F.W. Neukam

Panoramic radiograph, computed tomography or magnetic resonance imaging. Which imaging technique should be preferred in bisphosphonate-associated osteonecrosis of the jaw? A prospective clinical study

It was the aim of the present study to find out which radiological imaging techniques allow assessing the extent of bisphosphonate-associated osteonecrosis of the jaw (BONJ) in an adequate way. Twenty-four patients suffering from BONJ were included in the study. Before surgery, each patient was examined with panoramic radiograph, contrast-enhanced magnetic resonance imaging (MRI) and non-enhanced computed tomography. The detectability of BONJ was assessed for the three imaging techniques. The extent of the jaw region affected by BONJ was determined in MRI and CT scans and compared to the intra-operative situation. The detectability of BONJ lesions was 54% for panoramic radiographs, 92% for MRI scans and 96% for computed tomography (CT) scans. The intra-operatively assessed extent of BONJ correlated significantly with the measurements on CT scans (p = 0.0004) but did not correlate significantly with the measurements in MRI scans (p = 0.241). The intra-operatively measured extent of BONJ differed significantly from the CT measurements (p = 0.00003) but not from the MRI data (p = 0.137). Although MRI as well as CT have a high detectability for BONJ lesions that exceeds that of panoramic radiographs by far, both techniques show problems with the exact assessment of the extent of BONJ lesions in the individual patients. Therefore, the relevance of MRI and CT for the preoperative assessment of the extent of BONJ lesions is limited. Future research should focus on the identification of imaging techniques that allow assessing the extent of BONJ lesions with a higher accuracy.

Long-term results of distraction osteogenesis of the maxilla and midface

Since the beginning of 1998, eight patients have been treated by osteodistraction to correct hypoplasia of the maxilla and midface of various origins. Among them were five patients who were treated by high LeFort I osteotomies and insertion of subcutaneous intraoral distraction devices in the malar region. In the remaining three patients, extraoral distraction devices were applied after LeFort II and III osteotomies. Distraction osteogenesis was successful in all cases, resulting in a mean sagittal bone gain measured parallel to the skull base of 9.0 mm (range 4.5-12.0) in the group treated with intraoral distractors and a mean of 20.3 mm in the extraoral distraction group (range 15.0-25.0). All patients were kept under orthodontic supervision before, during, and after osteodistraction. Long-term cephalometric and clinical evaluation after a mean follow-up period of 24 months in the intraoral distraction group (range 22-26) and 12 months in the extraoral distraction group (range 10-14) show stable results concerning the skeletal and dental relations. Long-term follow-up is necessary.

Methylenetetrahydrofolate reductase polymorphism and minor increase of risk for oral cancer

Purpose: We investigated whether the mutant methylenetetrahydrofolate reductase (MTHFR) increases risk for oral cancer. The common germ-line mutation C677T in the MTHFR gene significantly diminishes specific activity of the enzyme, which is responsible for the circulating form of folate. Folate deficiency is associated with increased risk for thrombosis, as well as for several types of cancer, through disruption of DNA methylation, DNA synthesis and deficient DNA repair. Methods: We searched for the C677T mutation by restriction fragment analysis of PCR products in DNA samples of 110 patients with oral squamous cell carcinoma and 120 healthy controls of comparable ethnicity, age and sex. Results: The number of heterozygotes was significantly different in the two groups (P<0.005), as well as in subgroups of patients with or without a positive family history for cancer, compared to normal controls (P<0.01 and P<0.005, respectively). Furthermore, the subgroup of patients with a positive family history for thrombophilia had a significant increase both in the frequencies of mutant alleles (P<0.01) and heterozygotes (P<0.001) in comparison to normal controls. Conclusions: The obtained results suggest that the MTHFR mutation is a minor contributing factor in oncogenesis in the oral region, in conjunction with low dietary uptake of folate.

Effects of osteoinduction on bone regeneration in distraction: Results of a pilot study *

Rate and frequency of distraction as well as stimulatory effects transmitted by growth factors and local gene therapy have a decisive influence on bone regeneration. In a pilot study we tested the effect of four different morphogenetic and mitotic proteins and a genetically transferred vector system on bone healing in continuous osteodistraction in a large animal experiment on 24 Goettingen mini-pigs. For this purpose bone morphogenetic protein (BMP-2), BMP-7, TGF-beta, IGF-1 and a liposome vector were instilled into the distraction gap. The animals were killed after 1-4 weeks of consolidation. Histological and radiological evaluations showed maximum bone formation after the application of BMP-2/7, whereas the application of TGF-beta, IGF-1 and the liposomal vector had only a limited effect on bone regeneration. The quantitative analysis demonstrated an average amount of bone in the distraction gap of 50% and 61% after instillation of BMP-2 and 7, respectively. The BMP-2 expression, however, was maximal after induction with the non-viral vector. Only after BMP-2/7 application could physical, radiographic and histological evidence of bone union be detected. In bone distraction with a short observation period the application of morphogenetic proteins seems to enhance bone regeneration significantly. Before application in humans further studies are necessary to measure the dose-effect relationship, the mode of application and the efficacy of different inductive proteins. The combination of osteodistraction with osteoinduction, however, could shorten treatment times dramatically.

