Evaluation of the Maxillary Sinus of Patients with Maxillary Posterior Implants: A CBCT Cross-Sectional Study.

BACKGROUND: During oral rehabilitation, dental implants in the posterior maxilla can penetrate the maxillary sinus. The aim was to evaluate the presence of maxillary sinus abnormalities in patients with dental implants in the posterior maxillary region using cone-beam computed tomography (CBCT) images. MATERIALS AND METHODS: This was a retrospective cross-sectional study, and CBCT scans of 199 patients (459 dental implants) were evaluated. Implants were assessed according to their relative location to the maxillary sinus floor (up to 2 mm from the maxillary sinus cortex, within 2 mm to intimate contact with the maxillary sinus cortex, apical third inside the maxillary sinus, two-thirds or more inside the maxillary sinus) and bone-fixation tissue (Alveolar ridge or Bone graft). Maxillary sinus abnormalities were classified. Kappa and Weighted Kappa and the Kruskal-Wallis test were applied. RESULTS: A higher prevalence of mucosal thickening and non-specific opacification were observed in implants located within 2 mm to intimate contact with the cortex of the maxillary sinus floor. Of the 66 implants with apical thirds located inside the maxillary sinus, 31 (46.7%) were associated with sinus abnormalities and of all implants (n = 5) with two-thirds or more located inside the maxillary sinus, all of these were associated with sinus abnormalities. No association was observed in relation to implant bone-fixation tissue. CONCLUSIONS: This study found a significant association between dental implant placement near or within the sinus and sinus abnormalities, mainly mucosal thickening and non-specific opacification.

Cross-Sectional Study of Mandibular Canal Branching in Regions Affected by Dental Inflammation with Cone Beam Computed Tomography / Estudio Transversal de la Ramificación del Canal Mandibular en Regiones Afectadas por Inflamación Dental con Tomografía Computarizada de Haz Cónico

ABSTRACT: The present study aimed to investigate the occurrence of mandibular canal alterations in regions with dental inflammation by means of cone beam computed tomography (CBCT). A database of 2,484 CBCTs was reviewed for identifying dental inflammation in mandibular alveolar ridges. The final sample consisted of 150 CBCTs, including 91 females and 59 males, with ages ranging from 13 to 89 years (mean age of 47.06; ± SD=18.722). The presence and location of dental inflammation, gender, age, as well as presence and location of mandibular canal branching (MCB) were evaluated. The Kolmogorov-Smirnov, Chi-square, and T-test were applied to verify the statistical relationship of the data. There were 178 images of dental inflammation on 150 CBCTs, mainly located at molars' region (75 %). Apical lesions were the most common type of dental inflammation found (79 or 44.4 % of the sample), followed by pericoronitis (32; 18.0 %). This study identified 135 mandibular canal branches in the exams that presented dental inflammation. The MCB were also most commonly located at molars' region (74.07 %). No statistical difference was identified regarding the distribution of mandibular canal branching in relation to the sites with dental inflammation (p=0.370).The MCB found were mostly single (86 or 63.7 % of the total). Sex had no influence on mandibular canal branching occurrence (p=0.308), not did age (p=0.728). A high prevalence of mandibular canal branching was observed in the regions where dental inflammation were identified, most commonly found in the molar region.

