Incisor Position Research Articles

Evaluation of Diagnostic Agreement Among Cephalometric Measurements for Determining Incisor Position and Inclination

Evaluation of Diagnostic Agreement Among Cephalometric Measurements for Determining Incisor Position and Inclination

A 10‐year prospective study on single immediate implants

Aim To evaluate the clinical, aesthetic and radiographical outcome of single immediate implant placement (IIP) after 10 years (a) and to identify putative risk factors for advanced mid-facial recession (b). Material and methods Periodontally healthy patients with a thick gingival biotype and intact buccal bone wall were consecutively treated with a single immediate implant and crown in the aesthetic zone (15-25). Flapless surgery and socket grafting with deproteinized bovine bone mineral were performed. Seven patients received a connective tissue graft (CTG) at 3 months due to obvious alveolar process deficiency (n = 5) or advanced mid-facial recession (n = 2). Clinical, aesthetic and radiographical outcomes at 10 years were compared to those at 5 years and CBCTs were taken at 10 years. Results Twenty-two patients (10 women; mean age 50) were consecutively treated and 18 could be re-examined. Two implants failed and two patients died. None of the parameters differed between the 5- and 10-year re-assessment (marginal bone loss: 0.31 mm; plaque score: 15%; probing depth: 3.4 mm; bleeding on probing: 32%; pink aesthetic score: 10.61; mesial papillary recession: -0.03 mm; distal papillary recession: 0.22 mm; mid-facial recession: 0.58 mm). Six implants (33%) demonstrated ≥1 mm mid-facial recession. Putative risk factors were merely based on descriptive statistics and included buccal shoulder position, no CTG, convex emergence profile and central incisor position. Three implants (17%) had no visible buccal bone on CBCT. One of these was too buccally positioned, another yielded peri-implant mucositis and another demonstrated peri-implantitis. Conclusions Advanced mid-facial recession is common in the long term following IIP. Therefore, caution is required for IIP in the aesthetic zone.

Quantifying changes in incisor inclination before and after orthodontic treatment in class I, II, and III malocclusions

BackgroundThis study was designed to determine if orthodontic treatment significantly changes the upper incisor position in Class I, II, and III dental and skeletal malocclusions. MethodsNinety nonextraction-treated patients were included in this retrospective cohort study and divided into three groups: Class I, Class II, and Class III. All cephalometric measurements (ANB, Wits, U1-PP, U1-SN, U1-NA, U1 perpendicular to FH and U1-L1) were taken using the Dolphin Management and Imaging Software, Version 05.05.5070.221436 (United States and Canada). ResultsThe posttreatment values of ANB, Wits appraisal, U1-NA mm, U1-FH mm, IMPA and U1-L1° are statistically significant (P < 0.05) among the Class I, II, and III when compared with the normal values. Also ANB° changes after orthodontic treatment in Class I, II, and III were statistically significant with the greater changes in Class III malocclusion. ConclusionsThere is a significant amount of dento-alveolar compensation for the maxillary incisors not only in patients with Class II and III but also in Class I malocclusions that underwent nonextraction treatments.

Long-term dental stability after orthognathic surgery: a systematic review

Long-term dental stability is one of the main objectives following combined orthodontic and orthognathic surgical treatment. It is influenced by multiple factors such as surgical, patient-related, and orthodontic aspects. While recent reviews mainly focus on short-term dental changes (0.5-2 years), longer follow-up dental stability remains hardly reviewed. The aim of this study was to evaluate long-term stability of dental and dentolabial changes following combined orthodontic and orthognathic surgical treatment with a minimum follow-up period of 5 years. A systematic search was conducted up to December 2019 using Pubmed, Embase, Web of Science, and Cochrane Central. Randomized controlled trials (RCTs), prospective and retrospective cohort studies, and case series with a minimum of 10 patients, which reported long-term dental stability following combined orthodontic and orthognathic treatment, were included. Long-term changes were assessed for overjet, overbite, maxillary, and mandibular incisors' position and relationship of lip position to maxillary and mandibular incisors. Risk of bias was assessed according to the Cochrane Handbook. Following the screening of 3178 articles, 11 studies were included (2 RCT, 9 retrospective) with a postoperative follow-up period ranging from 5 to 15 years. A decrease in overjet was observed for patients with skeletal class III malocclusion, whereas overjet increased in class II patients at long-term follow-up. Overbite increased in class II patients, whereas class III showed variable results. The lower incisor position was more stable vertically than horizontally; the latter showing more outcome variability. Dentolabial changes corresponded to the normal ageing process and results were not clinically significant after long-term follow-up. Current evidence suggests variability of dental and dentolabial stability in both skeletal class II and III patients. Further prospective studies are required to develop guidelines for long-term follow-up assessment using computer tomography or cone-beam computed tomography imaging, before final conclusions can be drawn. The protocol for this systematic review (CRD42020133844) was registered in the International Prospective Register of Systematic Reviews (PROSPERO).

