Publications by authors named "Jonathan Shum"

Oral squamous cell carcinoma (OSCC) biomarker studies rarely employ multi-omic biomarker strategies and pertinent clinicopathologic characteristics to predict mortality. In this study we determine for the first time a combined epigenetic, gene expression, and histology signature that differentiates between patients with different tobacco use history (heavy tobacco use with ≥10 pack years vs. no tobacco use).

View Article and Find Full Text PDF

Craniofacial defects require a treatment approach that provides both robust tissues to withstand the forces of mastication and high geometric fidelity that allows restoration of facial architecture. When the surrounding soft tissue is compromised either through lack of quantity (insufficient soft tissue to enclose a graft) or quality (insufficient vascularity or inducible cells), a vascularized construct is needed for reconstruction. Tissue engineering using customized 3D printed bioreactors enables the generation of mechanically robust, vascularized bony tissues of the desired geometry.

View Article and Find Full Text PDF

Objectives: The purpose of this manuscript is to review the current literature on osteoradionecrosis of the cervical spine (C-ORN) and to summarize the risk factors, presenting symptoms and management strategies of this rare condition.

Study Design: A systematic review of the literature on C-ORN was completed using PubMed. Nineteen articles met criteria; 97 patient cases were identified.

View Article and Find Full Text PDF

The pursuit of fellowship training stems from one's desire to master a focused area of surgery. Successful applicants tend to have published articles and participated in other scholarly activities. They commonly have a mentor within the subspecialty of their interest.

View Article and Find Full Text PDF
Article Synopsis
  • Oral cavity squamous cell carcinoma (OCSCC) is challenging to treat, often leading to toxic side effects from conventional chemotherapy like platinum-based drugs.
  • PRV111 is a new nanotechnology that allows for localized delivery of cisplatin to tumors, minimizing systemic exposure and toxicity while enhancing drug retention in the tumor.
  • In animal studies and a clinical trial, PRV111 showed significant effectiveness with a 69% reduction in tumor size in about a week, no serious side effects, and suggests potential for better patient outcomes when combined with existing treatments for OCSCC.
View Article and Find Full Text PDF

We describe a method for performing mandibular resection and vascularized tissue transfer via an intraoral and contralateral submandibular approach to minimize the risk of wound complications in a radiated field. Surgery on radiated tissue associated with osteoradionecrosis of the mandible can present with oral cutaneous fistulas, dense fibrotic skin, and altered tissue planes to make dissection through this tissue tedious and can place the marginal mandibular nerve at increased risk of injury. The use of custom plates allows surgeons to minimize incisions and depend less on anatomic/visual cues during surgery to obtain an accurate result.

View Article and Find Full Text PDF

Background: Oral squamous cell carcinoma (OSCC) has poor survival rates. There is a pressing need to develop more precise risk assessment methods to tailor clinical treatment. Epigenome-wide association studies in OSCC have not produced a viable biomarker.

View Article and Find Full Text PDF

Mandibular reconstruction requires functional and aesthetic repair and is further complicated by contamination from oral and skin flora. Antibiotic-releasing porous space maintainers have been developed for the local release of vancomycin and to promote soft tissue attachment. In this study, mandibular defects in six sheep were inoculated with 10 colony forming units of Staphylococcus aureus; three sheep were implanted with unloaded porous space maintainers and three sheep were implanted with vancomycin-loaded space maintainers within the defect site.

View Article and Find Full Text PDF

Virtual surgical planning provides the ability to visualize the patient anatomy and pathologic condition, establish pertinent reference points, and simulate osteotomies and reconstruction design in advance of the surgery. Virtual surgical planning is also an ideal environment for improved communication between the patient and the surgical team.

View Article and Find Full Text PDF

Microvascular free tissue transfer has revolutionized the reconstruction of complex maxillofacial defects. These cases often necessitate a 2-teamed approach, with an ablative surgeon at the head and a reconstructive surgeon at a distant site for flap harvest. Careful attention to recipient vessel identification and preservation establishes the foundation for successful reconstruction.

View Article and Find Full Text PDF

Large mandibular defects are clinically challenging to reconstruct due to the complex anatomy of the jaw and the limited availability of appropriate tissue for repair. We envision leveraging current advances in fabrication and biomaterials to create implantable devices that generate bone within the patients themselves suitable for their own specific anatomical pathology. The in vivo bioreactor strategy facilitates the generation of large autologous vascularized bony tissue of customized geometry without the addition of exogenous growth factors or cells.