RESUMEN: El presente estudio tuvo como objetivo investigar la ocurrencia de ramificación del canal mandibular (RCM) en regiones con inflamación dental mediante tomografía computarizada de haz cónico (TCHC). Se revisó una base de datos de 2.484 TCHC para identificar la inflamación dental en las crestas alveolares mandibulares. La muestra final consistió en 150 TCHC, incluidas 91 mujeres y 59 hombres, con edades comprendidas entre 13 y 89 años (edad media de 47,06 ± DE = 18,722). Se evaluaron el sexo, la edad, la presencia y la ubicación de la inflamación dental, así como la presencia y ubicación de RCM. KolmogorovSmirnov, Chi-cuadrado y prueba-T se aplicaron para verificar la relación estadística de los datos. Hubo 178 imágenes de inflamación dental en 150 TCHC, ubicados principalmente en la región de los molares (75 %). Las lesiones apicales fueron el tipo más común de inflamación dental encontrada (79 o 44,4 % de la muestra), seguidas por pericoronitis (32; 18,0 %). Este estudio identificó 135 ramas del canal mandibular en las regiones que presentaron inflamación dental. El RCM también se localizó con mayor frecuencia en la región de los molares (74,07 %). No se identificaron diferencias estadísticas con respecto a la distribución de la ramificación del canal mandibular en relación con los sitios con inflamación dental (p = 0,370). Las RCM encontrados fueron en su mayoría solteros (86 o 63,7 % del total). El sexo no tuvo influencia en la ocurrencia de la ramificación del canal mandibular (p = 0,308), no la edad (p = 0,728). Se observó una alta prevalencia de ramificación del canal mandibular en las regiones donde se identificó la inflamación dental, que se encuentra con mayor frecuencia en la región molar.

Mandibular canal branching assessed with cone beam computed tomography.

PURPOSE: The mandibular canal must be considered in dental procedures to avoid injuries of the alveolar inferior nerve. The occurrence of anatomical variations of the mandibular canal increases the risk of neurovascular injuries. The purpose of this study was to identify and describe the prevalence of mandibular canal branching (MCB) using cone beam computer tomography (CBCT). METHODS: Seven hundred standardized CBCTs were selected. The images were evaluated for the presence of MCB and for the detection of pathologies that could affect the structure of the canals. The data were analyzed using descriptive statistics and the Chi-squared test. RESULTS: The prevalence of MCB was 41.1%. There was no statistical difference between genders with the presence of the branches (p > 0.005). The highest prevalence was in the premolar and retromolar regions. Pathologies found in the molar region were frequently connected with MCB (77.8%), and the most common pathology related to branches was periapical lesion. CONCLUSIONS: Mandibular canal branching presented a high prevalence in CBCT imagery, more frequently located in regions of the premolar and retromolar. An adequate diagnosis of the MCB is necessary to perform dental procedures and verify possible associated pathologies.

Medial preoptic area adrenergic receptors modulate glycemia and insulinemia in freely moving rats.

In order to investigate the role of medial preoptic area (MPOA) adrenoceptors in regulation of plasma glucose and insulin secretion, we injected 40 nmol of noradrenaline, clonidine or isoproterenol into the MPOA of freely moving Wistar rats. The animals were fitted with chronic jugular catheters for blood sampling and unilateral intracerebral cannulae placed into MPOA. The results showed that noradrenaline injection into MPOA produced a rapid increase in plasma glucose levels and insulin secretion, reaching a peak at 15 min post stimulus (25% over basal, P<0.01) for plasma glucose and at 30 min for insulin secretion (94% over basal, P<0.05). Injection of the alpha2-adrenergic agonist clonidine into MPOA produced a faster, more intense and longer-lasting hyperglycemic response (69% over basal, P<0.01). In contrast to the noradrenaline effect on insulin secretion, clonidine markedly decreased plasma insulin levels, reaching a maximal suppression at 10 min (72% below basal, P<0.01). On the other hand, the beta-adrenergic agonist isoproterenol only produced a small, transient increase in plasma glucose levels. When rats were pre-treated with guanethidine (10 mg/100 g, i.p.), despite reduced baseline of plasma glucose (35% smaller then control group, P<0.01) and increased plasma insulin baseline (300% higher then control group, P<0.01), they still showed a hyperglycemic response to noradrenaline injection into MPOA. We conclude that the activation of preoptic alpha2-adrenoceptors induced hyperglycemia and inhibit insulin secretion, probably by activation of the sympathoadrenal system that cannot be blocked by prior administration of guanethidine.