The Clinical Behavior and Recurrence Patterns of Oral Cavity Cancer in Oral Lichen Planus Patients

OBJECTIVES

Oral lichen planus (OLP) is a chronic inflammatory disorder involving epithelia with squamous differentiation. Although described as a potential malignant precursor, the characteristics of malignancies arising among these patients are not widely described. Our goal was to describe the patterns of disease recurrence of patients with oral cavity squamous cell carcinoma (OSCC) arising on the background of OLP.

METHODS

A retrospective analysis of all surgically treated patients with OSCC at a university-affiliated tertiary care center between 2000 and 2020.

RESULTS

Two hundred seventy-nine patients with OSCC treated surgically were included. Forty (14.3%) had OLP. The mean age of patients with OLP was 70.9 years compared with 64.3 years for non-OLP patients (p = 0.03). OLP patients had a significantly higher rate of disease recurrence, persistence, or multiple primary disease (70% vs. 33.9%, p < 0.001). The mean number of sequential oncologic events for each patient with recurrence was also significantly higher among OLP patients (1.86 vs. 1.36, p = 0.03), a difference explained by a higher rate of multiple primary presentations (0.71 vs. 0.28, p = 0.008). A significant difference in disease-free survival (DFS) was demonstrated between the groups as patients with OLP had a lower 5-year DFS (34.7% vs. 61.3%, log-rank p value <0.001). On multivariate analysis, OLP was significantly associated with multiple primary events (p < 0.001, Odds ratio = 7.42, 95% confidence interval 2.9-19).

CONCLUSIONS

OSCC patients with OLP background demand close clinical follow-up, as multiple primary disease is significantly more common and the DFS is significantly lower among these patients. A thorough clinical evaluation for all oral cavity subsites is mandatory.

LEVEL OF EVIDENCE

3 Laryngoscope, 2024.

Risk factors contributing to early implant failure following sinus augmentation: A study of a challenging cohort

BACKGROUND

Sinus augmentation has become a more predictable and successful procedure as the knowledge of its indications and complications increased. However, knowledge of risk factors leading to early implant failure (EIF) among challenging systemic and local conditions is insufficient.

OBJECTIVES

The present study aims to assess risk factors for EIF following sinus augmentation in a challenging cohort.

METHODS

A retrospective cohort study conducted during a period of 8 years in a tertiary referral centre providing surgical and dental health care. Implant and patient variables including age, ASA (American Society of Anesthesiology) physical status classification, smoking, residual alveolar bone, type of anaesthesia and EIF were collected.

RESULTS

Cohort was comprised of 751 implants placed in 271 individuals. EIF rates at the implant and patient level were 6.3% and 12.5%, respectively. EIF was found to be higher among smokers (patient level: χ2 (1) = 8.74, p = .003), ASA 2 physical classification patients (patient level: χ2 (2) = 6.75, p = .03), sinuses augmented under general anaesthesia (patient level: χ2 (1)=8.97, p = .003), higher bone gain (implant level: W = 12 350, p = .004), lower residual alveolar bone height (implant level: W = 13 837, p = .001) and multiple implantations (patient level: W = 3016.5, p = 0.01). However, other variables such as age, gender, collagen membrane and implant's dimensions did not reach significance.

CONCLUSIONS

Within the limits of the study, we can conclude that smoking, ASA 2 physical status classification, general anaesthesia, low residual alveolar bone height and numerous implants are risk factors for EIF following sinus augmentation in challenging cohorts.

Anatomical Features of the Parotid Duct in Sialography as an Aid to Endoscopy—A Retrospective Study

Sialography is used for diagnosis of obstructive salivary gland diseases and prior to sialendoscopy. Three-dimensional cone beam computerized tomography (CBCT) sialography allows imaging and measurement of salivary duct structures. Salivary gland endoscopy has a long learning curve. The aim of this retrospective study is to create an anatomical quantitative guide of different distances and angles significant for endoscopy. Twenty-six CBCT sialographies of healthy parotid ducts were included. Outcome parameters included diameters, distances, angles and number of minor tributaries. Results show the average distance from the papilla to the curvature of the gland was 41.5 mm (Q1 36.97 mm–Q3 45.32 mm), with an angle of 126.9° (Q1 107.58°–Q3 135.6°) of the curvature and a distance of 35.25 mm (±7.81 mm) between the curvature and the hilus. The mean width of the duct was 0.8 mm (Q1 0.7 mm–Q3 1.15 mm) at its narrowest and 2 mm (Q1 1.4 mm–Q3 2.2 mm) at its widest. This is the first anatomical quantitative study of the parotid duct in relation to sialendoscopy.

The earliest known reported occurrence of dentigerous cyst in a six-month-old child

The earliest reported case of the occurrence of a dentigerous cyst is described; the cyst surrounded an unerupted permanent tooth bud in a 6-month-old infant. Most commonly these lesions present between the second and third decades of life. They rarely occur before 10 years of age and have not been documented prior to 1 year of age. In the case reported here, the treatment instituted was extraction of the adjacent deciduous tooth and enucleation of the cyst along with the permanent molar tooth bud. Clinicians should be aware of the potential for this lesion to occur across a wide range of ages and the importance of prompt diagnosis and treatment to prevent complications and reduce morbidity.

