Condylar Position is Maintained in Maxillomandibular Advancement Surgery Utilizing Custom Cutting Guides and Plates.

PURPOSE: The objective of this study is to compare virtual surgical planned (VSP) and postoperative condylar positioning outcomes in patients who underwent maxillomandibular advancement surgery with custom mandibular cutting guides and osteosynthesis plates to establish reliability and effectiveness using these forms of technology. METHODS: An ambispective case series was performed by obtaining preoperative and postoperative computed tomography (CT) scans of obstructive sleep apnea patients who underwent maxillomandibular advancement surgery with VSP and custom printed mandibular cutting guides and plates at the San Francisco Veterans Affairs Healthcare System from February 2019 to October 2021. The primary predictor variables were the use of custom guides and plates compared to VSP over the course of a year. The outcome variable was the maintained condylar position, defined as the mean differences between the VSP and postoperative positioning. The comparison group was the preoperative VSP position. Covariates were planned surgical movements, age, and gender. Measurements were taken bilaterally in sagittal CT sections measuring the condylar positioning within the posterior space, superior space, and anterior space of the glenoid fossae. Similarly, coronal CT section measurements were taken to measure the condylar positioning within the coronal lateral space, coronal central space, and coronal medial space. A Wilcoxon signed rank test was used. RESULTS: This study included 6 male participants (n = 6) aged 32 to 57 years (mean 46.5). The median differences for the posterior space, superior space, and anterior space planned versus postoperative position were 0.25 (0.40), 0.40 (0.35), and 0.40 (0.55) mm, respectively. The median differences for the coronal lateral space, coronal central space, and coronal medial space planned versus postoperative position were 0.30 (0.30), 0.78 (0.70), and 0.40 (0.30) mm, respectively. There was no statistically significant difference in the planned and postoperative condylar position (Wilcoxon signed rank test, P > .5). A qualitative analysis showed little to no displacement or rotation of the condyle in the virtually planned and postoperative condylar positions. CONCLUSIONS: Qualitative and quantitative comparisons of the preoperative virtual surgical planned and the postoperative condylar position with the use of custom-printed mandibular cutting guides and plates support the null hypothesis that there is no difference between planned and postoperative positioning.

Use of Viable Cryopreserved Placental Membrane as an Adjunct to Facial Keloid Resection.

Keloids are the physical manifestation of an exaggerated inflammatory response resulting in excess collagen deposition. The resulting fibroproliferative mass can be distressing for patients due to appearance, pruritus, and/or pain. Despite extensive research into the pathophysiology of keloid formation and the development of numerous treatments, keloids remain a challenge to treat. Even when the initial treatment is successful, a risk of recurrence remains. Basic science research into viable cryopreserved placental membranes and viable cryopreserved umbilical tissue has demonstrated their anti-inflammatory and anti-fibrotic effects, which may decrease keloid recurrence after excision. In this article, we present the first-reported case of viable cryopreserved placental membrane, with living mesenchymal stem cells, to treat a painful preauricular keloid in conjunction with surgical resection.

Deletion of vanilloid receptor 1-expressing primary afferent neurons for pain control.

Control of cancer, neuropathic, and postoperative pain is frequently inadequate or compromised by debilitating side effects. Inhibition or removal of certain nociceptive neurons, while retaining all other sensory modalities and motor function, would represent a new therapeutic approach to control severe pain. The enriched expression of transient receptor potential cation channel, subfamily V, member 1 (TRPV1; also known as the vanilloid receptor, VR1) in nociceptive neurons of the dorsal root and trigeminal ganglia allowed us to test this concept. Administration of the potent TRPV1 agonist resiniferatoxin (RTX) to neuronal perikarya induces calcium cytotoxicity by opening the TRPV1 ion channel and selectively ablates nociceptive neurons. This treatment blocks experimental inflammatory hyperalgesia and neurogenic inflammation in rats and naturally occurring cancer and debilitating arthritic pain in dogs. Sensations of touch, proprioception, and high-threshold mechanosensitive nociception, as well as locomotor function, remained intact in both species. In separate experiments directed at postoperative pain control, subcutaneous administration of RTX transiently disrupted nociceptive nerve endings, yielding reversible analgesia. In human dorsal root ganglion cultures, RTX induced a prolonged increase in intracellular calcium in vanilloid-sensitive neurons, while leaving other, adjacent neurons unaffected. The results suggest that nociceptive neuronal or nerve terminal deletion will be effective and broadly applicable as strategies for pain management.

