After cleaning and shaping of the root canal the final objective of the endodontic procedure is to obtain a three-dimensional obturation of the root canal space with a fluid-tight seal at the apical foramen. The objective of this in vitro study was to evaluate four different obturation techniques in respect of: • the radiographic quality of root canal obturation, • apical leakage and • the potential of these techniques to obdurate lateral canals One hundred and sixty canals were prepared by using RaCe nickel titanium rotary files to a size 30 with 6% taper. During preparation irrigation was done with TopClear Solution (17% EDTA and 0.2% cetremide) and ChlorXTRA (6% sodium hypochlorite). The canals were divided in four groups of forty canals each and were obturated using the Hybrid Root SEAL technique, the EndoREZ technique, the System B/Obtura technique and the Thermafil technique. The Radiographic Quality of Root Canal Obturation: Digital radiographs were taken of the four groups of obturated canals from a buccolingual and a mesiodistal direction. The quality of obturation was determined for the coronal and apical halves of each canal and scored according to radiographic appearances. The data was tabulated and statistically analyzed using the Mann- Whitney U test. The Hybrid Root SEAL technique demonstrated a statistically significant higher number of radiographic defects in the coronal aspects of the root canals when compared to the System B/Obtura and Thermafil techniques (p<0.05). There was no statistically significant difference between the radiographic defects in the coronal aspects of the root canals between Hybrid Root SEAL and EndoREZ techniques (p>0.05). The Hybrid Root SEAL technique demonstrated a statistically significantly higher number of radiographic defects in the apical aspects of the root canals compared to all the other groups (p<0.05). Apical Leakage: Twenty obturated canals of each of the four groups were processed for evaluation of apical leakage. The root surfaces were coated with nail varnish and sticky wax, leaving 4.0 mm around the apical foramen exposed. Specimens were immersed in 2% methylene blue dye for 48 hours, rinsed in distilled water and embedded in clear acrylic resin. Specimens were sectioned horizontally in 1 mm increments and the extent of dye penetration was measured to the nearest millimeter using a stereomicroscope. The data was tabulated and statistically analyzed using the Man-Whitney U test. The specimens that were obturated with the EndoREZ technique demonstrated the least apical leakage compared to all the other groups tested in this study. However, there was only a statistically significant difference when the EndoREZ technique was compared to the Hybrid Root SEAL and System B/Obtura techniques (p<0.05). The specimens that were obturated with the System B/Obtura technique demonstrated the most apical leakage compared to all the other groups tested in this study. However, there was only a statistically significant difference when the System B/Obtura technique was compared to the EndoREZ and Thermafil techniques (p<0.05). The Potential to Seal Lateral Canals: Twenty obturated canals of each of the four groups were processed for evaluation of the potential to seal lateral canals. The specimens were subjected to a clearing technique and a morphological analysis was performed using a stereomicroscope. Lateral canals were counted and graded within the coronal, middle and apical thirds of the roots. The data was tabulated and statistically analyzed using the Man-Whitney U test. The Thermafil technique demonstrated the greatest number of filled lateral canals. However, there was no statistically significant difference between the Thermafil technique and all the other techniques (p<0.05). / Dissertation (MSc)--University of Pretoria, 2009. / Odontology / unrestricted

The retromolar foramen represents a little known anatomical variation in the posterior mandible of uncertain clinical importance. It has been the subject of limited study. Findings and conclusions of these studies have been placed under little scrutiny. Suggested clinical consequences associated with the presence of the retromolar foramen include local anaesthetic failure, local haemorrhage during surgery, perineural spread of infectious and invasive pathology, and loss of sensation in the normal distribution of the buccal nerve due to surgical intervention. Reports of the possibility of these complications seem to suggest that the retromolar foramen, canal and its associated neurovascular bundle are structures of great clinical importance. Case reports seem to have, however, only included reports of loss of gingival and buccal sensation as a consequence of third molar surgery in the presence of this anomaly. This study therefore aimed to report the prevalence of the retromolar foramen and canal in the South African population, describe its course and structure, and produce a clinical framework in which to approach the presence of the retromolar foramen. Comparisons between the present and existing studies were made and conclusions concerning the clinical importance of this structure were drawn. Inspection of a sample containing 946 mandibles was performed. Of these, 885 were regarded as suitable for inclusion. These mandibles were inspected for the presence of a retromolar foramen in which a 1 mm diameter needle could pass through without resistance. The distance from the last tooth in the arch to the retromolar foramen was also measured. Fifty of these mandibles were then randomly selected and scanned using microfocus computed tomography. Seventy mandibles were found to have at least one retromolar foramen (7.9% of the total sample). No statistically significant differences were found when the presence of the retromolar foramen was correlated with race, sex or age. The finding that sex and age played no significant role in the presence of the retromolar foramen is in agreement with available literature. Detected prevalence seemed to be heavily influenced by the method used to determine the presence of the retromolar foramen. The average