The correlation of different methods for the assessment of bone quality in vivo: an observational study.

Different methods for the assessment of bone quality were evaluated in this study. Sixty alveolar bone areas were investigated. Peri-apical and panoramic radiographs were obtained with an aluminium scale to assess optical density. The Lekholm and Zarb (L&Z) classification was determined through radiographic analysis and the surgeon's tactile perception. A trephine was used to obtain a bone biopsy for assessment by micro-computed tomography (micro-CT) and histomorphometry. Primary stability of the implants was assessed using insertion torque (IT) and the implant stability quotient (ISQ). The optical density on peri-apical radiographs was correlated with IT, ISQ, and micro-CT (BV, BV/BT, Tb.Th, Tb.N, BS/BV, Tb.Pf, and SMI) (rho ≤ 0.471, P ≤ 0.028). Panoramic radiography showed a correlation only with bone surface (BS) and bone surface/volume ratio (BS/TV) (rho ≤ 0.290, P ≤ 0.031). IT showed a correlation with ISQ, histometry, and micro-CT (BV, BS/TV, Tb.Th, Tb.N, BS/BV, Tb.Pf, Tb.Sp, BV/BT) (rho ≤ 0.550, P ≤ 0.022). ISQ did not show any correlation with micro-CT. The L&Z classification showed correlations with the optical density obtained in the peri-apical radiographs, histometry, osteocyte count, IT, and micro-CT (BS/BV, Tb.Sp, Tb.Pf, BV, BS/TV, Tb.Th, Tb.N) (rho ≤ 0.344, P ≤ 0.042). The L&Z bone classification and IT are reliable methods, peri-apical radiographs and ISQ are acceptable, and panoramic radiography is not a reliable method for the assessment of bone quality.

Dynamic three-dimensional finite element analysis of orbital trauma.

This study comprises a dynamic finite element (FE) analysis of the mechanisms of orbital trauma, specifically buckling and hydraulic theories. A digital model of the orbital cavity - including the eyeball, fatty tissue, extraocular muscles, and the bone orbit - was created from magnetic resonance imaging and computed tomographic data from a real patient. An impactor hit the FE model following two scenarios: one was a hydraulic mechanism for direct impact to the eyeball and the other a buckling mechanism for direct impact over the infraorbital rim. The first principal stress was calculated to determine the stress distribution over the orbital walls. The FE model presented more than 900,000 elements and time of simulation was 4.8 milliseconds (ms) and 0.6 ms, for the hydraulic and buckling mechanisms, respectively. The stress distribution in the hydraulic mechanism affected mainly the medial wall with a high stress area of 99.08 mm2, while the buckling mechanism showed a high stress area of 378.70 mm2 in the orbital floor. The presence of soft tissue absorbed the energy, especially in the hydraulic mechanism. In conclusion, the applied method of segmentation allowed the construction of a complete orbital model. Both mechanisms presented results that were similar to classic experiments. However, the soft tissue in the hydraulic mechanism absorbed the impact, demonstrating its role in orbital pathophysiology.

Nasomaxillary effects of miniscrew-assisted rapid palatal expansion and two surgically assisted rapid palatal expansion approaches.

This retrospective study was performed to evaluate nasomaxillary changes in 36 patients at an advanced stage of skeletal maturity who underwent miniscrew-assisted rapid palatal expansion (MARPE) or surgically assisted rapid palatal expansion (SARPE) with/without an alar base cinch. Cone beam computed tomography images taken before and after expansion were analysed. Changes in the width of the dental arch (D66S, D66I), maxillary base (MxMol), and nasal floor and nasal cavity in the molar and canine regions (NaFMol, NaFCan, NaCMol, NaCCan) were compared, as well as changes in the choanal aperture (CA) and nasal soft tissue (NW). The MARPE technique produced smaller dental changes (D66S; P=0.025) and greater nasomaxillary expansion (MxMol, P=0.010; NaCMol, P=0.016; NaCCan, P=0.017; NaFMol, P=0.001; CA, P=0.002) than both SARPE techniques. Changes in NW did not differ significantly between the groups (P=0.200). MARPE uniformly increased the anterior and posterior widths of the nasal cavity. SARPE expanded the nasal cavity in a 'V-shape' pattern. Changes in the nasal cavity and choanal aperture related to the amount of dental arch expansion were greater for MARPE than for SARPE. All three approaches increased the width of the nasal soft tissue, although the cinch in SARPE limited this increase.

Surgically assisted rapid maxillary expansion: a systematic review of complications.

