Amount Of Recession Research Articles

Preimpression troughing with the diode laser: A preliminary study

Statement of problemThe mechanical-chemical technique and the use of a laser are methods for displacing the gingiva to make an accurate impression of the preparation for a complete crown. The tissue needs to be displaced and the hemorrhage controlled to capture the prepared finishing line in the impression. The degree of undesirable gingival recession after these displacement techniques is unknown. PurposeThe purpose of this pilot clinical study was to clinically monitor and compare the regeneration of the gingival tissue by using 2 methods of gingival displacement in the same participant: the mechanical-chemical technique with double cords impregnated with aluminum chloride and the 810 nm diode laser (Odyssey; Ivoclar Vivadent AG). Material and methodsA total of 6 participants needing 2 crowns on natural teeth were included in this study. At the first visit, the teeth were prepared with a 0.5-mm subgingival finishing line and interim crowns were fabricated. One of the teeth was randomly assigned to the double cord technique with 2 (# 000 and # 1) impregnated 5% aluminum chloride cords and the other to the 810 nm diode laser. An adjacent tooth served as a control. A device was made that would function as a fixed reference point for the measurements at different time intervals. A notch was created on the device to position the digital ruler between the occlusal notch and the free gingival margin to measure the distances. The measurements were recorded for each patient before displacement of the gingiva and at the time of cementation of the definitive crowns. The patients were followed at 1 week, 3 weeks, and 8 weeks after cementation of the definitive crowns. ResultsThe amount of recession with the cord impregnated with aluminum chloride was 0.26 mm 8 weeks after cementation of the definitive crowns with a range between 0.00 mm and 0.72 mm. The diode laser showed an average recession of 0.27 mm with a range between 0.01 mm and 0.68 mm. ConclusionsThis study found an average loss of gingival height of 0.26 mm for the double cord technique and 0.27 mm for the laser. The amount of recession was considered not clinically significant.

Effect of fixed orthodontic appliance on some factors and elements of saliva

Objectives: to determine the prevalence, severity and extension of gingival recession in an adult population in Sulaimani city – Iraq.
 Materials and Methods: 627 subjects, males and females were examined at Shorsh teaching hospital - dental center in Sulaimani city to determine the prevalence, severity and extension of gingival recession. The sample was divided into four age groups, group 1 (20 to 29 years) 232 patients, group 2 (30 to 39 years) 223 patients, group 3 (40 to 49 years) 128 patients and group 4 (above 50 years) 44 patients. A calibrated periodontal probe marked up to 15 mm was employed for measuring the amount of gingival recession from cementoenamel junction to the gingival margin on four surfaces of each tooth - mesial, buccal, distal and lingual. Miller’s classification was used to evaluate the severity of the recession.
 Results: In this study a total of 249 subjects out of 627 recorded gingival recession. Whereas, 1453 teeth out of 6776 adding up to 2340 sites displayed (≥1 mm) gingival recession. Furthermore, the majority of older age group (≥ 50 years) sample revealed gingival recession (93.2%). Statistically gingival recession among male subjects were non-significantly higher than female subjects 46% against 34.5% respectively, whereas females recorded higher number of teeth and sites affected by gingival recession than males (823 teeth against 630 teeth and 1277 sites against 1063 sites). According to Miller’s classification, class one recession was most prevalent (55%) followed by class III (38.2%). According to age, Class I recessions decreased as age increased, however, Class III and Class IV recessions showed an increasing status as age increased. According to tooth type, mandibular central and lateral incisors showed the highest percentages of gingival recession (23.6% and 19.4%) respectively.
 Conclusion: Prevalence of the gingival recession was high among the population examined in this study with a predilection for males. Gingival recession was more prevalent in higher age groups. Furthermore, mandibular central and lateral incisors were the most frequent teeth revealing recession among the total dentition.

