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Purpose: To carry out a comparative evaluation of the intra- and postoperative complications, and bone healing, following bilateral sagittal split osteotomy (BSSO) with or without concomitant removal of third molars.Material and methods: A retrospective analysis was performed of two cohorts subjected to BSSO with the intraoperative removal of third molars (test group) versus the removal of third molars at least 6 months prior to BSSO (control group), comprising at least 1 year of clinical and radiographic follow-up. Partially or completely erupted third molars were extracted immediately before completing the osteotomy, whereas impacted third molars were removed after the osteotomy had been performed. Hardware reinforcement was performed in bimaxillary cases where concomitant molar extraction impeded placement of the retromolar bicortical screw of the hybrid technique.Results: A total of 80 surgical sites were included (40 in each group). Concomitant extraction of the molar represented a mean increase in surgery time of 3.7 min (p < 0.001). No additional complications occurred in the test group (p = 0.476). The gain in bone density was preserved in both groups (p = 0.002), and the increase was of the same magnitude in both (p = 0.342), despite the fact that the immediate and final postoperative bone densities were significantly higher in the control group (p = 0.020).Conclusion: The results obtained support concomitant molar extraction with BSSO as a feasible option. Purpose: To carry out a comparative evaluation of the intra- and postoperative complications, and bone healing, following bilateral sagittal split osteotomy (BSSO) with or without concomitant removal of third molars. Material and methods: A retrospective analysis was performed of two cohorts subjected to BSSO with the intraoperative removal of third molars (test group) versus the removal of third molars at least 6 months prior to BSSO (control group), comprising at least 1 year of clinical and radiographic follow-up. Partially or completely erupted third molars were extracted immediately before completing the osteotomy, whereas impacted third molars were removed after the osteotomy had been performed. Hardware reinforcement was performed in bimaxillary cases where concomitant molar extraction impeded placement of the retromolar bicortical screw of the hybrid technique. Results: A total of 80 surgical sites were included (40 in each group). Concomitant extraction of the molar represented a mean increase in surgery time of 3.7 min (p < 0.001). No additional complications occurred in the test group (p = 0.476). The gain in bone density was preserved in both groups (p = 0.002), and the increase was of the same magnitude in both (p = 0.342), despite the fact that the immediate and final postoperative bone densities were significantly higher in the control group (p = 0.020). Conclusion: The results obtained support concomitant molar extraction with BSSO as a feasible option.

Objectives: A systematic review was performed to analyze the current evidence on three-dimensional (3D) computed tomography (CT) superimposition protocols used to assess dentomaxillofacial changes after orthognathic and orthofacial surgery. Accuracy, reproducibility, and efficiency were evaluated. Methods: The search was divided into Main Search (PubMed, EMBASE, Cochrane Library, LILACS, and SciELO), Grey Literature search (Google Scholar and Open Grey), and Manual search. Thirteen studies were included. Of these, 10 reported data on accuracy, 10 on reproducibility and five on efficiency. Seven proposed or evaluated methods of voxel-based superimposition, three focused on the surface-based technique, one compared surface- and voxel-based superimposition protocols, one used the maximum mutual information algorithm, and one described a landmark-based superimposition method. Cone-beam computed tomography (CBCT) was the most common imaging technique, being used in 10 studies. Results: The accuracy of most methods was high, showing mean differences smaller than voxels’ dimensions, ranging between 0.05 and 1.76 mm for translational accuracy, and 0.10–1.09° for rotational accuracy. The overall reproducibility was considered good as demonstrated by the small mean error (range: 0.01–0.26 mm) and high correlation coefficients (range: 0.53–1.00). Timing to complete virtual superimposition techniques ranged between a few seconds up to 40 min. Conclusions: Voxel-based superimposition protocols presented the highest accuracy and reproducibility. Moreover, superimposition protocols that used automated processes and involved only one software were the most efficient.

The purpose of this study was to evaluate maxillary expansion, operative time and pain associated with a new minimally invasive surgical technique to treat maxillary hypoplasia in adult patients. Consecutive patients were included and prospectively analyzed. The technique consists in miniscrew-assisted rapid palatal expansion (MARPE), minimally invasive approach to maxillary osteotomies, latency period and activation period until the desired expansion. The parameters evaluated included operative time, treatment-related pain by the visual analog scale (VAS), and transverse maxillary expansion. The Shapiro-Wilk test was used to assess the normality of data distribution. A paired t-test was used to compare the data between T0 (preoperative) and T1 (postoperative - end of activation). The significance level was set at 5%. Eleven patients were included. Mean operative time was 24.11 min (14.4-32 min) and overall postoperative VAS score was 2.81 (0-9). A comparative analysis showed significant increases in maxillary width at the skeletal, alveolar, and dental levels (p 0.0001 for all), with a mean range of 1.8 (SD 0.3) mm to 4.7 (SD 0.5) mm. The present minimally invasive surgical MARPE (MISMARPE) technique appears to yield good skeletal outcomes with minimal trauma. It might have potential for clinical use, but larger comparative studies are needed to confirm the clinical relevance of the approach.

