Cone-Beam Computed Tomography for Oral and Maxillofacial Imaging

The invention of computed tomography (CT) technique revolutionized diagnostic imaging. Compared to conventional X-ray imaging procedures, CT involves higher radiation doses. Recently, cone-beam CT (CBCT) specifically designed for maxillofacial imaging was introduced. CBCT technique is based on a cone-shaped X-ray beam centered on a two-dimensional (2D) detector. The detector system performs one rotation around the patient, producing a series of 2D images which are then reconstructed in a 3D data set. The contemporary knowledge regarding CBCT and its proper application guides the practitioner for improvement in diagnostic purposes and treatment planning. The aim of this chapter is to focus on the details, advantages, drawbacks, and clinical applications of CBCT as a headmost CT imaging technique in the oral and maxillofacial (OMF) region. The main clinical applications of CBCT in the OMF region are dentistry including dentoalveolar and maxillofacial surgery, orthodontics, endodontics, and periodontics; and otolaryngology. The aforementioned clinical use of CBCT was described in detail with illustrated sample cases. In most of the cases in OMF region, CBCT takes the place of multi-slice CT. Thus, clinicians should know the clinical applications and capabilities of CBCT technique with its drawbacks

Bone Engineering of Maxillary Sinus Bone Deficiencies Using Enriched CD90+ Stem Cell Therapy: A Randomized Clinical Trial

Bone engineering of localized craniofacial osseous defects or deficiencies by stem cell therapy offers strong prospects to improve treatment predictability for patient care. The aim of this phase 1/2 randomized, controlled clinical trial was to evaluate reconstruction of bone deficiencies of the maxillary sinus with transplantation of autologous cells enriched with CD90+ stem cells and CD14+ monocytes. Thirty human participants requiring bone augmentation of the maxillary sinus were enrolled. Patients presenting with 50% to 80% bone deficiencies of the maxillary sinus were randomized to receive either stem cells delivered onto a β‐tricalcium phosphate scaffold or scaffold alone. Four months after treatment, clinical, radiographic, and histologic analyses were performed to evaluate de novo engineered bone. At the time of alveolar bone core harvest, oral implants were installed in the engineered bone and later functionally restored with dental tooth prostheses. Radiographic analyses showed no difference in the total bone volume gained between treatment groups; however, density of the engineered bone was higher in patients receiving stem cells. Bone core biopsies showed that stem cell therapy provided the greatest benefit in the most severe deficiencies, yielding better bone quality than control patients, as evidenced by higher bone volume fraction (BVF; 0.5 versus 0.4; p = 0.04). Assessment of the relation between degree of CD90+ stem cell enrichment and BVF showed that the higher the CD90 composition of transplanted cells, the greater the BVF of regenerated bone (r = 0.56; p = 0.05). Oral implants were placed and restored with functionally loaded dental restorations in all patients and no treatment‐related adverse events were reported at the 1‐year follow‐up. These results provide evidence that cell‐based therapy using enriched CD90+ stem cell populations is safe for maxillary sinus floor reconstruction and offers potential to accelerate and enhance tissue engineered bone quality in other craniofacial bone defects and deficiencies (Clinicaltrials.gov NCT00980278). © 2015 American Society for Bone and Mineral Research. © 2015 American Society for Bone and Mineral ResearchPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112016/1/jbmr2464.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/112016/2/jbmr2464-sup-0009-SupLegend-S1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/112016/3/jbmr2464-sup-0008-SupTab-S4.pd

Radiographic outcome of secondary alveolar bone grafting in patients with alveolar clefts

Objective: To determine the outcome of secondary alveolar bone grafting (SABG) in a series of consecutive patients with clefts involving the alveolus.Design and Setting: Retrospective cohort study of consecutive operations per-formed between June 2011 and September 2016 by a single surgeon at a single United Kingdom cleft center.Participants: A total of 160 patients with a cleft/s involving the alveolus, inclusive of syndromic patients and those with atypical facial clefts.Interventions: A standard protocol involved an oral hygiene program, pre-surgical orthodontics where necessary and autologous bone grafting from the iliac crest.Main Outcome Measure(s): The Kindelan bone-fill index was used to evaluate suc-cess using occlusal radiographs. Weighted Cohen's kappa coefficient was used as a measure of intra- and inter- rater agreement. Fisher's exact test was used to examine the effects of type of cleft, pre-surgical orthodontics or age at time of SABG on ra-diographic outcome.Results: There were 200 SABGs assessed. Mean age at time of SABG was 9.1 years old (SD 1.1) with 99% (n =198) of grafts deemed successful. There were two fail-ures where re- graft was performed successfully during the study period. A grade 1 outcome was achieved for 92.5% (n = 185) of grafts and this did not appear to be af-fected by type of cleft (P= .290), pre-surgical orthodontics (P= .380) or age at time of SABG (P= .081).Conclusions: The high success rate reported in this study supports the favorable out-comes of a high-volume cleft surgeon. These findings can be used for comparative audit with similar units providing cleft care

3D Morphometric Quantification of Maxillae and Palatal Defects for Patients with Unilateral Cleft Lip and Palate via Auto-segmentation

