Comparison of cone beam CT scans with enhanced photostimulated phosphor plate images in the detection of root fracture of endodontically treated teeth.

OBJECTIVES: Two-dimensional intraoral radiography is the most common tool for diagnosing root fractures (RFs). Cone beam CT (CBCT) is widely used to depict RFs in endodontically treated teeth. Beam hardening and other artefacts caused by gutta percha may result in an incorrect diagnosis when using CBCT only. A comparison of two CBCT machines with photostimulated phosphor (PSP) plate images enhanced with the equalization tool was carried out to detect RFs in endodontically treated teeth. METHODS: 66 roots were collected, decoronated and treated endodontically using the same technique with gutta percha. 33 of these roots were randomly selected and fractured; the 2 root fragments were glued together with 1 layer of methyl methacrylate and placed randomly in 8 prepared beef rib fragments. Large fields of view (FOVs) were acquired with one CBCT unit and small FOVs with the second CBCT unit. Periapical radiographs (using intraoral PSP plates) were also acquired. A contrast enhancement tool was used when evaluating the PSP plate images. RESULTS: Small FOV images had significantly higher accuracy (area under the receiver operating characteristic curve) and sensitivity in detecting RFs than PSP plates and large FOV images. The specificity of the enhanced PSP images was higher than, although not significantly higher than, the small FOV images and was significantly higher than the large FOV images. CONCLUSIONS: CBCT small FOVs should be acquired for depicting RFs of endodontically treated teeth. Images obtained using PSP plates had the lowest rate of false-positive results and their use can save the patient a radiation dose.

Cone beam CT scans with and without artefact reduction in root fracture detection of endodontically treated teeth.

OBJECTIVES: Cone beam CT (CBCT) is used widely to depict root fracture (RF) in endodontically treated teeth. Beam hardening and other artefacts due to gutta-percha may increase the time of the diagnosis and result in an incorrect diagnosis. Two CBCT machines, ProMax(®) (Planmeca, Helsinki, Finland) and Master 3D(®) (Vatech, Hwaseong, Republic of Korea), have the option of applying an artefact reduction (AR) algorithm. The aim of this study was to determine whether using an AR algorithm in two CBCT machines enhances the accuracy of detecting RFs in endodontically treated teeth. METHODS: 66 roots were collected and decoronated. All roots were treated endodontically using the same technique with gutta-percha and zinc oxide cement. One-half of the roots were randomly selected and fractured using a nail that was tapped gently with a hammer until complete fracture resulted in two root fragments; the two root fragments were glued together with one layer of methyl methacrylate. The roots were placed randomly in eight prepared beef rib fragments. RESULTS: The highest accuracy was obtained when the ProMax was used without AR. The lowest accuracy was obtained with the Master 3D when used with AR. For both machines, accuracy was significantly higher without AR than with AR. Both with and without AR, the ProMax machine was significantly more accurate than the Master 3D machine. The same rank ordering was obtained for both sensitivity and specificity. CONCLUSIONS: For both machines, AR decreased the accuracy of RF detection in endodontically treated teeth. The highest accuracy was obtained when using the ProMax without AR.

A mathematical model relating changes of grey values to changes of thicknesses of a stepwedge.

The purpose of this report is to present a mathematical model relating changes in grey values to changes of thicknesses of a stepwedge. Radiographs of a stepwedge were obtained through a limited exposure range on a single Kodak 6100 charge-coupled device detector at 63 kVp and 70 kVp. Grey values from each step were evaluated relative to the corresponding step thickness. All possible regression fits were evaluated based on their coefficient of determination (R(2)) value and their mean squared errors (MSEs) relative to the original thickness. For all exposure settings, the fifth-degree polynomial was the best possible fit, with the highest R(2) value and the lowest MSE.

Evaluation of a cone beam CT artefact reduction algorithm.

OBJECTIVES: An algorithm and software to reduce metal artefact has been developed recently and is available in the Picasso Master 3D® (VATECH, Hwaseong, Republic of Korea), which under visual assessment produces better quality images than were obtainable previously. The objective of this in vitro study was to investigate whether the metal artefact reduction (MAR) algorithm of the Picasso Master 3D machine reduced the incidence of metal artefacts and increased the contrast-to-noise ratio (CNR) while maintaining the same gray value when there was no metallic body present within the scanned volume. METHODS: 20 scans with a range of 50-90 kVp were acquired, of which 10 had a metallic bead inserted within a phantom. The images obtained were analysed using public domain software (ImageJ; NIH Image, Bethesda, MD). Area histograms were used to evaluate the mean gray level variation of the epoxy resin-based substitute (ERBS) block and a control area. The CNR was calculated. RESULTS: The MAR algorithm increased the CNR when the metallic bead was present; it enhanced the ERBS gray level independently of the presence of the metallic bead. The image quality also improved as peak tube potential was increased. CONCLUSION: Improved quality of images and regaining of the control gray values of a phantom were achieved when the MAR algorithm was used in the presence of a metallic bead.

