Maxillary sinus vascular anatomy and its relation to sinus lift surgery.

OBJECTIVES: To investigate the prevalence, location, size and course of the anastomosis between the dental branch of the posterior superior alveolar artery (PSAA), known as alveolar antral artery (AAA), and the infraorbital artery (IOA). MATERIAL AND METHODS: The first part of the study was performed on 30 maxillary sinuses deriving from 15 human cadaver heads. In order to visualize such anastomosis, the vascular network afferent to the sinus was injected with liquid latex mixed with green India ink through the external carotid artery. The second part of the study consisted of 100 CT scans from patients scheduled for sinus lift surgery. RESULTS: An anastomosis between the AAA and the IOA was found by dissection in the context of the sinus anterolateral wall in 100% of cases, while a well-defined bony canal was detected radiographically in 94 out of 200 sinuses (47% of cases). The mean vertical distance from the lowest point of this bony canal to the alveolar crest was 11.25 ± 2.99 mm (SD) in maxillae examined by CT. The canal diameter was <1 mm in 55.3% of cases, 1-2 mm in 40.4% of cases and 2-3 mm in 4.3% of cases. In 100% of cases, the AAA was found to be partially intra-osseous, that is between the Schneiderian membrane and the lateral bony wall of the sinus, in the area selected for sinus antrostomy. CONCLUSIONS: A sound knowledge of the maxillary sinus vascular anatomy and its careful analysis by CT scan is essential to prevent complications during surgical interventions involving this region.

Trends in matrix metalloproteinase research from 1986-2007: a bibliometric study.

Using the SCI-expanded database, this study provides a quantitative description of the development of the research involving matrix metalloproteinase (MMP) over a period of 20 years. From 1986 to 2007 the scientific literature related to MMP increased sevenfold (397 papers in 1986-1987 and 2834 in 2006-2007). The number of countries participating in MMP-related research doubled during this period (33 in 1986-1987 to 67 in 2006-2007), and the USA continually remained the leader. Several industrialized nations (Japan, Germany, UK, Canada, and France) also continuously played important roles, with some emerging Asian countries joining the top 10 most productive countries in 2006-2007: China (ranked 5th), South Korea (6th), and Taiwan (10th). The MMP-related literature was distributed among a continuously growing number of journals (188 in 1986-1987, 527 in 1996-1997, and 913 in 2006-2007) and The Journal of Biological Chemistry remained the most prolific throughout the entire period. The development of the research involving MMPs during the past two decades was also characterized by a progressive transfer of interest from basic research to clinical medicine; cell biology and pharmacology were important routes of investigation generally pursued by researchers. Journals dedicated to oncology have progressively risen to the top 8 most prolific journals during the 20 year period analyzed.

Maxillary sinus septa: a cadaveric study.

PURPOSE: The goal of this study was to investigate the incidence, location, and height of antral septa and to offer the clinician, through an accurate investigation of the anatomy of the maxillary sinus region, the tools to carry out sinus-lift procedures under safe conditions. MATERIALS AND METHODS: The study consisted of 60 sinuses from 30 human cadavers with an age range of 59 to 90 years. Only septa measuring 3.0 mm or greater in height were considered in our analysis. RESULTS: A total of 20 incomplete septa were found, showing an incidence of 33.3%, and no more than 1 septum per sinus was identified. All septa were located in the anterior-lateral wall and were either sagittal or transversal. Of the septa, 6 (30%) were located in the anterior region of the antral wall (between the second premolar and first molar roots), 8 (40%) were in the middle region (between the first and second molar roots), and 6 (30%) were in the posterior region (distal to the third molar roots). Antral septa height showed great variability, with a mean value of 8.72 mm (SD, 4.26; range, 3.7-18.4 mm). Our study also showed that 40% of our specimens (12 of 30 maxillas) have bony septa that can partially divide the sinus, and they were symmetric in 8 of 12 cases. CONCLUSIONS: A sound knowledge of the maxillary sinus anatomy and of the possible anatomic variations is essential to prevent complications during surgical interventions involving this region.

Evolution of the scientific literature on pain from 1976 to 2007.