distance between the second mandibular molar and the retromolar foramen was 16.83 ± 5.57 mm and the average distance between the third mandibular molar and the retromolar foramen was 10.47 ± 3.77 mm. These findings were found to be in agreement with most other reports. Fifty retromolar canals were selected at random and scanned using microfocus computed tomography. Analysis revealed four basic patterns. These were type A, a vertical canal between the inferior alveolar canal and the retromolar area of the mandible, type B, a curved canal taking a recurrent course between the inferior alveolar canal and the retromolar area, type C, a canal with an approximately horizontal path between the inferior alveolar canal and the retromolar area, and the temporal crest canal (TCC, not designated as type D to create a distinction between it and types A, B and C), a canal terminating on either side of the temporal crest. Type B was the most common presentation (68% of retromolar canals in the study), a finding contrary to that of other studies. The presence of the retromolar neurovascular bundle is of uncertain clinical importance and requires further anatomical and pharmacological study to determine its effect on local anaesthetic failure. A model in which the retromolar canal branches from the inferior alveolar canal does not seem to support a conclusion in which local anaesthetic failure may be directly attributable the presence of this anatomical variation alone. Classification of the retromolar canal is of limited clinical use and may require a revised scheme if clinical application is sought. Complications associated with the presence of the retromolar foramen are poorly documented and seem to be of little consequence. / Dissertation (MSc)--University of Pretoria, 2014. / tm2015 / Anatomy / MSc / Unrestricted

No description available.

Introduction: The mental nerve, a branch of the trigeminal nerve’s mandibular division provides sensory innervation to the lower lip, dentition, gingiva, and mucosa. Knowing the exact location of the mental foramen along with its accompanying structures including possible accessory foramina, and the anterior loop is crucial for avoiding surgical complications. Advancements in Cone Beam Computed Tomography (CBCT) have provided unparalleled insights into these anatomical structures. This study uses the CBCT modality to investigate the anatomical variations of the mental foramen and anterior loop within a United States dental school patient population, aiming to improve surgical outcomes and patient safety. Materials and Methods: A retrospective cross-sectional analysis was conducted on 1,006 CBCT scans from patients at Temple University's Dental School between January 2020 and July 2022. Inclusion criteria encompassed patients aged 18 years and above who underwent pre-operative CBCT scans, with exclusions for maxillary-only scans and images lacking crucial mandibular structures. A total of 558 scans met these criteria and were analyzed. Data collected included patient demographics noting the location of the mental foramen, presence of accessory foramina, presence of the anterior loop and the length of the anterior loop for both the right and left side of the mandible. Results: The total number of scans included in the study was 558. The mean age of the patients from whom the data was collected was 54.95. Of the total subjects 185 were older than 50, and 373 were younger than 50 years of age. 311 of the subjects were female and 247 were male. The race distribution is as follows: 263 Caucasians, 170 African Americans, 72 Hispanics, and 53 Asians. As for the dentition status: 454 individuals had partial dentition, 79 had complete dentition, and 25 were edentulous. The study revealed a 0.05% occurrence of accessory mental foramina and a predominant location of the mental foramen apical to the second premolar, consistent across racial groups but not significantly influenced by age or gender. The anterior loop was present in 56.5% of scans, with an average length of 3.3 mm. Notably, the distance between the anterior loop and the mental foramen correlated significantly, suggesting potential surgical implications. Discussion: The findings highlight significant anatomical variability, challenging the reliability of traditional anatomical landmarks in surgical planning. The presence of the anterior loop and its variable length underscores the importance of individualized CBCT analysis before dental implant placement. Search for comparison within existing literature indicates a lower prevalence of accessory mental foramina in our study, suggesting population-specific anatomical variations. Conclusion: This study underscores the critical role of CBCT in identifying the anatomical nuances of the mental foramen and anterior loop, advocating for its routine use in pre-surgical planning for dental implants. The variability observed in these structures, even within the same patient, emphasizes the need for personalized surgical approaches to mitigate risks and enhance patient care. Future research should aim to expand the sample size and diversity to validate these findings further and explore their clinical implications. / Oral Biology

The purpose of this study was to use existing Cone Beam Computer Tomography images to determine the vertical and horizontal location of the mental foramen in relation to the mandibular first and second premolars, as well as the distance in millimeters from the apex of each. The distance from the inferior border of the foramen to the inferior border of the mandible was also recorded. The average distance from the apices of the mandibular first and second premolars to the mental foramen was 7.43mm (SD= 1.97) and 5.30mm (SD=1.65) respectively. The foramen was located 11.44mm (SD=1.49) from the inferior border of the mandible. The foramen was in line with the apex of the mandibular second premolar 41% of the time. The mental foramen was further away from the inferior border of the mandible in males and older patients. Mental foramina seemed to be positioned more apically and distally in older patients.