To describe the benefits of covering the extrasinusal length of extramaxillary zygomatic implants with a pedicled buccal fat pad flap through a tunnel approach.Four extramaxillary zygomatic implants were placed in 10 patients and loaded immediately with an acrylic provisional fixed prosthesis. The extrasinusal length of every implant was covered with a pedicled buccal fat pad flap. Study variables were implant survival rate, peri-implant soft tissue recession (PISTR), peri-implant soft tissue condition (PISTC), modified Bleeding Index (mBI), and suppuration. The statistical analysis comprised the Brunner-Langer model of longitudinal data for each variable and the analysis of variance to assess main effects and interactions.All the zygomatic implants showed osseointegration, resulting in a survival rate of 100%. The PISTR was evaluated after surgery (T0) and after 12 months (T1), statistically significant differences being observed (P = .014). Recession also depended on specific implant positioning; zygomatic implants in the anterior were found to have a higher risk of recession vs implants in the posterior (P = .065). The PISTC was assessed at T0 and T1, and no statistically significant changes were observed (P = .718). Bleeding on probing was present in 10% of the implants at T0 and in 15% at T1, the difference being nonsignificant (P = .317).The use of a pedicled buccal fat pad flap to cover the extrasinusal length of extramaxillary zygomatic implants appears to reduce the risk of soft tissue recession and exposure of the implant surface to the oral cavity.

Purpose The aim of this study was to evaluate the nasolabial soft tissues effects in three different Le Fort I osteotomy techniques using cone beam computed tomography (CBCT) evaluation of three-dimensional (3D) volume surfaces. Materials and methods A retrospective study was designed, and three groups were evaluated: group 1, patients who underwent conventional Le Fort I osteotomy; group 2, patients who underwent subspinal Le Fort I osteotomy; and group 3, patients who underwent conventional Le Fort I osteotomy with ANS recontouring or removal. CBCT evaluation was performed at two time points: T0, 1 week before surgery; T1, 6 months after surgery. Results A total of 90 patients were enrolled in this study (group 1: 30; group 2: 30; group 3: 30). Mean maxillary advancement was 4.26 mm. For group 1, mean change in inter-alar width was 2.29 ± 1.57 mm (minimum -2mm; maximum 6.1 mm; for group 2 it was 1.20 ± 1.56 mm (minimum −1.7 mm; maximum 5.9 mm), and for group 3 was 1.84 ± 1.76 mm (minimum −2.3 mm; maximum 5.9 mm). For group 1, mean change in alar base width was 1.69 ± 2.32 mm (minimum −4.8 mm; maximum 6,1 mm); in group 2 it was 0.85 ± 2.08 mm (minimum -4mm; maximum 6 mm), and group 3 was 1.21 ± 1.83 mm (minimum -2mm; maximum 5 mm). Results showed statistically significant differences in nasolabial area (P Conclusion Results point to a better control of nasal tip projection, interalar and alar base width as well as upper lip form and function when comparing subspinal Le Fort I osteotomy and conventional techniques. This technique should be chosen when these changes in nasolabial region are to be avoided.

Objectives: The objective was to assess the accuracy of orthognathic surgical planning using three-dimensional virtual planning compared with conventional two-dimensional planning.Material and Methods: MEDLINE (PubMed), Embase and Cochrane Library search combined with hand-search of relevant journals was conducted to identify randomized controlled trials (RCTs) published in English through August 2nd, 2022. Primary outcomes included postsurgical accuracy of hard and soft tissue. Secondary outcomes included treatment planning time, intraoperative time, intraoperative blood loss, complications, financial expenses, and patient-reported outcome measures (PROMs). Quality and risk-of-bias assessment were evaluated by Cochrane risk of bias tool and GRADE system.Results: Seven RCTs characterised by low, high, and unclear risk of bias fulfilled inclusion criteria. Included studies disclosed conflicting results regarding accuracy of hard and soft tissue as well as treatment planning time. The intraoperative time was shortened, and financial expenses were increased with three-dimensional virtual surgical planning (TVSP), while no planning-related complications were revealed. Comparable improvement in PROMs were reported with TVSP and two-dimensional planning.Conclusions: Future orthognathic surgical planning will indisputable be performed by three-dimensional virtual planning. The financial expenses, treatment planning time, and intraoperative time will therefore probably decrease due to further development of three-dimensional virtual planning techniques. The hard and soft tissue accuracy between planned position and achieved surgical outcome seems to be improved by three-dimensional virtual planning compared with two-dimensional planning, although results are inconsistent. Further development of three-dimensional virtual planning involving cutting guides and patient-specific osteosynthesis plates are therefore needed to improve the accuracy of orthognathic surgical planning. Objectives: The objective was to assess the accuracy of orthognathic surgical planning using three-dimensional virtual planning compared with conventional two-dimensional planning.Material and Methods: MEDLINE (PubMed), Embase and Cochrane Library search combined with hand-search of relevant journals was conducted to identify randomized controlled trials (RCTs) published in English through August 2nd, 2022. Primary outcomes included postsurgical accuracy of hard and soft tissue. Secondary outcomes included treatment planning time, intraoperative time, intraoperative blood loss, complications, financial expenses, and patient-reported outcome measures (PROMs). Quality and risk-of-bias assessment were evaluated by Cochrane risk of bias tool and GRADE system.Results: Seven RCTs characterised by low, high, and unclear risk of bias fulfilled inclusion criteria. Included studies disclosed conflicting results regarding accuracy of hard and soft tissue as well as treatment planning time. The intraoperative time was shortened, and financial expenses were increased with three-dimensional virtual surgical planning (TVSP), while no planning-related complications were revealed. Comparable improvement in PROMs were reported with TVSP and two-dimensional planning.Conclusions: Future orthognathic surgical planning will indisputable be performed by three-dimensional virtual planning. The financial expenses, treatment planning time, and intraoperative time will therefore probably decrease due to further development of three-dimensional virtual planning techniques. The hard and soft tissue accuracy between planned position and achieved surgical outcome seems to be improved by three-dimensional virtual planning compared with two-dimensional planning, although results are inconsistent. Further development of three-dimensional virtual planning involving cutting guides and patient-specific osteosynthesis plates are therefore needed to improve the accuracy of orthognathic surgical planning.