Implant rehabilitation in fibula-free flap reconstruction: A retrospective study of cases at 1-18 years following surgery.

PURPOSE: To determine the dental implant and prostheses success rate in a cohort of patients who underwent a vascularized fibula-free flap (FFF) for maxillary or mandibular reconstruction. METHODS: The investigators implemented a retrospective cohort study composed of patients who had undergone primary or secondary FFF reconstruction jaw surgery plus placement of 2-6 implants in the reconstructed arch, which were restored with an implant-supported prosthesis. The sample was composed of all patients who underwent FFF surgery between 1998 and 2012 and had either simultaneous or secondary dental implant placement. A total of 28 patients met inclusion criteria. Of these, 22 patients participated in the retrospective review. Patients were examined by an independent observer between January-December 2015. In addition, all patients completed a questionnaire to access satisfaction with the implant-supported prosthesis. RESULTS: The patient cohort consisted of 12 males and 10 females, age 12-70 years. A total of 100 implants were placed, 92 implants in fibular bone and 8 implants in native bone. In the maxilla, 35 implants were placed into fibular bone and 4 into native bone (11 in irradiated patients and 28 in non-irradiated patients). In the mandible, 57 implants were placed into fibular bone and 4 into native bone (15 in irradiated patients and 46 in non-irradiated patients). The mean follow-up after implant loading was 7.8 years (range 1.3-17.5 years). The implant survival rate was 98% (95% CI: 92.2%-99.5%). No statistically significant difference was found in implant success between maxillary and mandibular implants, or between radiated and non-radiated bone. The prostheses success rate, determined by clinical exam and patient satisfaction, was 100%. CONCLUSION: The results of this study suggest that implant survival is high and implant-supported prostheses are a reliable rehabilitation option in patients whose jaws have been reconstruction with a FFF.

Increased nitric oxide levels and iNOS over-expression in oral squamous cell carcinoma.

Inducible nitric oxide synthase (iNOS) is responsible for generating high levels of nitric oxide (NO) in tissues. Increased iNOS expression has been demonstrated in a number of carcinomas including head and neck squamous cell carcinoma (SCC). However, iNOS levels have not been evaluated specifically in oral cavity SCC, or in the precancerous lesions that progress to oral SCC. Also, NO levels have not been measured in oral precancerous or cancerous tissues. We therefore measured iNOS mRNA, iNOS protein and NO in oral SCC, oral dysplasias and normal oral epithelium. We used RT-PCR to quantify and compare iNOS mRNA levels in these oral tissue specimens. We found that iNOS mRNA was overexpressed in 41% of oral SCC but in only 8% of dysplasia specimens (P = 0.003). Immunohistochemistry was used to evaluate iNOS protein levels in oral SCC, oral dysplasias and normal oral epithelium. A significantly higher percentage of oral SCC specimens showed the highest level of iNOS staining relative to the oral dysplasias and normal oral epithelial samples (95% of oral SCC, 50% of dysplasias, and only 0% of normal epithelial controls, P < 0.0001). The positive staining for iNOS was limited to the SCC cells. Production of NO from iNOS was quantified using HPLC and found to be significantly higher in oral SCC (1.45 +/- 0.56 microg/ml) than normal epithelial controls (0.43 +/- 0.26 microg/ml) (P = 0.0013). We conclude that iNOS mRNA levels and NO production are significantly increased, in oral SCC compared to oral dysplasias and normal epithelial controls. These findings suggest that increased iNOS expression and the generation of high NO levels might have a role in oral SCC development.