Este estudo objetivou avaliar a influência do diâmetro do forame e do instrumento endodôntico na leitura odontométrica de dois aparelhos localizadores apicais eletrônicos. Foram utilizados 40 dentes incisivos inferiores, divididos em 4 grupos, de acordo com o diâmetro do forame apical (100, 200, 300 e 400 µm). Após a abertura coronária desses dentes e o acesso aos canais radiculares, realizou-se a medição do comprimento dos mesmos com auxílio de um microscópio clínico com ampliação de 7,8X, da incisal até que a ponta da lima surgisse no forame apical. Os dentes foram colocados em potes individuais contendo solução de ágar a 1% em solução salina de fosfato tamponado, mantendo-se cerca de 2/3 de suas raízes imersas na solução para que pudesse ser feita a leitura com o Root ZX® (J.Morita, Japão) e o NovApex® (Fórum, Israel). Os mesmos foram medidos com limas nº10 até que a distância de 0,5 mm do ápice fosse acusada no display dos aparelhos. Uma outra medida foi realizada nos dentes utilizando-se lima nº10 e limas com diâmetros correspondentes ao diâmetro dos forames (200µm, 300µm e 400µm). Para a análise estatística foi empregado o teste de Análise de Variância a dois critérios para o confronto global entre os aparelhos e o emprego da lima nº10 em todos os dentes e teste de Tukey para as comparações individuais. Os resultados demonstraram diferença estatística na precisão dos dois aparelhos com um resultado mais preciso para o Root ZX® (p<0,05). Dentes com forame, de menor diâmetro, apresentaram uma medida mais precisa com o localizador apical e dentes com forame de maior diâmetro apresentaram uma maior discrepância na medida. O emprego de limas tipo K nº10 nos dentes com forames de diâmetros maiores apresentaram maior precisão na medição quando comparadas às limas coincidentes aos diâmetros dos forames para o aparelho Root ZX®. Para o NovApex® esta correlação só passou a ocorrer a partir da lima nº40. / This study evaluated the influence of foramen diameter and endodontic instrument size on the odontometry reading of two electronic apical measuring devices. Forty mandibular incisors were used, which were divided into four groups according to the apical foramen diameter (100, 200, 300 and 400µm). After coronal opening of these teeth and access to the root canals, the root canal length was measured with aid of a clinical microscope with 7.8x magnification, from the incisal edge until the file tip reached the apical foramen. Ten teeth with 100-µm diameter were placed in individual jars containing 1% agar solution in phosphate-buffered saline, maintaining around 2/3 of their roots immersed in the solution to allow measurement with Root ZX (J. Morita, Japan) and NovApex (Forum, Israel). Teeth were measured with files n. 10 until the distance of 0.5mm from the apex was indicated by the device. Another measurement was performed on the other thirty teeth with files n. 10 and files with diameters corresponding to the foramen diameters (200µm, 300µm and 400µm). Statistical analysis was performed by two-way analysis of variance for overall comparison between the devices and employment of file n. 10 in all teeth, and Tukey test for individual comparisons. The results demonstrated statistical difference in the precision of both devices, with a more accurate result for Root ZX (p<0.05). Teeth with narrower foramina presented a more accurate measurement with the apical measuring device, and teeth with wider foramina presented larger discrepancy in the measurement. Utilization of K file n. 10 in teeth with wider foramina showed more accurate measurements compared to files with size corresponding to the foramen diameters with the Root ZX® device. With the NovApex® device, this correlation was only observed with file n. 40.

