Publications by authors named "Samuel Porfírio Xavier"

35 Publications

Sinus augmentation - autograft vs. fresh frozen allograft: Bone density dynamics and implant stability.

J Stomatol Oral Maxillofac Surg 2020 Sep 29. Epub 2020 Sep 29.

Department of Oral and Maxillofacial Surgery and Periodontology. School of Dentistry of Ribeirão Preto, University of São Paulo, São Paulo, Brazil. Electronic address:

Objectives: Compare bone density changes and initial implant stability following sinus augmentation with autogenous bone (AB) vs. fresh frozen bone (FFB).

Materials And Methods: Randomized, prospective, split mouth study. Sinus augmentation executed using either AB or FFB. Dental implants were inserted after 6 months of healing. Implant dimensions and insertion torques were recorded. Prostheses were delivered 6 months thereafter. All patients had computerized tomography (CT) scans 1 week (T1) and 6 months (T2) after initial bone grafting. Third CT (T3) was taken 12 months after prosthesis delivery. Data from CT scans was used to analyze bone density at each period.

Results: A total of 15 patients (8 males, 7 females) following bilateral sinus augmentation procedures, were included. Mean age was 54 ± 5 years (range 48-60 years). All patients had 3 CT examinations. The initial augmented AB density was higher than the initial FFB density. Nevertheless, density differences between the two groups were not statistically significant at any time frame. At T2 density of both grafts showed a statistically significant increase. A significant increase from T2 to T3 was noted only for the FFB group. Implant insertion torque was significantly higher in the FFB group. Insertion torque ≥32 N/cm was achieved in significantly more patients in the FFB group.

Conclusion: The use of FFB for sinus augmentation is a reliable option of graft material. The newly formed bone quality performance, evaluated by CBCT density, is as good as AB, allowing predictable initial implant stability and osseointegration. Unnecessary morbidity associated with AB harvesting is thus avoided.
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http://dx.doi.org/10.1016/j.jormas.2020.08.012DOI Listing
September 2020

The Influence on Healing of Bony Window Elevated Inward in the Sinus Cavity as Cortical Bone Graft: A Histomorphometric Study in Rabbit Model.

Int J Oral Maxillofac Implants 2020 Sep/Oct;35(5):879-887

Purpose: To evaluate the influence on healing of the bony window elevated inward in the sinus cavity as a cortical bone graft.

Materials And Methods: Eighteen rabbits were included in the experiment. At the test sites (bony window), the antrostomy was prepared and the remaining bony window was elevated together with the sinus mucosa. At the control sites, the bony window was gently detached before the sinus mucosa elevation and discarded. The space obtained was grafted with deproteinized bovine bone mineral (DBBM). A collagen membrane was positioned on the antrostomy at both sides. The rabbits were euthanized after 2, 4, and 8 weeks in groups of six each. Histologic analyses in different regions of the elevated space were carried out, and a Wilcoxon test was used to estimate differences. Microcomputed tomography (microCT) analyses were also performed.

Results: After 2 weeks of healing, higher proportions of new bone were found in the test group compared with the control group due to the higher amount of bone formed in the region subjacent to the sinus mucosa. In this region, higher amounts of new bone were also found in the test group after 4 (P = .028) and 8 weeks of healing (P = .345). After 8 weeks of healing, the percentage of new bone was higher at the control sites compared with the test sites, with the proportions being 25.4% ± 3.2% and 21.3% ± 6.1%, respectively. In this period of evaluation, the bony window contributed with 20.1% ± 5.3% of vital bone in the test group. A fraction of 60.4% ± 10.8% of its surface was surrounded by new bone. In the microCT analysis, after 8 weeks of healing, fractions of 22.3% ± 1.6% and 22.2% ± 0.7% of bone were found in the test and control groups, respectively.

Conclusion: The presence of the bony window positively influenced the healing in the elevated space, especially in the submucosa region. The bony window was vital and incorporated into newly formed bone.
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http://dx.doi.org/10.11607/jomi.8226DOI Listing
October 2020

Histologic and Micro-CT Analyses at Implants Placed Immediately After Maxillary Sinus Elevation Using Large or Small Xenograft Granules: An Experimental Study in Rabbits.

Int J Oral Maxillofac Implants 2020 Jul/Aug;35(4):739-748

Purpose: To compare the osseointegration at the portion of the implant within the elevated space after sinus elevation using different sizes of xenograft.

Materials And Methods: Eighteen New Zealand rabbits were selected, antrostomies were prepared bilaterally through the nasal dorsum, and the sinus mucosa was elevated. Deproteinized bovine bone mineral with granules of either 1 to 2 mm (large sites) or 0.250 to 1.0 mm (small sites) were randomly used to fill the elevated space of the two sinuses. Subsequently, mini-implants were placed through the antrostomy, one in each sinus. The animals were euthanized 2, 4, and 8 weeks after surgery, six animals for each group. Microcomputed tomography (micro-CT) and histologic analyses were performed.

Results: In the elevated space, at the histologic analysis after 2 weeks of healing, new bone formed on the implant surface was found in fractions of 18.8% ± 6.8% and 15.8% ± 9.6% in the large and small sites, respectively (P = .249). After 4 weeks, the respective fractions of new bone were 20.3% ± 3.5% and 23.3% ± 5.6% (P = .249). After 8 weeks, the proportions reached 33.9% ± 9.5% and 28.5% ± 10.3% (P = .173), respectively. At the micro-CT analysis, bone-to-implant contact percentage (BIC%) was 21.0% ± 2.3% and 21.2% ± 2.4% in the large and small sites, respectively (P = 1.000). The respective proportions of BIC% at the large and small sites were 20.5% ± 3.3% and 23.4% ± 5.4% after 4 weeks (P = .463), and 23.0% ± 2.7% and 25.8% ± 4.1% after 8 weeks (P = .249).

