The effect of inadequate access to peri-implant hygiene on marginal bone level. A 4-year cohort prospective study.

OBJECTIVE: The objective of this four-year cohort prospective study was to evaluate the effect of inadequate access to peri-implant hygiene on marginal bone level (MBL). MATERIAL AND METHODS: Forty-one partially edentulous patients (16 males and 25 females, aged 49.8 ± 11.9 years) who had implants with at least one year in function were selected. Patients were clinically and radiographically evaluated at three different times: baseline (T0), 2-year (T1), and 4-year (T2) follow-up intervals. At baseline, implants were classified and allocated into two groups: those presenting adequate access (ACC) and inadequate access (no-ACC) to peri-implant hygiene. A linear mixed-effects model for clustered longitudinal data was used to analyze MBL, probing depth (PD), plaque index (PI), and bleeding on probing (BoP). RESULTS: Of 131 implants, 74 were considered as having ACC, and 57 as having no-ACC at T0. Implants in the no-ACC group presented a statistically greater mean MBL measurement at T2 than implants in the ACC group (p = .011). In the no-ACC group, a significant reduction in PD from T0 to T1 (p = .019) and from T0 to T2 (p = .010) was observed. Regardless of the group, PI significantly increased at both T1 (p = .00001) and T2 (p = .00004). Regardless of time, the prevalence of BoP was significantly higher in the no-ACC group than in the ACC group (p = .012). CONCLUSION: Inadequate access to peri-implant hygiene frequently resulted in more peri-implant inflammation and MBL over time. Proper accessibility to peri-implant hygiene should be carefully considered during planning of implant restoration, and patients properly motivated into maintenance care.

Accuracy of 3D virtual surgical planning for maxillary positioning and orientation in orthognathic surgery.

OBJECTIVE: This retrospective and observational study evaluated the accuracy of a 3D virtual surgical planning (VSP) for the maxillary positioning and orientation in patients undergoing bimaxillary orthognathic surgery, comparing the planned and postoperative outcomes. SETTING AND SAMPLE POPULATION: Seventy consecutive patients of both sexes, who were submitted to bimaxillary orthognathic surgery between 2015 and 2019 were included in our study. MATERIAL AND METHODS: The patients were evaluated by fusing preoperative planning and postoperative outcome using cone-beam computed tomography scan evaluation. Three-dimensional VSP and postoperative outcomes were compared by using three linear and three angular measurements. The main outcome interest was the difference between the VSP movement, and the surgical movement obtained. The success criterion adopted was a mean linear difference of <2 mm and a mean angular difference of <4°. RESULTS: Results were analysed using a linear mixed model with fixed and random effects, at α = .05. No significant statistical differences were found for linear and angular measurements between the planned and postsurgical outcomes (P > .05). All overlapping points presented values within the range considered clinically irrelevant (<2 mm; <1°). CONCLUSIONS: Three-dimensional VSP was executed with a high degree of accuracy. When comparing the planned and postsurgical outcomes, all overlapping points presented values within the range considered clinically irrelevant.

Technique for Darkening of Extracted Teeth Simulating Pulpal Necrosis Discoloration.

Background: The use of discolored teeth is required to test whitening products, and it is difficult to obtain them, given their scarcity. Objective: To present a technique for in vitro darkening of extracted teeth simulating pulpal necrosis discoloration. Materials and Methods: Hemolysates I and II from human blood were subjected or not to laser irradiation (442 nm) for 1 h. The concentration of oxyhemoglobin (O2Hb) was analyzed by ultraviolet/visible spectroscopy, and the conversion of O2Hb to methemoglobin (MetHb) by transmission spectroscopy was assessed immediately and after 3 and 40 days. For darkening evaluation, bovine incisors were divided into two groups (n = 25), and their pulp chambers were filled with hemolysate solution II (HSII) and hemolysate II solution + laser (HSII+L). After storage in artificial saliva for 40 days at 37°C, color changes were measured by a colorimeter and ΔE was compared with the NBS parameters. Data were analyzed using a mixed linear model (α=5%). Results: HSII+L presented the lowest O2Hb and higher MetHb. The conversion of O2Hb to MetHb in HSII+L was 42% higher than in HSII. Both groups were effective in darkening the teeth, according to the NBS. Darkening stabilized from day 35. HSII promoted a marked color difference. Conclusion: The proposed technique was effective in darkening the extracted teeth simulating necrosis discoloration for in vitro models.