De nouvelles approches quantitatives ou fonctionnelles d'imagerie de la BPCO (bronchopneumopathie chronique obstructive) sont possibles en scanner à 64 coupes par rotation. Elles impliquent l'utilisation de logiciels dédiés, permettant la quantification de l'emphysème ou la détection de shunts via le foramen ovale, plus fréquents dans la BPCO, par analyse des courbes de rehaussement auriculaire gauche.<br />Une autre approche est d'utiliser la synchronisation cardiaque, pour évaluer les structures d'intérêt à différentes phases du cycle cardiaque, ce qui donne une information fonctionnelle utile pour la détection de l'hypertension artérielle pulmonaire (HTAP) de la BPCO.<br />Le but de ce travail, organisé en 3 parties, a été d'évaluer la faisabilité et les performances diagnostiques obtenues avec ces nouvelles applications.<br />1- Quantification des volumes pulmonaires et du pourcentage d'emphysème<br />Nous avons évalué un logiciel protoytpe (Mevis Pulmo) qui permet un calcul des volumes pulmonaires et une quantification de l'emphysème, après segmentation pulmonaire et seuillage des densités. Les résultats peuvent être obtenus de façon globale, individuellement pour chaque poumon et séparément pour chacun des 5 lobes. Les limites anatomiques lobaires sont reconnues de façon automatique (quantification automatique) mais elles peuvent être corrigées si nécessaire (quantification semi-automatique).<br />Nous avons comparé quantification automatique, semi-automatique et visuelle selon un score classique en 5 grades, chez 47 patients présentant une BPCO sévère. Ces patients étaient évalués avant éventuelle réduction endoscopique, par un scanner sans injection en inspiration et expiration.<br />Il n'y a pas de différence significative du pourcentage d'emphysème estimé par quantification automatique et semi automatique (p>0.05 dans les 5 lobes). Les coefficients de corrélation intraclasse sont supérieurs à 0.8 (concordance excellente) sauf pour le lobe supérieur droit (0.68, bonne concordance) et le lobe moyen (0.53, concordance moyenne). La concordance avec le score visuel est bonne (kappa: 0.76; IC 95% 0.58 à 0.94).<br />Le logiciel utilisé permet également d'évaluer les volumes pulmonaires en inspiration et expiration et de les comparer aux volumes de référence en pléthysmographie. Le volume tomodensitométrique (TDM) inspiratoire est corrélé à la capacité pulmonaire totale (CPT) en pléthysmographie (r= 0.8, p< 0.0001) ; la différence moyenne est de -7.7% (valeurs extrêmes: -48.8 à 28.2%). Le volume TDM expiratoire est corrélé au volume résiduel (VR) (r=0.79, p< 0.0001) ; la différence moyenne est de 9.7% (valeurs extrêmes: - 17.9 à 43.3%). Le volume TDM expiratoire est également corrélé au Volume expiratoire maximal en 1 seconde (VEMS) (r=-55, p<0.0001). Le pourcentage d'emphysème est corrélé aux volumes TDM inspiratoire et expiratoire (r= 0.56 et 0.53, p< 0.0001) et au VEMS (r= -0.69, p<0.0001).<br />Le logiciel testé permet donc une quantification lobaire automatique fiable de l'emphysème et une mesure des volumes pulmonaires en TDM pertinente pour évaluer fonctionnellement la sévérité de la BPCO.