The Use of Bone Block Allografts for Vertical Augmentation of the Extremely Atrophic Mandible

PURPOSE

Treatment alternatives based on implant-supported prostheses (ISPs) may be almost impossible in cases with extremely atrophic mandibles. Vertical bone augmentation is then the only possibility to achieve an ISP.

MATERIALS AND METHODS

The consequences of vertical augmentation in extremely atrophic mandibles (≤ 10-mm bone height) of edentulous patients using allogeneic block grafts via a submental approach were assessed. The recorded parameters were sex, age, physical status, hospitalization duration, postoperative complications, implant characteristics (length, diameter), early and late implant failure (yes/no; primary outcome variable). Bone height was measured at three points using the pre-grafting and pre-implant placement CBCT imaging. The difference between the measurements was defined as bone gain (primary outcome variable).

RESULTS

Sixteen patients (2 men, 14 women) were included. The preoperative bone height ranged from 4 to 10 mm. A mean of 5.3 ± 1 months was allowed for graft consolidation. The average bone height gain was 11.2 ± 3.1 mm. Two to six dental implants were placed in the grafted bone. Early implant failure occurred in 4 out of 73 (5.5%). Follow-up ranged from 12 to 92 (mean: 48 ± 30) months. All patients were followed for more than a year, and two additional late implant failures were recorded, rendering a 92% cumulative survival rate.

CONCLUSION

Bone grafting using allogeneic bone blocks via a submental approach seems to be a promising solution for reconstruction of the extremely atrophic mandible.

Factors affecting the decision to rehabilitate the posterior maxilla following surgical closure of oroantral communications/fistulae - A cohort study

BACKGROUND

Search of the English literature yielded no studies assessing the chosen dental treatment following surgical closure of oroantral communication/oroantral fistula (OAC/OAF). The purpose of the present study was to assess factors affecting the decision to rehabilitate the posterior maxilla following surgical closure of OAC/OAF.

METHODS

Consecutive patients at a single center. A structured form served to collect the data. The differences between groups (cases with versus cases without restoration) were assessed statistically.

RESULTS

A total of 58/121 responding individuals (62.1% men). Average age 51.57 years. Average waiting time prior to restoration 10.34 months. Most (51.7%) healthy. Most had a dental etiology (60.3%). Thirty-nine (67.2%) patients had a restoration of the posterior maxilla. Most of the patients responded that the reason not to do any restoration is the fear of failure (65.5%). Most of the patients completed the restoration procedure in a private clinic (87.2%). Only one patient (2.6%) reported a complication. Approximately half of the patients had implant supported prosthesis (ISP) following sinus augmentation (48.3%) with delayed implant placement. Most of the patients responded that the reason not to have ISP was the fear of failure (72.7%), and the rest responded because of financial issues (27.3%). For tooth supported restoration, most of the patients responded removable (90.9%).

CONCLUSIONS

Surgeons generally wait 6-12 months following surgical treatment of OAC/OAF prior to reconstruction with ISP. The chance for complications is low. Healthy women after dental induced OAC/OAF have the highest chances to seek for ISP in such circumstances.

Is the Risk to Develop Osteoradionecrosis of the Jaws Following IMRT for Head and Neck Cancer Related to Co-Factors?

Background and Objectives: Determine the contribution of coexisting factors to the risk to develop Osteoradionecrosis (ORN) of the jaws among patients who have received radiotherapy by intensity modulated radiation therapy (IMRT) for head and neck cancer (HNC) between 2013 and 2016, in a single medical center. Materials and Methods: The records of all patients treated with IMRT for HNC between 2013 and 2016 in The Davidoff Center for the treatment and Research of Cancer in Rabin Medical Center—Beilinson hospital, Petah-Tikva, Israel were screened. Patients who have received a minimum mean dose of 40 Gy to the oral cavity entered the research and their medical records were retrospectively reviewed. Collected background data included: age, gender, smoking, diabetes mellitus (DM), ASA score, mean and maximal radiation doses (Gy), and diseases characteristics including histological diagnosis, primary tumor site, and disease stage. Results: A total of 1232 patients were surveyed. Out of all screened patients, 93 received a minimum mean dose of 40 Gy to the oral cavity. Out of the 93 patients, 7 (7.52%) developed ORN (ORN+) and 86 did not develop ORN (ORN−). Tumor type in all seven patients in the ORN+ group was Squamous Cell Carcinoma (SCC). In three out of those seven patients (42.9%), the tumor was located in the mandible. Conclusions: within the limits of the relatively small cohort in the current study, we suggest that the development of ORN due to Radiation therapy (RT) with IMRT is related significantly only to the location of a tumor in the mandible. Other co-factors do not significantly increase the risk to develop ORN when RT is delivered via IMRT.

Clinical and radiological characteristics of oro-antral communications/fistulae due to implant dentistry procedures: A cross-sectional retrospective study

OBJECTIVES

Assess the unique clinical and radiological sequelae following oro-antral communications/fistulae (OAC/OAF) due to implant dentistry vs other etiologies.

MATERIALS AND METHODS

A structured form served to collect data from medical records. All consecutive patients who underwent surgical closure of OACs/OAFs between 2003 and 2020, at a single center were included. Demographic, radiological, clinical, operative and postoperative characteristics were collected. The differences between groups (cases with implant dentistry etiology [IDE] vs cases with other etiologies) were assessed statistically.

