A quick guide to positioning the transbuccal set.

Exact positioning of the transbuccal set can be tricky, especially under aggravating circumstances as present scarring or high body mass index. It may result in multiple skin incisions. This article presents a simple and fast guidance technique that can help in the exact positioning of skin incision and transbuccal set.

3-Dimensional imaging for lower third molars: is there an implication for surgical removal?

PURPOSE: Surgical removal of impacted third molars may be the most frequent procedure in oral surgery. Damage to the inferior alveolar nerve (IAN) is a typical complication of the procedure, with incidence rates reported at 1% to 22%. The aim of this study was to identify factors that lead to a higher risk of IAN impairment after surgery. MATERIALS AND METHODS: In total 515 surgical third molar removals with 3-dimensional (3D) imaging before surgical removal were retrospectively evaluated for IAN impairment, in addition to 3D imaging signs that were supposed predictors for postoperative IAN disturbance. Influence of each predictor was evaluated in univariate and multivariate analyses and reported as odds ratio (OR) and 95% confidence interval (CI). RESULTS: The overall IAN impairment rate in this study was 9.4%. Univariate analysis showed narrowing of the IAN canal (OR, 4.95; P < .0001), direct contact between the IAN and the root (OR, 5.05; P = .0008), fully formed roots (OR, 4.36; P = .045), an IAN lingual course with (OR, 6.64; P = .0013) and without (OR, 2.72; P = .007) perforation of the cortical plate, and an intraroot (OR, 9.96; P = .003) position of the IAN as predictors of postoperative IAN impairment. Multivariate analysis showed narrowing of the IAN canal (adjusted OR, 3.69; 95% CI, 1.88 to 7.22; P = .0001) and direct contact (adjusted OR, 3.10; 95% CI, 1.15 to 8.33; P = .025) to be the strongest independent predictors. CONCLUSION: Three-dimensional imaging is useful for predicting the risk of postoperative IAN impairment before surgical removal of impacted lower third molars. The low IAN impairment rate seen in this study-compared with similar selected study groups in the literature of the era before 3D imaging-indicates that the availability of 3D information is actually decreasing the risk for IAN impairment after lower third molar removal.

Anatomy of impacted lower third molars evaluated by computerized tomography: is there an indication for 3-dimensional imaging?

OBJECTIVE: Surgical removal of impacted third molar is one of the most frequent procedures in oral surgery. Today 3-dimensional (3D) imaging is occasionally used. The aim of this study was to describe and estimate the frequencies of anatomic variations of lower third molars in patients with panoramic findings at high risk for inferior alveolar nerve (IAN) injury. STUDY DESIGN: The investigators designed and implemented a retrospective cases series study with a study population composed of patients presenting with an impacted lower third molar with projection of the tooth over the full width of the IAN in panoramic radiograph and, therefore, 3D imaging before a planned surgical removal. Spatial relationship to the IAN, type of angulation, root configuration and maturation were primary study variables. Descriptive statistics were computed for all variables. RESULTS: A total of 707 wisdom teeth in 472 patients (54% female, 46% male) were evaluated. A close relationship to the IAN was seen in 69.7%, and in 45.1% the diameter of the mandibular canal was reduced. In 52.8% the IAN was vestibular and in 37.3% lingual to the roots; there were 9.9% with an inter- or intraroot course. Most teeth had 1 or 2 roots (86.7%), but 13.3% had ≥3 roots. Mesial angulation was the main type (40.2%), followed by vertical (29%), horizontal (13.9%), distal (10.2%), and transverse (6.8%) positions. CONCLUSION: Based on the range of variations in the course of the nerve and the number of roots the authors recommend 3D imaging before surgical removal of a lower third molar that shows signs of a close relationship to the IAN.

First clinical application of a liquid-core light guide connected to an Er:YAG laser for oral treatment of leukoplakia.

For medical applications, erbium lasers are usually equipped with articulated mirror arms or special glass fibers. However, only with mirror arms is it so far possible to transmit high average powers or pulse energies in the region of 1 J to achieve suitable energy densities for fast tissue preparation. An alternative to the glass fiber systems mentioned above are liquid-core light guides. An extremely flexible liquid-core light guide was used to connect a dental Er:YAG laser system to an especially adapted dental laser applicator. The core liquid was continuously circulated during laser irradiation to transmit pulse energies up to 1.1 J. A modified laser handpiece was used for exemplary clinical treatment. The experimental setup with the highly flexible light guide was completed successfully, and its ease of handling for a dental surgeon was demonstrated in the clinical treatment of leukoplakia of the oral cheek mucosa. Complete ablation of the epithelium with the laser was performed. One year postoperatively, the patient remains disease-free. This article describes the technical realization of a liquid-core light guide system for medical applications. We report about the first successful clinical treatment of oral hyperkeratosis using this new light guide technology.