OBJECTIVE: This study traces the evolution of the scientific literature on pain published during the last 30+ years (1976-2007). METHODS: Using the Web of Science, pain-focused journal articles from the Science Citation Index Expanded published in 1977, 1987, 1997, and 2007 were retrieved and analyzed. RESULTS: The number of pain-related publications rose from 1,562 articles for 1976-77 to 9,159 PubMed for 2006-2007, with slow growth for the period 1976-1995, and rapid increases from 1995-2007. The analysis of contributing countries showed two major players, the United States and the UK; the doubling of the number of countries involved in pain research from 40 in 1977 to 82 in 2007; and the appearance in 2007 of The Netherlands, Turkey, China, and Brazil among the top-15 most prolific contributors. During the 30-year period, the number of journals publishing pain-related research increased nearly 2.5-fold (363 journals in 1977 vs 972 in 2007), including 14 new, international pain-focused journals since 2000. Additionally, while there were only two pain journals (Pain and Headache) in 1977, 15 pain-focused journals were indexed in 2007 with the result that 17 of the top-20 pain-focused journals in 2007 did not exist in 1977. CONCLUSION: The rapid evolution and explosion of pain research in the last 30+ years was reflected in substantial changes in the landscape of the contributing countries and in the scientific journals targeted by pain researchers.

Anatomic assessment of the anterior mandible and relative hemorrhage risk in implant dentistry: a cadaveric study.

OBJECTIVES: To evaluate prevalence, size, location and content of foramina and bony canals located on the lingual side of the mandibular midline. MATERIAL AND METHODS: The prevalence and the size of midline lingual foramina and canals visible above and/or below genial spines and their distances from the mandibular base were measured in 60 dry mandibles from adult human cadavers. In addition, macro-anatomic dissections were performed on another 20 mandibles injected with red latex to investigate the vascular canal contents associated with these midline lingual foramina and canals. RESULTS: A total of 118 foramina were detected. All mandibles investigated had at least one lingual foramen at the midline above the genial spines, located at a mean height of 12.5+/-2.1 mm (SD) from the inferior border of the mandible. Macro-anatomic dissections showed a clear vascular branch entering the mandibular midline as a single vessel from a sublingual-sublingual anastomosis in 19 out of 20 mandibles studied (95%). CONCLUSION: Blood vessels in the floor of the mouth may be in close proximity to the lingual cortical plate of the mandibular midline in most cases. This implies that bleeding can occur when the mandibular cortical plate is perforated even minimally. As a consequence, the authors suggest a careful planning of implant positioning at mandibular midline, possibly opting for the use of an even number of implants in the interforaminal region, avoiding the risk of surgical trauma to the lingual cortical plate of the mandibular midline.

Maxillary sinus vascularization: a cadaveric study.

The goal of this study was the investigation of the arterial blood supply to the maxillary sinus to give clinicians the basis for a better understanding of the origin of vascular complications that can derive from surgical procedures at this level. The study consisted of 30 sinuses from 15 human cadavers with an age range of 59 to 90 years. To define the complex vascularization of the maxillary sinus, the afferent vascular network was injected with liquid latex mixed with red india ink through the external carotid arteries. An intraosseous anastomosis between the dental branch of the posterior superior alveolar artery, also known as alveolar antral artery, and the infraorbital artery was found in 100% of cases. Such an anastomosis seemed to guarantee the blood supply to the sinus membrane, to the periosteal tissues, and especially to the anterior lateral wall of the sinus. Moreover, the gingival branch of the posterior superior alveolar artery was found to anastomose an extraosseous branch of the infraorbital artery in 10 sinuses. The examination of the maxillary sinus also showed a close anatomic relationship among the sinus posterior wall, the descending palatine artery, and the sphenopalatine artery in all 30 sinuses. Small branches deriving from the posterior lateral nasal arteries have been found to perforate the nasal wall laterally and reach the mucosa of the maxillary sinus. A sound knowledge of the maxillary sinus vascularization is essential to prevent vascular complications during surgical operations involving this region.

Quantitative analysis of the scientific literature on acetaminophen in medicine and biology: a 2003-2005 study.