A 10-year prospective study on single immediate implants.

To evaluate the clinical, aesthetic and radiographical outcome of single immediate implant placement (IIP) after 10years (a) and to identify putative risk factors for advanced mid-facial recession (b). Periodontally healthy patients with a thick gingival biotype and intact buccal bone wall were consecutively treated with a single immediate implant and crown in the aesthetic zone (15-25). Flapless surgery and socket grafting with deproteinized bovine bone mineral were performed. Seven patients received a connective tissue graft (CTG) at 3months due to obvious alveolar process deficiency (n=5) or advanced mid-facial recession (n=2). Clinical, aesthetic and radiographical outcomes at 10years were compared to those at 5years and CBCTs were taken at 10years. Twenty-two patients (10 women; mean age 50) were consecutively treated and 18 could be re-examined. Two implants failed and two patients died. None of the parameters differed between the 5- and 10-year re-assessment (marginal bone loss: 0.31mm; plaque score: 15%; probing depth: 3.4mm; bleeding on probing: 32%; pink aesthetic score: 10.61; mesial papillary recession: -0.03mm; distal papillary recession: 0.22mm; mid-facial recession: 0.58mm). Six implants (33%) demonstrated ≥1mm mid-facial recession. Putative risk factors were merely based on descriptive statistics and included buccal shoulder position, no CTG, convex emergence profile and central incisor position. Three implants (17%) had no visible buccal bone on CBCT. One of these was too buccally positioned, another yielded peri-implant mucositis and another demonstrated peri-implantitis. Advanced mid-facial recession is common in the long term following IIP. Therefore, caution is required for IIP in the aesthetic zone.

Malocclusion in Children Aged 8 to 10 Years Old With Operated Isolated Cleft Palate.

This study aims to characterize dental malocclusion in children with operated isolated cleft palate aged 8 to 10 years old. Cross-sectional study with medical charts and complementary orthodontics exams and a sample for convenience. The study population was children aged 8 to 10 years registered at a Brazilian center from 2005 to 2009, diagnosed with isolated cleft palate and operated. the population of children registered at a Brazilian center from 2005 to 2009, diagnosed with isolated cleft palate. The data obtained from clinical records were analyzed by 2 orthodontists using the initial orthodontic documentation. The variables were: isolated cleft, sex, time of palatoplasty, malocclusion. The statistics included chi-square and Fisher exact tests (error 5%) to assess the malocclusion according to sex, type of cleft palate and time at palatoplasty. The sample resulted in 28 children (50% males, 50% females), average 8.5 years of age; the inter arch Class III relation was predominant (41.7%); a normal transverse relation was present in 48.1% of the sample; the majority presented a normal position of the upper incisors (61.5%);anterior open bite and excessive overjet was observed in 15.4% each and anterior cross-bite in 40.7%. There was no significant association between malocclusion with cleft type and surgery timing. The association between malocclusion and sex was significant (P = 0.049). Class III malocclusion was observed in most cases and females showed worse occlusal relations. Early orthodontic treatment is necessary in these patients.

Evaluation of the ideal position of the maxillary incisor relative to upper lip thickness

The anteroposterior position of the maxillary incisors has been studied since the beginning of cephalometric research. Most reports of ideal position have been based on measurements made on subjects with Class I occlusion without consideration of other facial variables. However, the ideal position is reflected in the soft tissues by the position of the lips. The purpose of this study was to consider the position of the maxillary incisor relative to other factors, including the thickness of the upper lip, and to evaluate its most aesthetic position using profile photographs. The subjects in this study were 130 patients with Class I occlusion; their sex, age, thickness of the upper lip, and angular position of the maxillary incisor were recorded. From these 130 patients, 70 profile photographs that met the inclusion criteria were chosen for further evaluation. A survey was conducted among 60 lay people, 60 dentists, and 60 orthodontists. They were asked to classify the sets of photographs, from the most esthetic position of the upper lip to the least esthetic. For patients with thin lips, raters tended to prefer a more protruded position of the incisor than normal or between 8.0mm and 11.5mm in front of the Na-B bone and 4mm in front of the Na-A bone. For patients with thick lips, the position of the incisor did not affect the perception of the profile. A correct skeletal scheme or Class I occlusion does not necessarily result in ideal facial harmony. Therefore, it will be necessary to consider all the factors that come into play, especially the lips, which are a key element in facial esthetics.

