In cases where oral cancer spreads toward the maxillary tubercle, surgery may extend to the pterygopalatine fossa. There are 2 main extraoral approaches: anterior and lateral. Previously, we introduced a modified lateral approach with a mouth corner incision from the lower lip, that preserves the mental and marginal mandibular nerves. Now, we present a further modification that allows safer preservation of the peripheral branches of the marginal mandibular nerve around the mouth. The procedure has 2 key points. The first is to follow the course of the marginal mandibular nerve from the submandibular incision. The second is to begin the mouth corner incision from the upper lip. Deploying the cheek flap ensured the marginal mandibular nerve was contained within a preserved platysma band. The postoperative contours and unremarkable scar on the face were acceptable to the patient. Paralysis of the facial and mental nerves was almost nonexistent. In conclusion, this newly modified lateral approach is useful in fully exposing the pterygopalatine fossa while preserving the mental nerve and not only the main trunks of the marginal mandibular nerves but also the peripheral branches around the mouth.

Masticatory muscle tendon-aponeurosis hyperplasia (MMTAH) is a disease that presents as a hard trismus due to hyperplasia of the masseter and temporalis aponeurosis. Standard surgical methods for MMTAH include masseter resection, temporalis aponeurosis, and coronoidectomy. The operation of resecting the tendon aponeurosis attached to the posterior surface of the coronoid process carries the risk of bleeding and nerve damage because it cannot be observed directly. Therefore, the authors introduce a safer method by using an ultrasonic bone scalpel for this procedure. The authors used an ultrasonic bone scalpel with a long neck blade to scrape the posterior side of the coronoid process from the bottom to the top. The authors have treated 4 cases using this technique, and in all cases, the surgical procedure was performed safely and easily. In conclusion, ultrasonic bone scalpels are effective in MMTAH surgery for removing the attachment of the stiffened temporalis muscle tendon and aponeurosis.

Background/Objectives: Previously, we reported that high molecular weight hyaluronic acid (HMW-HA) exerts chondroprotective effects by enhancing dual specificity protein phosphatase 10/mitogen-activated protein kinase (MAPK) phosphatase 5 (DUSP10/MKP5) expression and suppressing inflammatory cytokine-induced matrix metalloproteinase-13 (MMP13) expression in a human immortalized chondrocyte line (C28/I2 cells) via inhibition of MAPKs. The aim of this study was to elucidate the molecular mechanisms underlying the enhancement of DUSP10/MKP5 expression by HMW-HA in C28/I2 cells. Methods: C28/I2 cells were treated with HMW-HA, and the activation of intracellular signaling molecules was determined using Western blot analysis. The expression levels of mRNAs and microRNAs (miRNAs) were evaluated through real-time quantitative reverse transcription PCR analysis. Results: HMW-HA treatment induced Akt phosphorylation via interaction with CD44, and pretreatment with specific inhibitors of phosphatidylinositol-3 kinase/protein kinase B (PI3K/Akt) signaling attenuated the HMW-HA-induced expression of DUSP10/MKP5. HMW-HA suppressed the expression of miR-92a, miR-181a, and miR-181d. Loss-of-function and gain-of-function analyses of these miRNAs indicate that miR-92a, miR-181a, and miR-181d negatively regulate DUSP10/MKP5 expression. Moreover, HMW-HA-induced Akt phosphorylation was partially suppressed by miR-181a and miR-181d mimics. Finally, we found that HMW-HA activates RhoA-associated protein kinase (ROK) signaling, which contributes to Akt phosphorylation. Conclusions: These findings suggest that the induction of DUSP10/MKP5 expression by HMW-HA binding to CD44, leading to MMP13 suppression, involves multiple regulatory mechanisms, including PI3K/Akt and RhoA-activated ROK signaling, in addition to miRNA-mediated regulation. Elucidating these detailed molecular mechanisms may reveal novel biological activities that contribute to the therapeutic efficacy of HMW-HA against osteoarthritis.