Assessment of root canal anatomy of maxillary and mandibular canine teeth: a cone-beam computed tomography study / Evaluación de la anatomía del canal radicular de caninos maxilares y mandibulares: un estudio de tomografía computarizada de haz cónico

Abstract To investigate the root canal anatomy of permanent maxillary and mandibular canines in a Turkish subpopulation using cone beam computed tomography (CBCT). Retrospective CBCT data of 300 patients admitted to our clinic between 2016 and 2018 were screened and evaluated. A total of 235 patients, 100 males and 135 females, aged 14-76 years (mean age 37.27±13.40) were included in this study. A total of 191 (44,8%) maxillary canine teeth and 235 (55,2%) mandibular canine teeth were examined. The number of roots and root canal morphology according to Vertucci's classification, the presence of accessory canals, and the position of the apical foramen of the root were analyzed. The effect of gender and age on the incidence of root canal morphology was also investigated. The majority of the teeth had a Type I canal configuration in both maxillary canines (100%) and mandibular canines (92,8%). In the mandibular canines the other canal patterns found were Type III (6,8%), and Type II (0,4%). Apical foramen was centrally positioned in the majority of the teeth, 70,2% and 66,8% in maxillary and mandibular canines, respectively. The occurrence of two roots in mandibular canines was 3,8% and the root canal separation was found 53,8% and 46,2% in the middle and cervical third of the root, respectively. No significant statistical difference was observed effect of gender and age on the incidence of the root canal morphology and the position of the apical foramen. Due to the diverse morphology and the potential presence of a second canal for canine teeth among the Turkish subpopulation, dentists should perform endodontic treatments with greater care. CBCT is an accurate tool for the morphological assessment of the root canals.

Resumen Investigar la anatomía del conducto radicular de los caninos maxilares y mandibulares permanentes en una subpoblación turca utilizando la tomografía computarizada de haz cónico (CBCT). Se examinaron y evaluaron los datos CBCT retrospectivos de 300 pacientes ingresados en nuestra clínica entre 2016 y 2018. Un total de 235 pacientes, 100 hombres y 135 mujeres, de entre 14 y 76 años (edad media de 37,27±13,40) fueron incluidos en este estudio. Se examinaron un total de 191 (44,8%) dientes caninos maxilares y 235 (55,2%) dientes caninos mandibulares. Se analizó el número de raíces y la morfología del conducto radicular según la clasificación de Vertucci, la presencia de conductos accesorios y la posición del foramen apical de la raíz. También se investigó el efecto del sexo y la edad en la incidencia de la morfología del conducto radicular. La mayoría de los dientes tenían una configuración de conductos de tipo I tanto en los caninos maxilares (100%) como en los caninos mandibulares (92,8%). En los caninos mandibulares los otros patrones de conductos encontrados fueron el Tipo III (6,8%) y el Tipo II (0,4%). El foramen apical estaba situado en posición central en la mayoría de los dientes, 70,2% y 66,8% en los caninos maxilares y mandibulares, respectivamente. La ocurrencia de dos raíces en los caninos mandibulares es del 3,8% y la separación del conducto radicular se encontró en el tercio medio y cervical de la raíz en el 53,8% y el 46,2%, respectivamente. No se observó ninguna diferencia estadística significativa en el efecto del sexo y la edad sobre la incidencia de la morfología del conducto radicular y la posición del foramen apical. Debido a la diversa morfología y a la posible presencia de un segundo conducto en los dientes caninos entre la subpoblación turca, los odontólogos deberían realizar los tratamientos endodónticos con mayor cuidado. La CBCT es una herramienta precisa para la evaluación morfológica de los conductos radiculares.

Quantitative assessment of the jawbone quality classification: A meta-analysis study.

AIM: Bone quality is evaluated using bone density for qualitative classification, a characteristic that may be delicate to evaluate. Contemporary implantology that relies on modern measurement techniques, needs a more quantitative estimate of the bone quality. MATERIALS AND METHODS: PubMed and EMBASE databases were searched with no time restriction. Clinical and radiographic studies reporting on alveolar ridge dimensions and its parameters in different areas of the dentate and edentulous jaws were included. A meta-analysis was performed using random effect models to report a combined mean for alveolar ridge and its parameters. Meta regression statistical tests were performed in order to identify differences in those outcome parameters. RESULTS: 30 studies were included. The majority of the selected studies (total of 27) used live human subjects and CBCT to analyze alveolar ridge dimensions and its parameters. Using the combined mean obtained from the meta-analysis, a typical portrait of the alveolar ridge was constructed, and a geometrically based quantitative bone classification proposed. The quantitative classification was found to match the existing qualitative classification. CONCLUSION: A geometry-based analysis was constructed that yields valuable insights on the bone type based on its components and on the dynamics of the dentate / edentulous states.