OBJECTIVE A cohort prospective study was conducted to assess the three-dimensional positioning accuracy of the implant between pre-surgical and the final implant position using a static fully guided approach in the posterior area of the jaws. MATERIALS AND METHODS A total of 60 implants (30 patients) were digitally analyzed after superimposing the Digital Imaging and Communications in Medicine (DICOM) files obtained from the Cone Beam Computed Tomography (CBCT) pre- and post-implant placement. The software calculations included deviations at the implant shoulder and at the implant apex, global deviation (3D offset), and angle deviation. Statistical analysis was performed with α = 0.05. RESULTS Considering the total number of implants, mesiodistal, buccolingual, and apicocoronal mean deviations at the shoulder and implant apex were equal or below 0.21 ± 0.69 mm, and only the buccolingual mean deviation at the apex reached up to 0.67 ± 1.06 mm. The mesiodistal and apicocoronal deviations were not statistically significant at both the shoulder and apex levels of the implant. The mean total angular deviation was 5.62° ± 4.09. The main limitation of this surgical approach was the requirement for a wide mouth opening. CONCLUSIONS Static fully guided surgery for dental implant placement exhibits minimum deviations respect to presurgical planning. The main limitation in the posterior areas is the requirement for a wide mouth opening. CLINICAL RELEVANCE Even with minimum deviations clinically acceptable, precautions and safety margins must be respected when using static full-guided surgery to place dental implants.

Healing complications in guided bone regeneration (GBR) can be frequent when nonresorbable membranes are used. Exposure of dense polytetrafluoroethylene (d-PTFE) membranes to the oral cavity are usually located close to the incision line due to a lack of tension-free flap closure. This case report presents a safe, novel technique that uses d-PTFE membranes placed on the missing buccal and palatal bone walls without covering the coronal aspect of the regeneration. Therefore, these membranes can be kept away from the incision line to minimize the risk of exposure. The coronal part is then covered with a resorbable membrane. A clinical case is presented, using this novel technique to three-dimensionally reconstruct noncontained defects in the maxilla. This technique is safe and effective in regenerating these defects; after 8 months of healing, three implants could be placed with proper primary stability. Further, histologic and histomorphometric analyses revealed functional bone with areas of new bone formation. However, more long-term studies are required to validate this technique.

Currently, the wish to optimize facial esthetics-in the context of a dysfunctional occlusion or not-has become the main motivation for orthognathic surgery in many cases. In this context, considering that protrusive faces are advised more attractive and that the lack of skeletal support accelerates the aging process, orthognathic surgery will mostly involve a forward movement of the maxillamandibular complex..

A systematic review search was based on the PICOS approach, as follows: population: cleft lip and palate patients; intervention: Le Fort I osteotomy; comparator: different surgical protocols; outcome: stability, recurrence or surgical complications; study designs: only case reports were excluded from the review. No restrictions were placed on language or year of publication. Risk of bias was analyzed, heterogeneity was assessed, and subgroup analysis was performed using a level of significance of 1% (p = 0.01). The search identified 248 citations, from which 29 studies were selected and a total of 797 patients enrolled. The level of agreement between the authors was considered excellent (k = 0.810 for study selection and k = 0.941 for study eligibility). Our results reported a mean maxillary advancement of 5.69 mm, a mean vertical downward/upward of 2.85/−2.02 mm and a mean clockwise rotation of 4.15°. Greater surgical relapse rates were reported for vertical downward movement (−1.13 mm, 39.6%), followed by clockwise rotation (−1.41°, 33.9%), sagittal (−0.99 mm, 17.4%) and vertical upward (0.11 mm, 5.4%) movements. No relevance was found regarding the type of cleft, the type of Le Fort I osteotomy, concomitant bone grafting, surgical overcorrection, postoperative rigid or elastic intermaxillary fixation, or retention splint. Study limitations were heterogeneity and the low number of high-quality studies. In spite of reported high relapse rates, Le Fort I osteotomy for maxillary reposition is the first-choice procedure for selected cleft lip and palate patients in whom extensive maxillary movements are not required, because of its safety and its three-dimensional movement versatility in one-step surgery. Otherwise, distraction osteogenesis should be considered as the gold standard treatment.

The purpose of this study was to assess the relationship between the Frankfort horizontal (FH) and natural head orientation (NHO), their correlation between patients' malocclusion, and the impact of counterclockwise rotation (CCW) on the FH-NHO angle variation after orthognathic surgery. An evaluation of 187 consecutive patients was performed at the Maxillofacial Institute (Teknon Medical Center, Barcelona). FH-NHO° was measured pre- and postoperatively at 1 and 12 months, after three-dimensional (3D) superimposition using a software (Dolphin®). Patients were classified as follows: 3.2%, 48.7% and 48.1%, class I, II and III, respectively. Baseline FH-NHO° was significantly positive for patients with dentofacial deformities (2.73°±4.19 (2.12-3.33°, P

