware that medical devices such as vascular embolization coils can produce images similar to a dental-related foreign body on chest or abdominal radiographs, and dental-related foreign body ingestion or aspiration should be considered in the differential diagnosis.

Cancer Chemotherapy-associated Pigmentation of the Oral Mucosa.

BACKGROUND/AIM: Oral adverse events caused by anticancer drugs are diverse, but few reports have examined pigmentation of the oral mucosa. The aim of this study was to clarify the prevalence of oral mucosal pigmentation caused by anticancer drugs. PATIENTS AND METHODS: This single-centre retrospective study investigated patients who underwent oral examination in our hospital during cancer chemotherapy for 3 years from April 1, 2019 to March 31, 2021. Inclusion criteria were patients who could be followed-up for ≥3 months after completing chemotherapy with drugs that caused pigmentation. The primary predictive variable was the cancer chemotherapeutic agent used. The primary outcome variable was pigmentation of the oral mucosa. Collected data were statistically analysed using the χ2 test or Fisher's exact test, with the level of significance set at p<0.05. RESULTS: A total of 388 patients were enrolled in the study. Eleven patients (2.8%) showed oral mucosal pigmentation. Drugs causing pigmentation [deposition rate (number of patients with deposits/users)] were TS-1 (combination of tegafur, gimeracil, and oteracil potassium) [12.2% (5/41)], paclitaxel [4.0% (2/50)], gemcitabine [5.0% (1/20)], cyclophosphamide [2.3% (1/42)], carboplatin [1.6% (1/64)], fluorouracil [2.3% (1/43)], and capecitabine [3.4% (1/29)]. CONCLUSION: Oral pigmentation due to cancer chemotherapy was found in 2.8% of patients. TS-1, carboplatin, cyclophosphamide, capecitabine, fluorouracil, gemcitabine, and paclitaxel caused pigmentation of the oral mucosa. Among these, TS-1 was the most likely to cause pigmentation, affecting 12.2% of users.