Effect of alendronate on endochondral ossification in mandibular condyles of growing rats

The replacement of the calcified cartilage by bone tissue during the endochondral ossification of the mandibular condyle is dependent of the resorbing activity of osteoclats. After partial resorption, calcified cartilage septa are covered by a primary bone matrix secreted by osteoblasts. Osteoadherin (OSAD) is a small proteoglycan present in bone matrix but absent in cartilage during the endochondral ossification. The aim of this study was to analyze the effect of alendronate, a drug known to inhibit bone resorption by osteoclasts, on the endochondral ossification of the mandibular condyle of young rats, by evaluating the distribution of osteoclasts and the presence of OSAD in the bone matrix deposited. Wistar newborn rats (n = 45) received daily injections of alendronate (n = 27) or sterile saline solution as control (n = 18) from the day of birth until the ages of 4, 14 and 30 days. At the days mentioned, the mandibular condyles were collected and processed for transmission electron microscopy analysis. Specimens were also submitted to tartrate resistant acid phosphatase (TRAP) histochemistry and ultrastructural immunodetection of OSAD. Alendronate treatment did not impede the recruitment and fusion of osteoclasts at the ossification zone during condyle growth, but they presented inactivated phenotype. The trabeculae at the ossification area consisted of cartilage matrix covered by a layer of primary bone matrix that was immunopositive to OSAD at all time points studied. Apparently, alendronate impeded the removal of calcified cartilage and maturation of bone trabeculae in the mandibular ramus, while in controls they occurred normally. These findings highlight for giving attention to the potential side-effects of bisphosphonates administered to young patients once it may represent a risk of disturbing maxillofacial development.

Mini-implant insertion based on tooth crown references: a guide-free technique

Mini-implant insertion requires accurate surgical technique. This study shows an insertion technique using only tooth crown references; its scientific basis is evaluated radiographically. The sample consisted of 213 inter-radicular septa, evaluated in 53 bitewing radiographs. The proximal contour of adjacent tooth crowns was used to define septum width. The midpoint of the septum width was linked to the interdental contact point to determine septum midline. The distances from septum midline to "mesial and distal teeth were measured to evaluate the septum midline centralization degree in two different septum heights. The difference between mesial and distal distances represented the septum midline deviation degree. The mesial and distal distances were compared by t-tests, and the septum midline deviation was correlated with septum height using Pearson's correlation test. The mesial and distal distances were not statistically different in the midpoint of the septum height, but they were different at the apical septum height. There was a moderate correlation (r = 0.45) between septum midline deviation and septum height. The tooth crown references evaluated on interproximal radiographs determine a high centralization degree of the septum midline on which the insertion site could be defined. The greater centralization degree was observed at the coronal septum area.

Dentomaxillofacial manifestations of Gaucher's disease: preliminary clinical and radiographic findings

Objectives: A wide variety of manifestations is presented in patients with Gaucher's disease (GD), including bone, haematology and visceral disturbances. This study was conducted to ascertain the main maxillofacial abnormalities by means of clinical survey, panoramic and cone beam CT (CBCT); to compare the patient's group with an age-sex matched control group; and to correlate clinical and radiological data. Methods: Ten patients previously diagnosed with GD were submitted to clinical and radiological surveys (CBCT and panoramic radiographs). The examination consisted of anamnesis, extra- and intraoral examinations and analyses of each patient's records. Imaging data were collected from the point of view of 3 observers, and the results compared with a healthy group (20 individuals) by means of statistical analysis (Fisher's exact test). Results: Gaucher patients had significantly more manifestations than otherwise healthy carriers. The most prevalent findings were enlarged marrow spaces, generalized osteopenia and effacement of jaw structures (mandibular canal, lamina dura and mental foramen). Here we describe a case in which thickening of the maxillary sinus mucosa was observed on CBCT rather than opacification of the sinus as seen on panoramic radiographs. Pathological fractures, root resorption and delay on tooth eruption were not observed. Conclusions: A poor relationship could be observed between clinical and radiological data. Patients showed important bone manifestations, which require careful diagnostic and surgical planning whenever necessary. Although panoramic radiographs have shown significant differences, CBCT is more effective in pointing out differences between patients and a control group, thus showing it as an important tool for evaluation of Gaucher patients. Dentomaxillofacial Radiology (2012) 41, 541-547. doi: 10.1259/dmfr/143023353

Lower third molar infection with purulent discharge through the external auditory meatus. Case report and review of literature

