Efficacy of Platelet-Rich Fibrin After Mandibular Third Molar Extraction: A Systematic Review and Meta-Analysis.

PURPOSE: To assess the effect of platelet-rich fibrin (PRF) on the healing process of the alveolar socket after surgical extraction of the mandibular third molars. MATERIALS AND METHODS: PubMed, the Cochrane Central Register of Controlled Trials, Scopus, and relevant journals were searched using a combination of specific keywords ("platelet-rich fibrin," "oral surgery," and "third molar"). The final search was conducted on November 2, 2015. Randomized controlled clinical trials, as well as controlled clinical trials, aimed at comparing the effect of PRF versus natural healing after extraction of mandibular third molars were included. RESULTS: Five randomized controlled trials and one controlled clinical trial were included. There were 335 extractions (168 with PRF and 167 controls) in 183 participants. Considerable heterogeneity in study characteristics, outcome variables, and estimated scales was observed. Positive results were generally recorded for pain, trismus, swelling, periodontal pocket depth, soft tissue healing, and incidence of localized osteitis, but not in all studies. However, no meta-analysis could be conducted for such variables because of the different measurement scales used. The qualitative and meta-analysis results showed no significant improvement in bone healing with PRF-treated sockets compared with the naturally healing sockets. CONCLUSIONS: Within the limitations of the available evidence, PRF seems to have no beneficial role in bone healing after extraction of the mandibular third molars. Future standardized randomized controlled clinical trials are required to estimate the effect of PRF on socket regeneration.

Three-Dimensional Assessment of Temporomandibular Joint Using MRI-CBCT Image Registration.

PURPOSE: To introduce a new approach to reconstruct a 3D model of the TMJ using magnetic resonance imaging (MRI) and cone-beam computed tomography (CBCT) registered images, and to evaluate the intra-examiner reproducibility values of reconstructing the 3D models of the TMJ. METHODS: MRI and CBCT images of five patients (10 TMJs) were obtained. Multiple MRIs and CBCT images were registered using a mutual information based algorithm. The articular disc, condylar head and glenoid fossa were segmented at two different occasions, at least one-week apart, by one investigator, and 3D models were reconstructed. Differences between the segmentation at two occasions were automatically measured using the surface contours (Average Perpendicular Distance) and the volume overlap (Dice Similarity Index) of the 3D models. Descriptive analysis of the changes at 2 occasions, including means and standard deviation (SD) were reported to describe the intra-examiner reproducibility. RESULTS: The automatic segmentation of the condyle revealed maximum distance change of 1.9±0.93 mm, similarity index of 98% and root mean squared distance of 0.1±0.08 mm, and the glenoid fossa revealed maximum distance change of 2±0.52 mm, similarity index of 96% and root mean squared distance of 0.2±0.04 mm. The manual segmentation of the articular disc revealed maximum distance change of 3.6±0.32 mm, similarity index of 80% and root mean squared distance of 0.3±0.1 mm. CONCLUSION: The MRI-CBCT registration provides a reliable tool to reconstruct 3D models of the TMJ's soft and hard tissues, allows quantification of the articular disc morphology and position changes with associated differences of the condylar head and glenoid fossa, and facilitates measuring tissue changes over time.

Three-dimensional morphological changes of the temporomandibular joint and functional effects after mandibulotomy.