Morphometric evaluation of the alveolar bone around central incisors during surgical orthodontic treatment of high-angle skeletal class III malocclusion.

To evaluate morphometric characteristics of alveolar bone around the incisors of high-angle skeletal class III patients receiving surgical orthodontic treatment. Thirty high-angle skeletal class III patients (mean age, 20.94±3.25years) underwent cone-beam computed tomography before treatment (T0), after pre-surgical orthodontic treatment (T1) and after treatment (T2). The vertical bone level (VBL), alveolar bone thickness (ABT), alveolar bone area (ABA) and position of upper and lower central incisors (UCIs and LCIs) were evaluated. The ABT included five levels (4, 6, 8mm from the cemento-enamel junction, midroot and root apex level). One-way repeated measures ANOVA with Bonferroni's multiple-comparison test and matched t test was performed to compare variables. Before treatment, the average labial ABT was approximately 1mm in UCIs and 0.38~0.79mm in LCIs, and the VBL of the LCIs was over 2mm. After treatment, the VBL increased by 2.19±1.96mm (P<.001) on the lingual side of UCIs and 2.78±2.29mm and 3.09±2.52mm on the labial and lingual sides of LCIs, respectively (all P<.001). ABT at every level decreased significantly, decreasing by 1.66±1.93mm at the 8mm level of UCIs and 1.06±1.01mm at the apex of LCIs (P<.001). The lingual ABA of UCIs and LCIs decreased by over 50% (P<.001). In high-angle skeletal class III patients, the condition of alveolar bone around UCIs and LCIs was extremely poor before treatment. Further alveolar bone resorption occurred during surgical orthodontic treatment. More attention should be paid to the movement of anterior teeth in cases of severe alveolar bone loss.

Lips and incisors position in normal class I occlusion

In order to analyze the effectiveness of upper and lower incisors on the position of upper and lower lips, 100 students , 50 males and 50 females, aged 18-25 years from mosul university are selected with class I normal occlusion, good facial esthetic, normal overbite and overjet, having no history of orthodontic treatment. A standard cephalometric film was taken showing the soft tissue profile with the underlying skeletal frame work. Tracing of these films including the cranial, maxillary and mandibular bases, upper and lower incisors and soft tissue out line. Eight variables entered SPSS computer analysis to evaluate the mean value of the variables. The sample is distributed according to skeletal classification into skeletal class I, II, and III, and a high correlation was found only in position of upper incisors with lower incisors and upper lip with lower lip.

Correlations between objective measurements and subjective evaluations of facial profile after orthodontic treatment.

ObjectiveTo investigate the correlations between objective measurements and subjective evaluations of post-treatment facial attractiveness.MethodsTen orthodontists rated the subjective visual analog scale (VAS) scores of the facial profiles of 95 patients who had undergone orthodontic treatment. Post-treatment cephalograms and photographs were used. Eleven soft tissue measurements and eight maxillary incisor measurements were constructed and analyzed. Correlations between objective measurements and subjective VAS scores were evaluated using Pearson correlation and quadratic regression analysis.ResultsThe VAS scores of different facial proportions were all correlated with the total VAS score. Among soft tissue measurements, the distances from the upper and lower lips to the E line, H angle, forehead inclination, distance from lower lip to the H line, and pogonion-menton angle were negatively correlated with the VAS scores. The Z angle, with a parabolic distribution, was also correlated with the VAS scores. Among maxillary incisor measurements, the distance from the maxillary incisors to the forehead’s anterior limit line and the angulation of the maxillary incisors to the APo line were negatively correlated with the VAS scores.ConclusionsSeveral soft tissue and maxillary incisor position measurements were correlated with facial profile evaluation and therefore might be used to evaluate facial attractiveness.