RESULTS

Data were gathered from 121 cases. The findings show that IDE cases were more likely to be of older age (OR = 1.07, CI [1.02, 1.13] P = .02); to have a foreign body in the maxillary sinus (OR = 21.04, CI [4.34, 114.92] P < .01); to have fluid passage (OR = 11.40, CI [1.87, 118.73] P = .02) and purulent discharge through the fistula (OR = 3.52, CI [0.86, 16.34] P = .09).

CONCLUSIONS

Clinical and radiological sequelae due to OACs/OAFs secondary to implant dentistry procedures are more severe compared to other etiologies. The suggested pathogenesis is foreign body reaction. Early and accurate diagnosis of the foreign body location, followed by its early removal is recommended.

Is inferior meatal antrostomy still relevant? A 12-year analysis of 93 oroantral fistulae closure with concomitant Caldwell-Luc operations

OBJECTIVE

The aim of this study was to retrospectively evaluate clinical outcomes after closure of oroantral fistulae with concomitant Caldwell-Luc operations (OFCLOs) with or without inferior meatal antrostomy (IMA).

STUDY DESIGN

Records from consecutive OFCLOs carried out over a 12-year period at the oral and maxillofacial surgery department at a single medical center were reviewed. Background data included age, sex, medical status, indications, and etiologies. Outcome data included operative time, hospitalization time, and postoperative use of analgesics and complications.

RESULTS

From 2002 to 2013, 54 male patients (58%), 39 female patients (42%) (mean age 50 years; range 12-84 years) underwent OFCLOs. IMA was carried out in 66 cases (70%). All patients had minimal complications. We found statistically significant shorter operating times (72 vs 84 minutes), shorter postoperative hospitalization times (4.1 vs 5.6 days), lower need of analgesics (1.44 vs 2.88 per day), and fewer complications (11% vs 38%) when IMA was not used.

CONCLUSIONS

IMA during OFCLOs carries increased morbidity without apparent benefits. Its routine use should, therefore, be discontinued.

Evaluation of Surgical Treatment of Oroantral Fistulae in Smokers Versus Non-Smokers

Background and Objectives: Smoking has been found to interfere with wound healing processes. Therefore, the purpose of this study was to compare surgical treatment of oroantral fistulae (OAFs) in smokers and non-smokers. Materials and Methods: Medical records of all consecutive patients who underwent surgical closure of OAFs between 2003 and 2016 at the oral and maxillofacial surgery department, Rabin Medical Center, Israel were reviewed. Patients' demographic data, preoperative signs and symptoms, surgical method of repair, and postoperative complications were recorded. Results: The cohort consisted of 38 smokers and 59 non-smokers. Age and gender distributions were similar in both groups. The main etiology in both groups was tooth extraction, followed by pre-prosthetic surgery in smokers and odontogenic infection in non-smokers (p = 0.02). Preoperative conditions were not significantly different between smokers and non-smokers in terms of size of soft tissue fistula and bony defect, chronic sinusitis and foreign bodies inside the sinus. OAFs were repaired by local soft tissue flaps without consideration of smoking status. Smokers experienced more moderate-severe postoperative pain (p = 0.05) and requested more weak opioids (p = 0.06). Postoperative complications included infection, delayed wound healing, residual OAF, pain, sensory disturbances and sino nasal symptoms. These were mostly minor and tended to be more frequent in smokers (p = 0.35). Successful closure of OAFs was obtained in all patients except one smoker who required revision surgery. Conclusions: Smokers may be more susceptible to OAFs secondary to preprosthetic surgery. In this cohort, there was no statistically significant difference in outcome between smokers and non-smokers in terms of failure. However, smokers tended to have more severe postoperative pain and discomfort and to experience more postoperative complications. Further studies with larger sample sizes should be conducted to validate these results.

Abstract A10: Treatment of squamous cell carcinoma by alpha radiation-based brachytherapy (Alpha DaRT)

Objective: The first clinical trial in humans with skin and oral cavity squamous cell carcinoma (SCC) was performed in order to evaluate the effect of a unique intratumoral alpha radiation-based tumor ablation treatment termed Diffusing Alpha-emitters Radiation Therapy (DaRT).

Methods: Radium-224 loaded sources (DaRT seeds) were inserted into solid tumors and released by recoil short-lived alpha-emitting atoms (Rn-220, Po-216, Pb-212, Bi-212, Po-212, Tl-208). These atoms disperse in the tumor and spray it with highly destructive alpha radiation. The decay products diffuse in the tumor mass to a distance of at least 5 mm.

Results: A feasibility and safety clinical study is ongoing and currently 28 patients were treated at the Rabin Medical Center (Israel) and IRST (Italy). Patients with histopathologic confirmed skin or head and neck SCC, and tumor size ≤5 centimeters in the largest diameter, were enrolled. Treatment was delivered based on a CT-simulation pretreatment plan. The seeds (1 cm long and 0.7 mm in diameter), each carrying a dose of 2 μCi, were placed up to 5 millimeters from each other. CT was used in order to confirm the position of the radioactive seeds. Two weeks after implantation the seeds were removed, and six weeks after treatment a CT scan was performed to assess the effect of treatment. Study results are available for 18 cases that were treated per protocol and reached the 30-day follow-up period. Age of the patients ranged from 60 to 102 years (median 80 years). Ten patients had oral cavity SCC and 18 were diagnosed with cutaneous SCC. Thirteen subjects were treated within prior radiation failure fields (radiation dosage &gt;60Gy). All tumors responded to the treatment; 13 tumors exhibited a complete response and five tumors showed partial response. No major toxicity was noted.

