Surgery for maxillary oral squamous cell carcinoma: the effect of surgical resection margins and elective neck dissection on oncological outcomes.

Maxillary oral squamous cell carcinoma (OSCC) is uncommon. Surgical resection is challenging due to the anatomy, and the role of elective neck dissection (END) is not well-defined. A retrospective cohort study of patients with maxillary OSCC treated with primary surgery between 2007 and 2019 was conducted. Primary tumours of sinonasal origin with extension into the oral cavity were excluded. Survival analysis was performed using Kaplan-Meier and Cox proportional hazards models. Sixty-seven patients were included; mean follow-up was 55 months. On univariate analysis, clear (≥5 mm) margins were associated with higher disease-free (68% vs 36%, P = 0.019) and overall survival (75% vs 36%, P = 0.004) than close/involved (<5 mm) margins. In clinically node-negative patients, the risk of occult cervical metastasis in tumours with depth of invasion (DOI) ≥ 3 mm and T2-4 tumours was 22% and 25%, respectively. END in these groups was associated with a lower rate of loco-regional recurrence (DOI ≥3 mm subgroup: 5% vs 38%, P = 0.029; T2-4 subgroup: 6% vs 50%, P = 0.028) and longer time to recurrence (DOI ≥3 mm subgroup: 119 months vs 96 months, P = 0.042; T2-4 subgroup: 117 months vs 56 months, P = 0.031) than observation of the neck. On multivariate analysis, close/involved margins were associated with an increased risk of overall mortality (hazard ratio 3.4, 95% confidence interval 1.0-11.3, P = 0.043) and disease recurrence (hazard ratio 2.8, 95% confidence interval 1.1-7.1, P = 0.031). In maxillary OSCC, a ≥ 5 mm histological margin should remain the goal of ablative surgery. END should be considered in tumours with DOI ≥ 3 mm.

Can radiological examination of mandibular bone invasion accurately predict the need for mandibular resection in oral squamous cell carcinoma?

Bone invasion by oral squamous cell carcinoma necessitates jaw resection, with preoperative imaging ideally able to guide the resection. A retrospective review of 109 patients with oral squamous cell carcinoma who underwent mandibular resection was performed. Eighty-three had preoperative computed tomography (CT) imaging and 72 underwent magnetic resonance imaging (MRI). The presence of bone invasion on imaging was compared to histopathology. Bone invasion was detected in 44 of 109 resection specimens (40.4%) and was identified on CT in 31 of 83 cases (37.4%) and on MRI in 35 of 72 cases (48.6%). The sensitivity and specificity of CT for detecting bone invasion was 69.0% and 79.6%, respectively, while for MRI was 87.1% and 80.5%, respectively. Histological detection of bone invasion was associated with greater disease-specific mortality (P=0.002), as was MRI detection of bone invasion (P=0.027). CT detection was not significant (P=0.240). Negative prediction of bone invasion was 95% accurate for both modalities in clinically non-invaded mandibles. Survival was reduced in patients who underwent marginal mandibular resection when bone invasion was detected histologically (33.3% vs. 70.5%, P=0.277) and with CT, although this was not statistically significant. More data are required to determine whether more aggressive resection is warranted when bone invasion is detected preoperatively.

Generating Active "L-Pd(0)" via Neutral or Cationic π-Allylpalladium Complexes Featuring Biaryl/Bipyrazolylphosphines: Synthetic, Mechanistic, and Structure-Activity Studies in Challenging Cross-Coupling Reactions.

Two new classes of highly active yet air- and moisture-stable π-R-allylpalladium complexes containing bulky biaryl- and bipyrazolylphosphines with extremely broad ligand scope have been developed. Neutral π-allylpalladium complexes incorporated a range of biaryl/bipyrazolylphosphine ligands, while extremely bulky ligands were accommodated by a cationic scaffold. These complexes are easily activated under mild conditions and are efficient for a wide array of challenging C-C and C-X (X = heteroatom) cross-coupling reactions. Their high activity is correlated to their facile activation to a 12-electron-based "L-Pd(0)" catalyst under commonly employed conditions for cross-coupling reactions, noninhibitory byproduct release upon activation, and suppression of the off-cycle pathway to form dinuclear (µ-allyl)(µ-Cl)Pd2(L)2 species, supported by structural (single crystal X-ray) and kinetic studies. A broad scope of C-C and C-X coupling reactions with low catalyst loadings and short reaction times highlight the versatility and practicality of these catalysts in organic synthesis.

An acoustic startle alters knee joint stiffness and neuromuscular control.

Growing evidence suggests that the nervous system contributes to non-contact knee ligament injury, but limited evidence has measured the effect of extrinsic events on joint stability. Following unanticipated events, the startle reflex leads to universal stiffening of the limbs, but no studies have investigated how an acoustic startle influences knee stiffness and muscle activation during a dynamic knee perturbation. Thirty-six individuals were tested for knee stiffness and muscle activation of the quadriceps and hamstrings. Subjects were seated and instructed to resist a 40-degree knee flexion perturbation from a relaxed state. During some trials, an acoustic startle (50 ms, 1000 Hz, 100 dB) was applied 100 ms prior to the perturbation. Knee stiffness, muscle amplitude, and timing were quantified across time, muscle, and startle conditions. The acoustic startle increased short-range (no startle: 0.044 ± 0.011 N·m/deg/kg; average startle: 0.047 ± 0.01 N·m/deg/kg) and total knee stiffness (no startle: 0.036 ± 0.01 N·m/deg/kg; first startle 0.027 ± 0.02 N·m/deg/kg). Additionally, the startle contributed to decreased [vastus medialis (VM): 13.76 ± 33.6%; vastus lateralis (VL): 6.72 ± 37.4%] but earlier (VM: 0.133 ± 0.17 s; VL: 0.124 ± 0.17 s) activation of the quadriceps muscles. The results of this study indicate that the startle response can significantly disrupt knee stiffness regulation required to maintain joint stability. Further studies should explore the role of unanticipated events on unintentional injury.

