Three-dimensional dentoskeletal changes following minimally invasive surgically assisted rapid palatal expansion: a prospective study.

Dentoskeletal changes in minimally invasive surgically assisted rapid palatal expansion (SARPE) were evaluated using cone beam computed tomography (CBCT). This was a prospective study of 30 patients who underwent minimally invasive SARPE performed under local anaesthesia plus sedation by the same surgeon, in an ambulatory setting. Pre- and postoperative CBCT images were obtained for each patient. A statistically significant increase in the linear transverse dimensions of the maxilla occurred systematically. In the canine region, a mean increase of 5.84 mm occurred at the apex level and 7.82 mm at the crown level. These dimensions were 4.83 mm and 7.68 mm, respectively, in the molar region. The cross-sectional area of the maxilla increased by a mean 12.9 mm2 at the palate level and 23.3 mm2 at the crown level. Dental inclination to the buccal aspect was detected (mean 6.1° at the canines and 8.4° at the first molars). The alveolar process tipped buccally 10° at the molar level. Nasal width increased a mean of 3.0 mm at the canine level. Through a three-dimensional analysis, this study found that minimally invasive SARPE was effective in the correction of transverse maxillary discrepancies> 5 mm in non-growing patients. Although dental inclination to the buccal aspect occurred, significant expansion of the maxilla at the skeletal and dentoalveolar levels was confirmed.

Stability and surgical complications of tooth-borne and bone-borne appliances in surgical assisted rapid maxillary expansion: a systematic review.

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.

Nasolabial soft tissue effects of segmented and non-segmented Le Fort I osteotomy using a modified alar cinch technique-a cone beam computed tomography evaluation.

The aim of this study was to verify soft tissues changes and the effect of a minimally invasive surgical technique in the nasolabial region after segmented and non-segmented Le Fort I osteotomy, using cone beam computed tomography (CBCT) evaluation of three-dimensional (3D) volume surfaces. Two groups were evaluated: group 1, bimaxillary surgery with maxillary segmentation (n=40); group 2, bimaxillary surgery without maxillary segmentation (n=40). In both groups, a specific alar cinching technique was used to control nasal base broadening. CBCT evaluation was performed at three different treatment time points: T0, 1 month before surgery; T1, 1 month after surgery; T2, 1year after surgery. The results showed statistically significant differences in the nasolabial area (P<0.001). For group 1, the mean change in alar base width (Alinf-Alinf) was 1.31±1.40mm at T1 and 0.93±1.77mm at T2; for group 2 these values were 1.12±2.01mm at T1 and 0.54±1.54mm at T2. For group 1, the mean changes in inter-alar width (Al-Al) were 1.68±1.46mm at T1 and 1.49±1.33mm at T2; for group 2, they were 2.22±1.93mm at T1 and 1.34±1.79mm at T2. The alar cinch technique proposed here appears to be effective in controlling nasolabial soft tissue widening.

Hierarchy of surgical stability in orthognathic surgery: overview of systematic reviews.

The purpose was to perform an overview of systematic reviews in order to create a hierarchical scale of stability in orthognathic surgery with the aid of the highest level of scientific evidence. The systematic search was conducted in the PubMed, Embase, and Cochrane Library databases. The grey literature was investigated in Google Scholar and a manual search was done of the references lists of included studies. Fifteen studies were included in the final sample, of which eight were systematic reviews and seven were meta-analyses. These were assessed for methodological quality using the AMSTAR 2 tool and all were considered to be of medium to high methodological quality. The clinical studies included in the 15 reviews and meta-analyses were classified by the review authors as having a moderate to high potential for risk of bias. The hierarchical pyramid of stability in orthognathic surgery was established, with two surgical procedures considered highly unstable: (1) maxillary expansion with semi-rigid internal fixation evaluated at the dental level in the posterior region, and (2) clockwise rotation of the mandible with rigid internal fixation of bicortical screws in the sagittal direction.

Three-dimensional analysis of nasolabial soft tissue changes after Le Fort I osteotomy: a systematic review of the literature.