Conclusion: The use of xenograft granules of different dimensions resulted in similar amounts of bone-to-implant contact at implants placed simultaneously with sinus floor augmentation.
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http://dx.doi.org/10.11607/jomi.8067DOI Listing
August 2020

Hard and soft tissue changes around implants activated using plasma of argon: A histomorphometric study in dog.

Clin Oral Implants Res 2018 Apr 16;29(4):389-395. Epub 2018 Feb 16.

Depto CTBMF e Periodontia FORP-USP- Faculty of Ribeirão Preto, Ribeirao Preto, Brazil.

Objective: To histologically assess the hard and soft tissue changes after insertion of cleaned and activated titanium implants using plasma of argon.

Materials And Methods: Eight dogs were included in this study. The mandibular premolars and first molars were extracted. For each hemi-mandible, four implants, 7 mm long and 3.3 mm of diameter, with a ZirTi surface were used. The surface of two implants was randomly treated with argon plasma (test), while the other two implants were left untreated (control). After 1 month, the same procedure was performed in the contralateral hemi-mandible. The amount of old bone, new bone, overall value of old bone plus new bone, and soft tissue was histologically evaluated.

Results: After 1 month of healing, high percentages of new bone in close contact with the implant surface were found at both the treated (60.1% ± 15.6%; 95% CI 56.5%-78.0%) and untreated (57.2% ± 13.1%; 95% CI 49.3%-67.5%) implants. Low percentages of old bone were found at this stage of healing, at both the treated (4.4% ± 3.0%; 95% CI 1.2%-5.4%) and untreated (3.4% ± 3.1%; 95% CI 0.6%-4.9%) implants. Not statistically significant differences were found between groups (p > .05). After 2 months of healing, treated implants presented a significantly higher (p = .012) new bone formation (72.5% ± 12.4%; 95% CI 69.6%-86.8%) compared to untreated sites (64.7% ± 17.3%; 95% CI 59.4%-83.3%). Controversially, no difference (p = .270) in terms of old bone was present between treated (3.1% ± 1.7%, 95% CI 1.8%-4.2%) and untreated implants (3.8% ± 1.9%, 95% CI 3.2%-5.8%). Significant differences (p = .018) in terms of total mineralized bone were found between treated (75.6% ± 13.0%, 95% CI 73.3%-91.3%) and untreated implants (68.4% ± 16.8%; 95% CI 64.2%-87.6%).

Conclusions: Implants treated using plasma of argon was demonstrated to reach a higher bone-to-implant contact when compared to untreated implants.
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http://dx.doi.org/10.1111/clr.13134DOI Listing
April 2018

Healing at the Interface Between Autologous Block Bone Grafts and Recipient Sites Using n-Butyl-2-Cyanoacrylate Adhesive as Fixation: Histomorphometric Study in Rabbits.

J Oral Implantol 2017 Dec 24;43(6):447-455. Epub 2017 Oct 24.

2   Dept. CTBMF e Periodontia FORP-USP - Faculty of Ribeirão Preto, São Paulo, Brazil.

The aim of the present split-mouth (split-plot) study was to describe the sequential healing in the interface between autologous bone grafts and recipient parent bone, fixed using an n-butyl-2-cyanoacrylate adhesive with or without an additional titanium fixation screw. Bone grafts were collected from the calvaria and fixed to the lateral aspect of the mandible in 24 rabbits. The cortical layers of the recipient sites were perforated, and the grafts were randomly fixed using an n-butyl-2-cyanocrylate adhesive, either alone or in conjunction with a 1.5 mm × 6.0 mm titanium fixation screw. The animals were sacrificed after 3, 7, 20, and 40 days, and histomorphometric evaluations of the interface between graft and parent bone were performed. Only 2 of 6 grafts in each group were partially incorporated to the parent bone after 40 days of healing. The remaining grafts were separated from the parent bone by adhesive and connective tissue. It was concluded that the use of n-butyl-2-cyanoacrylate as fixation of an autologous bone graft to the lateral aspect of the mandible was able to maintain the fixation over time but did not incorporate the graft to the recipient sites. Use of fixation screws did not improve the healing.
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http://dx.doi.org/10.1563/aaid-joi-D-17-00108DOI Listing
December 2017

Volumetric Stability of Fresh Frozen Bone Blocks in Atrophic Posterior Mandible Augmentation.

J Oral Implantol 2017 Feb 18;43(1):25-32. Epub 2016 Oct 18.

1   Department of Oral and Maxillofacial Surgery and Periodontology, The School of Dentistry of Ribeirão Preto, University of São Paulo, Brazil.

Fresh frozen bone allografts (FFB) have become an alternative for bone augmentation in the past decades, especially because of the absence of recent reports of disease transmission or immunologic reactions when it is used. The aim of this prospective controlled study is to evaluate volumetric changes of newly created bone following reconstruction of the atrophic posterior mandible. Twenty consecutive patients presenting for reconstruction of posterior mandibular alveolar bone ridge width ≤6.0 mm and/or height ≤6.0 who met all inclusion and exclusion criteria were included. FFB blocks were used. The main outcome variable investigated was bone volume dynamics. Vertical, horizontal, and 3-dimensional bone gain data were measured from computerized tomography scans. The main predictor variable was time evaluated at 3 points: immediately after surgery (T1), at implant placement (T2), and 1 year after functional loading (T3). Secondary outcome parameters evaluated were implant survival, histologic findings, and microtomographic morphometry. The study included 28 hemi-mandibles, 50 FFB bone blocks, and 15 female and 5 male patients (mean age, 51.8 years). Block and implant survival rates were 100% and 96%, respectively, after 31.75 months of follow-up. Vertical and horizontal bone gain at T2 was 5.15 and 6.42 mm, respectively. Volumetric resorption was 31% at T2, followed by an additional 10% reduction at T3. Histologic evaluation showed newly formed vital bone in intimate contact with the remaining FFB. Microtomography revealed 31.8% newly formed bone, 14.5% remaining grafted bone, and 53.7% connective tissue and bone marrow. Thus, FFB blocks may lead to new bone formation and consolidation, with satisfactory volumetric bone maintenance, allowing implant-supported rehabilitation with high success rates.
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http://dx.doi.org/10.1563/aaid-joi-D-16-00095DOI Listing
February 2017

Marsupialisation of kerastocystic odontogenic tumours in a patient with Simpson-Golabi-Behmel syndrome.