In-line (18)F-fluorodeoxyglucose positron emission tomography with computed tomography (PET/CT) in patients with carcinoma of the sinus/nasal area and orbit.

BACKGROUND: Contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) are the standard imaging techniques to evaluate patients with carcinoma in the sinus/nasal area and orbit. The use of positron emission tomography (PET) with (18)F-fluorodeoxyglucose (FDG) in such patients is as yet less well established. PURPOSE: The aim of this study was to assess the clinical impact of PET co-registered with CT (PET/CT). PATIENTS: Evaluation of 21 consecutive patients. METHODS: A retrospective analysis of the whole body PET/CT studies was done. Images were assessed visually without knowing the results of the other imaging technique. Histology and clinical follow-up served to verify lesions. The clinical impact on therapy was assessed together with the physician in charge. RESULTS: All patients underwent PET/CT and CT or MRI for staging (n=9 scans) and restaging (n=17 scans) without treatment between the examinations. PET/CT changed the treatment protocol in 2 patients at staging and in 7 at re-staging. Distant metastases were found in 5 and a secondary tumour in 1 patient. CONCLUSIONS: Whole body PET/CT adds clinically important information to CT or MRI, thus, influencing treatment.

Bone invasion in patients with oral cavity cancer: comparison of conventional CT with PET/CT and SPECT/CT.

PURPOSE: To prospectively compare the accuracy of helical contrast material-enhanced computed tomography (CT) with that of CT and positron emission tomography (PET) combined and CT and single photon emission CT (SPECT) combined in the detection of bone invasion in patients scheduled to undergo surgery for clinically suspected oral cavity carcinoma with possible bone invasion, with surgical results as the reference standard. MATERIALS AND METHODS: This study had local ethical committee approval, and all patients gave written informed consent. Thirty-four consecutive patients (17 men, 17 women; mean age, 64.2 years; age range, 46.0-84.6 years) who were clinically suspected of having bone invasion from oral cavity carcinoma prospectively underwent helical contrast-enhanced CT, coregistered PET/CT, and coregistered SPECT/CT. Two radiologists assessed the contrast-enhanced CT images and two nuclear medicine physicians separately assessed the PET/CT and SPECT/CT images in consensus and without knowledge of the results of other imaging tests. The presence of bone involvement as suggested with an imaging modality was compared with histologic findings in the surgical specimen. RESULTS: With histologic findings as the standard of reference, the accuracy of SPECT/CT (88% [30 of 34 patients]) was lower than that of PET/CT and contrast-enhanced CT (94% [32 of 34 patients] and 97% [33 of 34 patients], respectively). Sensitivity was highest with PET/CT (100% [12 of 12 patients]), and specificity was highest with contrast-enhanced CT (100% [22 of 22 patients]). Fluorine 18 fluorodeoxyglucose (FDG) uptake seen on two sides of the same cortical bone was not a helpful imaging pattern for better identifying bone invasion in patients without evident cortical erosion on CT scans. CONCLUSION: The assessment of cortical erosion with contrast-enhanced CT and the CT information from PET/CT are the most reliable methods for detecting bone invasion in patients with oral cavity carcinoma. FDG uptake seen on PET/CT images does not improve identification of bone infiltration.

Is primary chronic osteomyelitis a uniform disease? Proposal of a classification based on a retrospective analysis of patients treated in the past 30 years.

