Christian Ulm

Prevalence, location and morphology of maxillary sinus septa: systematic review and meta-analysis

AIM To gain further insights and resolve conflicting results in the literature regarding prevalence, predominant location and morphologic variability of maxillary sinus septa. MATERIAL AND METHODS Electronic and hand searching of English literature identified 33 investigations published from 1995 to 2011. Septa were defined as at least 2-4 mm in height. RESULTS Septa were present in 28.4% of 8923 sinuses investigated (95% confidence interval: 24.3-32.5%). Prevalence was significantly higher in atrophic sinuses compared with dentate maxillae (p < 0.001). Septa were located in premolar, molar and retromolar regions in 24.4%, 54.6% and 21.0% respectively. Orientation of septa was transverse in 87.6%, sagittal in 11.1% and horizontal in 1.3% of cases. Septa height measured 7.5 mm on average. Complete septa (dividing the sinus into two separate cavities) were found in only 0.3%. Other rare conditions included multiple septa in one sinus (4.2%) and bilateral septa (17.2%). Septa diagnosis using panoramic radiographs yielded incorrect results in 29% of cases. CONCLUSIONS In view of their high overall prevalence and significant morphologic variability, 3D radiographic imaging prior to sinus floor augmentation may help to reduce complication rates in the presence of maxillary sinus septa.

Atrophy of the residual alveolar ridge following tooth loss in an historical population.

OBJECTIVES To study the natural aetiopathology of jaw atrophy after tooth loss, unaltered by prosthetic procedures, an historical population without modern dental treatment was examined. METHODS Based on the hypothesis that there are predictable changes in shape during jaw-atrophy, frequency and degree of atrophy as well as clinical aspects of bone quality and resorption were determined in the skeletal remains of 263 individuals. The potential association between age and frequency/severity of atrophy was analysed. RESULTS Atrophy in at least one jaw segment was present in 45.2% of the analysed jaw specimens. The residual ridge underwent a series of changes in shape and height following the pattern of resorption described for modern populations. The severity of these alterations was associated with the age of the individual and the region within the jaw. Atrophy was frequently related to structural degradation of the covering cortical layer. CONCLUSIONS These findings prove that atrophy of the jaw evidently does occur, displaying similar patterns of resorption in a population without modern prosthetics, where the negative effect of ill-fitting dentures is excluded. The basic information about alterations of shape and the cortical layer covering the residual crest might help to provide a deeper insight into aetiopathological mechanisms of this common oral disease.

Periodontal Probing of Dental Furcations Compared With Diagnosis by Low-Dose Computed Tomography: A Case Series

BACKGROUND Therapeutic decisions in periodontal surgery are based on the accurate diagnosis of the furcation. Clinical probing is the basic diagnostic tool; however, the accuracy of clinical probing to distinguish Class II and Class III furcation defects is unknown. Therefore, this study compares clinical probing diagnoses to those of computed tomography (CT). METHODS Seventy-five patients with severe periodontal disease were enrolled in this case series study. A total of 582 furcation sites in molars were assigned for the diagnosis of Class II and Class III furcation defects by clinical probing. Diagnosis based on CT served as a reference. RESULTS The degree of furcation involvement on clinical findings was confirmed in 57% of the sites, whereas 20% were overestimated and 23% were underestimated compared with the radiologic analysis. Only 32% of Class III furcations in the CT scan were detected clinically. The best correlation of CT scan and clinical probing was found at buccal furcation sites in the mandible, with a κ-coefficient of 0.52, and buccal furcation sites in the maxilla, κ = 0.38. The κ-coefficient was 0.35 for lingual furcations, 0.29 for mesial furcations, and 0.27 for distal furcations, showing weaker correlations. CONCLUSIONS CT scans offer more detailed information on furcation involvement than clinical probing. Especially before surgical treatment, three-dimensional radiographic imaging can be a useful tool to assess the degree of furcation involvement and optimize treatment decisions.