Assessment of mandibular characteristics in patients affected with ß-thalassaemia major: A retrospective case-control study.

OBJECTIVE: Thalassemia is the most common hereditary blood disorder across the world. This study aimed to identify some mandibular features of thalassaemic patients and compare them with unaffected counterparts. MATERIAL AND METHODS: This retrospective case-control study was carried out on lateral cephalograms of 60 subjects (26 males, 34 females) with class II malocclusion and age range of 11 to 15 years. The control group consisted of 60 non-thalassaemic subjects with class II malocclusion and similar chronological age, gender and vertical facial dimension. Based on the Jarabak index, the case and control subjects were classified into hyperdivergent, normodivergent and hypodivergent growth patterns. Four linear (ramus height, ramus width, mandibular depth, and antegonial notch depth) and 3 angular (symphyseal angle, gonial angle, and mandibular arc angle) cephalometric parameters were measured to represent mandibular morphology. The data were analysed using Chi-square test and Student's t-test. RESULTS: No significant difference was found in linear measurements between thalassaemic patients and controls. The symphysis angle was significantly greater and the mandibular arc angle was significantly smaller in the total thalassaemic sample than the control individuals (P<0.001 and P=0.004, respectively). The difference in symphysis angle was significant in both hyperdivergent and normodivergent subjects (P=0.004 and P=0.002, respectively), whereas the difference in mandibular arc angle was only significant in the normodivergent subgroup P=0.001). CONCLUSIONS: The smaller mandibular arc angle in the thalassaemic sample suggests a more superior than posterior growth direction of condyles compared with healthy individuals. The difference in symphyseal angle represents inherent differences in chin morphology between thalassaemic subjects and controls.

Computed Tomography Scan Assessment of the Anatomy of the Pterygomaxillary Junction and Its Relevance in Le Fort I Osteotomy.

Knowledge of the morphometry and types of pterygomaxillary junction (PMJ) during Le-Fort I osteotomy is an important consideration in the reduction of intraoperative complications. The PMJ is known to display population variations and with the recent increase in these surgical interventions in Kenya, a detailed description of the PMJ is warranted. Computed tomography scan images of PMJ obtained from 63 patients were analyzed at the level of the posterior nasal spine to assess types and the morphometry of the PMJ. A fissure type of PMJ was present in 65.9% (83/126 sides) while a synostosis type was present in 34.1% (43/126). Bilateral fissures were found in 58.73% (37/63), bilateral synostosis in 26.98% (17/63), and an asymmetric PMJ in 15.25% (9/63). The average height, width, and thickness of the PMJ were 17.45 ±â€Š5.26 mm, 10.24 ±â€Š1.97 mm, and 6.40 ±â€Š1.97 mm respectively. Males had a significantly greater height (P = 0.003) and width (P = 0.000). The average width was greater in cases with a synostosis as compared with those with a fissure (P = 0.019). Average distance of greater palatine canal was 40.41 ±â€Š2.28 mm and 7.19 ±â€Š2.20 mm from the piriform rim and the pterygoid fossa respectively. The PMJ among Kenyans is characterized by a higher occurrence of synostosis, greater height, and thickness compared with previous findings from other populations. The results of this study can be helpful for surgeons in selecting the most appropriate techniques to achieve successful pterygomaxillary disjunction and minimize avoid attendant complications such as vascular and nerve injuries.

CBCT assessment of bone thickness in maxillary and mandibular teeth: an anatomic study.