Conclusions: In this first feasibility and safety human study we demonstrated that alpha-based treatment (DaRT) resulted in enhanced radiobiologic potential. Furthermore, the treatment was effective against radioresistant SCC tumors without any major side effects.

Citation Format: Aviram Mizrachi, Aron Popovtzer, Eli Rosenfeld, Ran Ben-Hur, Itzhak Kelson, Yona Keisari. Treatment of squamous cell carcinoma by alpha radiation-based brachytherapy (Alpha DaRT) [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr A10.

Single-Spin Magnetomechanics with Levitated Micromagnets

We demonstrate a new mechanical transduction platform for individual spin qubits. In our approach, single micromagnets are trapped using a type-II superconductor in proximity of spin qubits, enabling direct magnetic coupling between the two systems. Controlling the distance between the magnet and the superconductor during cooldown, we demonstrate three-dimensional trapping with quality factors around 1×10^{6} and kHz trapping frequencies. We further exploit the large magnetic moment to mass ratio of this mechanical oscillator to couple its motion to the spin degrees of freedom of an individual nitrogen vacancy center in diamond. Our approach provides a new path towards interfacing individual spin qubits with mechanical motion for testing quantum mechanics with mesoscopic objects, realization of quantum networks, and ultrasensitive metrology.

Initial Safety and Tumor Control Results From a "First-in-Human" Multicenter Prospective Trial Evaluating a Novel Alpha-Emitting Radionuclide for the Treatment of Locally Advanced Recurrent Squamous Cell Carcinomas of the Skin and Head and Neck

PURPOSE

Our purpose was to report the feasibility and safety of diffusing alpha-emitter radiation therapy (DaRT), which entails the interstitial implantation of a novel alpha-emitting brachytherapy source, for the treatment of locally advanced and recurrent squamous cancers of the skin and head and neck.

METHODS AND MATERIALS

This prospective first-in-human, multicenter clinical study evaluated 31 lesions in 28 patients. The primary objective was to determine the feasibility and safety of this approach, and the secondary objectives were to evaluate the initial tumor response and local progression-free survival. Eligibility criteria included all patients with biopsy-proven squamous cancers of the skin and head and neck with either primary tumors or recurrent/previously treated disease by either surgery or prior external beam radiation therapy; 13 of 31 lesions (42%) had received prior radiation therapy. Toxicity was evaluated according to the Common Terminology Criteria for Adverse Events version 4.03. Tumor response was assessed at 30 to 45 days at a follow-up visit using the Response Evaluation Criteria in Solid Tumors, version 1.1. Median follow-up time was 6.7 months.

RESULTS

Acute toxicity included mostly local pain and erythema at the implantation site followed by swelling and mild skin ulceration. For pain and grade 2 skin ulcerations, 90% of patients had resolution within 3 to 5 weeks. Complete response to the Ra-224 DaRT treatment was observed in 22 lesions (22/28; 78.6%); 6 lesions (6/28, 21.4%) manifested a partial response (>30% tumor reduction). Among the 22 lesions with a complete response, 5 (22%) developed a subsequent local relapse at the site of DaRT implantation at a median time of 4.9 months (range, 2.43-5.52 months). The 1-year local progression-free survival probability at the implanted site was 44% overall (confidence interval [CI], 20.3%-64.3%) and 60% (95% CI, 28.61%-81.35%) for complete responders. Overall survival rates at 12 months post-DaRT implantation were 75% (95% CI, 46.14%-89.99%) among all patients and 93% (95% CI, 59.08%-98.96%) among complete responders.

CONCLUSIONS

Alpha-emitter brachytherapy using DaRT achieved significant tumor responses without grade 3 or higher toxicities observed. Longer follow-up observations and larger studies are underway to validate these findings.

Metastatic tumors in oral mucosa and jawbones: Unusual primary origins and unusual oral locations

AIM

To perform clinico-pathological characterization of a large series of oral metastases, collected from 3 main medical centers in Israel and compare findings to data on frequency of primary cancer types in the population.

MATERIALS

Pathology archives were searched for cases of metastatic tumors to the oral soft tissues and jawbones, 1990 - 2016. Metastases to the skin of face or to major salivary glands have been excluded. Demographic data and histopathological features were analyzed.

RESULTS

Study population included 60 patients, 35 females and 25 males (ratio of 1.4:1). The age range was 17-87 years, mean 67.7 + 14.36 years. Only 3 (5%) patients were under 40 years, the remaining clustered predominantly in the 60-80 year age group. The mean age of females (59 + 13.84) was significantly lower than that of males (67.44 + 14) (p = 0.03). There was an almost equal distribution between the oral soft tissue and the jawbones (48.3% and 51.7%, respectively). The five most common organs from which metastases were distributed to the oral cavity and jawbones combined were kidney (20%), breast (15%), cutaneous (predominately melanoma, 13%), lung (11.7%) and soft tissue-sarcomas (8.3%). For comparison, Israel National Cancer Registry 2013 reported that the most frequent malignancies were breast (25.8%), colorectal cancer (16.3%), lung (12%) and prostate (10%). Malignant melanoma was 6th (5.4%), kidney malignancy was only 9th in frequency (4.2%). Although the gingiva and jawbones were the most frequent locations, some cases presented in unusual locations, (mandibular vestibule, lower lip, posterior dorsal tongue), without any specific clinical feature to suggest metastasis.