Outcomes of patients with adenoid cystic carcinoma of the minor salivary glands.

Adenoid cystic carcinoma is a tumour of glandular cells responsible for 10% of salivary gland neoplasms. It has a high rate of perineural spread but limited involvement of regional lymphatics even in late stage disease. Early survival is typically good (60-90%) although long term survival is poor with spread to distant sites in 40-60% of cases. The authors performed a retrospective review of clinical and pathological records for 24 patients managed by their institution over a 22-year period. The overall 5, 10 and 20-year survival rates in this study were 92%, 72% and 54%, respectively. Perineural invasion was seen in 63% and close or positive margins seen in 64% of all primary resection specimens although survival was not associated with any clinical factor other than the initial size of lesion. Most patients presented complaining of a lump, whilst a burning neuralgia-type pain was the second most common symptom. The study confirms the conclusion of previous studies that tumour size at diagnosis is the most important predictor of outcome.

The accuracy of medical history information in referral letters.

BACKGROUND: Accurate medical history information is essential for good patient care and should be notified in the letter of referral. The aim of this study was to investigate the subjective opinion that the medical information in a large number of referrals is either inaccurate or non-existent. METHODS: Medical histories from 54 patients with positive medical history findings upon taking the medical history at the initial consultation appointment were compared to the medical information supplied in the referral letter. RESULTS: Overall, medical information was only 58.8% complete with dental referrals being 55.2% complete and medical referrals 62.4%. The majority of referral letters (70.4%) missed at least one relevant finding and only 29.6% of referrals were 100% complete. CONCLUSIONS: The results of this study suggest that the standard of referral letters needs to be improved as the received referrals were generally incomplete and contained inaccurate information. This highlights the need for each and every practitioner to take their own detailed medical history and not rely on the information supplied in the referral.

Temporomandibular joint disorders in patients referred for third molar extraction.

BACKGROUND: Third molar removal has been implicated as a precipitating event for temporomandibular joint disorders. The aim of this study was to determine what proportion of patients had pre-existing pain and dysfunction that could be attributed to the temporomandibular joints. METHODS: Sixty patients referred for third molar removal were clinically examined and a history of their presenting complaint recorded at the initial consultation visit. Patients were then diagnosed and categorized. RESULTS: Of the total number of patients examined, 13.3 per cent showed signs and symptoms of temporomandibular joint pain and dysfunction while a further 23.3 per cent also had symptomatic third molar teeth. CONCLUSIONS: The results of this study suggest that the signs of temporomandibular joint disorders are common in patients referred for third molar extractions.

Development of an integrated microelectrode/microelectronic device for brain implantable neuroengineering applications.

An ultra-low power analog CMOS chip and a silicon based microelectrode array have been fully integrated to a microminiaturized "neuroport" for brain implantable neuroengineering applications. The CMOS IC included preamplifier and multiplexing circuitry, and a hybrid flip-chip bonding technique was developed to fabricate a functional , encapsulated microminiaturized neuroprobe device. As a proof-of-concept demonstration, we have measured local field potentials from thalamocortical brain slices of rats, suggesting that the new neuroport can form a prime platform for the development of a microminiaturized neural interface to the brain in a single implantable unit.

Randomized clinical trial comparing low power-slow heating versus high power-rapid heating noncontact neodymium:yttrium-aluminum-garnet laser regimens for the treatment of benign prostatic hyperplasia.

OBJECTIVES: To evaluate and compare the safety and effectiveness of two noncontact laser regimens for the treatment of human benign prostatic hyperplasia (BPH), and to assess the impact of the spatial distribution of the laser-induced lesions on treatment outcome. METHODS: This was a prospective, double-blind, randomized study that included 29 patients with BPH (both the patients and the study physician assistant in charge of the follow-up evaluation were blinded to the treatment rendered). The patients were randomized to receive either a 15 W for 180 s (15 patients) or 50 W for 60 s (14 patients) laser regimen (powers measured at the fiber tip). There were two study phases for each treatment group: the irradiated sites were not overlapping during the first phase (lesions 1.5 cm apart), and were overlapping during the second phase (lesion less than 1.0 cm apart). RESULTS: Morbidity was minimal in both groups. At 1 year of follow-up, there was significant improvement of the American Urological Association-7 symptom score, the peak urinary flow rate, and the postvoid residual in both treatment groups. These improvements were not statistically significantly different regardless of time or the phase of the study for the two treatment groups. There were 3 treatment failures, 2 of whom were later successfully re-treated with larger amounts of laser energy. Furthermore, the peak flows in the second phase of the study were statistically significantly higher than those in the first phase of the study, regardless of the treatment group. CONCLUSIONS: Our results suggest that both the 15 W for 180 s and the 50 W for 60 s are equally safe and effective treatments for BPH. Perhaps more importantly, they also suggest that the spatial distribution of lesions and overlapping of treated (irradiated) sites has significant impact on treatment outcome.