View Article and Find Full Text PDF

The complex 3-dimensional anatomy of the facial skeleton creates a unique challenge for surgical reconstruction. Even more difficult is the precise reconstruction of the maxilla owing to its lack of solid bony support after large resections. Virtual surgical planning (VSP) technology has many applications in head and neck surgery, such as preoperative planning, fabrication of cutting guides and stereolithographic models, and fabrication of custom implants.

View Article and Find Full Text PDF

Purpose: The purpose of this review is to 1) evaluate our early experience with urinary bladder matrix as a dressing for the management of complex wounds subsequent to fasciocutaneous or osteocutaneous vascularized tissue harvests, 2) assess coverage of exposed tendons and the duration of granulation and epithelial coverage, and 3) assess esthetic and functional outcomes compared with traditional means for the management of vascularized tissue harvest sites.

Patients And Methods: This prospective study consisted of 8 consecutive patients in whom a substantial cutaneous component was harvested as part of a vascularized tissue reconstruction, which did not permit for primary closure (n = 7) or had skin graft failure (exposed tendon) that required additional treatment (n = 1).

Results: Functional and esthetic outcomes were comparable to those of traditional methods of donor site closure as determined by clinical evaluation and subjective assessment by the patient.

View Article and Find Full Text PDF

The complex shapes of skeletal components of the craniofacial region combined with the prominence of the face and paucity of overlying soft tissue create significant challenges for the reconstructive surgeon. The in vivo bioreactor strategy is a promising alternative to microvascular surgical techniques that combines tissue engineering principles with microvascular reconstructive techniques to create patient-specific, prevascularized bone flaps for reconstruction of complex maxillofacial defects. This article discusses the use of traditional vascularized bone flaps; preclinical studies using the in vivo bioreactor approach; case reports that have attempted this novel technique; and future challenges and considerations in the development of patient-specific, prevascularized bone flaps for maxillofacial reconstruction.

View Article and Find Full Text PDF

Purpose: Reconstruction of hard tissue continuity defects caused by ablative tumor surgery has been traditionally reconstructed with autogenous bone grafts or microvascular free flaps. Although results have been predictable from these 2 methods of reconstruction, the morbidity associated with bone harvest is quite serious for the patient. Predictable results have been obtained with using a combination of 100% cadaver bone, bone marrow aspirate concentrate (BMAC), and recombinant human bone morphogenic protein in immediate reconstruction for benign tumor extirpations through the extraoral approach.

View Article and Find Full Text PDF

Unlabelled: Reconstruction of large mandibular defects is clinically challenging due to the need for donor tissue of appropriate shape and volume to facilitate high fidelity repair. In order to generate large vascularized tissues of custom geometry, bioreactors were implanted against the rib periosteum of 3-4year-old sheep for nine weeks. Bioreactors were filled with either morcellized autologous bone, synthetic ceramic particles, or a combination thereof.

View Article and Find Full Text PDF

Background And Overview: Ameloblastoma is an odontogenic tumor predominantly occurring in patients who are in their 20s and 30s. Approximately 10% to 15% of ameloblastomas occur in patients younger than 18 years. Although it is a benign tumor, an ameloblastoma can have a devastating effect on children both physically and emotionally.

View Article and Find Full Text PDF

Objective: Bisphosphonates and monoclonal antibodies directed at osteoclastic function are frequently used to treat postmenopausal and corticosteroid-induced osteoporosis. They are also used in the treatment of certain metastatic malignancies. However, osteonecrosis of the jaw has been reported after intravenous, subcutaneous, or oral use of these agents.

View Article and Find Full Text PDF

Recurrent invasive ameloblastoma of the infratemporal fossa is an uncommonly encountered phenomenon in the practice of oral and maxillofacial surgery and presents many surgical challenges for the practitioner. This case report describes a patient who underwent previous resection of a mandibular ameloblastoma with multiple recurrences. The patient was diagnosed with a recurrent ameloblastoma of the infratemporal fossa that was subsequently resected and reconstructed using an anterolateral thigh (ALT) free tissue transfer.

View Article and Find Full Text PDF

Purpose: Buccal squamous cell carcinoma is an aggressive form of oral carcinoma with a high recurrence rate. Injury to the parotid duct is often unavoidable when surgically treating buccal squamous cell carcinoma because of the intimate anatomic relation among the buccal mucosa, Stensen duct, and parotid gland. It is often difficult to achieve negative margins and preserve the integrity of the parotid duct.

View Article and Find Full Text PDF