CONCLUSIONS

The most frequent primary origins for oral metastasis do not correspond to the relative frequency of the primary tumors in the population, indicating that metastatic spread is not a random process. Although the majority of metastasis involves the gingiva and jawbones, any other oral mucosal location might be involved. Thus, in adult/older patients, metastasis from a distant site should be included in the differential diagnosis of oral masses at any oral location, whether the existence of a primary tumor is reported or not.

Preoperative Maxillary Sinus Imaging and the Outcome of Sinus Floor Augmentation and Dental Implants in Asymptomatic Patients

OBJECTIVES

Preoperative maxillary sinus imaging findings have been suggested to be associated with complications and outcomes of sinus lift and dental implant procedures; nonetheless the evidence is controversial. The aim of this study was to examine the association between preoperative maxillary sinus imaging findings and outcomes of sinus lift and dental implant procedures in asymptomatic patients.

METHODS

We included all patients who underwent maxillary sinus lift and dental implant procedures between 2014 and 2017. Maxillary sinus imaging findings were extracted from pre-procedural dental computed tomography scans, and outcomes of the procedures were assessed.

RESULTS

A total of 145 procedures were included. No sinonasal symptoms were reported preoperatively. In 46% of cases maxillary sinus imaging was abnormal. The most common imaging finding was peripheral mucosal thickening (38%). Sinus floor cyst/polyp was identified in 13% of the cases, of which 47% occupied more than 50% of the sinus volume. Partial or complete opacification of the maxillary sinus was documented in 3% of cases. The sinus ostium and ostiomeatal complex were obstructed in 7% and 1%, respectively. Mucosal perforation was documented in 22% of cases and was inversely related to mucosal thickening (P = 0.011). Other minor post-operative complications did not correlate with radiological findings. Post-surgical sinusitis was not observed in any of the patients regardless of pre-surgical imaging findings.

CONCLUSIONS

Incidental maxillary sinus imaging findings such as mucosal swelling, cysts or polyps, regardless of their severity or size, and maxillary ostial obstruction may not need to be addressed prior to sinus augmentation and dental implant procedures in asymptomatic patients. Patients with complete sinus opacification should be referred to an otolaryngologist prior to surgery. Further controlled trials, in larger cohorts, are needed to corroborate our findings.

Four-year cross-sectional study of bleeding risk in dental patients on direct oral anticoagulants

OBJECTIVE

New oral anticoagulants, or "direct oral anticoagulants" (DOACs), have been used worldwide in recent years. An evidence-based enigma regarding dental patients using DOACs still exists.

METHOD AND MATERIALS

This was a 4-year, cross-sectional study on individuals receiving DOAC therapy, treated in a single maxillofacial center. A bleeding event was the outcome parameter. Potential contributing risk factors were evaluated.

RESULTS

Of a total of 111 patients, 72 underwent a total of 305 oral procedures in 115 sessions. The overall frequency of bleeding events was 6.1% per session. One "major" (0.9%) and six "minor" (5.2%) events were recorded. The management was simple, local hemostasis. Statistically significant association was found between bleeding events and (1) history of spontaneous hemorrhage and (2) surgical procedures involving soft tissue manipulation. Withdrawal of DOAC therapy was not associated with decreased postoperative bleeding events.

CONCLUSION

The risk of bleeding in dental patients using DOACs is low with no major consequences. The data support not stopping DOACs prior to dental treatment, regardless of the complexity or the extent of the procedure. Dosage adaptation is recommended in patients with a history of spontaneous hemorrhage.

[Bone augmentation of the extremely atrophic anterior mandible, using allogeneic block grafts, via submental approach]

Edentulous patients with advanced resorption of the mandible (atrophic mandible) suffer major discomfort when using dentures. Furthermore, placing dental implants is impossible due to lack of sufficient bone volume. In the past, several methods of bone grafting to the anterior mandible have been proposed. Most of them were unpredictable in either the short or long-term. In 2002 a technique for bone grafting of the anterior mandible via a submental approach was published. A wide reflection of the soft tissue was followed by implant placement. Autogenous particulate posterior iliac crest bone graft was used. The presence of the implants did not allow for contraction of the soft tissue and bone resorption. The addition of bone volume to the chin improved the facial aesthetics of the patients due to a fuller appearance of the chin and tightening of the skin of the neck. The submental approach changes the spatial orientation of the surgeon and placement of implants in the correct location and angle become challenging. Placement of the implants too far buccally was a prosthetic problem. A major disadvantage of autogenous bone grafting is the necessity to operate a donor site. The increasing experience in use of allogenic bone grafts with resorbable collagen membranes, allowed us to modify the submental approach for bone grafting of the anterior atrophic mandible, avoiding a donor site surgery. We chose to perform the bone graft as a first stage surgery, in which, via a submental approach allogenic bone blocks were adapted and fixated to the anterior mandible with titanium screws, xenograft and resorbable collagen membranes were used. A few months (>4) were allowed for graft consolidation and then a second stage surgery was performed, via an intraoral approach dental implants were placed. In this way we avoided loss of orientation and had a familiar setting for implant location and angulation. Five patients with atrophic mandibles were treated using this surgical protocol. Based on cone beam CT imaging, average bone height in the anterior mandible prior to treatment was 5.52 mm. After bone graft, the average gain in bone height was 12.74 mm. No major post-operative complications were noted. After bone graft consolidation, 4 or 5 dental implants were placed, most of the implants used were longer than 11.5 mm. 22 implants were placed, out of which 21 integrated (95.5%). Some of the patients were rehabilitated with overdentures and locators and some with PFM bridges. All patients were followed up for more than a year and no implant failure was recorded. Bone grafting to the anterior mandible using allogenic blocks with collagen membranes via a submental approach with second stage implant placement seems to be a viable solution for rehabilitation of the atrophic mandible.