OBJECTIVE: The site of the sinus tract depends on the rate of resistance against abscess exudate drainage, bone morphology, and distance from the root apex to the outer cortical bone. To assess apical bone thickness in buccal and palatal/lingual aspects of maxillary and mandibular teeth, using a high-resolution cone-beam computed tomography (CBCT) system. METHODOLOGY: In total, 422 CBCT examinations were included in the study, resulting in a sample of 1400 teeth. The scans were acquired by PreXion 3D, with a high-resolution protocol. The bone thickness was taken as the distance between the center of the apical foramen and the buccal and lingual/palatal cortical bone. The quantitative variables were expressed as mean values±standard deviation. The independent samples were analyzed using the t-test or the Mann-Whitney test (p<0.05). RESULTS: The lowest mean value of bone thickness was observed in the buccal cortical bone of the upper canines (1.49 mm±0.86) and in the upper central incisors (1.59 mm±0.67). In premolar teeth, the lowest values were found in the buccal cortical bone of upper first premolars (1.13 mm±0.68). In the posterior teeth, the lowest values were found in the buccal cortical bone of upper first molars (1.98 mm±1.33). In the lower second molar region, the buccal cortical bone (8.36 mm±1.84) was thicker than the lingual cortical bone (2.95 mm±1.16) (p<0.05). CONCLUSIONS: The lowest mean values of bone thickness are in the buccal cortical bone of the maxillary teeth. In the mandible, bone thickness is thinner in the buccal bone around the anterior and premolar teeth, and in the lingual aspect of mandibular molars. All these anatomic characteristics could make the occurrence of the sinus tract more susceptible in these specific regions of the maxillary and mandibular alveolar bone.

Micro-computed tomographic assessment of the variability and morphological features of root canal system and their ramifications.

OBJECTIVES: This study assessed the incidence and variability features of root canals system (RCS) and their ramifications according to Pucci & Reig (PR) (1944) and the American Association of Endodontists (AAE) (2017) by micro-computed tomography (µCT). METHODOLOGY: 500 representative extracted human teeth of each tooth group (n=50) (maxillary/mandibular central and lateral incisors, canines, first and second premolars and molars) were scanned by µCT with a resolution of 26.70 µm. The reconstructed cross-sections images and the visualization of the continuous slices in the transversal axis were performed using DataViewer software. RCS were classified according to Pucci & Reig (main canal, collateral canal, lateral canal, secondary canal, accessory canal, intercanal, recurrent canal) and AAE (main canal, accessory canal, lateral canal). The apical deltas were assessed for both classifications. The prevalence of apical deltas was evaluated using the Chi-squared test (p<0.05). RESULTS: According to PR, a higher incidence of lateral canals was observed in maxillary canines (10%), central incisors (8%) and first premolars (6%). Using AAE, the highest incidence of lateral canals was observed in the mandibular first premolars (85%), first and second molars (84%), lateral incisors (67%), canines (59%), and in maxillary first premolars (52%). Regarding accessory canals, the PR showed a frequency in 2% of the maxillary lateral incisors and maxillary and mandibular first premolars and 3% of mandibular first and second molars. On the other hand, the AAE showed the highest incidence of accessory canals in 86% of the maxillary first premolars, 71% in mandibular lateral incisors, 69% in mandibular first premolars, 65% in mandibular canines, and 56% in maxillary canines. The PR showed the lowest incidence of apical deltas for all dental groups when compared with AAE (p=0.004). Interestingly, distal canals in maxillary molars showed a significant discrepancy between classifications (p=0.027). CONCLUSIONS: µCT enabled accurately describing the RC system and related ramifications, adding to the PR and AAE classifications, with some discrepancies reported for maxillary molars. Clinical Relevance This µCT study enabled a thorough description of the variability among root canals and their ramifications, including clinically relevant details on the presence and location of lateral canals and accessories in all human tooth groups, beyond the currently existing classification systems.

CBCT assessment of bone thickness in maxillary and mandibular teeth: an anatomic study

Abstract The site of the sinus tract depends on the rate of resistance against abscess exudate drainage, bone morphology, and distance from the root apex to the outer cortical bone. Objective To assess apical bone thickness in buccal and palatal/lingual aspects of maxillary and mandibular teeth, using a high-resolution cone-beam computed tomography (CBCT) system. Methodology In total, 422 CBCT examinations were included in the study, resulting in a sample of 1400 teeth. The scans were acquired by PreXion 3D, with a high-resolution protocol. The bone thickness was taken as the distance between the center of the apical foramen and the buccal and lingual/palatal cortical bone. The quantitative variables were expressed as mean values±standard deviation. The independent samples were analyzed using the t-test or the Mann-Whitney test (p<0.05). Results The lowest mean value of bone thickness was observed in the buccal cortical bone of the upper canines (1.49 mm±0.86) and in the upper central incisors (1.59 mm±0.67). In premolar teeth, the lowest values were found in the buccal cortical bone of upper first premolars (1.13 mm±0.68). In the posterior teeth, the lowest values were found in the buccal cortical bone of upper first molars (1.98 mm±1.33). In the lower second molar region, the buccal cortical bone (8.36 mm±1.84) was thicker than the lingual cortical bone (2.95 mm±1.16) (p<0.05). Conclusions The lowest mean values of bone thickness are in the buccal cortical bone of the maxillary teeth. In the mandible, bone thickness is thinner in the buccal bone around the anterior and premolar teeth, and in the lingual aspect of mandibular molars. All these anatomic characteristics could make the occurrence of the sinus tract more susceptible in these specific regions of the maxillary and mandibular alveolar bone.