<br />2- Détection de la perméabilité du foramen ovale en scanner 64 coupes non synchronisé<br />Cette étude a été menée prospectivement chez 105 patients évalués en échographie transoesophagienne (ETO) pour rechercher un foramen ovale perméable et qui donnaient leur consentement pour une exploration tomodensitométrique réalisée le même jour. Après injection de contraste au cours d'une manoeuvre de Valsalva, une acquisition couvrant toute la largeur du détecteur (28.8 mm) était centrée sur la fosse ovale, en continu toutes les 0.5 secondes pendant 7 secondes. Les 128 images résultantes ont été analysées visuellement, à la recherche d'une opacification auriculaire gauche précédant le retour veineux pulmonaire. Les courbes de rehaussement auriculaire gauche (Logiciel DynEva) ont été analysées à la recherche d'un pic précoce de rehaussement.<br />La perméabilité du foramen ovale est détectée avec une sensibilité globale de 55% (IC 95%, 0.38 - 0.70) et une spécificité de 98% (IC 95%, 0.91 - 0.99). Les performances dépendent du grade du shunt en ETO, utilisé comme gold standard. La sensibilité varie entre 28% pour les shunts de grade 1 et 91% pour les shunts de grade 4. L'analyse des courbes de rehaussement n'augmente pas la sensibilité du scanner. La dose moyenne requise est de 2.3 mSv.<br />Ces résultats permettent d'envisager d'associer la recherche de shunts de haut grade via le foramen ovale à l'analyse tomodensitométrique du parenchyme pulmonaire, dans des contextes d'hypoxémie inexpliquée ou paradoxale,<br />3- Proposition de nouveaux critères prédictifs d'HTAP en scanner multi coupes synchronisé<br />La synchronisation à l'ECG permet d'étudier des paramètres tels que la distensibilité artérielle pulmonaire, l'épaisseur du myocarde infundibulaire et les variations en systole et diastole des mensurations infundibulaires.<br />Ces paramètres ont été analysés dans 2 groupes de patients (groupe 1, 21 patients avec HTAP; groupe 2, 24 patients sans HATP) évalués par cathétérisme cardiaque droit dans le cadre de leur prise en charge clinique. Les données brutes des examens tomodensitométriques (TDM) ont été reconstruites en coupes de 1mm d'épaisseur jointives, tous les 10% du cycle cardiaque.<br />La distensibilité de l'artère pulmonaire droite est calculée à partir de mesures de la surface de section de l'artère, effectuées tous les 10% de l'intervalle R-R. A partir des 10 valeurs obtenues, la valeur maximale de surface de section (SSmax) et la valeur minimale (SSmin) sont repérées. La distensibilité est calculée par l'équation suivante : (SSmax-SSmin)/SSmax.<br />La distensibilité est également calculée selon une méthode simplifiée à partir de deux mesures l'une à 20% du R-R, l'autre à 80%. Ces fenêtres temporelles ont été identifiées comme celles où les valeurs extrêmes de surface de section sont observées dans les deux groupes de patients. L'épaisseur myocardique, le diamètre antéropostérieur et la surface de section infundibulaires sont mesurés en systole et diastole à 30% et 90% du R-R, 1 cm au dessous de la valve pulmonaire. Les mesures de ces paramètres montrent une bonne concordance inter observateur, à l'exception de l'épaisseur systolique infundibulaire. Les valeurs médianes sont significativement différentes pour les deux groupes de patients, à l'exception des dimensions diastoliques infundibulaires. La distensibilité artérielle pulmonaire est le paramètre pour lequel l'aire sous la courbe ROC est la plus large (0.951 ; IC 95%, 0.894 - 1) et qui apparaît le mieux corrélé à la pression artérielle pulmonaire (r=-073, p<0.0001).<br />La distensibilité calculée selon la méthode simplifiée a les mêmes performances. Ce paramètre pourrait être évalué en routine pour détecter l'HTAP chez les patients présentant une BPCO, afin de restreindre les indications de cathétérisme cardiaque droit, méthode d'exploration invasive.

