Inductive, scaffold-based, regenerative medicine approach to reconstruction of the temporomandibular joint disk.

PURPOSE: A device composed of extracellular matrix (ECM) was investigated as an inductive template in vivo for reconstruction of the temporomandibular joint (TMJ) disk after discectomy. MATERIALS AND METHODS: A scaffold material composed of porcine-derived ECM was configured to mimic the shape and size of the TMJ. This device was implanted in a canine model of bilateral TMJ discectomy. After discectomy, 1 side was repaired with an ECM scaffold material and the contralateral side was left empty as a control. At 6 months after implantation, the joint space was opened, the joints were evaluated for signs of gross pathologic degenerative changes, and newly formed tissue was excised for histologic, biochemical, and biomechanical analysis. RESULTS: The results showed that implantation of an initially acellular material supported the formation of site-appropriate, functional host tissue that resembled that of the native TMJ disk. Furthermore, this prevented gross degenerative changes in the temporal fossa and mandibular condyle. No tissue formation and mild to severe gross pathologic changes were observed in the contralateral controls. CONCLUSIONS: These results suggest that an ECM-based bioscaffold could represent an off-the-shelf solution for TMJ disk replacement.

Interfacility Transfer Guidelines for Isolated Facial Trauma: A Multidisciplinary Expert Consensus.

BACKGROUND: The objective of this study was to develop guidelines for the transfer of patients with isolated craniomaxillofacial trauma. METHODS: A national, multidisciplinary expert panel was assembled from leadership in national organizations and contributors to published literature on facial reconstruction. The final panel consisted of five plastic surgeons, four otolaryngologist-head and neck surgeons, and four oral and maxillofacial surgeons. The expert panelists' opinions on transfer guidelines were collected using the modified Delphi process. Consensus was predefined as 90 percent or greater agreement per statement. RESULTS: After four Delphi consensus building rounds, 13 transfer guidelines were established, including statements on fractures of the frontal sinus, orbit, midface, and mandible, as well as soft-tissue injuries. Twelve guidelines reached consensus. CONCLUSIONS: The decision to transfer a patient with craniomaxillofacial trauma to another facility is complex and multifactorial. While a percentage of overtriage is acceptable to promote safe disposition of trauma patients, unnecessarily high rates of secondary overtriage divert emergency medical services, increase costs, delay care, overload tertiary trauma centers, and result in tertiary hospital staff providing primary emergency coverage for referring hospitals. These craniomaxillofacial transfer guidelines were designed to serve as a tool to improve and streamline the care of facial trauma patients. Such efforts may decrease the additional health care expenditures associated with secondary overtriage while decompressing emergency medical systems and tertiary emergency departments.

Extracellular matrix as an inductive template for temporomandibular joint meniscus reconstruction: a pilot study.

PURPOSE: A device consisting of powdered porcine urinary bladder extracellular matrix (UBM-ECM) encapsulated within sheets of the same material was investigated as a scaffold for temporomandibular joint (TMJ) meniscus reconstruction. MATERIALS AND METHODS: Five dogs underwent unilateral resection of the native meniscus and replacement with a UBM-ECM device. Necropsies were performed at 3, 4, 8, 12, and 24 weeks. Two additional dogs underwent bilateral resection of the meniscus with replacement with a UBM-ECM device on 1 side, leaving the contralateral side empty as a control. Necropsies were performed at 24 weeks for bilaterally treated animals. RESULTS: Macroscopically, the UBM-ECM implants were remodeled rapidly and were indistinguishable from newly deposited host tissue at all time points. Microscopically, remodeling was characterized by a dense infiltration of predominantly CD68(+) mononuclear cells and smooth muscle actin-positive fibroblast-like cells at early time points changing with time to a sparse population of smooth muscle actin-negative spindle-shaped cells resembling those of the native fibrocartilaginous TMJ meniscus. Furthermore, the remodeling process showed deposition of predominantly type I collagen, the density and organization of which resembled those of the native meniscus by the 24-week time point. Ingrowth of calsequestrin-positive skeletal muscle tissue was also observed at the periphery of the remodeled UBM-ECM device and was similar to that found at the attachment site of the native meniscus to the surrounding soft tissues. Histologic results were identical for samples excised from both unilaterally and bilaterally treated animals. No adverse changes in the articulating surfaces of the condyle or fossa were observed in UBM-ECM-implanted joints. In the bilaterally treated animals, the unimplanted control side was characterized by degeneration and pitting of the articulating surfaces of both the condyle and the fossa, with disorganized bands of fibrous connective tissue observed within the joint space. CONCLUSION: Results of this study suggest that the UBM-ECM device provides an effective interpositional material while serving as an inductive template for reconstruction of the TMJ meniscus.