This manuscript reports an uncommon case of inferior third molar facial abscess with purulent secretion drainage through the left external acoustic meatus. The patient's left external acoustic meatus was filled with a purulent secretion observed on a CT scan. He underwent surgery to drain the facial abscess. Despite facial abscesses being routine occurrences, the literature does not contain many case reports of odontogenic facial abscesses with drainage via the external acoustic meatus. These situations occur in two possible ways: multiple fissures in the anterior wall of the cartilaginous portion of the external acoustic meatus; and congenital defects that are occasionally present in the anterior-superior aspect of the external acoustic meatus, known as the foramen of Huschke, which allow communication between the external acoustic meatus and mandibular fossa. These defects may also predispose the patient to the spread of the infection or tumour from the external auditory canal to the infratemporal fossa and vice versa. No otological sequelae were observed in this case. The authors conclude that the hypothesis of bone malformation cannot be excluded, and affirm that any facial abscess requires appropriate and immediate treatment for adequate resolution, by removing the causal factor and providing systemic support.

The influence of pore size on osteoblast phenotype expression in cultures grown on porous titanium

This study investigated the effect of pore size on osteoblastic phenotype development in cultures grown on porous titanium (Ti). Porous Ti discs with three different pore sizes, 312 mu m (Ti 312), 130 mu m (Ti 130) and 62 mu m (Ti 62) were fabricated using a powder metallurgy process. Osteoblastic cells obtained from human alveolar bone were cultured on porous Ti samples for periods of up to 14 days. Cell proliferation was affected by pore size at day 3 (p = 0.0010), day 7 (p = 0.0005) and day 10 (p = 0.0090) in the following way: Ti 62 < Ti 130 < Ti 312. Gene expression of bone markers evaluated at 14 days was affected, RUNX2 (p = 0.0153), ALP (p = 0.0153), BSP (p = 0.0156), COL (p = 0.0156), and OPN (p = 0.0156) by pore size as follows: Ti 312 < Ti 130 < Ti 62. Based on these results, the authors suggest that porous Ti surfaces with pore sizes near 62 mu m, compared with those of 312 mu m and 130 mu m, yield the highest expression of osteoblast phenotype as indicated by the lower cell proliferation rate and higher gene expression of bone markers.

Sleeve Gastrectomy With Transit Bipartition A Potent Intervention for Metabolic Syndrome and Obesity

Objective: To present 5-year results of sleeve gastrectomy (SG) with transit bipartition (TB) as a metabolic intervention for obesity. Background: Recent data suggest that high glycemic index foods may lead to a hormonally hyperactive proximal gut and a hypoactivate distal gut, which are linked to metabolic syndrome. TB was designed to counterbalance these effects. Methods: A total of 1020 obese patients with body mass index (BMI) ranging from 33 to 72 Kg/m(2) underwent SG and TB (SG + TB). TB creates a gastroileal anastomosis in the antrum after the SG; nutrient transit is maintained in the duodenum, avoiding blind loops and minimizing malabsorption. The stomach retains 2 outflow pathways. A lateral enteroanastomosis connects both segments at 80 cm proximal to the cecum. Results: Adequate follow-up data were collected in 59.1% of patients from 4 months to 5 years. The average percent of excess BMI loss was 91%, 94%, 85%, 78%, and 74% in the first, second, third, fourth, and fifth year, respectively. Patients experienced early satiety and major improvement in presurgical comorbidities, including diabetes (86% in remission), following surgery. Two deaths occurred (0.2%). Other surgical complications occurred in 6% of patients. Signs of malabsorption were rare. Conclusions: SG + TB is a simple procedure that results in rapid weight loss and remission or major improvement of comorbidities. Strictly aiming at physiological correction, TB avoids prostheses, narrow anastomoses, excluded segments, and malabsorption. Weight and comorbidities are much improved. Diabetes is improved without duodenal exclusion. TB is an excellent complement to an SG.

Masticatory efficiency in class II and class III dentofacial deformities

Masticatory efficiency may be impaired in individuals with dentofacial deformities. The objective of the present study was to determine the condition of masticatory efficiency in individuals with dentofacial deformities. 30 patients with class II (DG-II) and 35 patients with class III (DG-III) dentofacial deformity participated in the study, all had an indication for orthognathic surgery. 30 volunteers (CG) with no alterations of facial morphology or dental occlusion and with no signs or symptoms of temporomandibular joint dysfunction also participated. Masticatory efficiency was analysed using a bead system (colorimetric method). Each individual chewed 4 beads, one at a time, over 20 s measured with a chronometer. The groups were compared in term's of masticatory efficiency using analysis of variance (ANOVA), with the level of significance set at P < 0.05. Masticatory efficiency was significantly greater in CG (P < 0.05) than in DG-II and DG-III in all chewing tasks tested, with no significant difference between DG-II and DG-III (P > 0.05). It was observed that the presence of class II and class III dentofacial deformity affected masticatory efficiency compared to CG, although there was no difference between DG-II and DG-III.