Accuracy of three-dimensional soft tissue profile prediction in orthognathic surgery.

PURPOSE: To evaluate the accuracy of three-dimensional (3D) soft tissue prediction in bimaxillary orthognathic surgery. METHODS: Cone-beam computed tomographs of 88 patients with class II (n = 46) and class III (n = 42) malocclusions, who underwent bimaxillary orthognathic surgery, were included in this retrospective study. 3D soft tissue prediction and postoperative outcome were compared by using ten landmarks of facial soft tissues. Patients' sex and age were also assessed. Results were analyzed using a mixed model methodology (p < 0.05). RESULTS: The success criterion adopted was a mean discrepancy of < 2 mm. Most mandibular landmarks indicated a tendency for underprediction with a downward direction in class II patients, with some values > 2 mm. In class III, there was overprediction with a downward direction for the mandibular landmarks, with values < 2 mm. More accurate results were found in female and older patients. CONCLUSIONS: 3D surgical planning showed clinically acceptable results for predicting soft tissues in patients undergoing bimaxillary orthognathic surgery, with more accurate results for class III patients. Although some differences were found when age and sex were interacted, a consistent association between these variables could not be stated. These results support the clinician, as accuracy can provide a strong guide to the surgeon when planning surgical orthodontic treatment.

How does bimaxillary orthognathic surgery change dimensions of maxillary sinuses and pharyngeal airway space?

OBJECTIVES: To assess changes in the maxillary sinus (MS) and pharyngeal airway space (PAS) after bimaxillary orthognathic surgery using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: The CBCT scans of 48 patients were divided into two groups: group 1: maxillary advancement and mandibular setback (n = 24); group 2: maxillomandibular advancement (n = 24). The CBCTs were acquired 1 to 2 months preoperatively and 6 to 8 months postoperatively. A kappa test was used to determine intra- and interexaminer agreement. Area, volume, and linear measurements of MSs and PASs obtained before and after surgery were compared using a mixed model (P < .05). RESULTS: All variables of the MS showed significant postsurgical reductions in both groups, except the MS length, which showed a significant increase in group 2. Volume and minimum axial area of PAS showed statistically significant postsurgical increases in both groups (P < .05). CONCLUSIONS: Despite the reduction in the MS and the increase in the PAS, results indicated that the airway was not negatively affected after maxillomandibular advancement and maxillary advancement with mandibular setback.

Zafirlukast pocket delivery impairs the capsule healing around textured implants in rats.

BACKGROUND: The aim of this study was to investigate the effects of zafirlukast on capsule thickness, collagen fiber density, and myofibroblast cell count of the healing tissue around silicone textured implants in rats. METHODS: Thirty-six male Wistar rats were divided (n = 18) into two groups. In one group, two parallel incisions (1.5 cm long) were made into the right and left sides of the spine. Two pockets were then created in which shell-shaped textured implants were inserted. The left-side pocket was injected with 0.2 ml of saline solution (SSG) and the right-side pocket with a dose of 1.25 mg/kg of zafirlukast (ZLG). The other 18 rats (sham, SG) had only one pocket created, followed by the placement of an implant and injection of 0.2 ml of saline solution. The rats were euthanized on the 7th, 35th, or 90th days followed by careful dissection of the implant. The capsules and peri-implant tissues were prepared for histologic analysis. An ANOVA test and Tukey test were applied (p < 0.05). RESULTS: ZL was effective in impairing the capsule thickness on the 35th and 90th days compared to the other two groups (sham and saline). Not only was it effective in impairing the collagen density on the 35th and 90th days, but it also showed the same effect in the SSG (systemic); fewer myofibroblasts were counted on the 90th day in the ZLG compared to the SG group; the number of myofibroblasts was significantly lower in the ZLG than in the SSG. CONCLUSIONS: Pocket delivery of one dose of Zafirlukast was effective in impairing capsule formation around the textured implant.