Biometrische und funktionsanalytische Röntgenuntersuchungen des Kopf-Hals-Überganges von in dieser Region nicht erkrankten Hunden der Rasse Deutscher Schäferhund sowie verschiedener Zwergrassen werden verglichen. Für die Morphologischen Untersuchungen werden standardisiert gelagerte Röntgenaufnahmen von 129 anästhesierten Hunden angefertigt und die Parameter Atlaslänge, Axislänge (ohne Dens), Denslänge, Länge von C3 sowie Breite und Höhe des Foramen magnum vermessen. Die zur Länge von C3 ins Verhältnis gesetzten Längenparameter ergeben für Deutsche Schäferhunde eine signifikant größere relative Länge des dorsalen Atlasbogen (0,72 ± 0,07) als für Yorkshire Terrier (0,64 ± 0,08) und eine größere relative Länge des Dens axis beim Deutschen Schäferhund (0,40 ± 0,04) als bei Yorkshire Terriern (0,33 ± 0,05) und Zwergrassen allgemein (0,34 ± 0,06). Die relative Länge des Axiskörpers differierte dagegen unwesentlich. Der radiologisch ermittelte Foramen-magnum-Index ist bei den untersuchten Zwergrassen (0,57 ± 0,11) deutlich geringer als er bei kleinen Rassen mit dorsaler Kerbe des Foramen magnum (Mazerationspräparate) in der Literatur beschrieben wird. Für die Funktionsanalyse wird ein in der Humanmedizin etabliertes Verfahren nach ARLEN (1979) auf den Kopf-Hals-Übergang des Hundes angewandt und die Differenz der Intervertebralwinkel zwischen maximaler Beugung und Streckung im Bereich des Kopf-Hals-Überganges gemessen. Für Deutsche Schäferhunde wird eine signifikant höhere Beweglichkeit im Atlantookzipitalgelenk (89,26° ± 9,12°) als bei Zwergrassen (77,43° ± 11,91°) gemessen. Die Beweglichkeit im Bereich des Atlantoaxialgelenkes ist bei Zwergrassen (26,37° ± 6,32°) signifikant größer als bei Deutschen Schäferhunden (20,69° ± 5,29°). Bei der Beurteilung der funktionsanalytischen Parameter in Zusammenhang mit den morphologischen Parametern ergibt sich für die Rasse Yorkshire Terrier ein geringerer Bewegungsausschlag im Atlantookzipitalgelenk bei kurzem Dens (72,91° ± 11,82°) im Vergleich zum langen Dens (83,78° ± 10,34°). Eine positive Korrelation zwischen Denslänge und Bewegungsausschlag im Atlantookzipitalgelenk (r = 0,25) und eine negative Korrelation zwischen Atlaslänge und Bewegungsausschlag im Atlantoaxialgelenk (r = - 0,19) werden statistisch gesichert. Die Arbeit ist Grundlagenforschung, deren Ergebnisse verglichen mit Messwerten von im Kopf-Hals-Übergang funktionell erkrankten Hunden zu Aussagen mit klinischer Relevanz führen kann.

Made available in DSpace on 2014-06-11T19:28:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2002-02-28Bitstream added on 2014-06-13T20:57:39Z : No. of bitstreams: 1 sakakura_ce_me_arafo.pdf: 293566 bytes, checksum: b59ebffa797d41b6f4b75aa3ce197b82 (MD5) / Com o advento do implantes, a precisa localização de estruturas anatômicas, dentre elas o canal da mandíbula e o forame mentual, tornou-se uma necessidade primordial para os implantodontistas. O objetivo deste trabalho foi avaliar a reprodutibilidade diagnóstica da imagem panorâmica convencional e digitalizada invertida na detecção do teto do canal da mandíbula e do forame mentual. Foi utilizada uma amostra de setenta e sete radiografias panorâmicas de edentados totais. Estas foram digitalizadas por meio de um escaner, tendo o brilho e o contraste ajustado, bem como a transformação em negativo. A área posterior ao forame mentual foi dividida em três regiões e a presença do teto do canal foi classificada em uma escala de confiança de cinco pontos. O forame mentual foi classificado segundo os critérios propostos por Yosue et al.74 (1989). Tanto a panorâmica convencional, como a digitalizada invertida foram avaliadas por três implantodontistas, previamente calibrados, em duas ocasiões distintas com intervalo mínimo de dez dias. A reprodutibilidade intra-examinador foi avaliada empregando-se a estatística Kappa (k), segundo Light (kL). A concordância intra-examinador, segundo Landis & Kock31, variou em sofrível, regular e boa; entretanto, não houve diferença estatísticamente significante na maioria das situações. Concluímos que os valores foram de baixa concordância por ponto e por intervalo de confiança, quando os três examinadores avaliaram a presença do teto do canal da mandíbula e do forame mentual. / The knowledge of precise location of mandibular canal and mentual foramen are very important in mandibular implant surgery. The aim of this study was to evaluate the diagnostic reproducibility of conventional and negative digitized conventional panoramic images of superior wall of mandibular canal and mentual foramen. A sample of 77 edentulous patient's panoramic radiographs was used. These radiographs were digitized by a scanner with adjusted bright and contrast and it showed in a negative mode. The posterior segment behind mentual foramen was divided into three parts and the presence of the superior wall of mandibular canal was classified according to five points scale. The mental foramen was classified according to criteria of Yosue et al,77 (1989). The conventional panoramic and digitized radiographies were evaluated twice by three previously calibrated implantodontits. The intra-observer reproducibility was found using Kappa's statistic, according Ligth. The intra-observer agreement varied between bearable and good according to Landis & Kock. However, there was no significant difference. We observed low agreement in the Kappa's values.