Msx-1 is suppressed in bisphosphonate-exposed jaw bone analysis of bone turnover-related cell signalling after bisphosphonate treatment

OBJECTIVES Bone-destructive disease treatments include bisphosphonates and antibodies against receptor activator for nuclear factor κB ligand (aRANKL). Osteonecrosis of the jaw (ONJ) is a side-effect. Aetiopathology models failed to explain their restriction to the jaw. The osteoproliferative transcription factor Msx-1 is expressed constitutively only in mature jaw bone. Msx-1 expression might be impaired in bisphosphonate-related ONJ. This study compared the expression of Msx-1, Bone Morphogenetic Protein (BMP)-2 and RANKL, in ONJ-affected and healthy jaw bone. MATERIAL AND METHODS An automated immunohistochemistry-based alkaline phosphatase-anti-alkaline phosphatase method was used on ONJ-affected and healthy jaw bone samples (n = 20 each): cell-number ratio (labelling index, Bonferroni adjustment). Real-time RT-PCR was performed to quantitatively compare Msx-1, BMP-2, RANKL and GAPDH mRNA levels. RESULTS Labelling indices were significantly lower for Msx-1 (P < 0.03) and RANKL (P < 0.003) and significantly higher (P < 0.02) for BMP-2 in ONJ compared with healthy bone. Expression was sevenfold lower (P < 0.03) for Msx-1, 22-fold lower (P < 0.001) for RANKL and eightfold higher (P < 0.02) for BMP-2 in ONJ bone. CONCLUSIONS Msx-1, RANKL suppression and BMP-2 induction were consistent with the bisphosphonate-associated osteopetrosis and impaired bone remodelling in BP- and aRANKL-induced ONJ. Msx-1 suppression suggested a possible explanation of the exclusivity of ONJ in jaw bone. Functional analyses of Msx-1- RANKL interaction during bone remodelling should be performed in the future.

Long‐term changes in graft height after maxillary sinus augmentation, onlay bone grafting, and combination of both techniques: a long‐term retrospective cohort study

OBJECTIVES This investigation focused on long-term changes in graft height, implant survival rate, and peri-implant tissue conditions of dental implants placed in alveolar ridges after augmentation procedures with a follow-up of 10 years. MATERIAL AND METHODS We conducted a retrospective cohort study with prospective long-term follow-up of 25 patients with edentulous severe atrophic maxillary situations who received a vertical augmentation procedure with autologous bone prior to implant placement. The participants were divided into three groups according to whether they underwent sinus elevation, onlay grafting, or a combination of both techniques. After a four-month healing period, 127 implants were inserted in the corresponding regions. Following a six-month healing period, the participants underwent prosthodontic rehabilitation, incorporating a fixed or removable implant denture. The cohort was clinically and radiographically followed up 1, 5, and 10 years after augmentation. The following parameters were measured: radiographic vertical bone changes, implant loss, peri-implant pocket depth (PD), width of keratinized mucosa (KM), sulcus fluid flow rate (SFFR), and the radiographic distance between the implant shoulder and the first visible bone-to-implant contact (DIB). RESULTS Seven implants were lost during the observation period, resulting in a cumulative 10-year survival rate of 94.48%. Significant bone loss occurred during the first 12 months, after which the resorption slowed down and bone height eventually stabilized. After 10 years, the total vertical bone loss was 27.51% after onlay grafting, 28.14% after sinus elevation, and 30.24% in the combination group, with no statistically significant between-group differences. Peri-implant follow-up examinations revealed a positive correlation between SFFR and PD, respectively, DIB, and a negative correlation between SFFR and KM. CONCLUSION The treatment method does not seem to impact vertical bone loss following augmentation using autologous grafts. This approach results in long-term stability of dental implants. A sufficient width of keratinized peri-implant mucosa is important to prevent peri-implant bone loss and inflammation.

Factors influencing relative speech intelligibility in patients with oral squamous cell carcinoma: a prospective study using automatic, computer- based speech analysis

Oral squamous cell carcinoma (OSCC) and its treatment impair speech intelligibility by alteration of the vocal tract. The aim of this study was to identify the factors of oral cancer treatment that influence speech intelligibility by means of an automatic, standardized speech-recognition system. The study group comprised 71 patients (mean age 59.89, range 35-82 years) with OSCC ranging from stage T1 to T4 (TNM staging). Tumours were located on the tongue (n=23), lower alveolar crest (n=27), and floor of the mouth (n=21). Reconstruction was conducted through local tissue plasty or microvascular transplants. Adjuvant radiotherapy was performed in 49 patients. Speech intelligibility was evaluated before, and at 3, 6, and 12 months after tumour resection, and compared to that of a healthy control group (n=40). Postoperatively, significant influences on speech intelligibility were tumour localization (P=0.010) and resection volume (P=0.019). Additionally, adjuvant radiotherapy (P=0.049) influenced intelligibility at 3 months after surgery. At 6 months after surgery, influences were resection volume (P=0.028) and adjuvant radiotherapy (P=0.034). The influence of tumour localization (P=0.001) and adjuvant radiotherapy (P=0.022) persisted after 12 months. Tumour localization, resection volume, and radiotherapy are crucial factors for speech intelligibility. Radiotherapy significantly impaired word recognition rate (WR) values with a progression of the impairment for up to 12 months after surgery.