[Polymorphous low-grade adenocarcinoma of the maxilla simulating an odontogenic cyst]. / Adénocarcinome polymorphe de bas grade du maxillaire simulant un kyste odontogénique.

INTRODUCTION: In 1990, the WHO classified Polymorphous Low Grade Adenocarcinoma as a low-grade malignant tumor of the minor salivary glands. This tumor often originates from the hard or soft palate minor salivary glands. We report the first case revealed as an infected maxillary odontogenic cyst around an impacted tooth. CASE REPORT: A 50-year-old female presented 20 months ago with a bulging, painful oral mass in the right superior vestibule. The diagnosis was infected odontogenic cyst associated with an impacted canine tooth. A course of oral antibiotics was given and cyst enucleation and tooth extraction were performed 6 days later. Ameloblastoma was suggested on macroscopic findings; nevertheless, the pathologic end diagnosis was Polymorphic Low-Grade Adenocarcinoma of minor salivary gland origin. After negative carcinological screening, wide surgical resection was performed. Postoperative external radiotherapy was applied to the operated area as well as to cervical lymph node areas. DISCUSSION: Most of the 565 published cases concern a palatine location. Even though wide surgical resection is sufficient, external radiotherapy may be used on a case-by-case basis.

Patient-controlled analgesia in orthognathic surgery: evaluation of the relationship to anxiety and anxiolytics.

BACKGROUND: Although patient-controlled analgesia' (PCA) use has been reported in oral and maxillofacial surgery,(8) it has not been evaluated for use in orthognathic surgery. In this study, we evaluated the relationship between age, gender, and preoperative anxiety and postoperative morphine intake after orthognathic surgery in the PCA environment. STUDY DESIGN: Fifty-one patients (34 female, 17 male) underwent orthognathic surgery. Patients' anxiety was evaluated preoperatively. All patients received morphine-based postoperative PCA. Relationship between preoperative anxiety and postoperative visual analog scale (VAS) and 24 hour morphine intake was evaluated. Patients were randomly grouped according to whether preoperative oral anxiolytics were prescribed. RESULTS: Age and VAS were correlated, as well as preoperative anxiety score and postoperative morphine intake (P < .05). Female patients receiving anxiolytics before surgery had less morphine consumption than those who did not. CONCLUSION: Preoperative anxiety directly influences postoperative PCA morphine intake. Anxiolytics preoperatively seem to reduce the need for postoperative analgesics.

Polymorphous low-grade adenocarcinoma: a review regarding an unusual presentation as infected odontogenic cyst.

The World Health Organisation (WHO) classified polymorphous low-grade adenocarcinoma (PLGA) in 1990 as a low-grade malignancy; ICD-O 8525/3 being the assigned international code. It has been frequently described as occurring in hard- or soft-palate accessory salivary glands: some cases being described in the tongue and in major salivary glands. We present an extensive literature review about PLGA and the most common diagnostic pitfalls. We also report the first case where it was seen surrounding an impacted maxillary tooth and discuss it in regard to our review.

[Testicular choriocarcinoma presenting as cutaneous metastasis. A case report and review of the literature]. / Les métastases cutanées révélatrices des choriocarcinomes: revue de la littérature. A propos d'une localisation nasale d'origine testiculaire.

Choriocarcinoma are germinal tumors from testicular cells in men or foetal trophoblast in women. Cutaneous metastasis are very rare. The authors report a case of angioma-like tumor in a 22-year-old man which was a cutaneous metastasis of a testicular carcinoma. Diagnosis was of course histologic. Testicular echography showed an intra testicular tumor, pulmonary and abdominal CT-scan showed multiple metastases. Orchidectomy and retroperitoneal lymphadenectomy were performed before a general chemotherapy. Patient died 14 months after diagnosis. Only 11 cases of cutaneous metastasis of choriocarcinoma were found in the world literature (7 men and 4 women). All cases showed diagnosis trap for plastic surgeon.