A systematic review was conducted to investigate the three-dimensional (3D) effect of Le Fort I osteotomy on the nasolabial soft tissues. The literature search was conducted using the MEDLINE (accessed via PubMed), Embase, and Cochrane electronic databases until January 2018. A total of 333 studies were identified (PubMed, n=292; Embase, n=41; Cochrane Library, n=0). Seventeen met the inclusion criteria. The studies were essentially retrospective. The risk of bias was considered high in 15 studies, medium in one study, and low in one study. 3D soft tissue analysis was performed at least 6months after surgery (mean 8.3months). The main image acquisition technique reported was cone beam computed tomography (CBCT), associated or not with 3D photography. Approximately 50% of the studies performed two-jaw surgery, 25% performed maxillary surgery only, and the other 25% included heterogeneous intervention groups. The most reported nasolabial changes were anterior and lateral movements of the nasomaxillary soft tissues and upper lip, together with anterior and superior movement of the nasal tip. The alar cinch suture and V-Y closure technique seemed to have little effect in counteracting the undesirable postoperative nasolabial changes. CBCT superimposition presented a reliable 3D assessment for simultaneous measurement of skeletal and soft tissue changes.

Alveolar corticotomies for accelerated orthodontics: A systematic review.

INTRODUCTION: It has been suggested that alveolar corticotomies may accelerate tooth movement, broaden the scope of malocclusion types that can be treated orthodontically, decrease the need for extractions, and support long-term stability. Several techniques have been proposed, although the indications, ideal design and technical characteristics, potential complications, and objective clinician and patient satisfaction remain unclear. This systematic review aimed to provide scientific support to validate alveolar corticotomies as a reliable approach to accelerated orthodontics. MATERIAL & METHODS: A literature search was conducted using MEDLINE (via PubMed), Cochrane, and EMBASE electronic databases until December, 2016. Articles written in any language other than English, Spanish, French, German, and Portuguese were excluded. Randomized controlled trials, controlled clinical trials, and case series involving healthy adult patients, with a sample size of at least 5 patients, and using alveolar corticotomy techniques were included. Two reviewers extracted the data independently. RESULTS: Three randomized clinical trials, 2 prospective randomized clinical trials, 6 case series and 1 randomized controlled split-mouth study were included. No clinical trials were retrieved. Mean total treatment time in corticotomy-facilitated orthodontic cases was 8.85 months (range, 4-20 months); control groups treatment duration was 16.4 months (range, 7.8-28.3 months). Complications such as pain, swelling, and dentin hypersensitivity were reported. Few studies mentioned patient/clinician satisfaction. The faster and less invasive procedures appeared to be well tolerated. However, the methodological quality of the selected studies was low, with only low to moderate scientific evidence. CONCLUSIONS: Corticotomy-facilitated orthodontics resulted in decreased treatment time. Few complications and low morbidity were found. More solid evidence-based research is required to support these results.

Virtual quad zygoma implant placement using cone beam computed tomography: sufficiency of malar bone volume, intraosseous implant length, and relationship to the sinus according to the degree of alveolar bone atrophy.

The objective of this study was to investigate the malar bone volume and length that a zygomatic implant can engage, and the relationship to the sinus according to the degree of alveolar bone atrophy. A three-dimensional evaluation was performed using cone beam computed tomography scans from 23 patients with a totally edentulous maxilla; quad zygoma implants were virtually placed. The predictor variable was the amount of malar bone volume and length that a zygomatic implant can engage. The primary outcome variable was the relationship to the sinus according to the degree of alveolar bone atrophy. Other variables were the residual alveolar bone height to the floor of the sinus and the nasal cavity. The mean volume of malar bone engaged in this sample of 92 zygomatic implants was 0.19±0.06cm3. The implant had an extrasinus path in 60.9% of cases, a parasinus path in 25%, and an intrasinus path in 14.1%. The results suggest that the average volume of malar bone engaged by a zygomatic implant is constant regardless of implant position and the degree of alveolar bone atrophy. As alveolar atrophy increases, the trajectory of the implant becomes more parasinus and intrasinus. The examiners were able to find enough bone to adequately distribute the implants in all cases.

Stability and surgical complications in segmental Le Fort I osteotomy: a systematic review.

This systematic review was conducted to evaluate the stability and surgical complications of segmental Le Fort I osteotomy. The search was divided into a main search (PubMed, Embase, and Cochrane Library), grey literature search (Google Scholar), and manual search. Twenty-three studies were included: 14 evaluating stability as the outcome and nine evaluating surgical complications. The level of agreement between the authors was considered excellent (κ=0.893 for study selection and κ=0.853 for study eligibility). The segmental Le Fort I osteotomy provides stable outcomes in the sagittal plane, is less stable dentally than skeletally in the transverse plane, and provides little stability in the posterior segment after downward movement. The most frequent complications are oral fistula (six studies) and damage to the adjacent teeth (five studies), but the most prevalent complication is postoperative infection (32.62%). Four studies evaluating stability as the outcome showed a medium potential risk of bias, whereas all studies addressing surgical complications showed a high potential risk of bias. The segmental Le Fort I osteotomy should not be excluded from the technical armamentarium in orthognathic surgery. On the contrary, the literature consulted suggests it to be a useful tool for the three-dimensional surgical correction of maxillary malposition.