Effect of Horizontal Strabismus Surgery on the Refractive Status

Purpose: To evaluate the effects of horizontal strabismus surgery on the refractive and astigmatic status of eyes following horizontal muscle surgery using double-angle vector analysis.Materials and Methods: This was a retrospective analysis of 137 patients (250 eyes) conducted between February 1997 and October 2010 in patients who had unilateral or bilateral recession or monocular recession and/or underwent resection of horizontal muscles by a single surgeon. Refraction data were obtained at 1–2 weeks preoperative and at 4–6 weeks and 4–6 months postoperative. Surgically induced refractive changes were calculated using double-angle vector analysis.Results: The mean change in the spherical equivalent (SE) of the refraction was 0.23 ± 0.78 D for surgically induced refractive changes at 4–6 weeks postoperative (SIRC1; p < 0.0001) and 0.14 ± 0.85 D (p = 0.018) for surgically induced refractive changes at 4–6 months postoperative (SIRC2), indicating a small shift in the myopic direction with regression at 4–6 months. The mean amplitudes of the induced cylinders were 0.072 ± 1.22 D (p = 0.262) in SIRC1 and 0.20 ± 1.14 D (p = 0.012) in SIRC2, and the mean axis of the induced plus cylinder was 21.74° in SIRC1, indicating a small shift in the with-the-rule direction, but no statistically significant difference from zero (p = 0.331). The changes in the surgically induced refraction over time (SIRC d), ie, 0.05 ± 0.64 in SE (p = 0.255) and 0.09 ± 0.65 in the cylinder (p = 0.049), were stable. There was no significant correlation between the amounts of horizontal rectus muscle recession and/or resection and the cylinder power of individual induced astigmatism at 4–6 weeks after surgery (p = 0.266) and the myopic shift (p = 0.345). Moreover, there were no significant correlations between the ages of the patients and the spherical equivalent for SIRC1 (p = 0.858) and the induced cylinder for SIRC1 (p = 0.750).Conclusion: Horizontal rectus muscle surgery tended to induce a transient, statistically significant change in the spherical equivalent of refraction, with a myopic shift that was clinically not important. Our findings did not strongly support that the astigmatism induced changes. There was no correlation between the amount of recession and/or resection and the amount of induced refractive error.

Reduction in Rectus Muscle Recession Depending on the Distance Between Rectus Muscle Suture Placement and Scleral Insertion in Rabbit Eyes

To quantitatively determine how a large tendon remnant reduces the effect of the rectus muscle recession procedure with respect to the distance between the placement of the muscle suture and the scleral insertion. Thirty-six eyes from 18 rabbits were randomly divided into four groups according to the distance between the superior rectus muscle suture placement and the scleral insertion (1, 2, 3, and 4 mm). The superior rectus muscle was sutured at the previously listed distances from the insertion. Each superior rectus muscle was reattached using a scleral pass at a site 4 mm posterior to its original insertion. The amount of recession was measured as the distance between the most anterior aspect of the reattached muscle and the original insertion site. The mean amount of recession was 4.07 ± 0.25 mm in the 1-mm group and 2.76 ± 0.55 mm in the 4-mm group at postoperative week 4. There were significant differences in the amount of recession between the four groups. Linear regression analyses revealed a significant relationship between the distance of the muscle suture placement from the scleral insertion and the amount of recession (r(2) = 0.521). The superior rectus muscle was estimated to be reattached 0.437 mm anterior to the desired location for every 1 mm that the muscle suture was placed posterior to the scleral insertion. The potential error that depends on the distance between the muscle suture placement and the scleral insertion should be considered to reduce undercorrection and ensure a good surgical outcome.

Prevalence, Extension and Severity of the Gingival Recession in an Adult Population Sample of Sulaimani city– Iraq

Objectives: to determine the prevalence, severity and extension of gingival recession in an adult population in Sulaimani city – Iraq.&#x0D; Materials and Methods: 627 subjects, males and females were examined at Shorsh teaching hospital - dental center in Sulaimani city to determine the prevalence, severity and extension of gingival recession. The sample was divided into four age groups, group 1 (20 to 29 years) 232 patients, group 2 (30 to 39 years) 223 patients, group 3 (40 to 49 years) 128 patients and group 4 (above 50 years) 44 patients. A calibrated periodontal probe marked up to 15 mm was employed for measuring the amount of gingival recession from cementoenamel junction to the gingival margin on four surfaces of each tooth - mesial, buccal, distal and lingual. Miller’s classification was used to evaluate the severity of the recession.&#x0D; Results: In this study a total of 249 subjects out of 627 recorded gingival recession. Whereas, 1453 teeth out of 6776 adding up to 2340 sites displayed (≥1 mm) gingival recession. Furthermore, the majority of older age group (≥ 50 years) sample revealed gingival recession (93.2%). Statistically gingival recession among male subjects were non-significantly higher than female subjects 46% against 34.5% respectively, whereas females recorded higher number of teeth and sites affected by gingival recession than males (823 teeth against 630 teeth and 1277 sites against 1063 sites). According to Miller’s classification, class one recession was most prevalent (55%) followed by class III (38.2%). According to age, Class I recessions decreased as age increased, however, Class III and Class IV recessions showed an increasing status as age increased. According to tooth type, mandibular central and lateral incisors showed the highest percentages of gingival recession (23.6% and 19.4%) respectively.&#x0D; Conclusion: Prevalence of the gingival recession was high among the population examined in this study with a predilection for males. Gingival recession was more prevalent in higher age groups. Furthermore, mandibular central and lateral incisors were the most frequent teeth revealing recession among the total dentition.