The purpose of this study was to validate an already published facial anteroposterior reference: upper incisor (UI) to soft tissue plane or so-called Barcelona line (BL) to trace the most aesthetic sagittal position of the maxilla. A cross-sectional multicentre evaluation of Caucasian patients from Spain and Brazil with different anteroposterior maxillary positions was designed. Sagittal images in natural head orientation of grouped patients according to the horizontal distance from the UI to BL were ranked by healthcare professionals and non-professional Caucasian raters according to the aesthetic perception of each profile, using a digital survey. Seventy-four raters (50 laypeople, 12 orthodontists, and 12 maxillofacial surgeons) rated 40 profiles. The best-rated profile corresponded to group 3 (0-4 mm UI-BL) with 61.8% of positive evaluations, followed by group 4 (≥ 4 mm UI-BL): with 61.1%. On the other hand, group 1 (≤-4 mm UI-BL) was the worst-ranked profile with 71.8% of negative evaluations, followed by group 2 (-4-0 mm UI-BL): with 59.6% of negative evaluations. The correlation between the mean assessment score and UI-BL showed a moderately-strong association (r = 0.68, p 0.001). The inter-rater reliability of assessment (74 evaluators) was moderate (k = 0.49, 95% CI: 0.39 to 0.59). The results suggest that protrusive middle-third facial profiles are preferable. The BL is proposed as a simple, individualised, and reproducible tool to trace an aesthetic sagittal position of the maxilla in orthognathic surgery.

The objective of this systematic review was to evaluate the stability and complications of tooth-borne (TB), bone-borne (BB) and hybrid (TB-BB) appliances in surgically assisted rapid maxillary expansion (SARME). Database searches were conducted (PubMed, Embase, Cochrane Library and SciELO), as well as a grey literature search (Google Scholar) and hand searches of reference lists. Forty-six articles were included after study selection (κ=0.854). After eligibility assessment, 16 articles and one article from the grey literature were processed (κ=0.866) and six articles were selected by hand searching, for a total of 23 articles included. Regarding stability, TB appliances showed width relapse rates ranging from 4 to 35% in canines, from 1 to 37% in premolars and from 0.2 to 49.5% in molars. In BB appliances, width relapse rates were 1.7-21% in canines, 1.5% in premolars and 4.6-11.5% in molars. In hybrid appliances, the width relapse rate was 14% in premolars, with a 1.8% overexpansion reported in the molar region. In TB and BB appliances, skeletal relapse rates were similar on the nasal floor (11-53% and 41.6%, respectively) and at the level of the maxilla (18% and 16%, respectively). The most common complications were bone resorption in TB appliances (18.14%) and appliance-related complications in BB appliances (17.9%). The risk of bias was high in 19 studies, medium in three studies and low in one study. The TB and BB appliances used in SARME were considered to have a high long-term stability. BB appliances appeared to have fewer relapses than TB appliances due to a more parallel distribution of forces exerted. However, relapse appears to be highly influenced by postorthodontic treatments, where arch-form coordination is achieved in the consolidation period with the purpose of overexpansion correction, alignment and final vertical adjustments. Further randomised controlled trials with long-term data and large sample sizes are needed to support evidence-based clinical decision-making and to allow meta-analytic studies of stability outcomes regarding the type of anchorage in SARME.

Most studies have focused on airway changes after maxillomandibular advancement; however, airway size will change depending on the type, direction, and magnitude of each skeletal movement. The aim of this study was to assess the effect of the maxillary and/or mandibular movements on the pharyngeal airway volume and the minimum cross-sectional area using 3-dimensional cone-beam computed tomography voxel-based superimposition.The investigators designed and implemented a retrospective cohort study composed of patients with dentofacial deformity subjected to orthognathic surgery. The predictor variables were the surgical movements performed at surgery. The primary outcome variables were the pharyngeal airway volume and minimum cross-sectional area measured preoperatively, at 1- and 12-month follow-up. Skeletal and volumetric relapse and stability were recorded as secondary outcomes at 1 and 12 months, respectively. Descriptive, bivariate and correlation analyses were computed. Significance was set at P .05.The sample was composed of 103 patients grouped as follows: bimaxillary (53), maxillary (25), or isolated mandible (25). All of the surgical treatments resulted in a significant linear pattern of initial immediate increase of 33.4% (95% confidence interval [CI]: 28.2 to 38.7%; P .001) in volumetric (nasopharynx [28.7%, CI: 22.7 34.9%; P .001], oropharynx [36.2%, CI: 29.0 to 43.5%; P .001], and hypopharynx [31.5%, CI: 25.7 to 37.3%; P .001]) and minimum cross-sectional area parameters (bimaxillary = 104%, [CI: 87.1 to 122.1%; P .001], maxillary = 39.5%, [CI: 18.4 to 60.7%; P .05], and mandible = 65.8%, [CI: 48.1 to 83.6%; P .05]), followed by a slight downward trend (stabilization) at 12-month follow-up. Airway increase was favored by mandibular advancement (P .05) and mandibular occlusal plane changes by counterclockwise rotation (P .05).The results of this study suggest that there is a favorable effect of orthognathic surgery in the upper airway regardless of the surgical approach, with bimaxillary advancement and mandibular occlusal plane changes by counterclockwise rotation being the most significant contributors.