How perfect are you with defective probes? Information on the results of the mini-trial on technical quality assurance during the "Ultraschall 2012" conference in Davos

This article deals with the technical quality assurance of ultrasound B-systems. As part of a mini-trial during the Dreiländertreffen in Davos "Ultrasound 2012", we addressed the question as to whether physicians can detect faulty probes spontaneously during live scanning B-mode. For this purpose a special diagnostic device had been prepared so that groups of piezoelectric elements in the array were without function. Then the images had to be characterized by test persons without knowledge of the faulty elements. The results show that a deterioration of the image could be detected starting at five disabled elements. Due to the small number of test persons, our statements are only preliminary.

Investigation of the suitability of tissue phantoms for testing the constancy of ultrasonic transducer arrays in quality assurance

PURPOSE

To ensure high quality ultrasound diagnostics, proper functioning of the devices used is a necessary prerequisite. Ultrasound transducers have proven to be the most failure-prone part of the signal chain. Their technical monitoring is possible in principle with the help of tissue phantoms. The background of the present study is to determine which type of phantoms and which measurement parameters are best suited to a consistency test as part of routine quality assurance of ultrasound imaging systems.

MATERIALS AND METHODS

A classic wire-type phantom (ATS Mod. 539, ATS Labs Bridgeport, USA) and a 3 D cyst phantom (TCC, Timelkam, Austria) were used for the studies and comparative tests were conducted between intact transducers and those in which faults had been simulated. The collected measurement data show a relatively large scatter. Therefore, statistical analysis methods were used, and the discrimination analysis proved to be a useful tool.

RESULTS

Local failures which arise, e. g. due to the breakdown of individual piezoelectric elements or element groups in the transducer array, can be detected with the help of the gray value targets of the ATS phantom, but only in those cases in which the error-affected sound field part actually overlaps with the target under consideration. The TCC phantom is not suitable for the detection of such errors. Global transducer failures, i. e. those that affect the entire array, can even be detected with both types of phantoms.

CONCLUSION

When the emphasis of quality assessment is on the detection of local defects in the array that make up the largest part of the transducer faults, studies with conventional phantoms are only of limited value.

Physical activity and gestational weight gain: a meta-analysis of intervention trials

BACKGROUND

high gestational weight gain (GWG) has been found to be associated with a number of adverse perinatal and long-term outcomes.

OBJECTIVES

we aimed to perform a systematic review and meta-analysis to find out whether physical activity in pregnancy might help avoid high GWG.

SEARCH STRATEGY

a literature search in relevant databases and an additional search by hand through bibliographies of various publications were performed.

SELECTION CRITERIA

we included randomised controlled trials on healthy women, with increased physical activity as the only intervention. GWG had to be documented for the intervention and control group separately.

DATA COLLECTION AND ANALYSIS

two reviewers independently extracted data and performed quality assessment. Data from the included trials were combined using a random-effects model. The effect size was expressed as mean difference (MD).

MAIN RESULTS

of 1380 studies identified, 12 trials met the inclusion criteria. In seven trials, GWG was lower in the exercise group compared with the control group, whereas five trials showed a lower GWG in the control groups. The meta-analysis resulted in an MD of GWG of -0.61 (95% CI: -1.17, -0.06), suggesting less GWG in the intervention groups compared with the control groups. We found no indication for publication bias or dose effects.

AUTHOR'S CONCLUSIONS

in summary, our analyses suggest that physical activity during pregnancy might be successful in restricting GWG.

High yield expression of biologically active recombinant full length human tuftelin protein in baculovirus-infected insect cells

Tuftelin is an acidic protein expressed at very early stages of mouse odontogenesis. It was suggested to play a role during epithelial-mesenchymal interactions, and later, when enamel formation commences, to be involved in enamel mineralization. Tuftelin was also detected in several normal soft tissues of different origins and some of their corresponding cancerous tissues. Tuftelin is expressed in low quantities, and undergoes degradation in the enamel extracellular matrix. To investigate the structure and function of tuftelin, the full length recombinant human tuftelin protein was produced. The full length human tuftelin cDNA was cloned using Gateway recombination into the Bac-to-Bac system compatible transfer vector pDest10. This vector adds a hexahistidine tag to the N-terminus of the expressed protein, enabling one-step affinity purification on nickel column. The recombinant human tuftelin protein was transposed into the bacmid and expressed in Spodoptera frugiperda (Sf9) insect cells. The yield of the purified, his-tagged recombinant full length human Tuftelin (rHTuft+) was 5-8 mg/L culture. rHTuft+ was characterized by SDS-PAGE, Western blot, ESI-TOF spectrometry, restriction mapping and MS/MS sequencing. The availability of the purified, full length recombinant human tuftelin protein opened up the possibility to investigate novel functions of tuftelin. Application of rHTuft+ agarose beads onto embryonic mouse mandibular explants caused changes in the surrounding epithelial cells, including morphology, orientation and spatial organization. Further studies using DiI labeling, revealed that rHTuft+, placed on the tooth germ region, brought about recruitment of adjacent embryonic mesenchymal cells. These findings support the hypothesis that tuftelin plays an important role during embryogenesis.