The value of cone beam computed tomography imaging in surgically assisted rapid palatal expansion: a systematic review of the literature.

This study aimed to evaluate the reliability of cone-beam computed tomography (CBCT) imaging of the maxillary structures and the postoperative dentoskeletal, nasal airway, periodontal, and facial soft tissue changes after surgically assisted rapid palatal expansion (SARPE). A systematic review of the literature on CBCT analysis of SARPE was performed. The PubMed, Embase, and Cochrane Library databases were searched. Nine articles were included, involving a total of 228 patients. The general trend was tooth-borne distraction with pterygomaxillary dysjunction. A systematic increase in all transverse dimensions at the dentoalveolar and dental levels, as well as a certain degree of tipping and extrusion of the anchorage teeth and tipping of the skeletal segments, was detected. Soft tissue findings reflected the underlying dentoalveolar changes. A decrease in the buccal alveolar bone thickness and alveolar crest level occurred. Results confirm that CBCT is an accurate and reliable method to assess anatomical changes after SARPE. Although this systematic review provides valuable preliminary information about the effects of SARPE, results should be interpreted with caution due to the low level of evidence of the publications, great heterogeneity among study groups regarding outcome variables and surgical-orthodontic protocols, and lack of long-term data.

Three-dimensional surgical planning and simulation to improve surgical accuracy and reduce invasiveness of cranioplasties.

Patients with too large a frontal prominence may suffer discomfort and subsequent self-esteem problems. The case of a 29-year-old male with a prominent forehead is presented. After three-dimensional (3D) virtual simulation of the procedure, a stereolithographic model of the skull and a surgical cutting guide were fabricated. The forehead recontouring and reconstruction procedure was performed under general anaesthesia and the postoperative course was uneventful. At the 12-month postoperative follow-up, clinical and radiographic documentation confirmed softening of the frontal prominence from 14.48mm to 8.56mm, a nasofrontal angle increase of 22°, and overall high patient satisfaction. The proposed workflow results in greater surgical precision, shorter reconstruction times, reduced patient morbidity due to a reduced risk of dural exposure and postoperative infection, and overall higher predictability and patient satisfaction.

Inferior subapical osteotomy for dentoalveolar decompensation of class III malocclusion in 'surgery-first' and 'surgery-early' orthognathic treatment.

Increasing experience with alternative timing protocols in orthognathic surgery has given way to new surgical and orthodontic techniques to shorten treatment times, reduce biological costs, and improve the final outcome. A prospective evaluation of class III patients who received an inferior segmental osteotomy (ISO) for decompensation of significantly retroclined lower incisors in the context of 'surgery-first' (SF) or 'surgery-early' (SE) timing protocols was performed. Treatment was planned virtually. A thorough periodontal assessment was performed at baseline and periodically until debonding. A minimally invasive surgical technique including selective interdental corticotomies and elective bone augmentation was used. Patient and orthodontist satisfaction with the treatment was evaluated. Eight patients (mean age 26.3 years) underwent surgery. One had isolated maxillary surgery and seven had bimaxillary surgery in combination or not with additional cosmetic procedures. The periodontal status of all patients remained stable throughout the observation period. The mean duration of orthodontic treatment was 8.7 months in the SF group and 10.5 months in the SE group. Satisfaction with treatment was extremely high. The ISO is a safe, reliable technique for dentoalveolar decompensation in timing protocols with a short or no orthodontic preparatory phase. This methodology may represent a reasonable approach in selected class III patients.

Minimally invasive intraoral condylectomy: proof of concept report.

A significant proportion of facial asymmetry cases are caused by abnormal growth of the mandibular condyles. Surgical management is generally based on a condylectomy performed through a pre-auricular transcutaneous access. However, this approach entails potential neurovascular, salivary, and aesthetic complications. In this study, a proof-of-concept evaluation was performed of a novel minimally invasive technique for condylectomy performed through an intraoral approach. Based on precise three-dimensional virtual planning to define intraoperative references, this technique provides an excellent access for total or partial condylectomy through a limited intraoral incision. Piezoelectric surgery with customized attachments enables the safe, accurate execution of the condylectomy. In addition, experience gained in seven consecutive cases suggests that the need for coronoidectomy can be obviated, surgical time is reduced to an average of 16.9min, and postoperative morbidity is minimal. This alternative intraoral approach could become the treatment of choice for most condylar hyperplastic conditions.