This study quantifies the utilization of acetaminophen in life sciences and clinical medicine using bibliometric indicators. A total of 1626 documents involving acetaminophen published by 74 countries during 2003-2005 in the Thompson-Scientific Life sciences and Clinical Medicine collections were identified and analyzed. The USA leads in the number of publications followed by the UK, and industrialized countries, including France, Japan and Germany; the presence of countries such as China, India and Turkey among the top 15 countries deserves to be noticed. The European Union stands as a comparable contributor to the USA, both in terms of number of publications and in terms of profile of papers distributed among subcategories of Life Sciences and Clinical Medicine disciplines. All documents were published in 539 different journals. The most prolific journals were related to pharmacology and/or pharmaceutics. All aspects of acetaminophen (chemistry, pharmacokinetics, metabolism, etc.) were studied with primary interest for therapeutic use (42%) and adverse effects (28%) comprising a large part of publications focusing on acetaminophen hepatotoxicity. This quantitative overview provides as to the interest of the scientific community in this analgesic and completes the various review documents that regularly appear in the scientific literature.

A study of the vascularization of the auricle by dissection and diaphanization.

The vascularization of the auricle is poorly documented, despite the developments in auriculotherapy and reconstructive surgery. The aim of this study was to describe its arterial distribution using two techniques: diaphanization and anatomical dissection. The study was conducted after intravascular injection of eight diaphanized auricles and ten that were dissected. Dissection showed that the auricle is vascularized by an anterior flow arising in the superficial temporal artery and also by a posterior flow arising in the posterior auricular artery in eight cases out of ten, and in the occipital artery in the remaining two. Diaphanization revealed the three-dimensional arterial distribution of preserved specimens. This technique has a didactic use to complement to standard anatomical dissection.

World orofacial pain research production: a bibliometric study (2004-2005).

AIMS: To provide a snapshot of the scientific literature on orofacial pain. METHODS: The authors identified 975 papers related to orofacial pain in the Current Contents Life Sciences and Clinical Medicine collections of the Thomson Scientific database that were published during 2004 and 2005 and analyzed them using bibliometric indicators. RESULTS: Among the 54 countries involved, the United States ranks first by number of papers (293), followed by Japan (107), and the United Kingdom (90). The high volume of research activity in some Northern European countries is highlighted, along with that of the European Union (384 papers). The scientific literature on orofacial pain was published in 247 journals; 13 of the top 15 most prolific journals for articles on orofacial pain were found in the Dentistry, Oral Surgery and Medicine subdiscipline of Current Contents/Clinical Medicine, and the Journal of Orofacial Pain was the highest ranked for such articles. CONCLUSION: This study complements subject reviews of orofacial pain research and provides a more complete picture of the research activity in this field.

[Vascular anatomy of the mandibular symphysis and possible complications in oral surgery]. / Anatomie vasculaire de la symphyse de la mandibule et complications potentielles en chirurgie orale.

Surgical procedures carried out between the chin foramina at the anterior mandible level are usually considered free of severe neurovascular complications, due to the excellent bone density in that region and the absence of important neurovascular structures. However, the international scientific literature on this issue reports rare but severe hemorrhagic complications following implant surgery at this level. The aim of this review article is to offer the clinician, through an accurate investigation of the anatomy of the median mandibular region, the tools to carry out oral surgery operations at this level under safe conditions, reducing the possible intraoperative risks to a minimum.

Labiomandibular paresthesia caused by endodontic treatment: an anatomic and clinical study.

Labiomandibular paresthesia after root canal treatment is an accident that is still too frequent despite the development of new endodontic techniques. The aim of this anatomical and clinical study is to advance the understanding of how accidents occur so as to avoid them. This anatomical study made it possible to determine the variability of proximity of the apex of the tooth root to the mandibular bundle, as well as the relationship between the nerve and its satellite artery, and to understand how endodontic filling material spreads into the cancellous bone. The clinical study, which included examination with conventional radiology as well as with imaging techniques, enabled us to identify the exact location of the filling material in relation to the mandibular bundle and to correlate this to the occurrence of clinical symptoms and their diverse manifestations.