Changes in vermilion lip morphology following orthodontic treatment with premolar extraction for Angle Class II maxillary protrusion

Objectives: The objective of the study was to clarify the changes in vermilion lip morphology following orthodontic treatment in Japanese patients with Class II maxillary protrusion. Materials and Methods: The subjects were 15 adult women diagnosed as having Angle Class II maxillary protrusion who had undergone orthodontic treatment with premolar extraction. For analysis, profile photographs taken at the first examination and at completion of active treatment were used for linear and angular measurements. For linear measurements on the lateral facial photographs, an X–Y coordinate system was established using a lateral cephalogram superimposed along the line of the profile. Measurement points relating to the vermilion lip morphology were measured on the facial photographs by digital processing, with the Frankfort horizontal (FH) plane as the X-axis, and the line perpendicular to the X-axis passing through the alar curvature point (Ac) as the Y-axis. Results: The results of linear measurements showed significant retraction of approximately 3.0 mm in the upper vermilion lip, and mean retraction of the upper incisors after treatment was approximately 6.0 mm. However, whereas mean retraction of the lower incisors was approximately 1.0 mm, there was significant retraction of the lower vermilion lip of over 3.0 mm. Significant reduction in vermilion height was also found in the upper vermilion lip. With regard to angular measurements, the upper lip and total vermilion showed significant reductions that indicated inversion. Conclusion: Adequate retraction of the upper incisors in the maxillary protrusion with excessive overjet may retract not only the upper vermilion lip but also the lower one, suggesting that morphological changes in the lower lip are affected by the positioning of the upper incisors. In addition, the patterns of morphological changes differed between the upper and lower vermilion lips, with a large proportion of rotational change toward the mucous membrane in the upper vermilion lip and with a pattern of change resembling horizontal displacement in the lower vermilion lip. Total vermilion showed a significant reduction in vermilion height due to the reduction in height of the upper vermilion lip.

Quality of Life Assessment in Patients with Malocclusion Undergoing Orthodontic and Orthognathic Treatment.

IntroductionThe objective of this study was to assess pre-treatment quality of life and the relevant clinical variables in adult patients with malocclusion in order to improve orthodontic treatment strategies.MethodsThe study was conducted in 240 consecutive adult patients with malocclusions divided into two groups: patients for whom an orthodontic treatment plan was considered, and patients for whom an orthognathic treatment plan was selected. Patients were examined between December 2015 and February 2017, at the School of Dental Medicine, University of Belgrade. Malocclusion severity was recorded using the Peer Assessment Rating index pre-treatment score. Skeletal malocclusion parameters were measured using lateral cephalometric radiographs. Quality of life was assessed by means of a generic questionnaire (Medical Outcomes Study Short Form-36 (SF-36)), and the disease-specific Orthognathic Quality of Life Questionnaire (OQLQ).ResultsThere were significant differences in the mean values of the OQLQ domain scores between orthodontic and orthognathic patients. Patients for whom orthodontic treatment was planned had statistically significantly lower scores in comparison to those for whom orthognathic treatment was planned. This was the case in all OQLQ domains except for “Awareness of facial deformity”. Statistically significant correlations (p<0.05) were presented between OQLQ scores and following demographic and clinical variables: gender, age, malocclusion severity, maxillary and mandibular sagittal, maxillary vertical, and lower incisor positions, intermaxillary angle, and the Beck Depression Inventory and Beck Anxiety Inventory levels. The independent predictors for the planning of orthodontic and orthognathic treatment in patients with malocclusion were two OQLQ domains, “Facial aesthetics” and “Awareness of facial deformity”, as well as total OQLQ score, after adjustment for demographic characteristics, skeletal parameters, anxiety and depression.ConclusionsOur findings suggest that patients for whom orthodontic treatment was planned demonstrated better quality of life according to the OQLQ scores in comparison to those for whom orthognathic therapy was planned.

