Flávio Ricardo Manzi

Anatomic variations and lesions of the maxillary sinus detected in cone beam computed tomography for dental implants

OBJECTIVE To evaluate the presence of anatomic variations and lesions of the maxillary sinus in cone beam computed tomography (CBCT) of the maxilla required for dental implant planning. MATERIAL AND METHODS This transversal prevalence study evaluated a sample of 500 consecutive CBCT exams. The inclusion criteria were CBCT exams of the maxilla required for dental implant planning. The CBCT exams were independently evaluated by two oral and maxillofacial radiologists who assessed the presence of anatomic variations and lesions of the maxillary sinus. As most of the CBCT exams did not allow the evaluation of the area close to the maxillary sinus roof, anatomic variations that take place at this site were not assessed. RESULTS The anatomic variations detected were pneumatization (83.2%), antral septa (44.4%), hypoplasia (4.8%), and exostosis (2.6%). The identified lesions were mucosal thickening (≤3 mm in 54.8% and >3 mm in 62.6%), polypoid lesions (21.4%), discontinuity of the sinus floor (17.4%), air-fluid level (4.4%), bone thickening of the maxillary sinus wall (3.8%), antroliths (3.2%), discontinuity of the sinus lateral wall (2.6%), sinus opacification (1.8%), and foreign body (1.6%). CONCLUSION Anatomic variations and lesions of the maxillary sinus were common findings in CBCT exams of the maxilla required for dental implant planning. As some of these conditions can modify dental implant planning and must require specialized treatment, its recognition is noteworthy in dental practice, and especially in implantology. The amount and significance of the anatomic variations and lesions detected in this study reinforces the importance of computed tomography in preoperative dental implant planning.

Stylohyoid syndrome: surgical approach.

AbstractThe best-known cervicopharyngeal pain is Eagle syndrome, in which symptomatic elongation of the stylomandibular process occurs and may be accompanied by stylohyoid ligament calcification. Among the causes of elongation of the styloid process, the following may be mentioned: history of trauma, styloid ligament calcification, and formation of bony tissue in the insertion of the styloid ligament. When there is no history of trauma or surgery, it is called the stylohyoid syndrome. In the current study, the clinical case of 34-year-old woman is reported, complaining of pain in the region of the neck, without any history of neck surgery or trauma. A panoramic radiograph and computed tomographic scan showed bilateral elongation of the styloid process. Extraoral surgical intervention was the treatment of choice. It is important to point out that dentists should be aware of this condition to contribute to a better diagnosis and therapeutic procedure.

Anatomic variations of paranasal sinuses—clinical case report

This article describes the clinical case of an 86-year-old female patient with an asymptomatic clinical condition, without presenting a history of previous traumatisms. When routine radiographic exam—panoramic radiograph—was performed, the following extensions of the paranasal sinuses were found: maxillary sinus (palate), sphenoid sinus (pterygoid process, major wing, and anterior clinoid process), and supraorbital portion of the frontal sinus. Thus computerized tomography was performed to confirm the diagnosis.

Effect of sodium selenite on bone repair in tibiae of irradiated rats

This study evaluated the radioprotective effect of sodium selenite on the bone repair process in tibiae of female rats. For such purpose, 100 female Wistar rats (Rattus norvegicus, albinus) were randomly assigned to 4 groups (n=25), according to the treatment received: administration of distilled water (control); administration of sodium selenite; gamma radiation; and administration of sodium selenite plus gamma radiation. A bone defect was prepared on both tibiae of all animals. Three days after surgery, the gamma radiation and selenium/gamma radiation groups received 8 Gy gamma rays on the lower limbs. Five animals per group were sacrificed 7, 14, 21, 28 days after surgery for evaluation of the repair process by bone volumetric density analysis. The 5 animals remaining in each group were sacrificed 45 days postoperatively for examination of the mature bone by scanning electron microscopy. Based on all analyzed parameters, the results of the present study suggest that sodium selenite exerted a radioprotective effect in the bone repair of tibia of irradiated rats.