BACKGROUND: The midline and paramedian mandibulotomy are surgical procedures that divide the mandibular bone into two halves and disconnects the condylar heads of the TMJ from each other. This study aimed to prospectively evaluate the temporomandibular joint (TMJ) functional and morphological changes after mandibulotomy using a reconstructed 3D models of the TMJ. METHODS: Sixteen adult patients diagnosed with oral and oropharyngeal tumors with planned surgical mandibulotomy (test group, 9 patients) or transoral (control group, seven patients) treatments were included in the study. MRI and CBCT images were obtained immediately preceeding surgery and 6-8 weeks after surgery. Using the MRI-CBCT registered images, TMJ tissues were segmented at the two occasions by the same operator and 3D models were reconstructed for morphological assessment. Changes across time were measured using the volume overlap and Hausdorff distance of the disc and condyle 3D models. Disc-condyle relationship was measured using point-based and color map analysis. To assess the early functional changes, the Jaw function limitation scale (JFLS) and the maximum mouth opening were measured. Two-sample Hotelling T2 t-test was performed to determine the significance of the morphological and clinical outcomes' differences between the two groups. RESULTS: The two-sample Hotelling T2 t-test showed significant differences (T2 (df1,df2) = 0.97 (5,26), p <0.01) between the mean values of all outcomes among the 2 groups. The change in disc displacement was significantly different between the two groups (p <0.05). However, the condylar displacement was not significantly different between the two groups (p =0.3). The average of the JFLS score was five times larger after mandibulotomy, and was 2 times larger after transoral surgery (p < 0.01). Patients showed decrease in the average of the maximum interincisal mouth opening by 11 mm after mandibulotomy, and by 5.4 mm after transoral surgery. CONCLUSION: The quantitative assessment of the TMJ showed minimal changes of the condylar position and variable degrees of articular disc displacement associated with the paramedian split mandibulotomy. As well, limited jaw functions and vertical mouth opening were noticed more in the mandibultomy group compared to the transoral group in 6- weeks after surgery.

Usefulness of MRI-CBCT image registration in the evaluation of temporomandibular joint internal derangement by novice examiners.

OBJECTIVE: To assess whether novice examiners can more reliably determine temporomandibular joint (TMJ) disk derangements with the use of fused images of magnetic resonance imaging and cone beam computed tomography (MRI-CBCT) compared with MRI images alone. STUDY DESIGN: Thirty dental students with minimal exposure to TMJ imaging received a 30-minute calibration session in which TMJ diagnostic imaging and the normal anatomy of the TMJ internal derangement were explained. The students evaluated the disk positions of 16 TMJs in two sets of images (MRI images alone and MRI-CBCT images) randomly and independently. The disk positions evaluated by two experienced radiologists were used for comparison. RESULTS: The internal consistency among all students improved from an unacceptable consistency (α = 0.40) with MRI images alone to a good consistency (α = 0.84) with MRI-CBCT images. The agreement in evaluation between the students and the radiologists improved from a poor agreement with MRI images alone (k mean = 0.07 ± 0.12) to a moderate agreement with MRI-CBCT images (k mean = 0.55 ± 0.25). This improvement in the agreement was significant (P < .001). CONCLUSIONS: The use of fused MRI and CBCT images to visualize the TMJ in a single display significantly improved the examiners' reliability and accuracy of assessment of disk positions. The improvement of novice readers in assessing the disk positions highlights the potential use of MRI-CBCT image fusion as an educational tool.

MRI alone versus MRI-CBCT registered images to evaluate temporomandibular joint internal derangement.

OBJECTIVE: To evaluate the effect of magnetic resonance imaging-cone beam computed tomography (MRI-CBCT) image registration on inter- and intraexaminer consistency when evaluating temporomandibular joint (TMJ) internal derangement compared to MRI alone. METHODS: MRI and CBCT images of 25 patients (50 TMJs) were obtained and coregistered using mutual-information rigid image registration via Mirada XD software. Two experienced radiologists independently and blindly evaluated two types of images (MRI alone and MRI-CBCT registered images) at two different times (T1 and T2) for TMJ internal derangement, based on sagittal and coronal articular disc position in relation to the head of the condyle and the posterior slope of the articular eminence. RESULTS: The intraexaminer consistency with MRI alone (examiner 1 = 0.85 [0.74-0.92]; examiner 2 = 0.91 [0.84-0.95]) was lower than for the MRI-CBCT registered images (examiner 1 = 0.95 [0.91-0.97]; examiner 2 = 0.97 [0.96-0.99]). The interexaminer consistency of evaluating internal derangement with MRI alone (0.52 [0.18-0.73] at T1; 0.71 [0.45-0.84] at T2) was lower than for the MRI-CBCT registered images (0.97 [0.95-0.98] at T1; 0.98 [0.96-0.99] at T2). When disc position classification was dichotomized to normal versus anteriorly displaced, intraexaminer agreement for the two examiners was 0.52 and 0.63 for MRI alone, but was 0.91 and 0.92 for MRI-CBCT registered images. Interexaminer agreement for MRI alone was 0.29 at T1 and 0.42 at T2, but was 0.96 at both examination times for MRI-CBCT registered images. CONCLUSION: The MRI-CBCT registered images improved intra- and interexaminer consistency in the evaluation of internal derangement of TMJ.