The anterior maxilla as a potential source of bone grafts: a morphometric cone beam computed tomography analysis of different anatomical areas.

The aim of this research was to use cone beam computed tomography (CBCT) to analyze the volume, density, and morphology of the bone available in the anterior region of the maxilla, in order to investigate its potential as a source of bone grafts. Three independent zones were evaluated: the palatine process of the maxilla (PPM), anterior nasal spine (ANS), and subnasal bone (SN). The latter was analyzed bilaterally (SNR, SNL). One hundred CBCT scans were evaluated. The morphometric analysis comprised volumetric and subsequent automatic density calculations, as well as linear measurements. Potential correlations among these parameters, including demographic characteristics, were investigated. The study comprised 52 women and 48 men (mean age 49.6±14.5 years). The calculated bone volume averaged 2.41±0.72cm(3) for PPM, 0.46±0.16cm(3) for ANS, 0.58±0.2cm(3) for SNR, and 0.57±0.21cm(3) for SNL. The anterior region of the maxilla can provide a considerable amount of bone volume from different anatomical zones and should be regarded as a potential donor site for the regeneration of maxillary atrophic bones. Further investigation is required before these findings can be applied in the routine clinical setting.

Early changes in condylar position after mandibular advancement: a three-dimensional analysis.

The aim of this study was to perform a three-dimensional (3D) assessment of positional changes of the mandibular condyle after bilateral sagittal split osteotomy (BSSO). A prospective evaluation of 22 skeletal class II patients who underwent a BSSO for mandibular advancement was performed. Pre- and postoperative cone beam computed tomography scans were taken. Using the cranial base as a stable reference, the pre- and postoperative 3D skull models were superimposed virtually. Positional changes of the condyles were assessed with a 3D colour mapping system (SimPlant O&O). A Brunner-Langer statistical test was applied to test the null hypothesis that the condylar position remains stable after BSSO. The level of significance was set at 0.05. The mean mandibular advancement in the studied sample was 6.7±1.6mm. Overall, the condylar positional changes after BSSO for mandibular advancement were statistically significant (P<0.05). A positive correlation was found between the displacement of the left condyle and the amount of mandibular advancement (P<0.01). The results of this study suggest that statistically significant changes of condylar position occur after mandibular advancement. Long-term evaluation is needed to assess the capacity of the temporomandibular joint to adapt to these changes.

On a definition of the appropriate timing for surgical intervention in orthognathic surgery.

Together with the introduction of new orthodontic techniques and minimally invasive surgery protocols, the emergence of modern patient prototypes has given way to novel timing schemes for the handling of dento-maxillofacial deformities. The aim of this study was to define, justify, and systematize the appropriate timing for orthognathic surgery. A retrospective analysis of orthognathic surgery procedures carried out over a 3-year period was performed. Six timing schemes were defined: 'surgery first', 'surgery early', 'surgery late', 'surgery last', 'surgery only', and 'surgery never'. Gender, age at surgery, main motivation for treatment, orthodontic treatment length, and number of orthodontic appointments were evaluated. A total of 362 orthognathic procedures were evaluated. The most common approach was 'surgery late'. While aesthetic improvement was the leading treatment motivation in 'surgery first', 'surgery early', and 'surgery last' cases, occlusal optimization was the chief aim of 'surgery late'. Sleep-disordered breathing was the main indication for treatment in 'surgery only'. Compared to 'surgery late', orthodontic treatment was substantially shorter in 'surgery early' and 'surgery first' cases, but the number of orthodontic appointments was similar. In conclusion, the skilful management of dento-maxillofacial deformities requires a comprehensive analysis of patient-, orthodontist-, and surgeon-specific variables. Each timing approach has well-defined indications, treatment planning considerations, and orthodontic and surgical peculiarities.

Optimization of the interface between radiology, surgery, radiotherapy, and pathology in head and neck tumor surgery: a navigation-assisted multidisciplinary network.