Br J Oral Maxillofac Surg 2017 02 19;55(2):215. Epub 2016 Jul 19.

Department of Oral and Maxillofacial and Periodontology, Ribeirão Preto Dental School, University of São Paulo, Brazil. Electronic address:

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http://dx.doi.org/10.1016/j.bjoms.2016.06.022DOI Listing
February 2017

Maxillary sinus grafting with fresh frozen allograft versus bovine bone mineral: A tomographic and histological study.

J Craniomaxillofac Surg 2016 Jun 25;44(6):708-14. Epub 2016 Mar 25.

Laboratory of Investigative Pathology, University Hospital, Federal University of Sergipe, Aracaju, SE, Brazil.

We evaluated histologically and tomographically the effects of fresh frozen bone allograft (FFB) or bovine bone mineral (BBM) in maxillary sinus floor augmentations. In total, 30 maxillary sinuses from 30 patients (mean age = 51.17 ± 10.86 years) underwent sinus augmentation. Patients were divided in two test groups (15 sinuses each). The first group was grafted with allograft bone, and the second group received bovine bone mineral. After 6 months, bone samples from each group were collected for histological examination. Implant survival rates were 97.78% (FFB group) and 100% (BBM group) 6 months after functional loading. Median volumetric reductions of 31.2% (11.33-40.56) and 12.22% (9.91-20.59) were observed in the FFB and BBM groups, respectively. Comparisons between the groups for differences in initial and final volumes of bone (p = 0.015) and the rate of resorption (p = 0.009) showed statistically significant differences. The FFB group showed osteoblastic cells in close contact with osteoid matrix, connected through bridges between allograft bone particles and new bone formation. The BBM group showed BBM particles in close contact with new bone, with visible osteoid matrix bridges and osteoblastic cells surrounding it. None showed signs of acute or chronic inflammatory infiltrate. Despite better results with BBM, both FFB and BBM in maxillary sinus augmentation resulted in high percentages of new bone formation, and allowed implant placement with a low rate of failure of osseointegration at a 6-month follow-up.
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http://dx.doi.org/10.1016/j.jcms.2016.03.005DOI Listing
June 2016

Quantitative ultrasound at the hand phalanges in patients with bisphosphonate-related osteonecrosis of the jaws.

Braz Oral Res 2015 9;29(1):S1806-83242015000100301. Epub 2015 Oct 9.

Department of Gynecology and Obstetrics, School of Medicine of Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.

Patients with bisphosphonate-related osteonecrosis of the jaws (BRONJ) who received intravenous or oral bisphosphonates (BP) were selected for determination of their bone microarchitecture as a risk predictor of BRONJ development. The diagnosis of BRONJ was made based on clinical and radiographic findings. The control group consisted of healthy patients. All patients underwent quantitative and qualitative ultrasound measurements of bone at the hand phalanges carried out using the DBM Sonic BP. Ultrasound bone profile index (UBPI), amplitude-dependent speed of sound (AD-SoS), bone biophysics profile (BBP), and bone transmission time (BTT) were measured. The BRONJ group consisted of 17 patients (62 ± 4.24; range: 45-82); 10 (58.8%) were male and seven (41.1%) were female, of whom 11 (64.7%) suffered from multiple myeloma, three (17.6%) from osteoporosis, one (5.8%) from prostate cancer, one (5.8%) from kidney cancer, and one (5.8%) from leukemia. Fourteen (82.3%) of them received intravenous BP whereas three (17.6%) received oral BP. Nine (9/17; 52.9%) patients developed bone exposure: two in the maxilla and seven in the mandible. Regarding quantitative parameters, Ad-SoS was low in the BRONJ group, but not significant. The UBPI score was significantly reduced in BRONJ patients with exposed bone when compared to controls (0.47 ± 0.12 vs. 0.70 ± 0.15; p = 0.004). The present study demonstrated that quantitative ultrasound was able to show bone microarchitecture alterations in BRONJ patients, and suggests that these analyses may be an important tool for early detection of bone degeneration associated with BRONJ.
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http://dx.doi.org/10.1590/1807-3107BOR-2015.vol29.0106DOI Listing
October 2016

Maxillary Sinus Grafting with Autograft Versus Fresh-Frozen Allograft: A Split-Mouth Evaluation of Bone Volume Dynamics.

Int J Oral Maxillofac Implants 2015 Sep-Oct;30(5):1137-42

Purpose: To compare volumetric changes after sinus augmentation of completely edentulous maxillae with either autogenous or allogeneic fresh-frozen bone particles.

Materials And Methods: This split-mouth study in patients who required bilateral sinus grafting used autograft particles for one sinus and allograft particles for the contralateral sinus. The grafted sinuses were left to heal for 6 months prior to implant insertion. All patients underwent four computed tomography scans: prior to augmentation and 1 week, 6 months, and 12 months after grafting. Computer software was used to analyze bone graft volume in each scan.