Impact of human maxillary sinus volume on grafts dimensional changes used in maxillary sinus augmentation: a multislice tomographic study

PURPOSE To assess the influence of complete maxillary sinus volume on the dimensional changes of different grafts used in maxillary sinus lift. MATERIALS AND METHODS Analysis of 50 surgical procedures of maxillary sinus lift performed on 43 subjects using different grafting materials: fresh frozen allogenic particulated bone (11), hydroxyapatite (Endobon(®)) (17), 60% hydroxyapatite + 40% beta-tricalcium phosphate (Bone Ceramic(®)) (12) and Bone Ceramic(®) + Emdogain(®) (10). One hundred and fifty multislice tomographic images of the maxillary sinus were obtained using the software Syngo CT 2011 A VOLUME, measuring complete maxillary sinus volume (T0) and dimensional changes of different graft materials during periods of 15 days (T1) and 180 days (T2). The factor studied was the influence of maxillary sinus volume on the dimensional changes of different graft materials used in maxillary sinus lift in patients with posterior edentulism. Data obtained were assessed using the Students t-test and Pearsons correlation coefficient. RESULTS No correlation (r 0.112) between the total maxillary sinus volume and the dimensional changes of the different graft materials used in this study was observed (P > 0.05). CONCLUSION This study demonstrated that there is no sufficient evidence to support the thesis that the volume of the maxillary sinus influences the contraction of the grafts, at least on sample or the biomaterials evaluated in this cohort study.

Estudo morfológico do efeito radioprotetor da vitamina E (dl-alfa-tocoferil) na reparação tecidual em ratos

The purpose of this work was to evaluate the action of the vitamin E as a radioprotective agent in the process of tissue reparation in rats submitted to a surgical procedure, which consisted of a wound done in the fore dorsal area. The animals were divided into five groups: group C (controls) - wound; group VE - previous treatment with vitamin E (90 UI); group IR - wound and irradiation of the borders three days after surgery; group VEIR - previous treatment with 90 UI of the vitamin E and irradiation of the borders three days after the surgery; group OIR - previous treatment with olive oil and irradiation of the borders three days after surgery. The radioprotective effect of the vitamin E was evaluated using hematoxylin-eosin stained specimens in order to identify granulation tissue, at 4, 7, 14 and 21 days after the surgical procedures. The results showed that 6 Gy of electron irradiation with a beam of 6 MeV caused retardation of the tissue repairing process and that vitamin E was effective as a radioprotective agent.

Intermittent administration of parathyroid hormone improves the repairing process of rat calvaria defects: A histomorphometric and radiodensitometric study

Background The aim of this study was to evaluate the effects of intermittent treatment of parathyroid hormone (PTH (1-34)) on the bone regeneration of critically-sized rat calvarial bone defects. Material and Methods Thirty-two male rats were trephined (4mm fullthickness diameter), in the central part of the parietal bones and divided into 2 groups of 16. The PTH group received subcutaneous injections of PTH (1-34) at 40µg/kg, 3 times a week and the control (CTL) group received the vehicle in the same regimen. The rats were sacrificed at 4 weeks post-treatment regimen, the parietal bones were extracted and samples were evaluated through histomorphometry and radiodensitometry. Results The histological observations showed that the PTH group presented more “island-like” new bone between the defect margins with fibrous tissues than did the CTL group. The PTH group significantly exhibited greater histologic bone formation than did the CTL group (1.5mm ±0.7; 1.9 mm ± 0.6, p<0.05/ for residual bone defect). The radiodensitometry analysis revealed significant differences among the PTH and CTL groups (2.1 Al eq. ±0.04; 1.8Al eq. ±0.06, p<0.05), demonstrating an increase in bone mineral density. The PTH treatment contributed to the bone formation with a higher amount of mineral and/or fibrous tissue when compared with the CTL group. Conclusions The results suggest that it was possible to increase the process of bone regeneration by accelerating the healing process in rat calvarial defects through intermittent administration of the PTH treatment. Key words: Bone, skull, rats, bone regeneration, bone density.