Maxillary orthognathic surgery.

Maxillary surgery to correct dentofacial deformity has been practiced for almost 100 years. Significant advances have made maxillary surgery a safe and efficient means of correcting midface deformities. Anesthetic techniques, specifically hypotensive anesthesia, have allowed for safer working conditions. Landmark studies have proven manipulation and segmentalization of the maxilla is safe and allowed this surgery to become a mainstay in corrective jaw surgery. This article provides an overview of surgical techniques and considerations as they pertain to maxillary surgery for orthognathic surgery. Segmental surgery, openbite closure, vertical excess, grafting, and a technology update are discussed.

Preoperative incisor inclination in patients with Class III dentofacial deformities treated with orthognathic surgery.

Our aim was to evaluate cephalometrically the preoperative inclination of the incisors in a group of 50 patients with Class III dentofacial deformities whose immediate preoperative lateral cephalometric radiographs were analysed after they had been treated by maxillary advancement. The radiographs were hand-traced by the same operator who made the cephalometric analysis. Mean values for each measurement were compared with the normal values using Student's t-test (p<0.05). Results showed significantly increased inclination of the upper incisors, with a mean U1-NA angle of 27.58° and a mean U1-PP angle of 116°. The lower incisors were also inclined lingually, with a mean L1-NB angle of 22.53° and a mean IMPA of 83.13°. Thirty-five of the patients had labial inclination of the upper, and 28 lingual inclination of the lower, incisors. Mean inclinations of upper and lower incisors differed from the normal values, and the inclination of the lower incisors was more likely to be decompensated than that of the upper incisors.

Bone morphogenetic proteins in craniomaxillofacial surgery.

Craniomaxillofacial surgery has many indications for bone regeneration and augmentation, ranging from socket preservation to reconstruction of large skeletal defects. The discovery of bone morphogenetic proteins (BMPs) as osteoinductive agents and the subsequent development of commercially available recombinant forms of BMPs have offered the potential to replace traditional grafting techniques with de novo bone formation. Extensive preclinical and clinical research has focused on establishing the safety and efficacy of using recombinant BMPs to regenerate bone in the facial skeleton. This article reviews the development and current scientific basis behind the use of these new biologics.

A unique presentation of a squamous cell carcinoma in a pregnant patient.

The literature reports an increasing occurrence of carcinoma in the young adult nonsmoking and nondrinking population. With it, this trend brings the potential for new comorbidities. This report discusses one such case in which a 30-year-old woman, 28 weeks pregnant, was diagnosed with a hybrid verrucous carcinoma/squamous cell carcinoma. Several years preceding the presentation of the hybrid lesion, the patient had an odontogenic cyst associated with the same region. The original lesion was reported to have mucosal change overlying it. Newly available immunohistochemical stains were used to review the lesion to assess the potential for aggressiveness and proliferative changes. All the biomarkers were unremarkable, suggesting that the progression of the initial lesion could not have been predicted with the current immunohistochemical stains. This report discusses the diagnosis and treatment of this unusual scenario involving progression of a benign lesion to a malignant hybrid.