INTRODUCTION: Primary chronic osteomyelitis of the jaw is a rare, non-suppurative, chronic inflammatory disease of unknown aetiology. To date, classification is confusing due to a non-uniform terminology. The aim of this study was to establish a simple (clinical) classification based on patient data from our clinic. METHODS: Retrospective analysis revealed 30 cases of which clinical course, radiology, pathology, therapy and outcome were analysed. RESULTS: Both sexes were equally represented. The mean age at onset of disease was 35 years (range 5-76 years). Onset of disease revealed two peaks of incidence, one in adolescence and one after age 50 years. While clinical symptoms were similar in all cases, an increased intensity of these symptoms was noted in younger individuals as well as in the early stages of the disease. Five adults and one adolescent presented with additional non facial bone, joint and skin manifestations consistent with the diagnosis of SAPHO (synovitis, acne, pustulosis, hyperostosis, osteitis) syndrome, or chronic recurrent multifocal osteomyelitis. Radiology demonstrated sclerosis, osteolysis and periosteal reaction in variable stages in all cases. However, findings were more extensive in younger patients. Histology revealed different stages of chronic inflammation in all cases. Microabscess formation was noted in 11 cases, six of which were children/adolescents. Therapy consisted mainly of surgery, antibiotics and hyperbaric oxygen therapy. At the end of the follow up period, 11 patients demonstrated complete remission, while in 14 cases amelioration and in 5 no significant improvement was noted. CONCLUSION: Based on differences in age at presentation, clinical appearance and course, radiology and histology, a subclassification into early and adult onset primary chronic osteomyelitis has been established. Cases with purely mandibular involvement should further be distinguished from cases associated with other syndromes.

Staging of head and neck tumors: [18F]fluorodeoxyglucose positron emission tomography compared with physical examination and conventional imaging modalities.

PURPOSE: The aims of this study were to evaluate the use of [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) in the staging of primary and recurrent tumors of the head and neck in comparison to routine clinical methods (physical examination, ultrasonography, computed tomography) and to investigate the effect of FDG-PET scanning on therapeutic strategy. MATERIALS AND METHODS: Retrospective analysis of the results of FDG-PET and conventional diagnostic modalities were compared with biopsy results or patient outcome or both. In a period of 6 years, 78 FDG-PET studies were performed on 56 patients; 24 of them before therapy and 54 on suspicion of residual or recurrent tumor. The evaluation of the diagnostic results was performed separately for the primary site and the nodal sites of the neck and for tumor occurrence in the trunk. RESULTS: In detecting the primary site, FDG-PET results reached a sensitivity of 93%, a specificity of 100%, and an accuracy of 94%. In detecting the nodal sites, similar results of 94%, 97%, and 96% were seen, respectively. In detecting tumor occurrence in the trunk, results were 83%, 100%, and 98%, respectively. The McNemar test did not prove any statistically significant difference between FDG-PET and the evaluated conventional methods. When used in conjunction with conventional diagnostic tests, 22% of the PET scans gave important additional information. Finally, 11% of the performed PET scans led to a change in therapeutic planning. CONCLUSIONS: Our results show that FDG-PET is a reliable method to detect tumors in all tumor sites. Therefore, we recommend that FDG-PET scanning be performed routinely as a first diagnostic step in pretherapeutic staging of patients with biopsy-proven head and neck cancer.

Pulpal response to Er:YAG laser drilling of dentine in healthy human third molars.

BACKGROUND AND OBJECTIVES: Maintenance of pulpal health is a critical prerequisite for successful application of light amplification by stimulated emission of radiations (lasers) in the hard tissue management of vital teeth. The purpose of this study was to investigate the short- and long-term pulpal effects to cavity-preparations in healthy human teeth using erbium-doped:yttrium, aluminum, and garnet (Er:YAG) laser. MATERIALS AND METHODS: A total of seven healthy third molars that were to be removed due to space-problem were used. Following the laser excavation, the cavities in dentine were closed temporarily and the teeth were extracted after 7 days (n = 5) and 3 months (n = 2) post-operation. The specimens were fixed, decalcified, subdivided, and processed for light and transmission electron microscopy. RESULTS: In the short-term group, four of the five laser-drilled teeth did not reveal any pathological changes in the pulp-dentine complex. One tooth showed mild disruption of odontoblasts (OB) and vascular dilatation subjacent to the deepest point of the cavity-preparation with a remaining dentine thickness (RDT) of less than 80 microm. The two teeth under long-term observation revealed distinct apposition of tertiary dentine (TD), lined predominantly with cuboidal cells on its pulpal aspect. CONCLUSIONS: These results would allow a conclusion to be drawn that the Er:YAG laser under investigation is a pulp preserving hard-tissue drilling tool when used with the specific energy settings and emitting radiation at a wavelength of 2.94 microm.