Micro-computed tomographic assessment of the variability and morphological features of root canal system and their ramifications

Abstract Objectives This study assessed the incidence and variability features of root canals system (RCS) and their ramifications according to Pucci & Reig (PR) (1944) and the American Association of Endodontists (AAE) (2017) by micro-computed tomography (μCT). Methodology 500 representative extracted human teeth of each tooth group (n=50) (maxillary/mandibular central and lateral incisors, canines, first and second premolars and molars) were scanned by μCT with a resolution of 26.70 μm. The reconstructed cross-sections images and the visualization of the continuous slices in the transversal axis were performed using DataViewer software. RCS were classified according to Pucci & Reig (main canal, collateral canal, lateral canal, secondary canal, accessory canal, intercanal, recurrent canal) and AAE (main canal, accessory canal, lateral canal). The apical deltas were assessed for both classifications. The prevalence of apical deltas was evaluated using the Chi-squared test (p<0.05). Results According to PR, a higher incidence of lateral canals was observed in maxillary canines (10%), central incisors (8%) and first premolars (6%). Using AAE, the highest incidence of lateral canals was observed in the mandibular first premolars (85%), first and second molars (84%), lateral incisors (67%), canines (59%), and in maxillary first premolars (52%). Regarding accessory canals, the PR showed a frequency in 2% of the maxillary lateral incisors and maxillary and mandibular first premolars and 3% of mandibular first and second molars. On the other hand, the AAE showed the highest incidence of accessory canals in 86% of the maxillary first premolars, 71% in mandibular lateral incisors, 69% in mandibular first premolars, 65% in mandibular canines, and 56% in maxillary canines. The PR showed the lowest incidence of apical deltas for all dental groups when compared with AAE (p=0.004). Interestingly, distal canals in maxillary molars showed a significant discrepancy between classifications (p=0.027). Conclusions μCT enabled accurately describing the RC system and related ramifications, adding to the PR and AAE classifications, with some discrepancies reported for maxillary molars. Clinical Relevance This μCT study enabled a thorough description of the variability among root canals and their ramifications, including clinically relevant details on the presence and location of lateral canals and accessories in all human tooth groups, beyond the currently existing classification systems.

Computed tomographic assessment of the lacrimal sac fossa in the Japanese population.

PURPOSE: To analyze the morphology of the lacrimal sac fossa in the Japanese population using computed tomographic images. MATERIALS AND METHODS: One-hundred-fifty-five Japanese patients diagnosed with unilateral orbital fracture were retrospectively reviewed. Measurements of the dimensions of the lacrimal sac fossa were taken on three anatomical planes (upper, middle, and lower planes) using a digital caliper/protractor tool. RESULTS: The mean maximum thickness of the maxillary bone at the upper, middle, and lower planes of the lacrimal sac fossa were 4.60 mm, 5.07 mm, and 6.30 mm, respectively. The midpoint thickness of the maxillary bone at each plane were 3.04 mm, 3.00 mm, and 2.17 mm, respectively. The lacrimal bone thickness at each plane were 1.13 mm, 1.13 mm, and 1.08 mm, respectively. The proportion of the lacrimal sac fossa comprising of the lacrimal bone at each plane were 39.00%, 42.05%, 38.92%, respectively. On the middle plane, the mean angle between the lacrimal bone and sagittal plane was 131.92°. CONCLUSIONS: In Japanese patients, the proportion of the lacrimal bone on the lacrimal sac fossa tended to be of greater proportion compared to studies done on other races. The mean angle of the lacrimal sac fossa seemed to be comparatively high. These results indicate that performing an osteotomy during dacryocystorhinostomy could be relatively easier in the Japanese population compared to other races.

Three-Dimensional Assessment of Crown Size and Eruption Space for Developing Third Molars: Data Collection Techniques Based on Cone-Beam Computed Tomography (CBCT).