A systematic review of the literature on the complications of surgically assisted maxillary expansion (SARME) was performed. The search strategy was based on the PRISMA guidelines. The PubMed, SCOPUS, and Cochrane Library databases were searched. Data were extracted from the full texts after screening of the abstracts and titles. Human clinical studies encompassing 'maxillary expansion', 'palatal expansion', 'SARME', or 'SARPE' and that reported sufficient data for 'complication' were included. In vitro studies, case reports, meta-analyses, reviews, book chapters, animal studies, and studies with missing or insufficient data were excluded. The final selection included 12 articles for data extraction. A total of 851 patients underwent SARME, with 187 reported complications (21.97%). Epistaxis (2.47%) and postoperative pain (2.00%) were the most often reported minor complications, and asymmetric or inadequate expansion presented an occurrence rate of 4.47%. Minor complications were equally distributed between surgical (49.30%) and orthodontic complications (50.70%). The technique without pterygomaxillary disjunction increased the occurrence of minor complications (29.95% vs. 16.87%), and the expansion pattern with less than 0.5 mm/day increased the occurrence of orthodontic complications (30.93% vs. 1.83%), i.e. asymmetric expansion. In conclusion, SARME procedures mostly present minor complications. Although several types of complication are described in the literature, occurrence rates are low, and technical issues such as pterygomaxillary disjunction and the pattern of distraction can be predictors of the complication risk.

Titanium mesh associated with rhBMP-2 in alveolar ridge reconstruction.

A systematic review of the literature was performed regarding the use of titanium mesh in association with recombinant human bone morphogenetic protein (rhBMP) for alveolar ridge reconstruction. The PubMed, Scopus, and Cochrane databases were searched for articles in English published up until June 2017. The inclusion criteria encompassed studies in humans - randomized clinical trials, prospective and retrospective studies, and case series. The screening and selection process was performed by three independent reviewers, with verification by a senior researcher in the case of disagreement. The initial search identified 92 studies. After removal of duplicates, 70 remained for title and abstract reading. Fifty-four articles were considered non-relevant, resulting in a total of 16 studies. Following application of the inclusion criteria, 10 studies were selected. An additional study was added after the hand search, giving a total of 11 articles. These reported on 106 patients who had undergone alveolar ridge augmentation with rhBMP and titanium mesh. There were 74 maxillary grafts and 22 mandibular grafts, and the success rate of rehabilitation was 93.4% to 100%. The most frequently reported complications were suture dehiscence and mesh exposure, but without graft loss. rhBMP associated with titanium mesh is a viable method for alveolar reconstruction with high success rates and low rates of local complications.

Buccal fat pad removal to improve facial aesthetics: an established technique?

BACKGROUND: Buccal fat pad (BFP) is a singular structure between the facial muscles. Its removal may enhance the zygomatic prominences resulting in an inverted triangle of beauty. OBJECTIVE: The aim of this study was to perform a systematic review of literature about BFP removal for facial aesthetic improvement. In order to answer the following research question: What are the indications, complication types and rates, surgical techniques and outcomes of the technique? MATERIAL AND METHODS: The initial search in Pubmed, Scopus, and Cochrane databases recognized 220 articles. The final review included eight of them. None of the included studies were clinical trials. RESULTS: BPF removal was performed by intraoral incision or associated with the face lift procedure. In 71 patients submitted to the procedure and evaluated about complications, only 8.45% presented minor complications. Parotid duct and facial nerve injuries were not found. No study evaluated facial aging and long-term effects, therefore the harmless effect of the procedure to those features is not clear. CONCLUSIONS: Although it is not a novel procedure, there is a lack of information about long-term outcomes. Thus, controlled clinical studies should be performed to achieve adequate clinical evidence of those aspects.

Three-dimensional strut plate for the treatment of mandibular fractures: a systematic review.

The treatment of mandibular fractures by open reduction and internal fixation is very variable. Thus, there are many controversies about the best fixation system in terms of stability, functional recovery, and postoperative complications. This systematic review sought scientific evidence regarding the best indication for the use of three-dimensional (3D) plates in the treatment of mandibular fractures. A systematic search of the PubMed/MEDLINE, Elsevier/Scopus, and Cochrane Library databases was conducted to include articles published up until November 2016. Following the application of the inclusion criteria, 25 scientific articles were selected for detailed analysis. These studies included a total of 1036 patients (mean age 29 years), with a higher prevalence of males. The anatomical location most involved was the mandibular angle. The success rate of 3D plates was high at this location compared to other methods of fixation. In conclusion, the use of 3D plates for the treatment of mandibular fractures is recommended, since they result in little or no displacement between bone fragments.