A navigation-assisted multidisciplinary network to improve the interface between radiology, surgery, radiotherapy, and pathology in the field of head and neck cancer is described. All implicated fields are integrated by a common server platform and have remote data access in a ready-to-use format. The margins of resection and exact locations of biopsies are mapped intraoperatively. The pathologist uses the numerical coordinates of these samples to precisely trace each specimen in the anatomical field. Subsequently, map-guided radiotherapy is planned. In addition to the benefits of image-guided resection, this model enables radiotherapy planning according to the specific coordinates of the resection defect plus any residually affected sites identified by the pathologist. Irradiation of adjacent healthy structures is thereby minimized. In summary, the navigation-assisted network described grants timely multidisciplinary feedback between all fields involved, attains meticulous pathological definition, and permits optimized coordinate-directed radiotherapy.

New protocol for three-dimensional surgical planning and CAD/CAM splint generation in orthognathic surgery: an in vitro and in vivo study.

Inaccurate visualization of the inter-occlusal relationship has raised an important challenge to virtual planning for orthognathic surgery based on cone beam computerized tomography (CBCT). The aim of this study was to evaluate an innovative workflow for orthognathic surgery planning and surgical splint fabrication. The clinical protocol consists of a single cone beam computerized tomography (CBCT) scan of the patient, surface scanning of the dental arches with an intraoral digital scanner, and subsequent fusion of the two datasets. The "virtual patient" thus created undergoes virtual surgery, and the resulting file with the intermediate intermaxillary relationship is used to obtain the intermediate splint by CAD/CAM technology (computer-aided design and computer-aided manufacturing). A proof-of-concept study was performed in order to assess the accuracy and reliability of this protocol. The study comprised two parts: an in vitro evaluation on three dentate skull models and a prospective in vivo assessment on six consecutive patients. Vector error calculation between the virtually simulated intermaxillary position and the intraoperative intermediate intermaxillary relationship revealed high accuracy. The greatest average variation corresponded to the y axis. Compared to previously described methods for obtaining an augmented three-dimensional virtual model, this procedure eliminates the need for dental impressions, simplifies the necessary technical steps and computational work, and reduces the patient's exposure to ionizing radiation.

Three-dimensional cone beam computed tomography definition of the anatomical subregions of the upper airway: a validation study.

The exact boundaries of the upper airway subregions remain undefined. Consequently, anatomical limits vary greatly among different research groups and impede unbiased comparisons. The aim of this study was to provide clinical three-dimensional anatomical limits for the upper airway subregions, translate them into accurate and reliable cephalometric landmarks in cone beam computed tomography (CBCT) data, and validate the proposed measuring protocol. The upper airway of 40 normative individuals aged 23-35 years was evaluated with Dolphin Imaging(®) software. An appropriate grey-scale threshold value was pre-calculated. After adapting specific head positioning and virtual orientation protocols, the volume and minimum cross-sectional area of the nasopharynx, oropharynx, and hypopharynx, as previously defined by the authors, were calculated. Intra- and inter-observer reliability was excellent for volumes and moderate for areas. The sexual dimorphism analysis revealed a significantly greater oropharyngeal volume, hypopharyngeal volume, and minimum cross-sectional oropharyngeal area in males than in females. In conclusion, the proposed subregion definition showed technical feasibility and statistical reliability, especially for three-dimensional calculations. The reliability of two-dimensional calculations may be increased with improved head positioning during CBCT scanning and subsequent virtual head orientation. Standardization of the proposed anatomical limits has the potential to homogenize upper airway subregion analysis and permit comparisons among future studies.

Cone-beam computerized tomography imaging and analysis of the upper airway: a systematic review of the literature.

A systematic review of the literature concerning upper airway imaging and analysis using cone-beam computed tomography (CBCT) was performed. A PubMed search (National Library of Medicine, NCBI; revised 9th January 2011) yielded 382 papers published between 1968 and 2010. The 382 full papers were screened in detail. 46 articles were considered clinically or technically relevant and were included in this systematic review. These were classified as articles on accuracy and reliability of CBCT imaging of the upper airway (n=4), accuracy and reliability of DICOM viewers (n=2), synopsis (n=10), technical (n=7) and clinical applications (n=27). When one paper was considered related to two or more categories, it was assigned to each relevant group. Results indicate that three-dimensional (3D) analysis of the upper airway using CBCT can be achieved in an accurate and reliable manner. Important obstacles still need to be addressed, including the impact of respiration phase, influence of tongue position and mandible morphology, longitudinal and cross-sectional 3D CBCT upper airway evaluation, and 3D CBCT definition of the anatomical boundaries of the upper airway.