Outcome of Inferior and Superior Rectus Recession in Graves’ Orbitopathy Patients

Purpose: To evaluate the surgical effect of unilateral inferior rectus recession (IR-group) with or without a recession of contralateral superior rectus (IR-SR-group) on squint angle and motility restrictions in Graves’ Orbitopathy (GO) patients.Design: Retrospective case series.Materials and Methods: Primary outcome parameters were the changes of squint angle 3 months and 6–12 months postoperatively. As in a previous study, success was defined as a postoperative vertical squint angle of ≤3° in primary position and on downgaze. Secondary outcome parameters were the influence of surgery on duction range and influence of muscle size on dose-effect response.Results: Fifty-six patients were included in the study; 31 patients in the IR-group and 25 patients in the IR-SR-group. The amount of (fixed suture) recession ranged from 2 mm to 7 mm. Vertical deviations in primary position changed from 8.0° [95% CI 6.6–9.7°] to 1.0° [95% CI −0.4–6.5°] in the IR-group and from 17.0° [95% CI 15.7–20.0°] to 1.5° [95% CI 0.8–2.9°] in the IR-SR-group. The success rate was 74% in the IR-group and 64% in the IR-SR-group. Elevation significantly improved in both groups (IR-group p = 0.007; IR-SR- group p = 0.000). The volume of vertical rectus muscles as assessed on CT-scans did not influence the dose-effect response.Conclusions: The highest success rate and highest reduction of depression was found in the IR-group. The total duction range remained stable after strabismus surgery (IR-group) or improved (IR-SR-group). Both squint angle and cyclodeviation remained stable during long time follow-up (6–12 months after surgery).

Retrospective study of recession of four horizontal rectus muscle in periodic alternating nystagmus.

PurposePeriodic alternating nystagmus (PAN) is a spontaneous horizontal nystagmus observed in disorders of the central nervous system. Patients with congenital PAN complain of oscillating vision at high rates. Medication is the first-choice treatment for PAN; however, clinicians still seek better therapy. The aim of this study was to evaluate outcomes of recession of four horizontal rectus muscle (R-FHR) in patients with congenital PAN.Patients and methodsThis study reports a retrospective case series of ten patients (seven males and three females; mean age 24.4±10.9) with congenital PAN who underwent R-FHR between 2007 and 2012, which was performed by the same surgeon at the Hyogo College of Medicine. Patients were evaluated for complications, recession amount, deviation angle, eye movements including a nystagmus amplitude, and visual acuity during pre- and post-operative periods.ResultsPre-operatively, patients complained of oscillating vision, abnormal head posture, esotropia, and congenital superior oblique palsy. Post-operatively, changes from the previous observations of nystagmus amplitudes and abnormal head posture demonstrated a complete reversal in all patients. In addition, visual acuity determined with a Snellen chart improved in two patients. However, esotropia occurred in three patients who underwent additional strabismus surgery 2 days after R-FHR. R-FHR was particularly effective in eight patients who pre-operatively had periodic oscillating vision with a regular pattern of periodic nystagmus.ConclusionWe demonstrated that ten patients with congenital PAN had improved vision following R-FHR, indicating that R-FHR was an effective procedure, especially in patients suffering PAN with periodic oscillating vision.

Use of a Carbon Dioxide Laser as an Adjunct to Scaling and Root Planing for Clinical New Attachment: A Case Series

Severe, chronic periodontitis (CP) is typically treated either with scaling and root planing (SRP) or surgical therapy in an effort to gain clinical attachment. The advantage of non-surgical therapy is decreased morbidity to the patient; however, the site typically heals by formation of a long junctional epithelium. The advantage of surgical therapy is access for debridement and the use of bone or bone substitutes in combination with a barrier membrane for epithelial exclusion. Compared with a non-surgical approach, surgical therapy is more invasive, and patient acceptance of treatment is typically more challenging. The use of lasers in dentistry appears to be rapidly increasing, as evidenced by the influx of new lasers into the dental market as well as numerous anecdotal reports of beneficial results with their use. This report presents a novel approach to the treatment of severe CP using a carbon dioxide (CO2) laser in combination with SRP. This study presents the findings of 17 patients (nine males and eight females, aged 34 to 71 years; mean age: 54 years) that were compared in a split-mouth design and followed for 3 months. To the best of the authors' knowledge, this is the first reported case series using a CO2 laser for de-epithelialization in combination with SRP for the treatment of CP. Sites treated with the CO2 laser tended to show a greater decrease in probing depths, greater amounts of recession, and greater gains in clinical attachment levels, but the results were not statistically significantly better than SRP alone.

Traditional and reduced recession surgical dosage for bilateral lateral rectus recession for infantile exotropia

BackgroundTo investigate the optimal surgical dose for treating infantile exotropia.MethodsIn this retrospective study, clinical records of 44 children who had undergone bilateral lateral rectus recessions before 4 years of age...