Sequencing of bimaxillary surgery in the correction of vertical maxillary excess: retrospective study.

The aim of this study was to evaluate the precision of bimaxillary surgery performed to correct vertical maxillary excess, when the procedure is sequenced with mandibular surgery first or maxillary surgery first. Thirty-two patients, divided into two groups, were included in this retrospective study. Group 1 comprised patients who received bimaxillary surgery following the classical sequence with repositioning of the maxilla first. Patients in group 2 received bimaxillary surgery, but the mandible was operated on first. The precision of the maxillomandibular repositioning was determined by comparison of the digital prediction and postoperative tracings superimposed on the cranial base. The data were tabulated and analyzed statistically. In this sample, both surgical sequences provided adequate clinical accuracy. The classical sequence, repositioning the maxilla first, resulted in greater accuracy for A-point and the upper incisor edge vertical position. Repositioning the mandible first allowed greater precision in the vertical position of pogonion. In conclusion, although both surgical sequences may be used, repositioning the mandible first will result in greater imprecision in relation to the predictive tracing than repositioning the maxilla first. The classical sequence resulted in greater accuracy in the vertical position of the maxilla, which is key for aesthetics.

Nasal airway evaluation in obstructive sleep apnoea patients: volumetric tomography and endoscopic findings.

Obstructive sleep apnoea (OSA) results from the recurrent collapse of the upper airway during sleep. Nasal abnormalities influence the stability of the pharynx. The aim of this study was to evaluate the volumetric and anatomical changes of the nasal cavity in patients with OSA. The Nasal Obstruction Symptom Evaluation (NOSE) scale was used to grade nasal obstruction. Sleep-related breathing disorders were evaluated by polysomnography. The nasal airway volume was obtained from computed tomography scans through volumetric reconstruction of the nasal airway. Alterations to the nasal anatomy were identified by nasal fibre-optic endoscopy. Ninety-four patient charts were analyzed. The final sample comprised 32 patients with severe OSA, 16 with moderate OSA, 23 with mild OSA, and 20 without OSA. Three groups were established based on nasal obstruction and OSA. The groups were compared for nasal airway volume (P=0.464) and body mass index (P=0.001). The presence of nasal septum deviation and inferior turbinate hypertrophy were related to the NOSE score (P=0.05 for both), apnoea-hypopnoea index (P=0.03 and P=0.05, respectively), and nasal airway volume (P=0.71 and P=0.78, respectively). In this nasal airway evaluation of OSA patients, the presence of sites of obstruction was correlated with the severity of OSA; this was not the case for the evaluation of the nasal airway volume dimensions.

Nasolabial changes after two different approaches for surgically assisted rapid maxillary expansion.

This retrospective study evaluated the nasolabial changes in patients who underwent surgically assisted rapid maxillary expansion (SARME) using two different approaches. Nineteen patients were included in the study, divided into two groups according to the kind of surgical approach performed: group 1 (n=9), SARME performed through the standard Le Fort I circumvestibular approach followed by the alar base cinch, and group 2 (n=10), SARME performed through a subtotal vestibular approach associated to a V-shaped incision at the maxillary midline in the labial frenulum region, without alar base cinch. Measurements of width, length, and nasal projection as well as upper lip length were taken from cone beam tomographic images obtained before surgery (T1) and 6 months postoperatively (T2). Both groups presented an increase in the alar base width postoperatively (P<0.05). The approach used in group 2 resulted in smaller changes in the alar base width as measured at the superior alar curvature (P<0.05). Nasal length and projection and upper lip length were not altered by SARME. The type of surgical approach influenced nasolabial changes, but did not eliminate increase in width of the alar base.

Effects of lateral osteotomy on surgically assisted rapid maxillary expansion.

This study aimed to assess the potential effects of two different osteotomy designs of the maxillary lateral wall on dental and skeletal changes after surgically assisted rapid maxillary expansion (SARME). Thirty adult patients were divided into two groups according to the lateral osteotomy design: group 1 (n=16) underwent lateral osteotomy performed in a horizontal straight fashion, and group 2 (n=14) underwent lateral osteotomy performed in parallel to the occlusal plane with a step at the zygomatic buttress. Cone beam computed tomography scans were obtained preoperatively (T1), immediately after expansion (T2), and 6 months after expansion (T3). Mixed analysis of variance (ANOVA) was used for the statistical analysis. The results showed no significant interaction effect between groups and time points. Therefore, maxillary expansion was effective in both groups. Statistically significant increases in all dental and skeletal measurements were observed immediately after expansion (P<0.001). Relapse of the nasal floor width, tipping of the supporting teeth, and an increase in root distance in molars occurred at T3 (P<0.05). In summary, the maxillary lateral osteotomy design did not influence the results of SARME, which occurred mainly through the inclination of maxillary segments.