Intraoral carcinosarcoma on the floor of the mouth mimicking a benign lesion

Carcinosarcoma is a rare malignant disease with aggressive behaviour rarely producing oral manifestations. This article reports a case of an intraoral carcinosarcoma affecting a 71-year-old black male; the diagnosis was made by histopathological and immunohistochemical analyses. Computed tomography scanning showed metastatic masses in the lungs. The patient was underwent a chemotherapy protocol regimen, but died as a consequence of the disease within 10 months of diagnosis. Distinctive characteristics of this presentation were the location of the lesion (floor of the mouth) and its clinical features resembling a benign lesion. A brief review of intraoral carcinosarcoma cases in the literature is also presented.

Evaluation of Chemical Treatment on Zirconia Surface with Two Primer Agents and an Alkaline Solution on Bond Strength

Objectives: This study evaluated the effect of an alkaline solution and two 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-based primer agents on bond strength to zirconia (yttria-stabilized tetragonal zirconium polycrystal [Y-TZP]) through the shear bond strength (SBS) test. Materials and Methods: Sixty square-shaped Y-TZP samples were embedded in an acrylic resin mold, polished, and randomly assigned to one of six groups (n=10) according to treatment surface: group CR, no treatment (control); group NaOH, 0.5 M NaOH; group AP, Alloy Primer; group ZP, Z-Primer Plus; group NaOH-AP, 0.5 M NaOH + Alloy Primer; and group NaOH-ZP, 0.5 M NaOH + Z-Primer Plus. The resin cement (Rely X U100) was applied inside a matrix directly onto the Y-TZP surface, and it was light-cured for 40 seconds. The samples were stored in distilled water at 37 C for 24 hours prior to the test, which was performed in a universal machine at a crosshead-speed of 0.5 mm/min. The data were analyzed by one-way analysis of variance and Tukey tests (p<0.05). Light stereomicroscopy and scanning electron microscopy were used to assess the surface topography and failure mode. Results: The SBS was significantly affected by the chemical treatment (p<0.0001). The AP group displayed the best results, and the use of NaOH did not improve SBS results relative to either AP or ZP. The samples treated with Alloy Primer displayed mainly mixed failures, whereas those conditioned with Z-Primer Plus or with 0.5 M NaOH presented a balanced distribution of adhesive and mixed failure modes. Conclusions: The use of a NaOH solution may have modified the reactivity of the Y-TZP surface, whereas the employment of a MDP/6-4-vinylbenzyl-n-propyl amino-1,3,5-triazine2,4-dithione-based primer enhanced the Y-TZP bond strength.

Clinical and surgical evaluation of the indication of postoperative antibiotic prescription in third molar surgery

Objective. The aim of this study was to evaluate the need for antibiotic prescription in third molar surgery. Study design. A double-blind randomized study was carried out with 71 patients from CODONT (Dentistry Center of the Police of Sao Paulo). Amoxicillin, clindamycin, or no medication was administered for 7 days immediately after surgery. The participants evaluated the presence of pain, edema, interincisal distance (ID), presence of infection, Pell and Gregory classification, rescue analgesia, osteotomy, and odontosection. Results. There was no difference (P < .05) between antibiotics and control over the surgery duration, dose, visual analog scale (VAS), ID, and edema, yet significant differences were seen over time for VAS, edema, and ID. Conclusions. Antibiotic prescription should not be indicated in all clinical conditions, yet it is necessary to correctly evaluate factors such as systemic condition of the patient, skill of the operator, and contamination of the surgical environment. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012; 114(suppl 5):S26-S31)

Implant Stability Measurements of Two Immediate Loading Protocols for the Edentulous Mandible: Rigid and Semi-rigid Splinting of the Implants