Regeneration of bone and periodontal ligament induced by recombinant amelogenin after periodontitis

Regeneration of mineralized tissues affected by chronic diseases comprises a major scientific and clinical challenge. Periodontitis, one such prevalent disease, involves destruction of the tooth-supporting tissues, alveolar bone, periodontal-ligament and cementum, often leading to tooth loss. In 1997, it became clear that, in addition to their function in enamel formation, the hydrophobic ectodermal enamel matrix proteins (EMPs) play a role in the regeneration of these periodontal tissues. The epithelial EMPs are a heterogeneous mixture of polypeptides encoded by several genes. It was not clear, however, which of these many EMPs induces the regeneration and what mechanisms are involved. Here we show that a single recombinant human amelogenin protein (rHAM⁺), induced in vivo regeneration of all tooth-supporting tissues after creation of experimental periodontitis in a dog model. To further understand the regeneration process, amelogenin expression was detected in normal and regenerating cells of the alveolar bone (osteocytes, osteoblasts and osteoclasts), periodontal ligament, cementum and in bone marrow stromal cells. Amelogenin expression was highest in areas of high bone turnover and activity. Further studies showed that during the first 2 weeks after application, rHAM⁺ induced, directly or indirectly, significant recruitment of mesenchymal progenitor cells, which later differentiated to form the regenerated periodontal tissues. The ability of a single protein to bring about regeneration of all periodontal tissues, in the correct spatio-temporal order, through recruitment of mesenchymal progenitor cells, could pave the way for development of new therapeutic devices for treatment of periodontal, bone and ligament diseases based on rHAM⁺.

Localization, quantification, and characterization of tuftelin in soft tissues

Tuftelin was initially found in the developing and mature extracellular enamel. Here we describe our novel discovery of tuftelin cellular distribution (protein and mRNA) in six soft tissues. The expression levels of tuftelin mRNA were significantly higher in mouse kidney and testis, in which oxygen levels are hovering closely to hypoxia under normal conditions.

Amelogenin expression in long bone and cartilage cells and in bone marrow progenitor cells

The amelogenin protein is considered as the major molecular marker of developing ectodermal enamel. Recent data suggest other roles for amelogenin beyond structural regulation of enamel mineral crystal growth. Here we describe our novel discovery of amelogenin expression in long bone cells, in cartilage cells, in cells of the epiphyseal growth plate, and in bone marrow stromal cells.

Amelogenin, a major structural protein in mineralizing enamel, is also expressed in soft tissues: brain and cells of the hematopoietic system

The amelogenin protein is considered as the major molecular marker of developing and mineralizing ectodermal enamel. It regulates the shape, size, and direction of growth of the enamel mineral crystallite. Recent data suggest other roles for amelogenin beyond regulation of enamel mineral crystal growth. The present study describes our recent discovery of amelogenin expression in soft tissues: in brain and in cells of the hematopoietic system, such as macrophages, megakaryocytes and in some of the hematopoietic stem cells. Reverse transcription-polymerase chain reaction (RT-PCR) followed by cDNA sequencing revealed, in mouse brain, two amelogenin mRNA isoforms: the full-length amelogenin including exon 4, and the isoform lacking exon 4. Immunohistochemistry revealed amelogenin expression in brain glial cells. Mouse macrophages were found to express the full-length amelogenin sequence lacking exon 4. Confocal microscopy revealed colocalization of amelogenin and CD41 (a megakaryocyte marker), as well as amelogenin and CD34 (a hematopoietic stem cell marker) in some of the bone marrow cells. The expression of amelogenin, a major structural protein of the mineralizing extracellular enamel matrix, also in cells of non-mineralizing soft tissues, suggests that amelogenin is multifunctional. Several different potential functions of amelogenin are discussed.

Anaerobic cells of Bacillus cereus F4430/73 respond to low oxidoreduction potential by metabolic readjustments and activation of enterotoxin expression

In the present study, a food-borne pathogen strain of Bacillus cereus (F4430/73) was anaerobically grown in controlled-batch conditions under low initial oxidoreduction potential (ORP=-148 mV) using hydrogen gas as reducing agent. Its physiological characteristics, including growth, glucose fermentation capacity and enterotoxin production, were compared with anaerobic conditions generated by nitrogen gas (ORP=+ 45 mV). The results showed that low ORP affected growth mainly during the early stages. Maximal specific rates of growth and glucose consumption were reduced, and drastic changes in time profiles of fermentation product concentration were observed. Production of lactate was promoted at the expense of acetate. Nevertheless, low ORP did not affect final biomass yield. Under both ORP conditions, Non-haemolytic enterotoxin (Nhe) was produced early during the exponential growth phase as a first enterotoxin and Haemolysin BL (Hbl) later during the early stationary growth phase as a second enterotoxin. The major effect of low ORP was the strong stimulation of Hbl production and, to a lesser extent, Nhe production. This control was complex, involving different levels of regulation. We discussed the regulation of enterotoxin expression and the involvement of the pleiotropic regulator PlcR.