New algorithm for semiautomatic segmentation of nasal cavity and pharyngeal airway in comparison with manual segmentation using cone-beam computed tomography.

INTRODUCTION: Our objectives were to assess reliability, validity, and time efficiency of semiautomatic segmentation using Segura software of the nasal and pharyngeal airways, against manual segmentation with point-based analysis with color mapping. METHODS: Pharyngeal and nasal airways from 10 cone-beam computed tomography image sets were segmented manually and semiautomatically using Segura (University of Alberta, Edmonton, Alberta, Canada). To test intraexaminer and interexaminer reliabilities, semiautomatic segmentation was repeated 3 times by 1 examiner and then by 3 examiners. In addition to volume and surface area, point-based analysis was completed to assess the reconstructed 3-dimensional models from Segura against manual segmentation. The times of both methods of segmentation were also recorded to assess time efficiency. RESULTS: The reliability and validity of Segura were excellent (intraclass correlation coefficient, >0.9 for volume and surface area). Part analysis showed small differences between the Segura and manually segmented 3-dimensional models (greatest difference did not exceed 4.3 mm). Time of segmentation using Segura was significantly shorter than that for manual segmentation, 49 ± 11.0 vs 109 ± 9.4 minutes (P <0.001). CONCLUSIONS: Semiautomatic segmentation of the pharyngeal and nasal airways using Segura was found to be reliable, valid, and time efficient. Part analysis with color mapping was the key to explaining differences in upper airway volume and provides meaningful and clinically relevant analysis of 3-dimensional changes.

MRI and CBCT image registration of temporomandibular joint: a systematic review.

PURPOSE: The purpose of the present review is to systematically and critically analyze the available literature regarding the importance, applicability, and practicality of (MRI), computerized tomography (CT) or cone-beam CT (CBCT) image registration for TMJ anatomy and assessment. DATA SOURCES: A systematic search of 4 databases; MEDLINE, EMBASE, EBM reviews and Scopus, was conducted by 2 reviewers. An additional manual search of the bibliography was performed. INCLUSION CRITERIA: All articles discussing the magnetic resonance imaging MRI and CT or CBCT image registration for temporomandibular joint (TMJ) visualization or assessment were included. RESULTS AND INCLUDED ARTICLES' CHARACTERISTICS: Only 3 articles satisfied the inclusion criteria. All included articles were published within the last 7 years. Two articles described MRI to CT multimodality image registration as a complementary tool to visualize TMJ. Both articles used images of one patient only to introduce the complementary concept of MRI-CT fused image. One article assessed the reliability of using MRI-CBCT registration to evaluate the TMJ disc position and osseous pathology for 10 temporomandibular disorder (TMD) patients. CONCLUSION: There are very limited studies of MRI-CT/CBCT registration to reach a conclusion regarding its accuracy or clinical use in the temporomandibular joints.

Accuracy of magnetic resonance imaging-cone beam computed tomography rigid registration of the head: an in-vitro study.

OBJECTIVE: To evaluate the performance of cross-modality image registration procedure between magnetic resonance imaging (MRI) and cone beam computed tomography (CBCT). METHODS: In vitro diagnostic MRI and CBCT images of 5 cadaver swine heads were obtained prospectively. Five radiopaque fiducial markers were attached to each cadaver skull by using resin screws. Automatic MRI-CBCT rigid registrations were performed. The specimens were then scanned using a 3-dimensional (3-D) laser scanner. The 3-D coordinate points for the centroid of the attached fiducial markers from laser scan were identified and considered ground truth. The distances between marker centroids were measured with MRI, CBCT, and MRI-CBCT. Accuracy was calculated by using repeated measures analysis of variance and mean difference values. The registration method was repeated 10 times for each specimen in MRI to measure the average error. RESULTS: There was no significant difference (P > .05) in mean distances of the markers between all images and the ground truth. The distances' mean difference between MRI, CBCT, and MRI-CBCT and the ground truth were 0.2 ± 1.1 mm, 0.3 ± 1.0 mm, 0.2 ± 1.2 mm, respectively. The detected method error ranged between 0.06 mm and 0.1 mm. CONCLUSION: The cross-modality image registration algorithm is accurate for head MRI-CBCT registration.