Correlation between clinical variables and magnetic resonance imaging findings in symptomatic patients with chronic temporomandibular articular disc displacement with reduction: A retrospective analytical study.

Objective: To correlate the clinical aspects of symptomatic patients with chronic articular disc displacement with reduction with alterations in the articular disc (AD) morphology and sagittal position. Methods: Records from 109 patients were selected that included data on AD morphology and sagittal position as determined by MRI. According to the MRI results, the sagittal position and AD morphology with opened and closed mouth were correlated with many clinical variables. Results: More than half of the patients studied were female, and the biconcave and hemiconvex morphologies were most common. Thirty-four patients (31.3%) presented with restricted maximum interincisal distance (MID). The biplanar morphology was associated with eccentric bruxism and MID (p < 0.05). Visual analog scale (VAS) scores between 2 and 7 were shown to be risk factors (p < 0.05). Conclusion: The mouth position can influence AD morphology and eccentric bruxism. VAS scores and unknown etiology were risk factors.

Three-dimensional alterations in pharyngeal airspace, soft palate, and hyoid bone of class II and class III patients submitted to bimaxillary orthognathic surgery: A retrospective study.

INTRODUCTION: The aim of this retrospective study was to evaluate changes in pharyngeal airway space (PAS), soft palate, and hyoid bone position after bimaxillary orthognathic surgery in skeletal Class II and Class III patients. METHODS: Patients were divided into Group 1: Class III patients who underwent maxillary osteotomies and mandibular setback surgery (N = 43); and Group 2: Class II patients who underwent maxillomandibular advancement surgery (N = 36). Cone beam computed tomography (CBCT) images were acquired one month before and six to eight months after orthognathic surgery. PAS area, volume and minimum axial area (MAA), soft-palate morphology, and hyoid bone position measurements obtained before and after orthognathic surgery were compared using the Gamma family test (p ≤ 0.10). RESULTS: In Class II group the maxillomandibular advancement surgery significantly increased the PAS area, volume, and MAA and significantly affected hyoid bone position and soft-palate morphology. In Class III group, maxillary osteotomies and mandibular setback also showed increase in PAS area, however without statistically significant values for most of the evaluated measurements. CONCLUSION: The results of the present study indicate that PAS and related structures are expected to be improved in Class II patients submitted to bimaxillary surgery, and they are not negatively affected by bimaxillary surgery in Class III patients.

Effect of ultraviolet (UV-C) radiation on spores and biofilms of Alicyclobacillus spp. in industrialized orange juice.

Bacteria of the genus Alicyclobacillus pose serious quality problems for the juice processing industries that have sought effective alternatives for its control. The present study evaluated the effect of UV-C radiation on the reduction of spores and biofilm formation of Alicyclobacillus spp. on stainless steel and rubber surfaces using industrialized orange juice as a culture medium. Four reference Alicyclobacillus spp. species and different UV-C dosages were investigated. After exposed for 20 min (16.8 kJ/m2) to UV-C, the spores of Alicyclobacillus acidoterrestris, Alicyclobacillus herbarius, and Alicyclobacillus cycloheptanicus decreased drastically more of 4 log CFU/mL, with counts below the detection limit of the method (<1.7 log CFU/mL), while the Alicyclobacillus acidocaldarius spores were more sensitive to UV-C, once this spore reduction was observed within 15 min (12.6 kJ/m2). Morphological changes in the Alicyclobacillus acidoterrestris spores were observed by scanning electron microscopy. A reduction of biofilm formation was observed for all UV-C treatments, and the higher reductions (approximately 2 log CFU/mL) were found for the Alicyclobacillus acidocaldarius species after 30 min (26.2 kJ/m2), on the stainless steel and rubber surfaces. The results suggest that UV-C can be used to reduce the biofilm formation and could be a promising alternative for controlling Alicyclobacillus spp. spores in industrialized orange juice.

