3-Year Bone Remodeling in Mandibular Overdenture Wearers: Results from an RCT Comparing Immediate vs Conventional Loading Using Cone Beam Computed Tomography.

PURPOSE: To evaluate the circumferential bone level and the morphological changes in posterior mandibular ridge of mandibular overdenture wearers submitted to conventional and immediate loading through cone beam computed tomography (CBCT) at 1 and 3 years. MATERIAL AND METHODS: Twenty participants who received 2 NDI (Facility - 2.9x10 mm) were randomly allocated to the conventional loading (CL: n=10) or immediate loading (IL: n=10) groups. CBCT scans were performed in each group to analyze the vertical (VBL) and horizontal (HBL) bone level around the implants, analyzed together with the posterior bone remodeling of the mandible measured at distances of 5, 10, 15, and 20 mm from the mental foramen (L1-L4). Differences between groups were verified using the student t test at a significance level of 5%. RESULTS: The IL group showed a significantly higher HBL in the first year (P=.028) and a significantly higher VBL in the third year (P=.032), with HBL of -0.22 mm and VBL of -0.59 mm, respectively. After the third year, measurements of the percentage of cortical and medullar height indicated that the IL group presented a significantly higher percentage of cortical bone height (40.1 ± 9.3) compared to the CL group (31.8 ± 5.8) at position L1 (P=.05). No difference was found for posterior ridge remodeling (P>.05). CONCLUSIONS: IL group showed slightly higher values of HBL and VBL, and locally displayed more replacement of medullary by cortical bone. However, circumferential bone level values in the IL group are still clinically acceptable and the posterior resorption rate remained stable after 3 years of function, irrespective of the loading type.

Effect of mandibular bone atrophy on maxillary and mandibular bone remodeling and quality of life with an implant-retained mandibular overdenture after 3 years.

STATEMENT OF PROBLEM: The medium-term effect of an implant-retained mandibular overdenture on bone remodeling in the maxilla and posterior mandible of edentulous patients and the effects on quality of life have not been established. PURPOSE: The purpose of this prospective observational clinical study was to evaluate the 3-year effects of implant-retained mandibular overdentures on oral-health-related quality of life (OHRQoL) and bone remodeling in different regions of the maxilla and mandible in participants with atrophic or nonatrophic mandibles. MATERIAL AND METHODS: Twenty-six edentulous participants received 2 narrow-diameter implants in the anterior mandible. Mandibular bone atrophy was categorized from presurgical panoramic radiographs according to the Cawood and Howell criteria. OHRQoL was assessed by using the OHIP-EDENT questionnaire. Participants were evaluated annually for 3 years to measure the marginal bone loss and bone area of the posterior mandible, and the anterior and posterior regions of the maxilla were assessed annually through panoramic radiographs. The data were analyzed by using a mixed-effects linear regression to estimate time-dependent trends and a mixed-effect linear regression model to verify differences between groups. The Pearson correlation coefficients between bone variables and 3-year OHIP-EDENT outcomes were calculated. RESULTS: In the third year, atrophic participants had a significantly lower marginal bone loss (0.02 mm) than nonatrophic participants (-0.39 mm) (P=.030). Differences were also found in the functional limitation (nonatrophic=1.82 ±1.75, atrophic participants=1.92 ±1.54; P=.018) and handicap domains (nonatrophic=0.36 ±0.54, atrophic participants=0.08 ±0.27; P=.003). For nonatrophic participants, comparisons between baseline and 3-year outcomes showed significant bone resorption as indicated by the area ratio in the anterior maxilla (P=.035), posterior maxilla (P=.022), and posterior mandible (P=.009). Conversely, the bone area of the anterior maxilla (P=.019) decreased in atrophic participants between baseline and year 1, while the bone area of the anterior maxilla and posterior mandible increased (P<.001) between years 1 and 3. Higher effect sizes were observed in the OHRQoL domains of the atrophic participants. CONCLUSIONS: Bone atrophy influenced both the OHRQoL profile and bone remodeling profile in different regions of the mandible and maxilla in mandibular overdenture users. In atrophic participants, bone tissue in both jaws responded positively to overdenture use, with bone apposition after the first year and bone area preservation in the anterior maxilla, posterior mandible, and peri-implant regions after 3 years of follow-up.

Clinical performance of narrow-diameter implants with hydrophobic and hydrophilic surfaces with mandibular implant overdentures: 1-year results of a randomized clinical trial.