Background: The primary objective of this ex vivo study was to assess the influence of increasing insertion torques on three types of dental implants and possible alterations of their microgeometry after the application of three different torque intensities. Methods: 27 implants of 3 different implant brands (Groups A, B and C) were placed in cow ribs using 30 Ncm, 45 Ncm and 55 Ncm insertion torques. The implants were subsequently removed using trephine burs, and SEM analysis was carried out in order to detect implant surface and connection changes, as compared to the implant controls. Results: Surface deformations were predominantly observed on the third apical part of the implants. The alterations presented with increasing insertion torques, with 45 Ncm being the threshold value. Prosthetic connections were also compromised. Conclusions: The changes sustained by the implants were proportional to the insertion torque they were subjected to; 45 Ncm and greater insertion torques resulted in more consistent damage, both on the implant surface and the implant connection. info:eu-repo/semantics/publishedVersion

Summary Nasomaxillary hypoplasia is a rare congenital malformation involving the middle third of the face. The present paper describes a novel technique for restoring the nasal projection in a patient with nasomaxillary hypoplasia, analyses its advantages and limitations, and discusses its potential applicability in other similar contexts. After orthognathic surgery, lateral osteotomies of the nasal bones were performed integrally with a piezoelectric device using a long cutting saw tip through the intraoral approach. The nasal bones were then projected by interpositioning two triangular-shaped collagenated cancellous bone graft blocks on each side in the osteotomies between the nasal and the frontal processes of the maxillary bones. Cone-beam computed tomography (CBCT) data was used to perform a morphometric analysis at one and 12 months of follow-up through image superimposition, which revealed a stable increased projection of the nasal dorsum and an anterior nasal spine (ANS) of 5.18 mm and 5.52 mm, respectively. The results of this case suggest that the technique affords satisfactory nasal dorsum augmentation while avoiding the use of permanent foreign materials, with minimal morbidity, no unsightly and visible scars, great patient satisfaction, and adequate stability at 12 months of follow-up.

Background To describe a technical feature that increases the stability of the intermediate splint in patients where bimaxillary surgery with great maxillary/mandibular advancements are planned. Material and Methods Prospective evaluation of the intermediate splint dental vertical penetration in patients undergoing bimaxillary surgery where great sagittal discrepancy occur in the anterior sector between the upper and lower jaws when the intermediate splint is placed by adding an extra intermaxillary fixation (IMF) screw (2x9 mm) placed between the central incisors of the maxilla and fixed to the most anterior aspect of the intermediate splint following the direction of the sagittal maxillo-mandibular discrepancy from January to September 2018. Results The postoperative evaluation comparing the accuracy of conventional fixation versus fixation with an extra anterior anchorage point through photographic assessment and intraoral digital scanner demonstrated better dental penetration, and therefore improved intermediate splint precision with the latter in all cases Conclusions Our results suggest that this is a simple and safe technique that can be easily reproduced and optimizes the outcomes by increasing the accuracy of translation of the planned surgical movements to the operating room. Key words:Orthognathic surgery, intermediate splint, accuracy, intermaxillary fixation, bone screw.

The aim of this study was to describe the steps of a minimally invasive surgical technique used to perform a proportional intraoral condylectomy with a three-dimensionally (3D) printed cutting guide. The technique consists of two steps: virtual surgical planning and intraoral condylectomy. During virtual surgical planning, the mandibular ramus was measured bilaterally, the height of the proportional condylectomy was planned virtually, and a cutting guide was 3D printed. In the intraoral condylectomy, the mandibular condyle was approached intraorally, the 3D printed cutting guide was positioned in the sigmoid notch, and the proportional condylectomy was performed. The protocol reported in this technical note is the sum of knowledge acquired from a series of studies published previously by the authors, who have jointly developed a surgical technique that is both minimally invasive and accurate for the treatment of condylar hyperplasia.

Introduction Digital technology has been progressively introduced into tooth autotransplantation to enhance both treatment planning and surgery. The aim of this report was to describe a novel protocol for fully guided tooth autotransplantation. Methods This report includes 10 consecutive patients treated with a complete virtual planning and a multidrilling axis surgical guide in combination with the computer-aided rapid prototyping model. Results All transplanted teeth fulfilled the criteria for success over a mean follow-up duration of 13.1 months. No signs of progressive root resorption or pain were found during follow-up. One case required minimal adjustment of the surgical stent to allow correct seating, whereas a second case could not be performed fully guided because of limited mouth opening. Conclusions Our protocol for fully guided tooth autotransplantation is a viable option that involves minimal bone preparation in a short surgical time. Future research should focus on further investigation of the benefits of this novel protocol in a larger sample.

After sagittal split osteotomy, the mandibular distal and proximal fragments do not always align themselves passively to one another, resulting in bony interferences and subsequent anomalous settlement of the condyles. Predicting these interferences could be an important ancillary procedure for avoiding intra- and postoperative surgical complications, rendering orthognathic surgery more effective and safer. This study evaluated the relevance of virtual surgical planning in assessing the displacement of the proximal segments after virtual distal segment repositioning, for predicting bony interferences between the segments and thus avoiding related intra- and postoperative surgical complications. The presence of interferences between the distal and proximal segments was compared between virtually predicted (computer-assisted simulation surgery, Dolphin software) and real cases in 100 consecutive patients diagnosed with dentofacial deformities who underwent orthognathic surgery with mandibular repositioning (using a short lingual osteotomy (SLO)). The results indicated that clockwise rotation of the mandible was the mandibular movement most prone to segment interference. Furthermore, virtual planning was sensitive (100%) but had low specificity (51.6%) in predicting proximal and distal segment interferences. This low specificity was due to the software-based automated design of the mandibular osteotomy, where the length of the distal segment was longer than the real SLO, and the mandibular ramus sagittal split was located just behind Spix's spine. Thus, more precise simulated osteotomies are needed to further validate the accuracy of virtual planning for this purpose.