Este estudo objetivou avaliar a influência do diâmetro do forame e do instrumento endodôntico na leitura odontométrica de dois aparelhos localizadores apicais eletrônicos. Foram utilizados 40 dentes incisivos inferiores, divididos em 4 grupos, de acordo com o diâmetro do forame apical (100, 200, 300 e 400 µm). Após a abertura coronária desses dentes e o acesso aos canais radiculares, realizou-se a medição do comprimento dos mesmos com auxílio de um microscópio clínico com ampliação de 7,8X, da incisal até que a ponta da lima surgisse no forame apical. Os dentes foram colocados em potes individuais contendo solução de ágar a 1% em solução salina de fosfato tamponado, mantendo-se cerca de 2/3 de suas raízes imersas na solução para que pudesse ser feita a leitura com o Root ZX® (J.Morita, Japão) e o NovApex® (Fórum, Israel). Os mesmos foram medidos com limas nº10 até que a distância de 0,5 mm do ápice fosse acusada no display dos aparelhos. Uma outra medida foi realizada nos dentes utilizando-se lima nº10 e limas com diâmetros correspondentes ao diâmetro dos forames (200µm, 300µm e 400µm). Para a análise estatística foi empregado o teste de Análise de Variância a dois critérios para o confronto global entre os aparelhos e o emprego da lima nº10 em todos os dentes e teste de Tukey para as comparações individuais. Os resultados demonstraram diferença estatística na precisão dos dois aparelhos com um resultado mais preciso para o Root ZX® (p<0,05). Dentes com forame, de menor diâmetro, apresentaram uma medida mais precisa com o localizador apical e dentes com forame de maior diâmetro apresentaram uma maior discrepância na medida. O emprego de limas tipo K nº10 nos dentes com forames de diâmetros maiores apresentaram maior precisão na medição quando comparadas às limas coincidentes aos diâmetros dos forames para o aparelho Root ZX®. Para o NovApex® esta correlação só passou a ocorrer a partir da lima nº40. / This study evaluated the influence of foramen diameter and endodontic instrument size on the odontometry reading of two electronic apical measuring devices. Forty mandibular incisors were used, which were divided into four groups according to the apical foramen diameter (100, 200, 300 and 400µm). After coronal opening of these teeth and access to the root canals, the root canal length was measured with aid of a clinical microscope with 7.8x magnification, from the incisal edge until the file tip reached the apical foramen. Ten teeth with 100-µm diameter were placed in individual jars containing 1% agar solution in phosphate-buffered saline, maintaining around 2/3 of their roots immersed in the solution to allow measurement with Root ZX (J. Morita, Japan) and NovApex (Forum, Israel). Teeth were measured with files n. 10 until the distance of 0.5mm from the apex was indicated by the device. Another measurement was performed on the other thirty teeth with files n. 10 and files with diameters corresponding to the foramen diameters (200µm, 300µm and 400µm). Statistical analysis was performed by two-way analysis of variance for overall comparison between the devices and employment of file n. 10 in all teeth, and Tukey test for individual comparisons. The results demonstrated statistical difference in the precision of both devices, with a more accurate result for Root ZX (p<0.05). Teeth with narrower foramina presented a more accurate measurement with the apical measuring device, and teeth with wider foramina presented larger discrepancy in the measurement. Utilization of K file n. 10 in teeth with wider foramina showed more accurate measurements compared to files with size corresponding to the foramen diameters with the Root ZX® device. With the NovApex® device, this correlation was only observed with file n. 40.