OBJECTIVE: To compare peri-implant clinical and radiographic parameters between hydrophilic and hydrophobic narrow dental implants in patients with mandibular implant overdentures for 1 year. MATERIALS AND METHODS: In a randomized, double-blind, split-mouth study with a 1-year follow-up, sixteen edentulous participants received two narrow-diameter implants in the anterior mandibular region with 2 types of surfaces: hydrophobic (Neoporos surface, NS) and hydrophilic (Acqua surface, AS). During the osseointegration period and after loading with mandibular implant overdentures, the outcomes monitored were (i) peri-implant health: early healing index (EHI), visible plaque index (VPI), calculus presence (CP), peri-implant inflammation (PI), probing depth (PD), and bleeding on probing (BOP); (ii) implant stability quotient (ISQ), (iii) crestal bone loss (CBL) and bone level change (BLC); and (iv) implant success and survival rates. RESULTS: The PD in NS implants decreased by 31.78% between 15 and 30 days, while a similar reduction (-31.28%) occurred in the 3rd month in the AS group. The ISQ also decreased significantly during the 1st month in both groups: -10.95% after 7 days in the NS group and -7.46% after 15 days in the AS group. At 12 months, statistically significant differences were not observed; however, the AS surface presented 50.6% smaller CBL and 41.3% smaller BLC values. The success and survival rates were 62.5% for AS implants and 87.5% for NS implants. CONCLUSION: Narrow-diameter implants with hydrophilic and hydrophobic surfaces loaded with mandibular implant overdentures showed no differences in peri-implant healing, stability, and peri-implant bone remodeling in the 1st year of follow-up.

Circumferential bone level and bone remodeling in the posterior mandible of edentulous mandibular overdenture wearers: influence of mandibular bone atrophy in a 3-year cohort study.

OBJECTIVES: Evaluate circumferential bone level and morphological alterations in the posterior mandibular ridge of atrophic (AP) and non-atrophic (NAP) patients using implant-retained mandibular overdentures (MO) over 3 years. MATERIALS AND METHODS: Twenty-six edentulous patients categorized according to mandibular atrophy (AP = 13/NAP = 13) received two narrow diameter implants (Facility, 2.9 × 10 mm) in the anterior region of mandible. The vertical and horizontal bone level was measured along with bone remodeling at 4 distances from the mental foramen in the posterior region of the mandible (L1-L4) via CBCT. RESULTS: NAP showed significantly higher total height and medullary height in all posterior regions at 1 and 3 years (p ≤ 0.01). Cortical height and width were significantly higher (p ≤ 0.05) in this group at distances L1 and L4, respectively, in year 1. NAP shows a significantly higher % of medullary height at distances L1 (p ≤ 0.05), L2 (p ≤ 0.01), and L3 (p ≤ 0.05) after 1 year, and at all distances (p ≤ 0.05) after 3 years. Bone remodeling in the groups differed significantly (p ≤ 0.05) in terms of cortical width and % medullary width at L3. CONCLUSION: AP and NAP showed similar vertical and horizontal bone level. Bone resorption in the posterior ridge was stabilized by MO over 3 years; however, AP are more susceptible to the long-term substitution of medullary bone by cortical bone. CLINICAL RELEVANCE: This study is the first to longitudinally evaluate bone dimensions in atrophic and non-atrophic two-implant MO users by CBCT and revealed that MO is a predictable treatment based on the stabilization of the posterior bone resorption.

Imaging and histomorphometric evaluation of mandible and tibia of rats treated with bisphosphonates.

OBJECTIVES: To evaluate the mandible and tibia of rats treated with bisphosphonates (BPs) by imaging and histomorphometric analysis. STUDY DESIGN: Thirty-four rat specimens (Rattus norvegicus, Wistar strain) were distributed into 3 groups: (1) 12 rats treated with zoledronic acid; (2) 12 rats treated with clodronate; and (3) the control group, containing 10 rats that received saline. All bones were exposed to cone beam computed tomography (CBCT). The images were analyzed to determine bone density (BD), using the software OsiriX 7.0. Histological slides were prepared from the specimens and the proportion of bone volume (BV) was quantified using the software Adobe Photoshop CC. RESULTS: There was no statistically significant difference in BD either between the drug groups or between mandible and tibia. BV between BPs and control group did not show a significant difference. However, comparing the two bones, the mandibles in the control group displayed higher BV than did the tibiae in the same group. CONCLUSION: According to our results, we conclude that (1) BD was not altered by bone type or by type of BP administered, and (2) treatment with zoledronic acid or clodronate did not affect BV in the mandible or tibia of test groups.

Modified Approach to Central Giant Cell Lesion.

This case report discusses a modified technique for treatment of a central giant cell lesion (CGCL) in children, where a recontouring procedure is performed prior to the treatment with intra lesional corticosteroid. We discuss the advantages of this less invasive technique, specially considering the early age of the patient and its bone growth, as well as the conservative approach for lesions in those cases. The treatment of an 8-year-old female patient exhibiting CGCL in anterior region of mandible with bone expansion is described. The procedure was performed using blade #15 and rongeur forceps, in order to obtain an adequate jaw contour. Two weeks later, drug treatment started with triamcinolone 10mg/ml diluted in 0.5% bupivacaine without vasoconstrictor agent, 1:1 ratio, for eight sessions. There were no complications in surgery and postoperative period. In 3-year follow-up, anatomical preservation is present with no signs of recurrence.