Effect of enamel matrix derivative on proliferation and differentiation of osteoblast cells grown on the titanium implant surface

OBJECTIVES Enamel matrix derivative (EMD) is widely used in promoting periodontal regeneration, but the mechanisms underlying its effects are not entirely clear. In particular, the effect of EMD on osseointegration of dental implants and its application in the treatment of peri-implantitis are still debatable. The purpose of this study was to investigate the effect of EMD on proliferation and differentiation of osteoblasts grown on the Ti implant surface. STUDY DESIGN Osteoblast-like MG-63 cells were seeded on coarse-grit-blasted and acid-etched surface Ti implant disks and stimulated with various EMD concentrations. Cell proliferation/viability, alkaline phosphatase activity, osteocalcin production, and expression levels of osteoprotegerin (OPG) and receptor activator of nuclear factor κB ligand (RANKL) were determined. RESULTS EMD inhibited the proliferation/viability of MG-63 cells. Furthermore, EMD significantly increased the alkaline phosphatase activity and osteocalcin production in MG-63 cells grown on Ti surfaces. Finally, EMD enhanced mRNA expression level of OPG and did not influence that of RANKL. CONCLUSION(S) Application of EMD in the dental implantolology may have a positive effect on implant osseointegration, and further studies are required to improve clinical outcome.

Effect of Emdogain on proliferation and migration of different periodontal tissue–associated cells

OBJECTIVES Although Emdogain is widely used as a gel in periodontal therapy, the exact mechanisms underlying its regenerative ability still need to be further investigated. Therefore, we tested in vitro the effect of the product Emdogain on proliferation, viability, and migration of various human cell types of periodontium. STUDY DESIGN Proliferation and viability of alveolar osteoblasts (AOBs), epithelial cell line HSC-2, and human umbilical vein endothelial cells (HUVECs) were measured using [(3)H]-thymidine uptake and 3,4,5-dimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide (MTT)-assay, respectively. Cell migration was investigated in microchemotaxis chamber. RESULTS The proliferation and viability of AOB, HSC-2, and HUVECs were significantly stimulated by Emdogain (12.5-250 microg/mL) in direct relationship with the amount of product present in the cell culture medium. Cell migration was stimulated in AOB and HUVECs depending on Emdogain amount. In contrast, in HSC-2 cells the migration was stimulated only by less than 50 microg/mL of Emdogain, whereas at higher amounts this stimulating effect was either diminished or absent. CONCLUSION Emdogain stimulates proliferation, viability, and migration of AOB, HSC-2, and HUVECs in vitro. This biological versatility of Emdogain could correspond to an essential mechanism underlying its ability to promote periodontal regeneration.

Labial piercing and localized periodontal destruction – partial periodontal regeneration following periodontal debridement and free gingival graft

Localized periodontal destruction has been reported as a rare complication of intraoral piercings. The purpose of this case report was to illustrate the destructive nature of a lip stud and to describe the successful treatment of this case. The lip stud was removed and supra- and subgingival debridement was performed. Because of a shallow vestibule, the absence of keratinized gingiva, and the strong frenulum insertion at the gingival margins, a free gingival graft was placed. Subsequently the patient demonstrated a significant amount of osseous regeneration and partial coverage of the recession, which has been clinically and radiographically (computed tomography) documented.

Guided Modern Endodontic Surgery: A Novel Approach for Guided Osteotomy and Root Resection

Introduction: Continuous improvements in techniques, instruments, and materials have established modern endodontic microsurgery as a state‐of‐the‐art treatment method. The purpose of this approach was to introduce a new surgical endodontic technique by using a three‐dimensional printed template for guided osteotomy and root resection. Methods: A 38‐year‐old patient was diagnosed with periapical lesions of teeth #3 and #4 and extruded gutta‐percha material. Three‐dimensional radiographic and optical scan files were imported into surgical planning software designed for guided implant surgery. Within the adapted software program the periapical lesions and the extruded gutta‐percha were visualized and marked. With the aid of virtually positioned surgical pins and piezoelectric instruments, the osteotomy size, the apical resection level, and the bevel angle were defined before treatment. Three‐dimensional surgical templates for each tooth were designed within the software program for a guided treatment approach. Results: This approach comprised the treatment of periapical lesions of teeth #3 and #4 with root‐end fillings and the detection and complete removal of the extruded gutta‐percha material without perforation of sinus membrane. There were no postoperative complications, and clinical and radiologic assessments verified complete healing of the teeth. Conclusions: The guided microsurgical endodontic treatment presented appears to be a viable technique that allows for predefined osteotomies and root resections. HighlightsNovel surgical endodontic technique using a 3D template for guided osteotomy and root resection.Virtually pre‐planned implementation of recommended guidelines for a modern surgical endodontic treatment.Adaptation of a software program for guided implant surgery in endodontic treatments.Guided surgical osteotomies and root resections with piezoelectric instruments.