Air gun pellet remaining in the maxillary sinus for 50 years: a relevant risk factor for the patient?

The authors report the case of a 62-year-old man referred to the department of oral and maxillofacial surgery because of a clinical suspicion of palate carcinoma. Incidentally, diagnostic radiology showed a metallic foreign body in the left maxillary sinus. Anamnestic data revealed that a shot from an air gun accidentally hit the patients left cheek in 1957. The lead-containing air gun pellet was removed by endoscopic antrostomy and the diagnosis of squamous cell carcinoma was confirmed by histopathological examination. 50 years after the pellets impact, toxicological blood analysis showed no increased blood lead level. It remains unclear whether the air gun pellet has a potential toxicological effect or is related to the development of the patients oral carcinoma. In this context the article reviews the literature and discusses the necessity of removing metal-containing foreign bodies, the role of lead in chronic toxicity and its possible carcinogenic effect in humans.

Solitärer fibröser Tumor der Zunge

ZusammenfassungSolitäre fibröse Tumoren (SFT) sind seltene und zumeist benigne fibroblastäre Tumoren, die sich insbesondere in der Pleura manifestieren. Ein extrapleurales Auftreten von SFT ist zwar beschrieben worden, dennoch stellt die Mundhöhle eine außergewöhnliche Lokalisation für den SFT dar. Es wird über den sehr seltenen Fall eines SFT im Bereich der Zunge berichtet, der wegen seiner guten Abgrenzbarkeit vom umgebenden Gewebe problemlos entfernt werden konnte. Die intraoperative Schnellschnittdiagnostik diente zum Ausschluss eines malignen Prozesses. Für die definitive histopathologische Zuordnung war die Durchführung zusätzlicher immunhistologischer Untersuchungen hilfreich. Da sich SFT nur in Ausnahmefällen maligne verhalten und Rezidive nach vollständiger Entfernung bisher nicht bekannt sind, kann der Schwerpunkt bei der Operation auf die Funktionserhaltung der Zunge gelegt werden.AbstractSolitary fibrous tumors (SFT) are rare, mostly fibroblastic tumors usually situated in the pleura. Extrapleural manifestations have been described. However, the oral cavity is an uncommon localisation of this tumor. We report the very unusual case of an SFT affecting the tongue that could be removed completely because of its clear delineation. Intraoperative incisional biopsies were used to exclude malignancy. For definitive classification of the tumor, additional histopathologic examinations had to be carried out. Because SFT exhibit malignant behavior only in exceptional cases and their recurrence after complete removal has never been encountered, surgery can focus on the preservation of undisturbed function of the tongue.

[Solitary fibrous tumor in the tongue: case report and review of the literature].

ZusammenfassungSolitäre fibröse Tumoren (SFT) sind seltene und zumeist benigne fibroblastäre Tumoren, die sich insbesondere in der Pleura manifestieren. Ein extrapleurales Auftreten von SFT ist zwar beschrieben worden, dennoch stellt die Mundhöhle eine außergewöhnliche Lokalisation für den SFT dar. Es wird über den sehr seltenen Fall eines SFT im Bereich der Zunge berichtet, der wegen seiner guten Abgrenzbarkeit vom umgebenden Gewebe problemlos entfernt werden konnte. Die intraoperative Schnellschnittdiagnostik diente zum Ausschluss eines malignen Prozesses. Für die definitive histopathologische Zuordnung war die Durchführung zusätzlicher immunhistologischer Untersuchungen hilfreich. Da sich SFT nur in Ausnahmefällen maligne verhalten und Rezidive nach vollständiger Entfernung bisher nicht bekannt sind, kann der Schwerpunkt bei der Operation auf die Funktionserhaltung der Zunge gelegt werden.AbstractSolitary fibrous tumors (SFT) are rare, mostly fibroblastic tumors usually situated in the pleura. Extrapleural manifestations have been described. However, the oral cavity is an uncommon localisation of this tumor. We report the very unusual case of an SFT affecting the tongue that could be removed completely because of its clear delineation. Intraoperative incisional biopsies were used to exclude malignancy. For definitive classification of the tumor, additional histopathologic examinations had to be carried out. Because SFT exhibit malignant behavior only in exceptional cases and their recurrence after complete removal has never been encountered, surgery can focus on the preservation of undisturbed function of the tongue.