The accurate quantification of the complex 3D cleft defect structure is key for optimal treatment planning and patient outcomes. Furthermore, very little is known about the morphometric differences between the affected versus the unaffected maxillary halves. The aim of this study is to characterize the 3D morphometry of the maxillae and cleft defects in non-syndromic patients with unilateral cleft lip and palate. To test the hypothesis that the defect size is positively correlated with the affected maxillary half, CBCT images were acquired from 60 patients presenting with unilateral cleft lip and palate. The machine learning program LINKS was used to segment the maxilla and defect. The height, width, and length of the maxilla and defect were measured from the segmented images. To fully characterize the defect, the distribution probability was mapped from superimposed 3D models, paired t tests were performed for statistical analysis, and a multiple linear regression was completed. The defect side demonstrated a significant decrease in maxillary length, anterior width, and volume with mean measurements of 34.31±2.56mm, 17.83±2.06mm, and 18.02±3.24x103mm3, respectively, and an increased maxillary anterior height with a mean of 25.91±4.12mm as compared to the non-defect side. Defect superimposition displayed a concentrated distribution near the alveolar bone region and anterior maxillary structures appeared to contribute to defect variability.Master of Scienc

PRELIMINARY FINDINGS OF A POTENZIATED PIEZOSURGERGICAL DEVICE AT THE RABBIT SKULL

The number of available ultrasonic osteotomes has remarkably increased. In vitro and in vivo studies have revealed differences between conventional osteotomes, such as rotating or sawing devices, and ultrasound-supported osteotomes (Piezosurgery®) regarding the micromorphology and roughness values of osteotomized bone surfaces. Objective: the present study compares the micro-morphologies and roughness values of osteotomized bone surfaces after the application of rotating and sawing devices, Piezosurgery Medical® and Piezosurgery Medical New Generation Powerful Handpiece. Methods: Fresh, standard-sized bony samples were taken from a rabbit skull using the following osteotomes: rotating and sawing devices, Piezosurgery Medical® and a Piezosurgery Medical New Generation Powerful Handpiece. The required duration of time for each osteotomy was recorded. Micromorphologies and roughness values to characterize the bone surfaces following the different osteotomy methods were described. The prepared surfaces were examined via light microscopy, environmental surface electron microscopy (ESEM), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM) and atomic force microscopy. The selective cutting of mineralized tissues while preserving adjacent soft tissue (dura mater and nervous tissue) was studied. Bone necrosis of the osteotomy sites and the vitality of the osteocytes near the sectional plane were investigated, as well as the proportion of apoptosis or cell degeneration. Results and Conclusions: The potential positive effects on bone healing and reossification associated with different devices were evaluated and the comparative analysis among the different devices used was performed, in order to determine the best osteotomes to be employed during cranio-facial surgery

Current Treatment of Cleft Lip and Palate

Non-syndromic cleft lip and palate patients have the most common congenital anomalies that affect the middle and lower part of the face, and which impair aesthetic integrity. These anomalies also affect basic functions such as hearing, speaking, chewing, and breathing. Treatment of patients with cleft lip and palate requires multidisciplinary teamwork. The cleft child should be followed and treated by a team of experts from different disciplines who work well together. Although cleft surgery, orthodontic treatment, and speech therapy are the main disciplines, each of the other branches (maxilla-facial-surgeon, otolaryngologist, speech therapist, pediatric dentist, psychologist, nurse etc.) are also very important. In this book, we wanted to present the reader with the experiences and knowledge of some of these disciplines. This book also includes information on the quality of life of children with this anomaly and anesthesia evaluation, which is very important for the cleft surgery

3D soft-tissue, 2D hard-tissue and psychosocial chantes following orthognathic surgery

A 3D imaging system (C3D®), based on the principles of stereophotogrammetry, has been developed for use in the assessment of facial changes following orthognathic surgery. Patients’ perception of their facial appearance before and after orthognathic surgery has been evaluated using standardised questionnaires, but few studies have tried to link this perception with the underlying two-dimensional cephalometric data. Comparisons between patients’ subjective opinions and 3D objective assessment of facial morphology have not been performed. Aims: (1) To test the reliability of the 3D imaging system; (2) to determine the effect of orthognathic surgery on the 3D soft-tissue morphology; (3) to assess skeletal changes following orthognathic surgery; (4) to evaluate soft-tissue to hard-tissue displacement ratios; (5) to ascertain the impact of orthognathic surgery on patients’ perception of their facial appearance and their psychosocial characteristics, (6) to explore the dentofacial deformity, sex and age on the psychosocial characteristics; (7) to evaluate the extent of compatibility between the cephalometric and the three-dimensional measurements and (8) to determine if the magnitude of facial soft-tissue changes affects the perception of facial changes at six months following surgery. Results and Conclusions: C3D imaging system was proved to be accurate with high reproducibility. The reproducibility of landmark identification on 3D models was high for 24 out of the 34 anthropometric landmarks (SD£0.5 mm). One volumetric algorithm in the Facial Analysis Tool had an acceptable accuracy for the assessment of volumetric changes following orthognathic surgery (mean error=0.314 cm3). The error of cephalometric method was low and the simulation of mandibular closure proved to be reproducible. 2D soft-tissue measurements were compatible with 3D measurements in terms of distances, but angular measurements showed significant differences (p<0.05)

Applications of Cone Beam Computed Tomography in Orthodontics and Endodontics

Stelt, P.F. van der [Promotor]Sanderink, G.C.H. [Copromotor