MRI findings of radiation-induced changes of masticatory muscles: a systematic review.

BACKGROUND: Radiotherapy to the head and neck regions can result in serious consequences to the temporomandibular joint (TMJ) and chewing muscles. Magnetic resonance imaging (MRI) demonstrates soft-tissue alterations after radiotherapy, such as morphology and signal intensity. OBJECTIVE: The purpose of this review is to critically and systematically analyse the available evidence regarding the masticatory muscles alterations, as demonstrated on MRI, after radiotherapy for head and neck cancer. DATA SOURCES: Electronic search of MEDLINE, EMBASE, EBM reviews and Scopus. INCLUSION CRITERIA: Reports of any study design investigating radiation-induced changes in masticatory muscles after radiotherapy in patients with head and neck cancer were included. RESULTS AND SYNTHESIS METHODS: An electronic database search resulted in 162 papers. Sixteen papers were initially selected as potentially relevant studies; however, only four papers satisfied all inclusion criteria. The included papers focused on the MRI appearance of masticatory muscles following radiotherapy protocol. Two papers reported outcome based on retrospective clinical and imaging records, whereas the remaining two papers were case reports. Irradiated muscles frequently show diffuse increase in T2 signal and post-gadolinium enhancement post-irradiation. Also, muscle size changes were reported based on subjective comparison with the contralateral side. The quality of all included papers was considered poor with high risk of bias. CONCLUSION: There is no evidence that MRI interpretations indicate specific radiation-induced changes in masticatory muscles. There is a clear need for a cohort study comparing patients with pre- and post-radiotherapy MRI.

CBCT assessment of upper airway changes and treatment outcomes of obstructive sleep apnoea: a systematic review.

PURPOSE: The aim of this study was to review studies using cone beam computed tomography (CBCT) to assess dimensional changes in the upper airway after appliance or surgical therapy in subjects with obstructive sleep apnoea and to correlate CBCT findings with treatment outcome. METHOD: Several electronic databases were searched. Studies that met selection criteria were evaluated using a customized evaluation tool. RESULTS: Study parameters were met in seven articles. Fifty adults were assessed using CBCT 1.6-10 months after appliance therapy or maxillary mandibular advancement surgery with or without genial tubercle advancement. Airway parameters measured were linear, cross-sectional (CS) area, volume or airway function. In only two validated surgical case reports, airway volume increased by 6.5-9.7 cm(3) (>80 %) and minimum CS area by 0.1-1.2 cm(2) (21 and 269 %). CONCLUSION: The available published studies show evidence of CBCT measured anatomic airway changes with surgery and dental appliance treatment for OSA. There is insufficient literature pertaining to the use of CBCT to assess treatment outcomes to reach a conclusion. High-quality evidence level studies, with statistically appropriate sample sizes and cross validated clinically, are needed to determine if CBCT airway dimensional changes are suitable for assessment of treatment outcome.

Morphologic and functional changes in the temporomandibular joint and stomatognathic system after transmandibular surgery in oral and oropharyngeal cancers: systematic review.