Third molar development and eruption are two related areas of major interest in dental research into the etiology of "wisdom tooth" impaction. Third molars are not only an excellent model for studying dental development but also of fundamental clinical importance because they are very frequently impacted. Because the third molar is located in the distal-most region of the oral cavity, clinical access is relatively challenging. With the increasingly widespread use of cone-beam computed tomography (CBCT) in dentistry, studies and measurements of the third molar and its eruption area have become considerably easier to do. Here we present a novel CBCT-based measurement methodology we developed for our recent investigations that we hope will also be useful for the broader dental research community.

Dental age assessment on panoramic radiographs: Comparison between two generations of young Finnish subjects.

OBJECTIVE: To analyse the accuracy of a meta-analysis-based dental age assessment (DAA) method in Finnish paediatric patients and to compare the dental development between two generations of Finnish children. METHODS: Panoramic radiographs of Finnish Caucasian healthy children from two generations (early: born 1981-1984; subsequent: born 1996-2008) were analysed. All developing teeth on the left maxilla and mandible as well as the third permanent molars were analysed following Demirjian's classification. For each patient, dental age was calculated and compared with chronological age. Dental maturation patterns between the two groups were compared. RESULTS: The study included 200 Finnish Caucasian healthy children from two generations (early: aged 7-13 years; subsequent: aged 6-15 years). In the early generation, DAA underestimated the chronological age by a mean of 3.15 years. The underestimation was only 0.11 years in patients < 10 years, but 3.86 years in patients ≥ 10 years. In the subsequent generation, the dental age was overestimated by a mean of 0.34 years; by 0.40 years in patients < 10 years and by 0.08 years in patients ≥ 10 years. CONCLUSIONS: The present DAA method is applicable to current Finnish children. Differences in dental development between two generations of Finnish children were detected.

Reliability and validity of maxillary and sphenoid Sinus morphological variations in the assessment of Skeletal maturity.

BACKGROUND: The present study aimed at assessing the relationship between growth changes in maxillary (MS) and sphenoid sinus (SS) and cervical vertebral maturation (CVM) and to evaluate their reliability and validity in assessing the skeletal maturity of an individual. METHODS: A crosssectional study was conducted on the pretreatment lateral cephalograms of 224 patients (males=116, females=108) aged 8-17 years. MS and SS heights, widths and indices were evaluated. The subjects were classified according to six stages based on CVM using Baccetti's method. Kruskal-Wallis test was applied to compare MS and SS measurements at different cervical stages for each gender. Kappa statistics, positive predictive value, negative predictive value, sensitivity and specificity were calculated to test the diagnostic accuracy of MS and SS indices. RESULTS: The MS and SS indices varied significantly (p<0.001) at different cervical stages for both gender. Kappa statistics showed significant agreement using MS (p<0.001) and SS indices (p<0.05). The diagnostic performance of MS index (Sensitivity ≥71%) was found to be better than SS index (Sensitivity ≥65%).. CONCLUSIONS: The MS height, width and index in genders and SS height, width and index in males and only SS width and index in females were significantly associated with the CVM stages. The validity of MS and SS indices were comparable for females; whereas, the MS index offers significant advantage over SS index for the assessment of growth status of males.

Assessment of gingival zenith position and its level relative to age and gender in maxillary anterior teeth.

OBJECTIVE: The gingival tissues surrounding the maxillary anterior teeth play a pivotal role in fostering a beautiful smile. The gingival zenith position (GZP) and its spatial orientation in the mesiodistal and apicocoronal direction can provide a valuable reference point. The present study was undertaken to evaluate the GZP and gingival zenith line (GZL) in maxillary anterior teeth in different age groups and genders. METHOD AND MATERIALS: The study population comprised 124 periodontally healthy patients equally divided into 21 to 40 years (Group I) and 41 to 60 years (Group II) age groups and gender distribution. The parameters of vertically bisected midline (VBM), GZP, and GZL were evaluated for all the teeth. RESULTS: The GZP was distally placed in 54.68% and 78.12% of the central incisors for males and females in Group I, while in Group II it was 65.62% and 75.00% respectively. The majority of lateral incisors and canines had coincidence of the GZP and VBM. The GZL was found to be at an apical position with reference to the GZP of lateral incisors. CONCLUSION: A distal deviation of GZP was observed for central incisors, while the GZP coincided with the VBM for lateral incisors and canines. The GZL was apically placed in relation to the GZP of lateral incisors. These elements can be taken up as reference points in periodontal and restorative procedures.