The aim of this in vitro study was to evaluate the influence of bone type, drill diameter, drilling speed, and irrigation on heat generation while performing osteotomy for dental implants. Six polyurethane foam blocks simulating type I (dense) and type IV (soft) bone were selected for the study. Each block was subjected to two different experimental conditions for each drill (2- and 3.5-mm diameter): three sub-groups were created: (a) revolutions per minute (50, 100, or 800 rpm) and (b) irrigation (with or without irrigation). In 2-mm drill group, maximum temperature attained was practically identical: 23.73 ± 2.28 °C in the cortical bone and 23.74 ± 2.03 °C in the cancellous bone. For 3.5-mm, groups showed similar results (25.01 ± 1.88 °C for cortical and 24.05 ± 1.94 °C for trabecular bone). In any type of bone, the presence of irrigating fluid helped to control the maximum temperature (p = 0.001). When comparing the 2-mm and 3.5-mm drills, most differences were found at 100 rpm without irrigation (p

The main objective was to evaluate the accuracy of dynamic navigation-guided surgery (DNGS) for implant positioning performed by a novice operator. The secondary objectives were to analyze the operator's learning curve and identify possible complications deriving from the technique.Twenty-five implants were placed in eight partially edentulous human heads. Preoperative CBCT scans were imported to planning software to determine the implant positions. Implants were placed using a dynamic navigation system. Postoperative CBCTs were superimposed onto the implant planning images. Discrepancies between the virtually planned implant positions and the postoperative positions were evaluated by measuring horizontal platform deviation, apex deviation, apicocoronal (vertical) deviation, and angular deviation.Mean platform, apex, vertical, and angle deviations were 1.55 ± 0.81 mm, 2.45 ± 0.84 mm, 1.59 ± 0.70 mm, and 5.56 ± 4.03 degrees, respectively. No significant differences were found between the maxilla and mandible or between anterior and posterior sites. A flat learning curve was observed, with the exception of the implant platform, where a tendency toward improvement in accuracy was observed between the 8th and the 17th implant placed. No complications were reported.Based on the results of a study performed by a novice operator on a cadaveric model, DNGS allows accurate implant placement within a 2-mm safety margin in terms of implant platform and vertical positions, and a 3-mm margin in apical vicinities. The technique requires practice to learn the required eye-hand coordination. (Int J Comput Dent 2022;25(4):377-0; doi: 10.3290/j.ijcd.b2588207).

The objective was to validate a semi-automated segmentation method for 3-dimensional (3D) reconstruction of the mandibular condyle from cone beam computed tomography (CBCT) data and illustrate its application in volumetric analysis of the condyle.Ten CBCT datasets were used to validate the proposed semi-automatic method for 3D rendering of mandibular condyles. First, a standardized orientation protocol of the skull was applied. After defining the volume of interest, a grey-scale cut-off value was selected to allow an automatic reconstruction of the condyle's surface. Subsequently, condylar contour was optimized manually. The whole process was repeated twice by 2 independent investigators. Volumetric measurements of the condyle were used as a measure of conformity between both investigators. The reproducibility of condylar volume reconstruction was excellent for intra-examiner measurements (CV = 3.65%, intraclass correlation coefficient = 0.97) and good for inter-examiner measurements (CV = 7.15%, ICC = 0.89). The overall mean time required for the segmentation process was 6.31 + 2.78 minutes. The proposed protocol provides an accurate and reproducible tool for 3D reconstruction of the mandibular condyle using CBCT data. Its implementation will enable adequate follow-up of morphological changes in bone tissue with a Hounsfield unit-based imaging segmentation method.

The use of customized plates in Orthognathic surgery offers precision in the repositioning of the jaws, according to the virtual planning performed, with the great advantage of avoiding the need for intermediate occlusal splints. However, the conventional customization process takes time to manufacture, present high cost and still involve legal issues with insurance companies. Moreover, a technical disadvantage is that the systems available for customized plates require large incisions, with large detachment of soft tissues for insertion of the guides and plates. The objective of this paper is to present the in-house hybrid technique for customization of guides and miniplates in orthognathic surgery using minimally invasive approaches.

Barrier membranes are essential biomaterials for guided bone regeneration. Due to different origin and structure of barrier membranes, singular mechanical properties and clinical behaviors can be expected. It is important to understand the physic and chemical properties of barrier membranes to select the needed biomaterial for each clinical situation. To date, no study has evaluated and compared the physicochemical properties of various families of barrier membranes. The aim of this study is to evaluate the physicochemical properties of various barrier membranes. Fifteen membranes of different origin were tested in this study. Membranes were divided into biological or synthetic origin and grouped in natural allogenic collagen, natural xenogenic collagen, cross-linked collagen and synthetic membranes. Physicochemical properties were evaluated in terms of tension, stiffness, absorption ability, pH and wettability. For the tension tests, all membranes showed similar low tension and low stiffness, especially after a 4-min hydration, except for bone laminas that showed a greater stiffness particularly in a dry status. Regarding wettability and hydration of the barrier membranes, porcine origin membranes had greater hydration; wettability was also superior in porcine derived barrier membranes and showed a faster absorption of the drop on the rough surfaces. All membranes had a stable pH, having the synthetic membranes the most stable pH when compared to physiologic. The wide variety of barrier membranes opens a debate in which the practitioner should select the adequate barrier membrane for each clinical situation. Different materials show singular potentials depending on their tissue origin making them suitable for specific clinical indications. More studies regarding adsorption, integration and degradation of barrier membranes are needed to understand their behavior.