BACKGROUND: Interruption of mandibular continuity in transmandibular (mandibulotomy and mandibulectomy) surgery for tumour resection in the oral cavity and oropharynx may alter oral and temporomandibular joint (TMJ) morphology and function. OBJECTIVE: To critically analyze available evidence regarding the effects of transmandibular surgeries on morphologic and functional changes in the TMJ and stomatognathic system. DATA SOURCES: Electronic search of Medline, Embase, Evidence-Based Medicine Reviews, Ovid HealthStar, and Scopus and hand searches. INCLUSION CRITERIA: Any article investigating the TMJ morphologic changes and/or functional outcomes following transmandibular surgeries. RESULTS AND SYNTHESIS METHODS: Two hundred seventy-one articles were obtained through the electronic database scan and six articles via a hand search. Twelve full articles were initially selected as potentially meeting the eligibility for this review; however, only five articles finally fulfilled the study inclusion criteria and were analyzed for their methodology. All articles used clinical records and/or patient reports to evaluate TMJ pain, motion, dental occlusion, mouth opening, and deflection during opening as outcome measures. In only four articles was a clinical examination conducted after surgery, with associated patients' interviews and reports. The quality of all included articles was considered poor with a high risk of bias according to the Research Triangle Institute item bank quality of assessment. CONCLUSION: Based on the limited available evidence for this systematic review and a high risk of bias of the analyzed articles, no firm conclusions can be established regarding the effects of transmandibular surgery on morphologic and functional changes in the TMJ and stomatognathic system.

Maxillary advancement with conventional orthognathic surgery in patients with cleft lip and palate: is it a stable technique?

PURPOSE: To evaluate the long-term skeletal stability after maxillary surgical advancement with conventional Le Fort I osteotomy in patients with cleft lip and palate by a systematic review of the published data. MATERIALS AND METHODS: Electronic databases, "gray literature," and reference list searches were conducted. The inclusion criteria were the stability of maxillary surgical advancement with conventional Le Fort I osteotomy fixed with plates and assessed at the post-treatment follow-up 1 year or more postoperatively in patients with cleft lip and/or palate. Full reports were retrieved from abstracts or titles that appeared to meet the inclusion criteria or lacked sufficient detail for immediate exclusion. Once full reports were collected, they were again reviewed, considering more detailed inclusion criteria for a final selection decision. A methodologic quality assessment tool was used. The quantity and quality of the obtained data precluded a meta-analytic approach. RESULTS: A total of 25 abstracts/titles met the initial search criteria, and 10 studies were finally selected. The overall methodologic quality scores were high for only 1 randomized clinical trial. After maxillary advancement with Le Fort I in patients with cleft lip and palate, the long-term horizontal relapse at the A-point was 20% to 30% in 4 studies and 30% to 40% in 3 studies. In addition, vertical relapse was more than 50% in 4 studies. The study judged as a high-quality study reported a 37% rate of horizontal relapse and a 65% rate of vertical relapse at the A-point. CONCLUSIONS: Current evidence suggests maxillary surgical advancement with conventional Le Fort I osteotomy in patients with cleft lip and palate appears to show a moderate relapse rate in the horizontal plane and a high relapse rate in the vertical plane.

Electromyography in diagnosing temporomandibular disorders.

BACKGROUND: Although electromyography (EMG) has been used extensively in dentistry to assess masticatory muscle impairments in several conditions, especially temporomandibular disorders (TMDs), many investigators have questioned its psychometric properties and accuracy in diagnosing TMD. TYPES OF STUDIES REVIEWED: The authors conducted a systematic review to analyze the literature critically and determine the accuracy of EMG in diagnosing TMDs. They conducted an electronic search of MEDLINE, Embase, all Evidence-Based Medicine Reviews, Allied and Complementary Medicine, Ovid HealthSTAR and SciVerse Scopus. The authors selected abstracts that fulfilled the inclusion criteria, retrieved the original articles, verified the inclusion criteria and hand searched the articles' references. They used a methodological tool (Quality Assessment of Diagnostic Accuracy Studies [QUADAS]) to evaluate the quality of the selected articles. RESULTS: The electronic database search resulted in a total of 130 articles. The authors selected eight articles as potentially meeting eligibility for the review. Of these eight articles, only two fulfilled the study inclusion criteria, and the authors analyzed them. Investigators in both studies reported low sensitivity (values ranged from 0.15 to 0.40 in one study and a mean of 0.69 in the second study). In addition, investigators in the two studies reported contradictory levels of specificity (values ranged from 0.95 to 0.98 in one study, and the mean value in the second study was 0.67). The likelihood ratios and predictive values were not helpful in diagnosing TMD by means of EMG. The quality of the two studies was poor on the basis of the QUADAS checklist. CLINICAL IMPLICATIONS: The authors of this systematic review found no evidence to support the use of EMG for the diagnosis of TMD.