Assessment of nasal obstruction symptoms using the NOSE scale after surgically assisted rapid maxillary expansion.

The Nasal Obstruction Symptom Evaluation (NOSE) scale is a reliable and valid instrument used widely in otorhinolaryngology to evaluate nasal obstruction symptoms in patients with nasal disorders. The purpose of this study was to assess nasal obstruction symptoms prospectively in patients undergoing surgically assisted rapid maxillary expansion (SARME) using the NOSE scale. Sixteen patients were studied (mean age 31±7.7 years), 10 women and six men, all with a transverse maxillary deficiency and an indication for SARME. Hyrax type devices were placed preoperatively and SARME was performed using Kraut's technique. The NOSE scale was applied prospectively to assess nasal obstruction symptoms. The results were recorded for each score on a scale ranging from 0 to 4, and these scores were multiplied by 5, generating a balanced scale from 0 to 100. Data were stratified according to NOSE scores, and nasal obstruction was categorized as mild (0-25), moderate (26-50), or severe (>50). The questionnaire was administered twice, first preoperatively and then at 6 months after surgery, and the results compared. Data were analyzed statistically using SAS statistical package software and showed that patients experienced a subjective improvement or did not have a worsening of nasal obstruction symptoms after SARME.

Evaluation of single implants placed in the posterior mandibular area under immediate loading: a prospective study.

The aim of this study was to evaluate the survival of single dental implants subjected to immediate function. Twelve patients with edentulous areas in the posterior mandible were included in the study. All received at least one regular platform dental implant (3.75mm×11mm or 3.75mm×13mm). Clinical and radiographic parameters were evaluated. The survival rate after 12 months was 83.3%. The implants showed no clinical mobility, had implant stability quotient values (ISQ; Osstell) around 70, bone loss of up to 2mm, and a probing depth of ≤3mm. Although the posterior mandible is an area in which the immediate loading of dental implants should be performed with caution, this treatment presented a good success rate in the present study sample.

In vitro biomechanical comparison of six different fixation methods following 5-mm sagittal split advancement osteotomies.

The sagittal split ramus osteotomy (SSRO) is a surgical technique used widely to treat many congenital and acquired mandibular discrepancies. Stabilization of the osteotomy site and the potential for skeletal relapse after the procedure are still major problems. The aim of this study was to compare the mechanical stability of six methods of rigid fixation in SSRO using a biomechanical test model. Sixty polyurethane replicas of human hemimandibles were divided into six groups. In group I, the osteotomies were fixed with two four-hole titanium miniplates; in group II, with one four-hole miniplate; in group III, with one four-hole miniplate+a bicortical screw; in group IV, with a grid miniplate; in group V, with a four-hole locking miniplate; and in group VI, with a six-hole miniplate. A linear load in the premolar region was applied to the hemimandibles. The resistance forces (N) needed to displace the distal segment by 1, 3, and 5mm were recorded and the data transmitted from the load cell to a computer. One-way analysis of variance with Tukey's post hoc test was performed to compare the means between groups. For the three displacement conditions, there was a strong tendency for the 2.0-mm plate+screw and the grid plate to have higher values.

Volumetric upper airway assessment in patients with transverse maxillary deficiency after surgically assisted rapid maxillary expansion.

Transverse maxillary deficiency is commonly found in patients with sleep apnea and is also related to abnormal breathing patterns. Maxillary expansion procedures promote widening of the nasal floor and reduce the resistance to airflow, and have a positive influence on nasopharynx function. In order to evaluate volume changes in the upper airway, 15 adult patients with transverse maxillary deficiency underwent surgically assisted rapid maxillary expansion (RME) until a slight overcorrection of the crossbite was obtained. Cone beam computed tomography (CBCT) volumetric images were obtained at three predefined time points. The mean age of the patients was 30.2 (±7.4) years; nine were females and six were males. The area, volume, and the smallest transverse section area of the airway were assessed using Dolphin Imaging 3D software. Statistical comparisons were made of the changes between time periods. No statistically significant differences were found for volume or area. However a significant difference was found between the preoperative and immediate postoperative smallest transverse section area (P<0.05). Maxillary expansion, as an isolated procedure, does not result in a statistically significant improvement in the airway dimensions and results in an inferior relocation of the smallest transverse section area.