The purpose of this animal study was to determine which ratio of hydroxyapatite (HA) and tricalcium phosphate (TCP) is the most appropriate in the composition of alloplastic biphasic block grafts, in terms of bone density and bone formation, for the regeneration of alveolar defects. Different concentrations of HA/TCP were used for the alloplastic block grafts: 100/0 (HA100 group), 79/21 (HA75 group), and 57/43 (HA50 group); the control treatment filled the defect with a collagen plug. All control and test sites were covered with a resorbable collagen membrane. Sacrifices were performed at 4, 12, and 24 weeks after grafting. Microcomputed tomography and histologic and histomorphometric analyses were performed to determine bone density and the characteristics of the regenerated bone as well as the percentages of newly formed bone (NB), residual material (RM), and connective tissue (CT). Bone density increased significantly over time (P < .001), with stabilization between 12 and 24 weeks (P = 1.000). No differences in density were observed between the different test blocks (P = .813). The percentage of NB increases over time, independent of the concentration (P < .001). At 12 weeks, the control group exhibited more NB than the HA100 group (P < .001). At 24 weeks, the HA50 group exhibited more NB than the HA100 (P < .001) and control (P = .066) groups. At 24 weeks, the HA100 and HA75 groups showed high RM percentages. The HA50 group exhibited an increased tendency of less RM percentage compared with the HA100 and HA75 groups. Although slight differences were found, the HA50 group's HA/TCP ratio seems the appropriate concentration when taking into account the bone density and percentage of NB and RM at 12 and 24 weeks of healing.

Orthognathic surgery, as part of maxillofacial surgery, involves the correction of dentofacial deformities for both functional (occlusion, speech and sleep disturbances) and aesthetic reasons. Deformities of this kind affect between 5–10% of the general population. The underlying causes are not clear, though genetic, environmental and embryonic factors have been suggested to play a role (1). The surgical techniques used are complex, with osteotomies of the mandible and upper maxilla that allow three-dimensional displacements of both bone structures with the purpose of aligning the facial axes. info:eu-repo/semantics/publishedVersion

Background Tooth autotransplantation is a valid method for replacing non-restorable teeth. This study aimed to assess mid-term survival and success of autotransplanted third molars and the clinical periodontal parameters and factors predicting successful periodontal attachment apparatus regeneration. Methods In total, 36 patients who had undergone extraction and subsequent autotransplantation of 36 third molars using virtual planning and computer-aided rapid prototyping models by an oral surgeon and endodontist were eligible. Probing pocket depth (PPD), gingival recession (REC), clinical attachment level (CAL), pulpal and periapical healing, root resorption, and radiographic bone loss (RBL) were evaluated. Additionally, a questionnaire evaluated patient-reported outcomes. Results The mean age of the participants was 30.2 years with a mean follow-up duration of 29.42 ± 14.56 months. The overall survival and success rates were 97.2% and 91.7%, respectively. No statistically significant differences were found in success and survival rates between open and closed apex groups or between compromised and intact buccal bone groups. No signs of pulp necrosis were found in the open apex group. Progressive replacement resorption was detected in one closed apex case. The mean PPD was 2.7 ± 0.45 mm for all transplanted teeth. REC was 0.13 mm higher in transplanted teeth than in previous hopeless teeth. CAL changes were neither clinically relevant (-0.17 ± 0.66 mm) nor statistically significant. The reported patient satisfaction was high. Conclusions Autotransplantation of third molars is a predictable treatment method, with a 2.5-year cumulative tooth survival and success of 97.2% and 91.7%, respectively, which were not influenced by recipient site integrity or root development.

Background Recently, dental implant technology has been widely used for oral reconstruction. Dental implants are the treatment of choice for those patients with dental absences. An optimal implant placement is based on the prosthetic driven concept in order to achieve an aesthetic and functional restoration with a long-term prognosis. There are two types of guided implant surgery that are described in the literature: Static Guided Surgery (SGS) and Dynamic Guided Surgery (DGS). The aim of this study is to be aware of the current state of dynamic surgery and compare in the literature the discrepancies between planning and placement of dental implants. Material and Methods The study consists of a bibliographic review on the topic. The research has been performed in the Medline/Pubmed of articles published by different professional associations and societies in the international context. Results Twenty two studies out of 100 articles from the initial search were finally included. Our results have been compared with other current available papers in the literature reviewed that obtained similar outcomes. Conclusions Dynamic navigation shows a better accuracy and precision of implant placement. To corroborate the results of this review as well as to evaluate the different variables that could influence the accuracy of this technique, future randomized control trials will be needed. Key words:Guided surgery, dynamic navigation, dynamic guided surgery, computer assisted surgery.

The digital workflow of computer-guided oral surgery procedures includes a number of steps that lead to guided execution of the prosthodontically driven surgical procedure through an intraoral surgical template (static guidance). Apart from the guided dental implant placement, the computer-aided approach has been introduced to certain bone regenerative procedures like sinus floor elevation with lateral window, guided bone regeneration with customized titanium mesh or bone block grafts, ridge split/expansion techniques, and distraction osteogenesis. The existing digital protocols seem to provide higher intraoperative accuracy rates and lower rates of complications and morbidity compared with conventional operational concepts. However, they engage the possibilities of inaccuracy and limitations. Thus, the surgeon must be qualified with freehand surgery knowledge if the complications of the digitally guided approach arise.