Assessment of Periodontal Biotype in a Young Chinese Population using Different Measurement Methods.

Periodontal biotype is used to describe the morphological characteristics of periodontal tissues and is closely related to periodontal health and prognosis of many dental treatments. This study was undertaken to explore the periodontal biotype distribution in a young Chinese population and to evaluate the accuracy of different methods for gingival thickness (GT) measurement. A total of 372 teeth from 31 periodontally healthy subjects were included. GT was measured simultaneously by probe transparency, transgingival probing and cone-beam computed tomography (CBCT). Some other anatomic parameters, including crown width/crown length ratio, attached gingival width, labial bone thickness and papilla volume were recorded for periodontal biotype classification. As found by probe transparency, the gingivae of 222 teeth (59.68%) were thick, while those of 150 teeth (40.32%) were thin. The mean GT of included subjects was 1.03 ± 0.31 mm as measured by transgingival probing and 1.03 ± 0.24 mm as measured by CBCT. Four groups were identified by cluster analysis. Thick-flap biotype, average-scalloped biotype, average-flap biotype and thin-scalloped biotype comprised 137 teeth (36.83%), 96 teeth (25.81%), 39 teeth (10.48%) and 100 teeth (26.88%), respectively. These results demonstrate that the most common periodontal biotype in this young Chinese population was the thick-flap type with low aesthetic risk.

Assessment of the potential toxicological hazard of the Green Parrot Snake (Leptophis ahaetulla marginatus): Characterization of its venom and venom-delivery system.

Snakes are the major group of venomous vertebrates, and the rear-fanged snakes represent the vast majority of species and occur worldwide; however, relatively few studies have characterized their venoms and evaluated their potential hazards for humans. Herein we explore the protein composition and properties of the venom of the rear-fanged Green Parrot Snake, Leptophis ahaetulla marginatus, the most common snake found in the Iguazu National Park (Argentina), as well as the main features of its venom delivery system. This species has venom reminiscent of elapid venoms, composed mainly of components such as 3FTxs, CRiSPs and AChE, but it shows low toxicity toward mammals (LD50 > 20 µg/g mouse). The histology of its Duvernoy's venom gland is similar to that of other colubrids, with serous secretory cells arranged in densely packed secretory tubules. The posterior end of its maxilla exhibits 1-3 blade-shaped and slightly recurved fangs but without grooves. This study provides an initial analysis of the biological role of venom in Leptophis, with implications for potential symptoms that might be anticipated from bites by this species.

Anatomic assessment of the mandibular buccal shelf for miniscrew insertion in white patients.

INTRODUCTION: Cortical bone thickness, bone width, insertion depth, and proximity to nerves are important factors when planning and placing orthodontic miniscrews. The objective of this study was to anatomically assess the mandibular buccal shelf in a white patient population as the insertion site for orthodontic miniscrews by investigating these 4 variables. METHODS: Measurements were made on cone-beam computed tomography scans of 30 white patients (18 girls, 12 boys; mean age, 14.5 ± 2 years). All measurements were taken adjacent to the distobuccal cusp of the first molar, and the mesiobuccal and distobuccal cusps of the second molar. Additionally, bone depth was measured at 2 height levels, 4 and 8 mm from the cementoenamel junction. Stereolithographic models of patients were superimposed on the cone-beam computed tomography volumes to virtually create an outline of the soft tissue on the cone-beam computed tomography image to allow identification of the purchase point height (mucogingival junction). The inferior alveolar nerve was digitally traced. Miniscrews (1.6 × 10 mm) were virtually placed at the buccal shelf, and their insertion depths and relationships to the nerve were assessed. Analysis of variance with post hoc analysis was used for data analysis. RESULTS: Insertion sites and measurement levels had significant impacts on both cortical bone thickness and bone width. Cortical bone thickness was typically greatest at the distobuccal cusp of the second molar. Bone width was also greatest at the distobuccal cusp of the second molar 8 mm from the cementoenamel junction. The greatest insertion depth was found again at the distobuccal cusp to the second molar, whereas the miniscrews had the greatest proximity to the nerve at this site also. CONCLUSIONS: The distobuccal cusp level of the mandibular second molar is the most appropriate site for miniscrew insertion at the buccal shelf in white patients.