Comparison of Two Different Intrusion Techniques (An in Vitro Study)

Aims: This study was aimed to compare the effects of two different techniques on the position of maxillary incisors during the intrusive movement. Materials and Methods: The sample consisted of two groups, the utility intrusion arch and continuous intrusion arch groups. Upper typodont arch of class II division I was used and the arches were activated to deliver 60 gram of force. Pre and postoperative digital images were taken and analyzed using Autodesk AutoCAD software™. For each group six parameters were measured and compared. A significance value of 0.05 was predetermined. Results: Significant difference was found in vertical change of estimated midpoint of root position, axial inclination, anteroposterior position of incisal edge, relative contribution of torque and protrusion to the change in inclination and insignificant difference in vertical change of incisal edge position. Conclusions: Maxillary incisors intrusion with a minimal protrusion could be achieved with the continuous intrusion arch technique

Ultrasound versus manipulation to determine an intercostal space for single-port thoracoscopy surgery: a diagnostic accuracy study

BackgroundMalposition of the intercostal space used for single-port thoracoscopy surgery can lead to problems. This study was to assess the accuracy of point-of-care ultrasound in verifying the position of intercostal space.MethodsA total of 200 patients, ASA (American Society of Anesthesiologists) physical status I or II, who underwent single-port thoracoscopic lobectomy, were enrolled. After the induction of anesthesia, a thoracic team confirmed the incision position. Firstly, the intercostal space was located by a young resident thoracic surgeon by ultrasound. Secondly, the intercostal space was located by an experienced thoracic surgeon by manipulation. Finally, the investigator verified the location of the intercostal space under direct vision through thoracoscopy, which was recognized as standard method. The time required by ultrasound and manipulation were recorded.ResultsThe inter-relationships between ultrasound and the standard method and between manipulation and the standard method were consistent. Manipulation positioning showed a sensitivity of 90.6% and specificity of 30% while ultrasound positioning showed a sensitivity of 87.1% and specificity of 60%. The specificity of ultrasound positioning was higher than that of manipulation position. The time required by ultrasound was shorter than that required by manipulation.ConclusionsCompared with the manipulation method, the ultrasound-guided method could accurately locate the intercostal space. Ultrasound requires less time than manipulation.Trial registrationISRCTN10722758. Registered 04 June 2019

Integrating CAD and 3D-Printing Techniques to Construct an In Vitro Laser Standard Treatment Platform for Evaluating the Effectiveness of Sterilization by Er:YAG Laser in Peri-Implant Intra-Bony Defects

This study established an in vitro model mimicking clinical peri-implant intra-bony defects. We investigated the effect of access limitation and the bactericidal effectiveness of erbium-doped yttrium, aluminum and garnet (Er:YAG) laser irradiation in shallow and deep peri-implant defects at different tooth positions. Reverse engineering, computer-aided design (CAD), and 3D-printing techniques were integrated to establish physical peri-implant intra-bony defect models at mandibular central incisor, first premolar, and first molar positions with shallow (2 mm depth) or deep (6 mm depth) defects and with 1.5 mm and 1.8 mm widths at the bottom and crestal portions of the alveolar process, respectively. Three-dimensional printed suites at the corresponding implant sites replaced experimental implant specimens for the investigation of bacterial adhesion in individuals. Dental implants with diameters of 3, 4 and 5 mm were utilized at the mandibular incisor, premolar, and molar positions, respectively. Bacterial adhesion of Gram (–) Escherichia coli on the exposed implant surfaces prior to sterilization was assessed. Sterilization with shallow and deep intra-bony defects was investigated by measuring the reduction of residual viable bacteria on implants after 60 s of irradiation with an Er:YAG laser. The adhesion rate of Gram (–) Escherichia coli on the investigated implant surfaces ranged from 1% to 3% (1.76 ± 1.25%, 2.19 ± 0.75% and 2.66 ± 1.26% for 3, 4, and 5 mm implants, respectively). With shallow peri-implant bony defects, the Er:YAG laser sterilization rates were 99.6 ± 0.5%, 99.3 ± 0.41% and 93.8 ± 7.65% at mandibular incisor, premolar, and molar positions, respectively. Similarly, sterilization rates in deep peri-implant defects were 99 ± 1.35%, 99.1 ± 0.98% and 97.14 ± 2.57%, respectively. A 3D-printed model with replaceable implant specimens mimicking human peri-implant intra-bony defects was established and tested in vitro. This investigation demonstrated effective sterilization using Er:YAG laser irradiation in both shallow and deep peri-implant intra-bony defects at different positions and diameters of dental implants.

