Prognosis of tongue squamous cell carcinoma associated with individual surgical margin and pathological features

The specific muscular structure of the tongue greatly affects margin shrinkage and tumor invasion, making the optimal surgical margin controversial. This study investigated surgical margin correlated prognosis of TSCC (tongue squamous cell carcinoma) according to margin location and its value, and the histopathologic factors which are suggestive of tumor invasion. And we would like to propose defining of the surgical margin for TSCC via prognosis according to location and margin values. We reviewed 45 patients diagnosed with TSCC who visited Seoul National University Dental Hospital (SNUDH) (Seoul, Republic of Korea) from 2010 to 2019, who were managed by a single surgical team. Patient clinical and pathological data of patients were retrospectively reviewed, and in 36 out of 45 patients, the pathologic parameters including the worst pattern of invasion (WPOI) and tumor budding were investigated via diagnostic histopathology slide reading. When standardized with as 0.25 cm anterior margins, as 0.35 cm deep margin, there was no significant difference in disease specific survival (DSS) or loco-regional recurrence-free survival (LRFS). Additionally, there was a non-significant difference in DSS and LRFS at the nearest margin of 0.35 cm (PDSS=0.276, PLRFS=0.162). Aggressive WPOI and high tumor budding showed lower survival and recurrence-free survival, and there were significant differences in close margin and involved margin frequencies. In TSCC, the value and location of the surgical margin did not have a significant relationship with prognosis, but WPOI and tumor budding suggesting the pattern of muscle invasion affected survival and recurrence-free survival. WPOI and tumor budding should be considered when setting an optimal surgical margin.

Effects of Chewing Exerciser on the Recovery of Masticatory Function Recovery after Orthognathic Surgery: A Single-Center Randomized Clinical Trial, a Preliminary Study

Background and Objectives: The aim of this study was to evaluate the effects of the chewing exerciser (CE) on the functional recovery of the masticatory muscles after orthognathic surgery. Material and Methods: This randomized clinical trial was conducted in patients undergoing bimaxillary orthognathic surgery including bilateral sagittal split ramus osteotomy. Postoperative physiotherapy (PT) was performed for 3 weeks starting 3 weeks after the surgery. The patients were randomly divided into two groups: control (Con) (conventional PT) group and CE group (use of CE in addition to conventional PT). The masticatory function was evaluated based on three standards: bite force (BF), amount of mouth opening (MO), and surface electromyography (sEMG) of the anterior temporal muscle (TA), masseter muscle (MM), sternocleidomastoid muscle, and anterior belly of digastric muscle before, 3 weeks (before PT) and 6 weeks after the surgery (after PT). Results: Finally, 22 subjects participated in this study: 10 patients for Con group and 12 patients for CE group. In both groups, the BF, which was reduced significantly after the surgery, recovered after the PT similar to that before the surgery. In both groups, the MO was also significantly reduced by the surgery. However, it did not recover as much, as it was before the surgery after applying the PT. There was no difference in BF and MO between the two groups. All muscles did not show significant changes in sEMG by surgery and PT at both resting and clenching states. Conclusion: Applying CE as a PT after orthognathic surgery did not cause any harmful side effects. In both groups, the weakened muscle activity after orthognathic surgery (OGS) was adequately restored 6 weeks after the surgery. However, CE did not offer a statistically significant benefit to the masticatory function in the recovery process after OGS.

Newly designed retentive posts of mandibular reconstruction plate in oral cancer patients based on preliminary FEM study

BACKGROUND

The reconstruction of a large mandibular defect poses a challenging issue in oral cancer ablation surgery. One popular option for mandibular continuity reconstruction after tumor resection involves the use of a reconstruction plate (R-plate), which maintains space and contour without bone harvesting. An R-plate, however, cannot provide final functional loading rehabilitation with implants or dentures.

METHODS

We suggest a new method of functional mandibular reconstruction using retentive posts and an upper prosthesis. The finite element method (FEM) was used to optimize the design. Surgery was needed to adapt the retentive posts. Prosthodontic procedures were required for the upper prosthesis.