Functional fixation of autotransplanted tooth germs by using bioresorbable membranes.

OBJECTIVE: The purpose of this study was to evaluate the contribution of a bioresorbable membrane placement to the healing of immature teeth after autotransplantation of tooth buds. STUDY DESIGN: Six cases were selected: 2 transplantations of wisdom teeth, 2 for premolar agenesis, 1 for ectopia, and 1 premolar in an incisor position. The crown of each tooth germ and the marginal alveolar bone were covered with a resorbable membrane. RESULTS: The radicular edification was nearly complete, neither ankylosis nor inflammatory resorption was observable, the pulp vitality was preserved, and the periodontal integration was identical to that of other teeth. The membrane ensured contention and stabilization of the transplant, allowed functional stimulation, permitted protection of the coagulum and periodontal cells, and kept the epithelium at a distance. CONCLUSIONS: The transplantations of immature teeth were improved by the use of a resorbable membrane, which caused an optimal functional fixation of the transplanted tooth.

Monitoring anesthesia using neural networks: a survey.

New methods of data processing combined with advances in computer technology have revolutionized monitoring of patients under anesthesia. The development of systems based on analysis of brain electrical activity (EEG or evoked potentials) by neural networks has provided impetus to many investigators. Though not claiming to be the end-all in patient monitoring, the potential and efficiency of the combination does indeed stand out. Various strategies are presented and discussed, as well as suggestions for further investigation.

Application of a 3-dimensional measurement system to complete denture impressions.

STATEMENT OF PROBLEM: Little is known about tissue displacement at the tissue/denture base interface during impression making. PURPOSE: This study used a new 3-dimensional measurement system to analyze and compare 2 complete denture reline impression techniques (1 occluding and 1 digital) to determine which resulted in less displacement of the tissue/denture base interface during impression making. MATERIAL AND METHODS: The experiment included 10 completely edentulous subjects. For each subject, 3 mandibular casts were obtained: (1) a reference cast of the existing denture base, (2) a cast made with an occluding reline impression technique, and (3) a cast made with a digital reline impression technique. With the use of an optical 3-dimensional measurement system, the corresponding casts in a common coordinate system were analyzed geometrically. For each cast, the coordinates of the barycentric point and the high point were determined. For the same subject, the differences between the coordinates of the barycentric points of the 3 casts were calculated 2-by-2. The same calculation was performed for the high points. To determine whether these differences, which represent the displacements of the barycentric points and the high points, were statistically significant, the Wilcoxon signed-rank test for paired group comparisons was applied (P<.05). Cartographic differences among the casts from the same subject also were compared. RESULTS: The uncertainty of measurement for the location of the barycentric and highest point was +/-57 microm. The uncertainty in the differences among the cartographic displays was +/-0.1 mm. Vertically, the mean distance that separated the barycentric points obtained with the 2 impression methods was 0.04 mm. Cartography data showed that the greatest dimensional differences between the 2 impression techniques (minimum 0.25 mm; maximum 1.5 mm) were located near the retromolar pad and along the lingual flange. CONCLUSION: Within the limitations of this 3-dimensional in vivo study, displacement of the tissue/denture base interface was essentially equivalent with the use of an occluding and a digital mandibular impression technique.

Electroencephalogram processing using neural networks.

The electroencephalogram (EEG), a highly complex signal, is one of the most common sources of information used to study brain function and neurological disorders. More than 100 current neural network applications dedicated to EEG processing are presented. Works are categorized according to their objective (sleep analysis, monitoring anesthesia depth, brain-computer interface, EEG artifact detection, EEG source-based localization, etc.). Each application involves a specific approach (long-term analysis or short-term EEG segment analysis, real-time or time delayed processing, single or multiple EEG-channel analysis, etc.), for which neural networks were generally successful. The promising performances observed are demonstrative of the efficiency and efficacy of systems developed. This review can aid researchers, clinicians and implementors to understand up-to-date interest in neural network tools for EEG processing. The extended bibliography provides a database to assist in possible new concepts and idea development.