A study on evaluation of acrysof toric intraocular lens implantation to correct pre-existing corneal astigmatism in patients undergoing cataract surgery- At a tertiary care hospital

The current study evaluates the results of acrysof toric intraocular lens implantation to correct pre-existing corneal astigmatism in patients undergoing cataract surgery. This study was done on Prospective interventional at Osmania Medical College, Sarojini Devi Eye Hospital, Hyderabad. The sample of the study is included 40 eyes of 38 consecutive patients with 1.5 D or more of pre-existing astigmatism consists of cataract surgery with toric open-loop IOL implantation (Alcon, Fort Worth, TX, USA). The pre-operative markings for the position of incisions and IOL placement were being done under the slit lamp. The visual acuity, residual keratometric and refractive cylinders, and toric IOL axis were being measured. 54.71 years was the mean age of the patients. All the 40 eyes at the final check-up had post-operative unaided visual acuity of 6/12 or better. 10 patients (25 %) had an unaided visual acuity of 6/6.37 eyes (92.5%) had best corrected post-operative visual acuity of 6/9 or better. The mean pre-operative refractive astigmatism in 40 eyes was 2.34D. 22 eyes had the Refractive astigmatism of &amp;#62;2D. No eyes had refractive astigmatism of &amp;#60;1.5D. The mean axial length was 24.22mmOut of 40 eyes in which Toric IOL was implanted, the post-operative residual refractive sphere was seen in 4 eyes. Out of 40 eyes in whom Toric IOL was implanted, a post-operative residual refractive cylinder was seen in 30 eyes. 10 patients had No post-operative refractive cylinder. The mean post-operative residual refractive cylinder was 0.58D. The mean Post-operative Keratometric cylinder was 2.24D. The mean post-operative Keratometric cylinder was 2.34D. In comparison, both pre-operative and post-operative keratometric astigmatism, it was found that there was no statistically significant difference between them.The misalignment of Toric IOL was 10 degrees or less in 36 patients (94.73%) and less than 5 degrees in 22 patients (57.89%). Misalignment of &amp;#62;10 degrees (11 degrees and 13 degrees) was seen in 2 patients. The mean IOL rotation among 38 patients was 4.55 degrees (Range 0-13 degrees, SD 3.43). None of the eyes required repositioning. The results of this study show that implantation of AcrysofTor ic IOL is a good surgical method to evaluate pre-existing corneal astigmatism in cataract surgery. Acrysoftoric IOL has shown good rotational stability.

Alveolar bone morphology in patients with a unilateral palatally displaced maxillary lateral incisor: A cone-beam computed tomography study

Lingual displacement of the maxillary anterior teeth is 1 of the most common forms of malocclusion. The labial alveolar bone is thinner for the maxillary lateral incisor than for the central incisor and canine; however, the alveolar bone width at the actual position of the maxillary lateral incisor has not been examined. We investigated the morphologic characteristics of the alveolar bone around palatally displaced maxillary lateral incisors using cone-beam computed tomography and a split-mouth model. Twenty-seven patients with a unilateral palatally displaced maxillary lateral incisor were included. Axial, sagittal, and horizontal measurements were recorded at 3 levels (ie, 25%, 50%, and 75% of the root length) using cone-beam computed tomography. All obtained data were statistically analyzed using paired t tests. The labial alveolar bone width at 25% of root length was significantly lesser on the affected side. At all 3 levels, the distance between a line tangential to the labial alveolar bone of the central incisor and canine and the position of the labial alveolar bone of the lateral incisor was significantly greater on the affected side. At 50% and 75% of root length, the horizontal distance between the posterior nasal spine and the labial alveolar bone of the lateral incisor was significantly lesser on the affected side. Palatal displacement of maxillary lateral incisors is significantly associated with decreased alveolar bone width at the apical level and asymmetry. However, a further elaborate investigation is necessary to determine the clinical relevance of the study.

Resistance to Fracture in Fixed Dental Prostheses Over Cemented and Screw-Retained Implant-Supported Zirconia Cantilevers in the Anterior Region: An In Vitro Study.