Results: Fifteen patients (8 men, 7 women) with a mean age of 54 ± 5 years (range, 48 to 60 years) took part and underwent 30 sinus augmentation procedures. Mean autograft and allograft volumes were not statistically significantly different at each time point (1 week: 2.01 ± 0.43 cm³ vs 2.46 ± 0.79 cm³; 6 months: 1.53 ± 0.49 cm³ vs 1.75 ± 0.64 cm³; and 12 months: 1.38 ± 0.43 cm³ vs 1.59 ± 0.56 cm³, respectively). Mean volumetric reductions of 31.35% and 35.36% (23.9% and 29.9% in the 6 months prior to implant insertion, followed by an additional 9% and 9% in the following 6 months), relative to 1 week postgrafting, were noted for the autograft and allograft groups, respectively, after 12 months.

Conclusion: On the basis of this split-mouth study of 15 patients, there was no statistically significant volumetric difference after 12 months between the use of autograft or allografts for sinus augmentation. Fresh-frozen bone allograft may serve as an alternative that avoids the morbidity associated with autograft harvesting.
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http://dx.doi.org/10.11607/jomi.3924DOI Listing
May 2016

Enlargement of the Pharynx Resulting From Surgically Assisted Rapid Maxillary Expansion.

J Oral Maxillofac Surg 2016 Feb 21;74(2):369-79. Epub 2015 Jun 21.

Professor, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.

Purpose: Given that transverse maxillary deficiency is an etiologic factor of obstructive sleep apnea and is intimately connected to pharyngeal size, the objective of this study was to determine whether surgically assisted rapid maxillary expansion (SARME) would promote pharyngeal enlargement in adults.

Materials And Methods: This prospective study was conducted in patients with uni- or bilateral posterior crossbite who underwent SARME. Participants were recruited from the Integrated Center for the Study of Face Defects, School of Medicine of Ribeirão Preto, University of São Paulo (São Paulo, Brazil). All patients underwent computed tomography of the pharynx before and after surgery (171.5 days on average), and the sagittal and transverse planes and the total area across 3 levels of the pharynx, including the upper (posterior nasal spine), middle (first cervical vertebra), and lower (second cervical vertebra) levels, were measured on the images. A paired-samples t test was used to evaluate changes in the pharynx before and after surgery.

Results: The studied sample consisted of 18 adult patients (10 women and 8 men) with an average age of 37.11 years (standard deviation, 11.73 yr); all patients resided in the region of Ribeirão Preto, São Paulo, Brazil. No statistical changes were observed in the upper level. An enlargement of 17.82% (P = .0107) was observed in the sagittal plane of the middle level. The cross-sectional and area values of this same portion were enlarged (16.96 and 37.38%, respectively), with a trend toward statistical significance (P = .067 and .051, respectively). The airway enlargements in the lower level were 26.41, 24.87, and 53.87% in the sagittal and transverse planes and total area, respectively; these differences were statistically significant (P = .0003, .0033, and .0016, respectively) for all 3 measurements.

Conclusions: SARME promotes pharyngeal enlargement, especially in the lower levels of the pharynx.
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http://dx.doi.org/10.1016/j.joms.2015.06.157DOI Listing
February 2016

Effects of surgically assisted rapid maxillary expansion on obstructive sleep apnea and daytime sleepiness.

Sleep Breath 2016 May 20;20(2):501-8. Epub 2015 Jun 20.

School of Medicine of Ribeirão Preto, University of São Paulo, Av. Bandeirantes, 3900, Ribeirão Preto, São Paulo, Brazil, 14049-900.

Purpose: The aim of the study was to evaluate the effects of surgically assisted rapid maxillary expansion (SARME) on obstructive sleep events and daytime sleepiness in adults with obstructive sleep apnea syndrome (OSAS).

Methods: Sixteen individuals (7 women/9 men) aged 40.2 ± 10.2 (range, 24.4 to 62.2 years) with maxillary transverse deficiency and OSAS (respiratory disturbance index [RDI] greater than 5) confirmed with full-night polysomnography (PSG) underwent SARME to evaluate its efficiency for OSAS treatment.

Results: Several PSG parameters and the Epworth Sleepiness Scale (ESS) results were compared in selected individuals before and after they underwent SARME. An RDI reduction from 35.4 ± 38.5 to 16.0 ± 19.7 was found, corresponding to a mean decrease of 54.6 % (p = 0.0013). A 56.2 % (33.23 ± 39.5 to 14.5 ± 19.4, p = 0.001) decrease was found in the apnea-hypopnea index (AHI), in addition to decreases in the desaturation and microarousal rates, among other parameters. The ESS scores improved from 12.5 ± 5.3 to 7.2 ± 3.5 (p < 0.001).

Conclusions: SARME promotes an improvement in OSAS symptoms; decreases the rates of respiratory disturbances; microarousal, and desaturation; and reduces daytime sleepiness.
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http://dx.doi.org/10.1007/s11325-015-1214-yDOI Listing
May 2016

Two-stage treatment of facial asymmetry caused by unilateral condylar hyperplasia.

Braz Dent J 2014 ;25(3):257-60

Department of Ophthalmology, Otorhinolaryngology and Head and Neck Surgery, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil.

Condylar hyperplasia (CH) is a rare, self-limiting process manifesting between the first and third decades of life. CH causes facial asymmetry and derangement of the occlusion. Management involves resection of the condylar head and orthognathic surgery. This paper describes the case of a 37-year-old woman with spontaneous onset of CH over a span of approximately 25 years. The condition was managed with resection of the condyle alone, which dramatically improved facial asymmetry and altered the occlusion within a few months of follow up. Orthodontic treatment was then carried out and the patient underwent orthognathic surgery after 3 years. The patient is currently satisfied with her appearance and function and there are no signs of recurrence.
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http://dx.doi.org/10.1590/0103-6440201302150DOI Listing
August 2016

Fresh-frozen allografts combined with bovine bone mineral enhance bone formation in sinus augmentation.