Guided Autotransplantation of Teeth: A Novel Method Using Virtually Planned 3-dimensional Templates

INTRODUCTION The aim of this study was to introduce an innovative method for autotransplantation of teeth using 3-dimensional (3D) surgical templates for guided osteotomy preparation and donor tooth placement. METHODS This report describes autotransplantation of immature premolars as treatment of an 11-year-old boy having suffered severe trauma with avulsion of permanent maxillary incisors. This approach uses modified methods from guided implant surgery by superimposition of Digital Imaging and Communications in Medicine files and 3D data sets of the jaws in order to predesign 3D printed templates with the aid of a fully digital workflow. RESULTS The intervention in this complex case could successfully be accomplished by performing preplanned virtual transplantations with guided osteotomies to prevent bone loss and ensure accurate donor teeth placement in new recipient sites. Functional and esthetic restoration could be achieved by modifying methods used in guided implant surgery and prosthodontic rehabilitation. The 1-year follow-up showed vital natural teeth with physiological clinical and radiologic parameters. CONCLUSIONS This innovative approach uses the latest diagnostic methods and techniques of guided implant surgery, enabling the planning and production of 3D printed surgical templates. These accurate virtually predesigned surgical templates could facilitate autotransplantation in the future by full implementation of recommended guidelines, ensuring an atraumatic surgical protocol.

Morphometric characteristics of cortical and trabecular bone in atrophic edentulous mandibles

OBJECTIVES Adaptations of the alveolar ridge after tooth loss have been well described. However, studies on the morphometric characteristics of cortical bone are rare; hence, this study of human atrophic edentulous mandibles was undertaken. MATERIAL AND METHODS Total cortical area, porosity, and thickness, and the percentage of cortical area in the complete mandibular area as well as in an area (height, 10 mm) starting at the most caudal point of the trabecular compartment and extending in the coronal direction were determined in 185 thin ground sections of edentulous mandibles (incisor region, 49; premolar region, 76; molar region, 60; 95 from females and 90 from males; mean age, 78.2 years, SD ± 7.8 years; Caucasian donors; cause of death: cardiovascular disease). Further, mandibular height and width and degree of residual ridge resorption (RRR) were recorded. RESULTS The percentage of cortical area in the complete mandibular area increased with increasing RRR. Yet, evaluation of the 10-mm caudal portion corresponding to the basal part of the mandibular body did not confirm these changes in cortical bone. Cortical porosity and thickness decreased from the mesial to the distal region. Cortical porosity was unaffected by RRR, while cortical thickness increased, mainly at lingual aspects. CONCLUSIONS In conclusion, cortical bone remained stable in different degrees of RRR except for some modulations in the lingual aspects. Changes in the relative composition between cortical and trabecular bone are due to loss of height and total area, mainly at expense of trabecular bone area, but not to adaptations of the cortical bone.

Relative Composition of Fibrous Connective and Fatty/Glandular Tissue in Connective Tissue Grafts Depends on the Harvesting Technique but not the Donor Site of the Hard Palate

BACKGROUND Whether the composition of palatal connective tissue grafts (CTGs) varies depending on donor site or harvesting technique in terms of relative amounts of fibrous connective tissue (CT) and fatty/glandular tissue (FGT) is currently unknown and is histologically assessed in the present study. METHODS In 10 fresh human cadavers, tissue samples were harvested in the anterior and posterior palate and in areas close to (marginal) and distant from (apical) the mucosal margin. Mucosal thickness, lamina propria thickness (defined as the extent of subepithelial portion of the biopsy containing ≤25% or ≤50% FGT), and proportions of CT and FGT were semi-automatically estimated for the entire mucosa and for CTGs virtually harvested by split-flap (SF) preparation minimum 1 mm deep or after deepithelialization (DE). RESULTS Palatal mucosal thickness, ranging from 2.35 to 6.89 mm, and histologic composition showed high interindividual variability. Lamina propria thickness (P >0.21) and proportions of CT (P = 0.48) and FGT (P = 0.15) did not differ significantly among the donor sites (anterior, posterior, marginal, apical). However, thicker palatal tissue was associated with higher FGT content (P <0.01) and thinner lamina propria (P ≤0.03). Independent of the donor site, DE-harvested CTG contained a significantly higher proportion of CT and a lower proportion of FGT than an SF-harvested CTG (P <0.04). CONCLUSION Despite high interindividual variability in terms of relative tissue composition in the hard palate, DE-harvested CTG contains much larger amounts of CT and much lower amounts of FGT than SF-harvested CTG, irrespective of the harvesting site.