Effect of the number of screws on the stability of locking mandibular reconstruction plates.

Atrophic mandible fractures are frequently a challenge to stabilize. This study evaluated, through mechanical testing in vitro, the number of locking screws that is sufficient to withstand loading when applied with a locking reconstruction plate in the fixation of atrophic mandible fractures. Polyurethane mandibles with a simulated linear fracture at the midline were used as substratum. Results show that resistance of the fixation is poor when one and two screws are used on each side of the fracture. Three screws on each side of the fracture significantly increases the resistance to displacement. However, no additional strength is added to the construct when more than three screws per side are used.

In vitro biomechanical evaluation of sagittal split osteotomy fixation with a specifically designed miniplate.

Recent studies have evaluated many methods of internal fixation for sagittal split ramus osteotomy (SSRO), aiming to increase stability of the bone segments while minimizing condylar displacement. The purpose of this study was to evaluate, through biomechanical testing, the stability of the fixation comparing a specially designed bone plate to other two commonly used methods. Thirty hemimandibles were separated into three equal groups. All specimens received SSRO. In Group I the osteotomies were fixed with three 15 mm bicortical positional screws in an inverted-L pattern with an insertion angle of 90°. In Group II, fixation was carried out with a four-hole straight plate and four 6mm monocortical screws. In Group III, fixation was performed with an adjustable sagittal plate and eight 6mm monocortical screws. Hemimandibles were submitted to vertical compressive loads, by a mechanical testing unit. Averages and standard deviations were submitted to analysis of variance using the Tukey test with a 5% level of significance. Bicortical screws presented the greatest values of loading resistance. The adjustable miniplate demonstrated 60% lower resistance compared to bicortical screws. Group II presented on average 40% less resistant to the axial loading.

Deep venous thrombosis prophylaxis in oral and maxillofacial surgery: a Brazilian survey.

BACKGROUND: Deep venous thrombosis (DVP) is a frequent disease. Prophylaxis is the best means to reduce its incidence, for lowering morbidity and mortality rates and treatment costs caused by its complications. OBJECTIVE: To evaluate the knowledge and use of any kind of DVT prophylaxis by Brazilian Oral and Maxillofacial surgeons. MATERIALS AND METHODS: A questionnaire was sent to all Oral and Maxillofacial surgeons associated to the Brazilian College of Oral and Maxillofacial Surgeons that have a valid e-mail address. The data retrieved was evaluated and tabulated. RESULTS: Of the 1100 questionnaires sent, only 4% were retrieved. The 42 retrieved were included in the study. Twenty six of the surgeons do not use any kind of deep venous thrombosis (DVT) prophylaxis, 11 use mechanical means as elastic compressive stockings or pneumatic compressive devices for prophylaxis, and 5 uses low-molecular weight heparins (LMWH) as the choice for prophylaxis. CONCLUSION: The data collected, despite the low rate of participation (4%) by the surgeons, shows that this subject still does not receive proper attention. Whereas other medical specialties make routine use of prophylactic means maybe the maxillofacial surgeons lack concern on that matter.

Rigid internal fixation with titanium versus bioresorbable miniplates in the repair of mandibular fractures in rabbits.

The purpose of this study was to compare by qualitative histology the efficacy of rigid internal fixation with titanium system and the Lacto Sorb system in mandibular fractures in rabbits. Thirty male adult rabbits Oryctolagus cuniculus were used. Unilateral mandibular osteotomies were performed between the canine and first premolar. The animals were divided into two groups: for Group I-rigid internal fixation was performed with titanium system 1.5 mm (Synthes, Oberdorf, Switzerland), with two screws of 6 mm (bicortical) on each side of the osteotomy. For Group II-rigid internal fixation was performed with PLLA/PGA system 1.5 mm (Lacto Sorb, WLorenz, Jacksonville, FL, USA). The histological analysis evaluated the presence of inflammatory reaction, degree of bone healing and degree of resorption of the Lacto Sorb screws. The results of both fixation systems were similar, only with a small difference after 15 and 30 days. In Group I a faster bony healing was noted. But after 60 days, bony healing was similar in both groups. It is concluded that both PLLA/PGA and titanium plates and screws provide sufficient strength to permit mandibular bone healing. The resorption process of PLLA/PGA osteosynthesis material did not cause acute or chronic inflammatory reaction or foreign body reaction during the studied period.