J Biomater Appl 2015 Feb 22;29(7):1003-13. Epub 2014 Sep 22.

Department of Oral and Maxillofacial Surgery and Periodontology. Ribeirão Preto Dental School, University of São Paulo, São Paulo, Brazil

We evaluated histologically, histomorphometrically, and tomographically the effects of the association of fresh-frozen bone allograft (FFB) with bovine bone mineral (BBM) in maxillary sinus floor augmentation. In total, 34 maxillary sinuses from 29 patients, with a mean age of 51.32 (±6.44) years, underwent sinus augmentation. Patients were divided into control and test groups (17 sinuses each). The controls were grafted with allograft bone, and the test group received a combination of FFB and BBM at a 2:1 ratio. After 6 months, bone samples were collected for histological and histomorphometric examinations. The implant survival rates were 93.02% (control group) and 100% (test group) at 6 months after functional loading. Median volumetric reductions of 28.32% (17.05-44.05) and 12.62% (5.65-16.87) were observed for the control and test groups, respectively. Statistically significant histomorphometric differences were found between the control and test groups regarding newly formed bone 12.54% (10.50-13.33) vs. 24.42% (17.62-35.92), p < 0.001, total bone 48.34% (39.03-54.42) vs. 61.32% (50.61-64.96), p = 0.007, and connective tissue 51.66% (45.57-60.97) vs. 39.30% (35.03-49.37), p = 0.007. The addition of BBM to allograft bone in maxillary sinus augmentation resulted in higher percentages of new bone formation and total bone, and permitted implant placement with a low rate of osseointegration failure at the 6-month follow-up.
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http://dx.doi.org/10.1177/0885328214552709DOI Listing
February 2015

Multiple supernumerary teeth in a nonsyndromic 12-year-old female patient - a case report.

Braz Dent J 2014 Jan-Feb;25(1):79-82

Department of Oral and Maxillofacial Surgery and Periodontology, Integrated Center for the Study of Facial Deformities, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto, SP, Brazil.

Supernumerary teeth (ST) are uncommon alterations of development that may appear in either of the dental arches and that are frequently associated with syndromes such as cleidocranial dysplasia and Gardner syndrome. Multiple ST in individuals with no other disease or syndrome are very rare. In view of this situation, correct diagnosis, treatment and evaluation of ST with the use of appropriate imaging techniques are highly important. This case report presents radiographic images of a nonsyndromic 12-year-old female patient who presented with 14 supernumerary teeth and was treated under general anesthesia, with the extraction of all ST in a single surgical intervention. During the postoperative period, the patient did not complain of pain nor did she present any signs or symptoms of infection. During late follow-up period, due to difficulty in traction of the maxillary right canine and mandibular left first premolar towards the dental arch, it was necessary to extract these teeth under local anesthesia. Radiographic examination 3 years after surgery revealed the absence of ST and of diseases related to the existence of these teeth.
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http://dx.doi.org/10.1590/0103-6440201301993DOI Listing
April 2016

Conservative approach: using decompression procedure for management of a large unicystic ameloblastoma of the mandible.

J Craniofac Surg 2014 May;25(3):1012-4

From the *Department of Oral and Maxillofacial Surgery and Periodontics, Faculty of Dentistry of Ribeirão Preto, University of São Paulo, São Paulo; †Department of Craniomaxillofacial Surgery, Faculty of Medicine of Ribeirão Preto, University of São Paulo, São Paulo; and ‡Department of Surgery and Integrated Clinic, Araçatuba Dental School, Universidade Estadual Paulista Júlio de Mesquita Filho-UNESP, Araçatuba, São Paulo, Brazil.

Ameloblastoma is a relatively uncommon benign odontogenic tumor, which is locally aggressive and has a high tendency to recur, despite its benign histopathologic features. This pathology can be classified into 4 groups: unicystic, solid or multicystic, peripheral, and malignant. There are 3 variants of unicystic ameloblastoma, as luminal, intraluminal, and mural. Therefore, in mural ameloblastoma, the fibrous wall of the cyst is infiltrated with tumor nodules, and for this reason it is considered the most aggressive variant of unicystic ameloblastomas. Various treatment techniques for ameloblastomas have been proposed, which include decompression, enucleation/curettage, sclerotizing solution, cryosurgery, marginal resection, and aggressive resection. Literature shows treatment of this lesion continues to be a subject of intense interest and some controversy. Thus, the authors aimed to describe a case of a mural unicystic ameloblastoma of follicular subtype in a 19-year-old subject who was successfully treated using conservative approaches, as decompression. The patient has been followed up for 3 years, and has remained clinically and radiographically disease-free.
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http://dx.doi.org/10.1097/SCS.0000000000000716DOI Listing
May 2014

Oral bisphosphonate-related mandible fracture.

J Craniofac Surg 2014 ;25(2):709-11

Oral and Maxillofacial Surgery Program Ribeirão Preto School of Dentistry (FORP/USP) São Paulo, Brazil Oral and Maxillofacial Surgery Program, Ribeirão Preto School of Dentistry (FORP/USP) São Paulo, Brazil.

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http://dx.doi.org/10.1097/SCS.0000000000000458DOI Listing
June 2015

Clinical, Histological and Cellular Evaluation of Vertico-Lateral Maxillary Reconstruction Associating Alveolar Osteogenic Distraction and Fresh-Frozen Bone Allograft.

J Oral Implantol 2015 Jun 31;41(3):326-31. Epub 2013 Oct 31.

1  Department of Oral and Maxillofacial Surgery and Periodontology, School of Dentistry of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP, Brazil.

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http://dx.doi.org/10.1563/AAID-JOI-D-13-00102DOI Listing
June 2015

Recurrence of ameloblastoma in soft tissue.