High yield of biologically active recombinant human amelogenin using the baculovirus expression system

The amelogenins are secreted by the ameloblast cells of developing teeth; they constitute about 90% of the enamel matrix proteins and play an important role in enamel biomineralization. Recent evidence suggests that amelogenin may also be involved in the regeneration of the periodontal tissues and that different isoforms may have cell-signalling effects. During enamel development and mineralization, the amelogenins are lost from the tissue due to sequential degradation by specific proteases, making isolation of substantial purified quantities of full-length amelogenin challenging. The aim of the present study was to express and characterize a recombinant human amelogenin protein in the eukaryotic baculovirus system in quantities sufficient for structural and functional studies. Human cDNA coding for a 175 amino acid amelogenin protein was subcloned into the pFastBac HTb vector (Invitrogen), this system adds a hexa-histidine tag and an rTEV protease cleavage site to the amino terminus of the expressed protein, enabling effective one-step purification by Ni2+-NTA affinity chromatography. The recombinant protein was expressed in Spodoptera frugiperda (Sf9) insect cells and the yield of purified his-tagged human amelogenin (rHAM+) was up to 10 mg/L culture. Recombinant human amelogenin (rHAM+) was characterized by SDS-PAGE, Western blot, ESI-TOF spectrometry, peptide mapping, and MS/MS sequencing. Production of significant amounts of pure, full-length amelogenin opened up the possibility to investigate novel functions of amelogenin. Our recent in vivo regeneration studies reveal that the rHAM+ alone could bring about regeneration of the periodontal tissues; cementum, periodontal ligament, and bone.

The human tuftelin gene and the expression of tuftelin in mineralizing and nonmineralizing tissues

Tuftelin has been suggested to play an important role during the development and mineralization of enamel, but its precise function is still unclear. This article reviews major milestones in the discovery, structural characterization, expression, localization, and conservation of tuftelin in different vertebrate species. It focuses on the structure of the human tuftelin gene, which has recently been deciphered [12]. It describes the exon-intron organization, sizes and structure, the promoter structure, and the newly discovered alternatively spliced human tooth-bud tuftelin mRNA transcripts. It also examines information on the structural motifs in the human-derived tuftelin protein and how they relate to tuftelin from other species. It reviews our recent results on the transcription of tuftelin mRNA and protein expression in several nonmineralizing soft tissues, using reverse-transcription polymerase chain reaction (RT-PCR) followed by DNA cloning and sequencing, indirect immunohistochemistry, immunohistochemistry combined with confocal microscopy, and in situ hybridization. These results and earlier Northern blot results show that tuftelin, in addition to being expressed in the developing and mineralizing tooth, is also expressed in several nonmineralizing soft tissues, suggesting that tuftelin has a universal function and/or a multifunctional role.

[Non-thermal non-cavitational effects of ultrasound]

The non-thermal, non-cavitational (NTNC-) effects of medical ultrasound are based essentially on the direct and indirect effects of the sound radiation pressure. This article introduces the biophysics of the basic mechanisms and describes possible clinical implications using selected examples. It has been determined that generally no additional risks ensue through the effects of NTNC used purely for diagnostic purposes. Significant effects can only be detected under the conditions which prevail during therapeutic exposure. The question as to whether the pulse Doppler technique is completely harmless cannot be answered conclusively at this time. The synergetic effects between ultrasound and contrast media have not yet been examined thoroughly.

Diabetes complications and risk factors in an Australian population. How well are they managed?

BACKGROUND

This study aimed to explore the relationship between complications and risk factors in the type 2 diabetes population, and to assess the level of assistance people with diabetes receive in controlling their risk factors.

METHODS

Participants were recruited from representative population surveys of South Australians aged over 18 years. Participants were asked a series of questions about their risk factors and the advice and assistance they received from their general practitioner (GP) in modifying their risk factors. Additionally, participants were clinically tested for a number of macro and microvascular complications.

RESULTS

South Australians with type 2 diabetes have a high prevalence of risk factors, with the majority being overweight or obese, doing no vigorous exercise and having high blood pressure. They also have a high prevalence of complications, with 53% having at least one macrovascular complication and 66% having at least one microvascular complication. Additionally, participants reported high levels of GP advice and assistance on the risk factors where pharmacological controls were available, but low levels of assistance where non-pharmacological interventions were needed to control the risk factor.

CONCLUSIONS

The prevalence of diabetes risk factors and complications among South Australians with type 2 diabetes is a cause for concern, as is the lack of assistance offered by GPs to modify risk factors. Multi-disciplinary approaches to the control of risk factors and patient self-management and education are critical to the progression and success of diabetes care.

Prospects for smoking cessation among people with insulin-dependent diabetes

As part of an initiative to develop a smoking cessation resource tailored to the needs of smokers with diabetes, we undertook a survey of 223 people with insulin-dependent diabetes (IDDM) aged 15-40 years, 54 of whom were smokers. Smokers had high levels of awareness that smoking increases the risk of heart and peripheral vascular disease, but were less aware of the risk of microvascular complications. Nearly half of the smokers had other members of the household who were smokers, and 56% indicated they would expect to receive no more than a little encouragement from friends and family members to quit. Concern about weight gain and dietary adherence was a barrier to quitting smoking for approximately one-third of smokers. Seventy percent of smokers recalled advice to quit smoking from a general practitioner, but this most often had involved minimal advice to quit. There is scope for patient education with respect to microvascular complications exacerbated by smoking, and a need to consider the smoking habits of other household members and enlist their active support for smoking cessation.