Aim: Primary and secondary stabilities of immediately loaded mandibular implants restored with fixed prostheses (FP) using rigid or semirigid splinting systems were clinically and radiographically evaluated. Methods: Fifteen edentulous patients were rehabilitated using hybrid FP; each had 5 implants placed between the mental foramens. Two groups were randomly divided: group 1-FP with the conventional rigid bar splinting the implants and group 2-semi-rigid cantilever extension system with titanium bars placed in the 2 distal abutment cylinders. Primary stability was evaluated using resonance frequency analysis after installation of the implant abutments. The measurements were made at 3 times: T0, at baseline; T1, 4 months after implant placement; and T2, 8 months after implant placement. Presence of mobility and inflammation in the implant surrounding regions were checked. Stability data were submitted to statistical analysis for comparison between groups (P, 0.05). Results: Implant survival rate for the implants was of 100% in both groups. No significant differences in the mean implant stability quotient values were found for both groups from baseline and after the 8-month follow-up. Conclusion: The immediate loading of the implants was satisfactory, and both splinting conditions (rigid and semi-rigid) can be successfully used for the restoration of edentulous mandibles. (Implant Dent 2012;21:486-490)

Finite element analysis of stress distribution in anchor teeth in surgically assisted rapid palatal expansion

The treatment of a transverse maxillary deficiency in skeletally mature individuals should include surgically assisted rapid palatal expansion. This study evaluated the distribution of stresses that affect the expander's anchor teeth using finite element analysis when the osteotomy is varied. Five virtual models were built and the surgically assisted rapid palatal expansion was simulated. Results showed tension on the lingual face of the teeth and alveolar bone, and compression on the buccal side of the alveolar bone. The subtotal Le Fort I osteotomy combined with intermaxillary suture osteotomy seemed to reduce the dissipation of tensions. Therefore, subtotal Le Fort I osteotomy without a step in the zygomaticomaxillary buttress, combined with intermaxillary suture osteotomy and pterygomaxillary disjunction may be the osteotomy of choice to reduce tensions on anchor teeth, which tend to move mesiobuccally (premolar) and distobuccally (molar)

Rehabilitative treatment of cleft lip and palate: experience of the Hospital for Rehabilitation of Craniofacial Anomalies/USP (HRAC/USP) – part 4

Treatment of patients with cleft lip and palate is completed with fixed prostheses, removable, total, implants and aims to restore aesthetics, phonetics and function and should be guided by the basic principles of oral rehabilitation, such as physiology, stability, aesthetics, hygiene and the expectations of the patient. In order to obtain longevity of a prosthetic rehabilitation, the periodontal and dental tissue as well as the biomechanics of the prosthesis are to be respected. The purpose of this article is to describe the types of prosthetics treatment, which are performed at HRAC/USP for the rehabilitation of cleft area in adult patients.

Influence of miniscrew dental root proximity on its degree of late stability

Purpose of this study was to evaluate the influence of miniscrew dental root proximity on its late stability degree. 40 miniscrews were inserted between maxillary second premolars and first molars for anterior retraction. Post-surgical radiographs were used to measure the septum width in the insertion site, insertion height, distal and mesial distance from miniscrew to dental root, and the smallest distance between miniscrew and dental root. The miniscrews were divided in two groups according to septum width: ?3 mm (20 miniscrews) and >3 mm (20 miniscrews). The soft tissue in the insertion site, sensitivity during load, plaque around the miniscrew, and evaluation period were also considered. The results showed no significant difference in miniscrew mobility degree and success rate between groups. Miniscrew dental root proximity did not influence the stability and success rate when the distance between the miniscrew and dental root indicated no periodontal ligament invasion. The overall success rate was 90% and no variable was associated with miniscrew failure. Nevertheless, patient sensitivity was frequently associated with some degree of mini-implant mobility. The septum width did not influence the stability and success rate of this anchorage system, but the extreme root proximity did.

Effect of framework soldering on the deformation of implant abutments after framework seating: a study with strain gauges

Introduction: Passive fit has been considered an important requirement for the longevity of implant-supported prostheses. Among the different steps of prostheses construction, casting is a feature that can influence the precision of fit and consequently the uniformity of possible deformation among abutments upon the framework connection. Purpose: This study aimed at evaluating the deformation of abutments after the connection of frameworks either cast in one piece or after soldering. Materials and Methods: A master model was used to simulate a human mandible with 5 implants. Ten frameworks were fabricated on cast models and divided into 2 groups. Strain gauges were attached to the mesial and distal sides of the abutments to capture their deformation after the framework’s screw retentions were tightened to the abutments. Results: The mean values of deformation were submitted to a 3-way analysis of variance that revealed significant differences between procedures and the abutment side. The results showed that none of the frameworks presented a complete passive fit. Conclusion: The soldering procedure led to a better although uneven distribution of compression strains on the abutments.