Comparison between tapered and cylindrical implants in the posterior regions of the mandible: A prospective, randomized, split-mouth clinical trial focusing on implant stability changes during early healing.

BACKGROUND: Companies affirm that tapered implants show adequate initial stability, while their installation in the lower arch is uncommon in clinical practice. PURPOSE: To compare the clinical outcomes of tapered and cylindrical implants and to study their effect on bone site characteristics and peri-implant health during healing. MATERIALS AND METHODS: The implant site dimensions were assessed by linear measurements using CBCT prior to the installation of 40 implants in the posterior mandible (20 tapered and 20 cylindrical). The bone type was registered during drilling via the surgeon's tactile perception, following the classification of Lekholm and Zarb. Primary stability (PS) was determined by the insertion torque (IT) and the implant stability quotient (ISQ). Secondary stability (SS) and the peri-implant health was monitored for 3 months through the visible plaque index (VPI), the peri-implant inflammation (PI), the probing depth index (PDI), and the gingival bleeding index (GBI). Significant differences were investigated with t-tests for independent samples, chi-square tests or Fisher's exact test. Pearson's correlation test was used to investigate the relationship between the bone site characteristics and PS (IT and ISQ), as well as the relationships between IT and ISQ for each implant type. RESULTS: Tapered and cylindrical implants showed no significant differences for any outcome variable (P > .05). A significant decrease in ISQ was observed after 7 days of healing (P = .0002), followed by a gradual increase beginning at 21 days (P = .0010) until the last follow-up time at 90 days (P = .0319). The cortical height was correlated with IT; while medullary bone dimensions were correlated with the PS as evidenced by the ISQ values. The insertion torque was significantly correlated with the PS only for the cylindrical dental implants. CONCLUSIONS: Tapered and cylindrical implants have similar biological behavior during the healing process. Bone site characteristics can influence insertion torque and implant stability.

Comparison of effects of zoledronic acid and clodronate on the bone structure: imaginological and histomorphometrical study in vivo.

OBJECTIVES: To compare histologically and imaginologically the bone structure of rats' mandibles treated with bisphosphonates (BPs) and rats that did not receive BPs. METHODS: Thirty-four rat specimens (Rattus novergicus, Wistar strain) were divided into three groups: (i) 12 rats treated with zoledronic acid; (ii) 12 rats treated with clodronate; and (iii) the control group, containing 10 rats that received saline solution. All individuals were exposed to cone beam computed tomography (CBCT). The images were processed and analyzed to obtain the Hounsfield scores, using the software OsiriX 7.0. Sixty-eight histological slides were obtained from the specimens and stained with hematoxylin and eosin (HE). Using the software Adobe Photoshop CS6, the histological areas containing non-vital bone were identified and quantified. RESULTS: Non-vital bone presented positive association with the zoledronic acid and clodronate groups. Statistically, no significant difference in bone density was observed among the groups. CONCLUSIONS: Based on the results, the BP therapy alone was sufficient to induce osteonecrosis. In addition, the CBCT was not a sensible method for detection of the early signs of bone modification in individuals under BP therapy.

Dentes supranumerários: etiologia, classificação, prevalência, diagnóstico, tratamento e complicações / Supernumerary tooth: etilogy, classification, prevalence, diagnosis, treatment and complications

Os dentes supranumerários representam um achado clínico bastante freqüente. Neste trabalho , os autores fazem uma ampla revisão na literatura, com o intuito de fornecer ao cirurgião-dentista informações relativas à etiologia, classificação, prevalência, diagnóstico, tratamento e possíveis complicações que a hiperdontia possa ocasionar

A importância do tratamento precoce da má-oclusäo dentária para o equilíbrio orgânico e postural / The importance of early malocclusion treatment importance to organic and postural balance

O tratamento precoce da má-oclusäo dentária, com aparelhos ortopédicos funcionais, impöe-se cada vez mais. Previne e intercepta alteraçöes morfo-funcionais que se manifestam no sistema estomatognático e órgäos relacionados, irradiando-se em cadeia e prejudicando o desempenho do corpo como um todo. O íntimo relacionamento da oclusäo dentária, da ATM e das funçöes da boca com a postura da cabeça e do corpo estabelece um novo paradigma para os tratamentos das má-oclusöes dentárias, a partir da filosofia da Ortopedia Funcional dos Maxilares. A má-oclusäo dentária aliada a respiraçäo bucal, com suas várias repercussöes orgânicas, desequilibra a organizaçäo muscular da mímica facial, da cervical e da cintura escapular e compromete a posiçäo ortostática da cabeça. A posiçäo anormal da cabeça altera as relaçöes bio-mecânicas cranio-cervicais e cranio-mandibulares, influindo no crescimento e na postura corporal do indivíduo, sendo importante a interceptaçäo dos desvios funcionais nos seus estágios iniciais