Accuracy of Digital Versus Conventional Periapical Radiographs to Detect Misfit at the Implant-Abutment Interface.

PURPOSE Misfit is a risk factor for rehabilitation with implants, and its detection is of fundamental importance to the success of treatment with implants. The use of appropriate radiographic imaging is key for a good prognosis. The aim of this study was to compare the efficacy of film and digital radiographs for the detection of misfit at the implant-abutment interface. MATERIALS AND METHODS Digital and conventional (manual and automatic processing) radiography was performed in seven test specimens, each one with a different vertical misfit between the abutment and the platform of the implant. Scanning electron microscopy was used to confirm the misfit and to measure it. Five dental radiologists independently and blindly evaluated the images. Cohens kappa with linear weighting was calculated to determine interexaminer and intraexaminer concordance. Statistical analyses were performed using the Cochrans Q test and the receiver operating characteristic curve (ROC). RESULTS Interexaminer analysis showed that the kappa value was equal to 0.74, whereas the average kappa value in the intraexaminer evaluation was 0.90. Digital imaging showed the largest area on the ROC graph, and conventional images with manual processing showed the smallest area. The images obtained through conventional radiography with both manual and automatic processing showed statistically significant differences from the measurement of the gold standard (P < .05). CONCLUSION Digital imaging can be used to evaluate misfit at the implant-abutment interface. Conventional systems of radiographic imaging do not provide sufficient information to evaluate misfit at the implant-abutment interface.

Efeito da radiação ionizante sobre o paladar em pacientes submetidos a radioterapia para a região da cabeça e pescoço

OBJETIVO: Avaliar os efeitos da radiacao ionizante sobre o paladar, em pacientes que foram submetidos a radioterapia na regiao de cabeca e pescoco. MATERIAIS E METODOS: Foram selecionados 20 pacientes que possuiam diagnostico de tumor na regiao de cabeca e pescoco, que iniciaram tratamento no Setor de Radioterapia da Santa Casa de Misericordia de Belo Horizonte, MG, Brasil. Para testes do paladar, foram manipuladas quatro solucoes (salgada - NaCl; doce - sacarose; azeda - acido citrico; amarga - ureia) em tres concentracoes diferentes (fraca, media e forte), administradas por meio de conta-gotas, tres gotas de cada solucao de maneira aleatoria, respeitando a ordem das concentracoes fracas, medias e fortes. Apos a aplicacao de cada solucao, o paciente relatava o sabor que sentia. O procedimento foi realizado semanalmente durante as tres primeiras semanas de radioterapia. RESULTADOS: Foi observada diferenca estatisticamente significante na perda do paladar dos pacientes em tratamento radioterapico, quando se compararam a 1a e 4a semanas de tratamento na solucao salgada, nas tres concentracoes, na solucao doce nas concentracoes fracas e medias e nas solucoes azedas e amargas, apenas quando se testaram as concentracoes fracas. CONCLUSAO: A radiacao ionizante altera o paladar de pacientes submetidos a radioterapia de cabeca e pescoco.

Comparison of 64-Detector-Multislice and Cone Beam Computed Tomographies in the Evaluation of Linear Measurements in the Alveolar Ridge.

This study compared the accuracy of linear measurements of the alveolar ridge in images obtained using 64-detector-multislice computed tomography (CT) and cone beam CT (CBCT). Eight sites were selected corresponding to the regions of molars, premolars, canines, and incisors in six dry human jaws. After the completion of multislice CT and CBCT, the jaws were sectioned into specific regions. Results showed there was no statistically significant difference between the measurements obtained from the CT images and those obtained from dry jaws (actual measurements) for all the evaluated sites (molars, premolars, and anterior teeth). There was also no statistically significant difference between the measurements obtained by the two CT methods.