Reliability and validity of MicroScribe-3DXL system in comparison with radiographic cephalometric system: Angular measurements.

AIM: The aim of the study was to assess the reliability and validity of cephalometric variables from MicroScribe-3DXL. MATERIALS AND METHODS: Seven cephalometric variables (facial angle, ANB, maxillary depth, U1/FH, FMA, IMPA, FMIA) were measured by a dentist in 60 Malay subjects (30 males and 30 females) with class I occlusion and balanced face. Two standard images were taken for each subject with conventional cephalometric radiography and MicroScribe-3DXL. All the images were traced and analysed. SPSS version 2.0 was used for statistical analysis with P-value was set at P<0.05. RESULTS: The results revealed a significant statistic difference in four measurements (U1/FH, FMA, IMPA, FMIA) with P-value range (0.00 to 0.03). The difference in the measurements was considered clinically acceptable. The overall reliability of MicroScribe-3DXL was 92.7% and its validity was 91.8%. CONCLUSION: The MicroScribe-3DXL is reliable and valid to most of the cephalometric variables with the advantages of saving time and cost. This is a promising device to assist in diverse areas in dental practice and research.

Postural assessment in class III patients before and after orthognathic surgery.

PURPOSE: This study aimed to assess body posture before and after bimaxillary orthognathic surgery by photogrammetry in skeletal class III patients. METHODS: Thirty-one patients with skeletal class III dentofacial deformities (14 men, 17 women) who underwent orthodontic preparation for surgery were included in this non-randomized controlled trial. Of these, 15 who did not undergo orthognathic surgery during the period of this study served as controls. Postural assessment was performed by photogrammetry using SAPO® (Postural Assessment Software) based on anterior-, posterior-, and lateral-view images taken 1 month before and 4 months after bimaxillary orthognathic surgery with internal rigid fixation (or 4 months after the initial assessment, for the control group). The study was approved by PUCRS Research Ethics Committee, and written informed consent was obtained from all individual participants prior to their inclusion in the study. RESULTS: There was no significant difference between groups for age, gender, and GAP. In the intervention group, the right leg/hindfoot angle, which initially indicated a valgus deformity, normalized after intervention (P < 0.048). Posterior displacement of the head (P < 0.005) and trunk (P < 0.004) were observed after intervention. CONCLUSIONS: These results suggest that correction of class III dentofacial deformities by bimaxillary orthognathic surgery can produce systemic postural adjustments, especially posterior displacement of the head and trunk and knee and ankle valgus.

Assessment of Bone Dimensions in the Anterior Maxilla: A Cone Beam Computed Tomography Study.

PURPOSE: To evaluate labial and palatal bone thickness at the maxillary anterior teeth as well as distance from cemento-enamel junction (CEJ) to bone crest using cone beam computed tomography (CBCT). MATERIALS AND METHODS: Measurements were obtained for maxillary anterior teeth of 120 subject CBCT volumes including thickness of labial and palatal plates of bone (coronal, middle, and apical thirds), and distance between CEJ and alveolar bone crest mid-labially, mesially, and distally. RESULTS: The mean value of bone thickness at coronal, middle, and apical thirds of the labial side for central incisor roots were respectively: 0.73, 0.69, 0.60 (mm), for lateral incisors: 0.70, 0.61, 0.49 (mm), and for canines: 0.74, 0.53, 040 (mm). The thickness of palatal bone was significantly larger. The mean distance between CEJ and mid-labial bone crest for all sites was 2.16 mm. CONCLUSION: Labial bone thickness is thin in the vast majority of maxillary anterior teeth. Use of CBCT facilitates planning for immediate implant placement and is helpful in the decision-making process when further bone augmentation is needed.

Assessment of the relationship between the maxillary sinus floor and the upper posterior root tips: Clinical considerations.

AIM: The purpose of the present study was to evaluate the relationship between the maxillary sinus floor and the upper posterior root tips in the Colombian population using cone-beam computed tomography. METHODS: A total of 1656 roots were analyzed (1104 molars and 552 premolars), classified as types I (outside the maxillary sinus) and II (inside the maxillary sinus). RESULTS: The results showed that the palatal root of the maxillary first molar was most frequently found inside the antrum. CONCLUSIONS: Understanding the relationship between the maxillary sinus floor and the upper posterior root tips is important to the clinician when performing conventional or surgical endodontic treatment and conventional surgery procedures in order to minimize or avoid the risk of damaging the maxillary sinus.