To evaluate the resistance to fracture in cantilevered fixed dental prostheses (cFDPs) of single implant-supported zirconia cantilevers in the anterior region. Thirty-two cemented and solely screw-retained cFDPs consisting of an implant-supported crown replacing the central incisor and an attached cantilever unit in the position of the lateral incisor in the maxilla were constructed by computer-aided design (CAD) and machined by computer-aided manufacturing (CAM). For the cemented solution, a cFDP was designed on top of a customized abutment luted to an adhesive base. For screw-retained cFDPs, abutment, cement gap, and restoration of the cementable design were combined. All cFDPs were veneered manually on the facial side. Half of the samples underwent artificial aging (thermocycling and chewing simulation) before fracture tests were conducted with loads applied to the pontic either parallel to the implant axis (axial loading on the pontic) or tilted lingually by α = 45 degrees (oblique loading on the pontic). Thus, there were eight groups differing in cFDP design, artificial aging, and load application (n = 8/group). If fracture (Fu,total) occurred within the implant components, the adhesive base was replaced by a cast CoCr base, and the cFDP's fracture resistance (Fu,cFDP) was also determined. Using statistical analyses (SPSS 24, IBM), factors affecting fracture resistance were identified. Fu,total was mainly correlated to screw fractures and therefore not affected by cFDP design. Oblique loading on the pontic (Fu,total = 231 N - 352 N), however, led to a significant (P < .001) decrease in ultimate load compared with axial loading on the pontic (Fu,total = 611 N - 815 N). In relation to Fu,total, Fu,cFDP was approximately twice as high for both loading conditions. When relating the results to maximum occlusal forces exerted in the maxillary anterior region, single implant-supported cFDPs can be a viable restorative treatment option.

Use of retrograde pyelogram to plan for miniature open incision in pediatric pyeloplasty

As robotic-assisted surgery becomes increasingly utilized for pediatric ureteropelvic junction (UPJ) obstruction, open surgeons have countered by using muscle-splitting, miniature (≤2cm) incisions. To prepare for this type of incision during pyeloplasty, it is necessary to define the exact location of the UPJ. The use of retrograde pyelogram (RPG) at the time of pyeloplasty helps the surgeon to identify the exact location of UPJ, and thus be able to use a muscle-splitting, miniature incision for open pyeloplasty. We hypothesize that when performing a muscle-splitting, miniature incision open approach; preoperative RPG frequently changes the traditional pyeloplasty flank incision at the tip of the 11th or 12th rib. A retrospective review of open pyeloplasties performed by a single surgeon at our institution from 7/1/2010 to 12/31/2018 was performed to determine rate of use of RPG, open pyeloplasty incision location and to determine what factors are predictive of incisional site. 114 of 122 (93.4%) patients with 115 renal units had pyeloplasties with preoperative RPG performed. Of the 8 procedures without RPG, two had a pelvic kidney diagnosed prior to surgery, two had narrow ureteric orifices that were difficult to cannulate, and four had associated reflux. In 31/115 (27%) pyeloplasties the incision was changed from a standard incision position at the 11th or 12th rib to an alternative incision (i.e. extended muscle-transecting incision at the tip of the 11th or 12th rib, or to an alternate incision site including Gibson, McBurney's incision, or low anterior abdominal incision). 84/115 (73.0%) had a miniature (<2cm) incision at the tip of the 11th or 12th rib. Grade IV hydronephrosis was a significant predictor for changing the traditional incision site (p=0.02). Preoperative nephrostomy tube insertion was also associated with an increased likelihood of having an alternate incision (p=0.04). Incision site was not significantly affected by age of the patient at surgery, patient sex, size of the affected kidney, T1/2 times of <30min, split function of <30%, kidney length differential, or laterality. The consistent use of RPG prior to pyeloplasty helps surgeons to plan for a small muscle-splitting, miniature open incisions. In our experience, 27% of pyeloplasties required alternative incision sites based on the results of pre-operative RPG.

To Determine the Anteroposterior Position of Incisors in Relation to Points A and B on Cephalogram and Study Models in North Indian Population

Abstract Introduction This study aimed to determine the upper and lower incisors to points A and B on lateral cephalogram and study model in North Indian population. This article evaluated the present relationship of upper and lower incisors position to point A and B on the cephalogram and studied the model as a diagnostic tool for orthodontic treatment planning. Materials and Methods The study included 32 patients, aged 15 to 25 years. The sample was divided into two groups as group I (n = 32, cephalometric analysis) and group II (n = 32, study model analysis) of the same patient. In group I incisors position was related to points A and B on the cephalograms and in group II incisors position was related to points A and B on study model by using transparent grid. Results As per Indian norms, outcome mean value for cephalometric norms was 6.3 and 3.2 mm and for study model norms was 4 and 1.3 mm. Statistically significant differences (p &lt; 0.002) were observed for mandibular incisor position on cephalograms and for maxillary incisors (p &lt; 0.001) on study casts when compared with Chile sample norm. Conclusion The anteroposterior position of upper and lower incisors in relation to points A and B on cephalogram and casts has been determined in North Indian patients.