J Craniofac Surg 2013 ;24(5):1866-7

University of São Paulo Ribeirão Preto Dental School Ribeirão Preto, Brazil University of São Paulo Ribeirão Preto Medicine School Ribeirão Preto, Brazil University of São Paulo Ribeirão Preto Dental School Ribeirão Preto, Brazil.

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http://dx.doi.org/10.1097/SCS.0b013e31829a84a1DOI Listing
September 2014

Three-stage mandible reconstruction after firearm injury.

J Craniofac Surg 2013 Jan;24(1):e87-8

Department of Oral and Maxillofacial Surgery and Periodontology, Ribeirão Preto Dental School, São Paulo, Brazil.

Firearm injuries in the lower jaw may cause significant loss of hard and soft facial tissues, resulting in aesthetic and functional deformity. In this article, we present a case of a patient who suffered avulsion of the soft and hard tissues of the left mandible body and symphysis. After the emergency treatment, the patient was referred to our service, and the treatment was performed in 3 stages: surgical reconstruction with vascularized fibula flap, distraction osteogenesis, and dental implant rehabilitation. During 5 years of follow-up period, the aesthetic and functional condition of the patient improved considerably.
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http://dx.doi.org/10.1097/SCS.0b013e3182713809DOI Listing
January 2013

Immunohistochemical, tomographic, and histological study on onlay bone graft remodeling. Part III: allografts.

Clin Oral Implants Res 2013 Oct 9;24(10):1164-72. Epub 2012 Jul 9.

Department of Oral and Maxillofacial Surgery, University of Sao Paulo, Ribeirao Preto, Brazil.

Objective: In the last decades aroused the interest for bone tissue bank as an alternative to autogenous grafting, avoiding donor sites morbidity, surgical time, and costs reduction. The purpose of the study was to compare allografts (ALg) with autografts (AUg) using histology, immunochemistry, and tomographic analysis.

Material And Methods: Fifty-six New Zealand White rabbits were submitted to surgical procedures. Twenty animals were donors and 36 were actually submitted to onlay grafting with ALg (experimental group) and AUg (control group) randomly placed bilaterally in the mandible. Six animals of each group were sacrificed at 3, 5, 7, 10, 20, and 60 postoperative days. Immunolabeling was accomplished with osteoprotegerin (OPG); receptor activator of nuclear factor-k ligand (RANKL); alkaline phosphatase (ALP); osteopontin (OPN); vascular endothelial growth factor (VEGF); tartrate-resistant acid phosphatase (TRAP); collagen type I (COL I); and osteocalcin (OC). Density and volume of the grafts was evaluated on tomography obtained at the surgery and sacrifice.

Results: The ALg and AUg exhibited similar patterns of density and volume throughout the experiments. The intra-group data showed statistical differences at days 7 and 60 in comparison with other time points (P = 0.001), in both groups. A slight graft expansion from fixation until day 20 (P = 0.532) was observed in the AUg group and then resorbed significantly at the day 60 (P = 0.015). ALg volume remained stable until day 7 and decreased at day 10 (P = 0.045). The light microscopy analysis showed more efficient incorporation of AUg onto the recipient bed if compared with the ALg group. The immunohistochemical labeling picked: at days 10 and 20 with OPG in the AUg group and at day 7 with TRAP in the ALg group (P = 0.001 and P = 0.002, respectively).

Conclusions: ALg and AUg were not differing in patterns of volume and density during entire experiment. Histological data exhibit more efficient AUg incorporation into recipient bed compared with the ALg group. Immunohistochemistry outcomes demonstrated similar pattern for both ALg and AUg groups, except for an increasing resorption activity in the ALg group mediated by TRAP and in the AUg group by higher OPG labeling. However, this latter observation does not seem to influence clinical outcomes.
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http://dx.doi.org/10.1111/j.1600-0501.2012.02528.xDOI Listing
October 2013

Enhanced bone apposition to Brazilian microrough titanium surfaces.

Braz Dent J 2010 Jan;21(1):18-23

Department of Oral and Maxillofacial Surgery and Periodontology, Ribeirão Preto Dental School, University of São Paulo, Ribeirão Preto, SP, Brazil.

It has recently been reported that machined and microrough (micro) Brazilian titanium (Ti) implants have good production standards. The aim of this study was to evaluate in vivo bone formation around 2 different implant surfaces placed in dog's mandible. Thirty-two screw-typed Ti implants were used in this study. Mandibular premolars were extracted in 8 dogs and, after 12 weeks, 2 machined (Neodent Titamax, Brazil) and 2 micro implants (Neodent Titamax Porous, Brazil) were placed in each animal. Biopsies were taken at 3 and 8 weeks post-implantation and stained with Stevenel's blue and Alizarin red for histomorphometric measurements of bone-to-implant contact (BIC), bone area between threads (BABT) and bone area within the mirror area (BAMA). Data were analyzed statistically by two-way ANOVA (alpha=0.05). While at 3 weeks micro implants exhibited significantly more BIC than machined ones (55 +/- 12.5% and 35.6 +/- 15%, p<0.05), no significant difference in such parameter was detected at 8 weeks (51.2 +/- 21% and 48.6 +/- 18.1%, p>0.05). There were no significant differences in BABT and BAMA between the implants. Micro surfaces promoted higher contact osteogenesis. These data indicate that this commercial micro Ti implant surface enhances contact osteogenesis at an early post-implantation period when compared to the machined one.
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http://dx.doi.org/10.1590/s0103-64402010000100003DOI Listing
January 2010

Influence of rhBMP-2 on bone formation and osseointegration in different implant systems after sinus-floor elevation. An in vivo study on sheep.

J Craniomaxillofac Surg 2010 Dec 8;38(8):571-9. Epub 2010 Apr 8.