Induced hypotension in orthognathic surgery: a comparative study of 2 pharmacological protocols.

PURPOSE: The objective of this comparative study was to report on the use of 2 different pharmaceutical protocols involving 2 different anesthetic techniques (IV and balanced) to induce hypotension in patients submitted to orthognathic surgery by assessing the patients' intra- and postoperative physiologic response and hemodynamic stability. PATIENTS AND METHODS: Twenty ASA I patients, between 17 and 44 years of age who had dental and skeletal deformities were subdivided into 2 groups: group I (clonidine associated to remifentanil), and group II (dexmedetomidine associated to isoflurane), in addition, other drugs were common to both groups. The following responses were assessed: arterial blood pressure, heart rate, temperature during intra- and postoperative periods, incidence of nausea and vomiting, postoperative pain, awakening time, extubation time, and postanesthetic recovery time. RESULTS: The results of the study using Repeated Measures Test statistical analysis showed that there were no significant differences between the 2 groups in respect to physiologic responses or surgery time. CONCLUSION: Both protocols tried in this study proved to be effective and safe, and they seem to be interesting alternatives in longer orthognathic surgeries with the expectation of an important blood loss. The choice for either protocol should be based on the inherent risks involved in their use and their cost-benefit ratio.

Retrospective study on sequelae in traumatized permanent teeth.

OBJECTIVE: This study aimed to identify possible associations of the presence or absence of posttrauma sequelae with the factors inherent to the traumatized tooth and treatment. MATERIALS AND METHODS: This retrospective study was performed through the evaluation of records and radiographs of a center of reference for dental trauma between January 2008 and December 2014. The factors were analyzed and associated with posttrauma sequelae, such as pulp necrosis and root resorption. STATISTICAL ANALYSIS USED: A binomial logistic regression model was fit (P < 0.05). RESULTS: In luxations, it was possible to observe 37% pulp necrosis, 16% inflammatory root resorption, and 8% replacement resorption. The binomial logistic regression revealed that male gender (P = 0.0392, odds ratio [OR] = 2.79), avulsion injury (P = 0.0009, OR = 12.27), and elapsed time >16 days between the time of trauma to the beginning of the endodontic treatment (P = 0.0450, OR = 7.53) showed a greater chance of presenting a posttrauma complication. CONCLUSIONS: Gender, type of injury, stage of root development, and time after trauma until the beginning of the endodontic intervention were related to the appearance of sequelae.

Three-dimensional analysis of the pharyngeal airway space and hyoid bone position after orthognathic surgery.

PURPOSE: The aim of this study was to evaluate changes in the pharyngeal airway space (PAS) and hyoid bone position after orthognathic surgery with cone-beam computed tomography (CBCT). MATERIAL AND METHODS: This study was conducted with the tomographic records of 30 patients with skeletal class II or III deformities submitted to two different types of orthognathic surgery: Group 1 (n = 15), maxillary advancement, and mandibular setback; and Group 2 (n = 15), maxillomandibular advancement. CBCT scans were acquired preoperatively (T0); and at around 1.5 months (T1) and 6.7 months (T2) postoperatively. PAS volume, minimum cross-sectional area (min CSA), and hyoid bone position changes were assessed with Dolphin Imaging 3D software, and results analyzed with ANOVA and a Tukey-Kramer test (p < 0.05). RESULTS: The hyoid bone was significantly displaced in the horizontal dimension, moving posteriorly in Group 1, and anteriorly in Group 2. Although PAS volume and min CSA increased after both surgeries, these measurements were significantly larger only in Group 2. The significant differences that existed between groups preoperatively no longer existed after the surgeries. CONCLUSIONS: Both orthognathic surgeries assessed resulted in changes in hyoid bone position and increased PAS volume and min CSA, particularly after maxillomandibular advancement surgery.