Immediate implant placement (IIP) in post-extraction sockets in the anterior zone, with intact facial bone wall and soft tissues (Elian type I), has presented high success rates. The midfacial recession has been reported as the most common post-healing complication. However, the correct diagnosis, the appropriate 3D positioning of the implant, the insertion of bone graft in the gap between the implant and the buccal bone, the placement of connective tissue graft beneath the facial soft tissues followed by immediate aesthetics, or customized abutment placement can significantly decrease the incidence of the referred complication. In sockets with compromised facial bone wall but intact soft tissues (Elian type II), some authors have presented promising results of IIP, but it needs further investigation. There is little evidence for the prognosis of IIP in sockets with resorbed facial bone and soft tissues (Elian type III).

Treatment of transverse maxillary deficiency requires maxillary expansion. Therefore, assessing the midpalatal suture maturation stage through CBCT is essential for treatment choice between RPE, MARPE, and SARPE, although it is not without risk of clinical error. In young adults with a potential suture opening, MARPE can be attempted unless in the following situations, where SARPE is advisable: large expansions (>5 mm) and the necessity of additional maxillary forward or downward movement.

The aim of this systematic review and meta-analysis was to determine the prevalence and characteristics of maxillary sinus septa using cone beam computed tomography and computed tomography data. Publications were searched until October 5, 2020 in three electronic databases. Additionally, article bibliographies were searched, and authors were contacted if required. This review has been registered in PROSPERO (CRD42019124933). Two independent evaluators assessed methodological quality using the Joanna Briggs Institute levels of evidence; inter-rater reliability tests were performed (Cohen's κ). The prevalence of maxillary sinus septa was expressed as a proportion; differences according to sex were reported in terms of the odds ratio (OR) and 95% confidence interval (95% CI). Heterogeneity and sources of heterogeneity were evaluated by meta-regression. Publication bias was assessed by visual analysis of the funnel plot. Statistical significance was set at P < 0.05. The 62 studies identified and included in the review involved 13,701 patients (22,460 sinuses). The meta-analysis of 35 studies (14,664 sinuses) revealed an overall mean sinus septa prevalence per sinus of 33.2% (95% CI 27.8-38.5%; I2 = 98.32%). The meta-analysis of 42 studies (9631 patients) found an overall mean sinus septa prevalence per patient of 41.0% (95% CI 36.0-46.0%, I2 = 96.45%). The OR for the difference in septa prevalence between sexes was 0.785 (95% CI 0.590-1.046; P = 0.098, I2 = 73.24%). Septa were most frequent in the middle area of the sinus and with a transverse orientation (86.0%). Within the limitations, the results suggest a high proportion of septa in the sinus, commonly in the middle area, which can interfere with the success of sinus floor elevation required for implant rehabilitation.

Background Immediate implants are frequently employed in the anterior maxillary area. However, the installation of dental implants simultaneously with tooth extraction can also provide with benefits in the posterior areas with a reduction in time prior the recovery of the masticatory function. Results previously reported in the literature show high-survival and success rates for implants placed in extraction sockets in molar areas; however, this topic has received limited systematic analysis. Material and methods Electronic and manual literature searches were performed by two independent reviewers in several data-bases, including MEDLINE, EMBASE, and Cochrane Oral Health Group Trials Register, for articles up to January 2019 reporting outcomes of immediate implants placed in molar areas. Primary outcomes included survival and success rates, as well as marginal bone loss. Secondary outcomes included the influence of implant position, type of implant connection, grafting protocol, flap or flapless approach, implant diameter, surgical phase, presence of buccal plate, and loading protocol. Results Twenty studies provided information on the survival rate, with a total sample of 1.106 implants. The weighted mean survival rate of immediate implants after 1 year of follow-up was 96.6%, and the success rate was 93.3%. On the other hand, marginal bone loss was 1.29 ± 0.24 mm. Secondary outcomes demonstrated that grafting the gap and the loading protocol have an effect on survival and success rates. Similarly, the presence or absence of the buccal bone affect crestal bone levels. Meta-analysis of 4 investigations showed a weighted mean difference of 0.31 mm ± 0.8 IC 95% (0.15–0.46) more marginal bone loss at immediate implant placement versus implants in healed sites (p < 0.001) I2 = 15.2%. Conclusion In selected scenarios, immediate implant placement in molar extraction socket might be considered a predictable technique as demonstrated by a high survival and success rates, with minimal marginal bone loss.

The aim of this in vitro study was to evaluate the influence of bone type, drill diameter, drilling speed, and irrigation on heat generation while performing osteotomy for dental implants.Six polyurethane foam blocks simulating type I (dense) and type IV (soft) bone were selected for the study. Each block was subjected to two different experimental conditions for each drill (2- and 3.5-mm diameter): three sub-groups were created: (a) revolutions per minute (50, 100, or 800 rpm) and (b) irrigation (with or without irrigation).In 2-mm drill group, maximum temperature attained was practically identical: 23.73 ± 2.28 °C in the cortical bone and 23.74 ± 2.03 °C in the cancellous bone. For 3.5-mm, groups showed similar results (25.01 ± 1.88 °C for cortical and 24.05 ± 1.94 °C for trabecular bone). In any type of bone, the presence of irrigating fluid helped to control the maximum temperature (p = 0.001). When comparing the 2-mm and 3.5-mm drills, most differences were found at 100 rpm without irrigation (p 0.001) and at 800 rpm with irrigation (p = 0.001).Maximum temperature attained was always below the critical threshold that can cause osteonecrosis, showing that both external irrigation with higher drilling speeds and no irrigation with lower speeds were effective methods to avoid excessive heat generation.Despite being always below the critical temperature, bone type, drill diameter, drilling speed, and irrigation must be considered temperature-influencing factors during implant osteotomies.