Department of Oral and Maxillofacial Surgery, University of Freiburg, Germany.

Background: Several studies have reported certain bone morphogenic proteins (BMPs) to have positive effects on bone generation. Although some investigators have studied the effects of human recombinant BMP (rhBMP-2) in sinus augmentation in sheep, none of these studies looked at the placement of implants at the time of sinus augmentation. Furthermore, no literature could be found to report on the impact that different implant systems, as well as the positioning of the implants had on bone formation if rhBMP-2 was utilized in sinus-lift procedures.

Purpose: The aim of this study was to compare sinus augmentation with rhBMP-2 on a poly-d, l-lactic-co-glycolic acid gelatine (PLPG) sponge with sinus augmentation with autologous pelvic cancellous bone in the maxillary sinus during the placement of different dental implants.

Materials And Methods: Nine adult female sheep were submitted to bilateral sinus-floor elevation. In one side (test group) the sinus lift was performed with rhBMP-2 on a PLPG-sponge, while the contralateral side served as the control by using cancellous bone from the iliac crest. Three different implants (Bränemark(®), 3i(®) and Straumann(®)) were inserted either simultaneously with the sinus augmentation or as a two staged procedure 6 weeks later. The animals were sacrificed at 6 and 12 weeks for histological and histomorphometrical evaluations during which bone-to-implant contact (BIC) and bone density (BD) were evaluated.

Results: BD and BIC were significantly higher at 12 weeks in the test group if the implants were placed at the time of the sinus lift (p<0.05). No difference was observed between the different implant systems or positions.

Conclusions: The use of rhBMP-2 with PLPG-sponge increased BIC as well as BD in the augmented sinuses if compared to autologous bone. Different implant systems and positions of the implants had no effect on BIC or BD.
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http://dx.doi.org/10.1016/j.jcms.2010.02.010DOI Listing
December 2010

Mesenchymal stem cells and bovine bone mineral in sinus lift procedures--an experimental study in sheep.

Tissue Eng Part C Methods 2010 Oct;16(5):1033-9

Department of Oral and Maxillofacial Surgery, Albert-Ludwigs-University, Freiburg, Germany.

Introduction: New reconstructive and less invasive methods have been searched to optimize bone formation and osseointegration of dental implants in maxillary sinus augmentation.

Purpose: The aim of the presented ovine split-mouth study was to compare bovine bone mineral (BBM) alone and in combination with mesenchymal stem cells (MSCs) regarding their potential in sinus augmentation.

Material And Methods: Bilateral sinus floor augmentations were performed in six adult sheep. BBM and MSCs were placed into the test side and only BBM in the contra-lateral control side of each sheep. Animals were sacrificed after 8 and 16 weeks. Augmentation sites were analyzed by computed tomography, histology, and histomorphometry.

Results: The initial volumes of both sides were similar and did not change significantly with time. A tight connection between the particles of BBM and the new bone was observed histologically. Bone formation was significantly (p = 0.027) faster by 49% in the test sides.

Conclusion: The combination of BBM and MSCs accelerated new bone formation in this model of maxillary sinus augmentation. This could allow early placement of implants.
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http://dx.doi.org/10.1089/ten.TEC.2009.0734DOI Listing
October 2010

Implant osseointegration in circumferential bone defects treated with latex-derived proteins or autogenous bone in dog's mandible.

Clin Implant Dent Relat Res 2012 Mar 29;14(1):135-43. Epub 2009 Sep 29.

Department of Oral and Maxillofacial Surgery and Periodontics, Faculty of Dentistry of Ribeirao Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.

Background: In sites with diminished bone volume, the osseointegration of dental implants can be compromised. Innovative biomaterials have been developed to aid successful osseointegration outcomes.

Purpose: The aim of this study was to evaluate the osteogenic potential of angiogenic latex proteins for improved bone formation and osseointegration of dental implants.

Materials And Methods: Ten dogs were submitted to bilateral circumferential defects (5.0 × 6.3 mm) in the mandible. Dental implant (3.3 × 10.0 mm, TiUnite MK3™, Nobel Biocare AB, Göteborg, Sweden) was installed in the center of the defects. The gap was filled either with coagulum (Cg), autogenous bone graft (BG), or latex angiogenic proteins pool (LPP). Five animals were sacrificed after 4 weeks and 12 weeks, respectively. Implant stability was evaluated using resonance frequency analysis (Osstell Mentor, Osstell AB, Göteborg, Sweden), and bone formation was analyzed by histological and histometric analysis.

Results: LPP showed bone regeneration similar to BG and Cg at 4 weeks and 12 weeks, respectively (p ≥ .05). Bone formation, osseointegration, and implant stability improved significantly from 4 to 12 weeks (p ≤ .05).

Conclusion: Based on methodological limitations of this study, Cg alone delivers higher bone formation in the defect as compared with BG at 12 weeks; compared with Cg and BG, the treatment with LPP exhibits no advantage in terms of osteogenic potential in this experimental model, although overall osseointegration was not affected by the treatments employed in this study.
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http://dx.doi.org/10.1111/j.1708-8208.2009.00238.xDOI Listing
March 2012

Immunohistochemical, tomographic and histological study on onlay bone graft remodeling. Part II: calvarial bone.

Clin Oral Implants Res 2009 Nov 15;20(11):1254-64. Epub 2009 Jun 15.

Department of Oral and Maxillofacial Surgery and Periodontics, Faculty of Dentistry of Ribeirão Preto, University of São Paulo at Ribeirão Preto, SP, Brazil.

Objectives: Little information is available on the molecular events that occur during graft incorporation over time. The calvarial bone (Cb) grafts have been reported to produce greater responses compared with other donor regions in maxillofacial reconstructions, but the scientific evidences for this are still lacking. The objectives of this study are (1) to study the morphological pattern of Cb onlay bone grafts and compare them with the biological events through immunohistochemical responses and (2) to establish the effects of perforations in maintaining the volume and bone density of the receptor bed.