RESULTS

Eight patients were treated with retentive posts and prostheses. All patients underwent wide resections of the mandible, and reconstruction with an R-plate and microvascular soft tissue transfer. We adapted the retentive posts on an R-plate and fabricated the upper prostheses with a flexible denture or a fixed resin prosthesis. Finally, the patients had functional rehabilitation, which restored proper mastication.

CONCLUSIONS

The retentive posts of the R-plate and upper prosthesis allow functional dental rehabilitation without the need for a bone graft. Virtual simulation using FEM will help to design and optimize the retentive posts. Two or three regular size posts are suitable for the quadrant jaw. This first preliminary step will allow improved patient-specific retentive post designs in the near future.

A standardized formula for aesthetic mandibular reconstruction using an osteocutaneous fibular free flap

Ameloblastoma is the most common benign odontogenic tumor of the jaw, and expansional growth of a huge untreated ameloblastoma can result in disturbances in facial aesthetics and function, such as difficulty with mouth opening, swallowing, chewing, breathing, neurologic deficits, and pathologic fractures. Radical wide resection with safety margins and subsequent reconstruction is generally recommended. A fibular free flap (FFF) is commonlyused to reconstruct the mandible in order to adequately restore both aesthetic appearance and function. The aim of this brief clinical report is to present a case of huge ameloblastoma after wide resection with free safety margins, and describe the immediate one-step mandibular reconstruction using a vascularized composite FFF. The sterolithographic(rapid prototype, RP) model, a wax pattern of the resected mandible, and a surgical fibular stent made from the wax pattern were constructed preoperatively. We suggest a standardized surgical protocol for mandibular reconstruction with FFF.Funding: Supported by the International Research & Development Program of the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2015K1A3A9A01028230)Keywords: Mandibular reconstruction, fibular osteocutaneous free flap, huge ameloblastoma, stereolithographicmodel, standardized formula

A standardized formula for aesthetic mandibular reconstruction using an osteocutaneous fibular free flap

Ameloblastoma is the most common benign odontogenic tumor of the jaw, and expansional growth of a huge untreated ameloblastoma can result in disturbances in facial aesthetics and function, such as difficulty with mouth opening, swallowing, chewing, breathing, neurologic deficits, and pathologic fractures. Radical wide resection with safety margins and subsequent reconstruction is generally recommended. A fibular free flap (FFF) is commonly used to reconstruct the mandible in order to adequately restore both aesthetic appearance and function. The aim of this brief clinical report is to present a case of huge ameloblastoma after wide resection with free safety margins, and describe the immediate one-step mandibular reconstruction using a vascularized composite FFF. The sterolithographic( rapid prototype, RP) model, a wax pattern of the resected mandible, and a surgical fibular stent made from the wax pattern were constructed preoperatively. We suggest a standardized surgical protocol for mandibular reconstruction with FFF.

FUNDING

Supported by the International Research & Development Program of the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2015K1A3A9A01028230).

Successful treatment of self-inflicted tongue trauma patient using a special oral appliance

A 7-year-old male presented with a painful ulcerative lesion on the right lateral tongue and left lower buccal mucosa due to self-inflicted trauma. Antibiotic medication and use of a mouthwash agent were not effective. We made a special oral appliance to cover the maxillary arch and teeth to protect the tongue. The patient showed immediate improvement and did not suffer from any complications. Invasive procedures such as biopsy were not needed. We believe that accurate clinical diagnosis is important and treatment with an oral appliance is effective in self-inflicted oral trauma in children.

Mandibular clear cell odontogenic carcinoma

Background

Clear cell odontogenic carcinoma (CCOC) is a rare intraosseous carcinoma of the jaw; only 81 cases have been reported in the English literatures.

Case presentation

We reported an additional case and reviewed the existing literature. A 70-year-old woman presented with a large painful radiolucent mandibular lesion from the right canine to the left angle area through the midline. No metastatic lymph nodes or distant metastases were detected. She underwent wide surgical resection and reconstruction with a composite fibula free flap. She had no recurrence or metastasis after 18 months.

Conclusion

CCOC occurs predominantly in women in their 50s–70s in the mandible. Painless swelling is the most common symptom, followed by pain, teeth loosening, and paresthesia. CCOC has a good prognosis after surgery. In large mandibular CCOC, wide resection and composite fibula free flap reconstruction is the treatment of choice.