Material And Methods: Sixty New Zealand White rabbits were submitted to Cb onlay bone grafts on the mandible. In 30 rabbits, the receptor bed was perforated (perforated group), while for the remaining animals the bed was kept intact (non-perforated group). Six animals from each group were sacrificed at 5, 7, 10, 20 and 60 days after surgery. Histological sections from the grafted area were prepared for immunohistochemical and histological analyses. Immuno-labeling was found for proteins Osteoprotegerin (OPG), receptor activator of nuclear factor-kappabeta ligand (RANKL), alkaline phosphatase (ALP), osteopontin (OPN), vascular endothelial growth factor (VEGF), tartrate-resistant acid phosphatase (TRAP), Type I collagen (COL I) and osteocalcin (OC). The tomography examination [computerized tomography (CT) scan] was conducted just after surgery and at the sacrifice.

Results: The histological findings revealed that the perforations contributed to higher bone deposition during the initial stages at the graft-receptor bed interface, accelerating the graft incorporation process. The results of the CT scan showed lower resorption for the perforated group (P
Conclusions: These findings indicate that the bone volume of calvarial grafts is better maintained when the receptor bed is perforated, probably resulting from more effective graft revascularization and greater bone deposition. The process of bone resorption peaked between 20 and 60 days post-operatively in both groups although significantly less in the perforated group.
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http://dx.doi.org/10.1111/j.1600-0501.2009.01747.xDOI Listing
November 2009

In vivo comparison of hard tissue regeneration with human mesenchymal stem cells processed with either the FICOLL method or the BMAC method.

Tissue Eng Part C Methods 2010 Apr;16(2):215-23

Department of Oral and Craniomaxillofacial Surgery, University Hospital Freiburg, Freiburg, Germany.

Objective: To compare new bone formation in maxillary sinus augmentation procedures using biomaterial associated with mesenchymal stem cells (MSCs) separated by two different isolation methods.

Background: In regenerative medicine open cell concentration systems are only allowed for clinical application under good manufacturing practice conditions.

Methods: Mononuclear cells, including MSCs, were concentrated with either the synthetic polysaccharide (FICOLL) method (classic open system--control group, n = 6 sinus) or the bone marrow aspirate concentrate (BMAC) method (closed system--test group, n = 12 sinus) and transplanted in combination with biomaterial. A sample of the cells was characterized by their ability to differentiate. After 4.1 months (SD +/- 1.0) bone biopsies were obtained and analyzed.

Results: The new bone formation in the BMAC group was 19.9% (90% confidence interval [CI], 10.9-29), and in the FICOLL group was 15.5% (90% CI, 8.6-22.4). The 4.4% difference was not significant (90% CI, -4.6-13.5; p = 0.39). MSCs could be differentiated into osteogenic, chondrogenic, and adipogenic lineages.

Conclusion: MSCs harvested from bone marrow aspirate in combination with bovine bone matrix particles can form lamellar bone and provide a reliable base for dental implants. The closed BMAC system is suited to substitute the open FICOLL system in bone regeneration procedures.
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http://dx.doi.org/10.1089/ten.TEC.2009.0269DOI Listing
April 2010

Clinical, microscopic and imaging findings associated to McCune-Albright syndrome: report of two cases.

Braz Dent J 2008 ;19(2):165-70

Department of Oral and Maxillofacial Surgery and Traumatology and Periodontics, Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.

McCune-Albright syndrome is characterized by the triad café-au-lait cutaneous spots, polyostotic fibrous dysplasia and endocrinopathies. This article presents two cases of McCune-Albright syndrome in a middle-aged woman and a young girl. Both patients presented café-au-lait spots on the face and other parts of the body and expansion of the mandible with radiopaque-radiolucent areas with ground-glass radiographic appearance, and were diagnosed as having fibrous dysplasia and endocrine disorders. The patient of Case 1 had fibrous dysplasia on the upper and lower limbs, thorax, face and cranium, early puberty, hyperglycemia, hyperthyroidism and high serum alkaline phosphatase levels. The patient of Case 2 presented lesions on the upper limbs and evident endocrine disorders. In both cases presented in this article, the initial exam was made because of the mandibular lesion. However, a diagnosis of fibrous dysplasia must lead to investigation of the involvement of other bones, characterizing polyostotic fibrous dysplasia, which is manifested in a number of diseases. An accurate differential diagnosis is mandatory to determine the best treatment approach for each case.
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http://dx.doi.org/10.1590/s0103-64402008000200014DOI Listing
March 2009

Mandibular ameloblastoma treated by bone resection and immediate reconstruction.

Braz J Otorhinolaryngol 2008 Jan-Feb;74(1):155-7

FMRP, USP, SP, Brazil.

Multicystic ameloblastoma mainly affects adult patients between the third and seventh decades of life, frequently in the posterior region of the mandible. The resection of a mandible segment without adequate reconstruction produces serious esthetic and functional sequelae leading to a loss of quality of life. The objective of this study is to show that multidisciplinary treatment of ameloblastomas helps in total lesion excision associated with complete reconstruction of the damaged area. We present a 47-year-old male patient with an ameloblastoma in the posterior mandible who was treated with complete resection of a mandibular segment. Reconstruction, carried out during the same surgical procedure, was performed using an iliac crest bone graft fixed with titanium plates and screws. Rehabilitation was completed eight months later with teeth implants in the grafted area. The advantages of this procedure include recurrence risk reduction due to segmental resection, reliable mandibular reconstruction and less surgical procedures, allowing full rehabilitation within a shorter period of time.
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http://dx.doi.org/10.1016/s1808-8694(15)30768-0DOI Listing
August 2008