Results of Bilateral Medial Rectus Recession for Comitant Esotropia in Patients with Developmental Delay

Purpose: There is paucity of literature on surgical outcomes after strabismus surgery in patients with developmental delay. There is no consensus regarding whether standard surgical tables are applicable to these children. The goal of our study was to determine results of strabismus surgery for esotropia among these children.Methods: Two retrospective cohorts of patients, with developmental delay (excluding Down syndrome) and without developmental delay, who underwent bimedial recession for comitant eso-deviation between January 2005 and January 2011, meeting our criteria, were selected. Amount of surgery performed in these children was compared with standard table. This comparison gave us operated angle of deviation. This operated angle of deviation was expressed as percentage of preoperative angle of deviation to get amount of surgery performed. Response to surgery was defined as percentage of change in angle of deviation after surgery to the operated angle of deviation. Amount of surgery performed, response to surgery, and results were compared between two groups.Results: This study included 25 patients with developmental delay and 53 normal children with comitant esotropia. Age, refractive error, and preoperative angle of deviation were comparable in patients with and without developmental delay. Among patients with developmental delay, on average 72.13% ± 16.08 of angle of deviation was operated; response to surgery gained was 134.06% ± 51.62. In the control group, the average amount of surgery done was 89.08% ± 10.83; response gained was 89.83% ± 22.49. Successful outcome (±10 PD of orthophoria) was noted in 60% patients with developmental delay compared to 73.58% in control group. On average 70.67% ± 17.95 angle of deviation was operated in patients with developmental delay with successful outcome.Conclusion: Surgical outcome in patients with developmental delay is very unpredictable. An exaggerated response to standard amounts of bimedial recession should be anticipated in these patients. Though there was no statistically significant difference, operating for 70.67% ± 17.95 angle of deviation is more likely to be successful.

Surgically Induced Astigmatism Following Medial Rectus Recession: Short-Term and Long-Term Outcomes

The current study aimed to investigate short- and long-term postoperative ocular refractive effects of medial rectus recession on the involved eye and to describe the detectable effects in detail by the results of vector analysis. Data of patients in whom medial rectus recession was performed between 2010 and 2012 were retrospectively evaluated. The study included 52 eyes of 32 patients. Patients with a history of previous ocular surgery, congenital or progressive corneal disease, familial or acquired posterior segment disease, glaucoma, a history of ocular trauma, or any neurological or systemic disease were excluded. Best-corrected and uncorrected visual acuities and refraction examination findings of the patients were recorded before the surgery and at the postoperative first month and first year. A vector analysis program was used to analyze surgically induced astigmatism. Significant myopic shift and astigmatic change were determined in the spherical equivalent refraction in the early postoperative period (first month); however, these changes disappeared in the long term (at the postoperative first year). A positive correlation was not observed between the amount of surgical recession and the results of ophthalmic examination at the postoperative first month and first year. Only postoperative first month spherical equivalent showed a positive correlation with the amount of surgical recession; however, this correlation disappeared at the postoperative first year.

Intermittent exotropia: relation between age and surgical outcome: a change-point analysis

To study the relationship between age and response to surgery in patients with intermittent exotropia and to identify change points in response to surgery. A retrospective analysis was conducted on 311 patients with intermittent exotropia who had bilateral lateral rectus recession using standard tables with minimum follow-up of 6 months. Data were analyzed using the change-point analysis software to identify cutoff points. A prospective pilot study was then performed on 171 consecutive patients with intermittent exotropia with the same clinical characteristics, in whom amount of recession was modified according to the identified cutoff points. In angles with two change points, 1-mm recession was reduced from patients younger than the lower change point and 1.5-mm recession was added to those older than the upper change point. In angles with one change point, 1.5-mm recession was added to those older than the change point. Satisfactory alignment was defined as esophoria/tropia ≤ 5Δ to exophoria/tropia ≤ 8Δ. There was a negative correlation (P<0.01) between response to surgery and age at surgery for all angles. In younger patients (<7 years) in whom surgical dose was reduced, there was no significant change in success rate (77%), compared with those who had surgery using standard tables (75%). In older patients (>12 years) in whom surgical dose was increased, there was a statistically significant increase in success rate (80% vs 41%). Modifying the surgical dose according to age can improve the success in patients with intermittent exotropia.

Gingival Margin Changes in Maxillary Anterior Sites After Single Immediate Implant Placement and Provisionalization: A 5-Year Retrospective Study of 47 Patients

To evaluate gingival margin changes in the esthetic zone after immediate implant placement and provisionalization over 5 years with a custom anatomic provisional abutment. Single maxillary incisor immediate implant placement and provisionalization procedures, completed and followed between February 2006 and August 2006, were analyzed retrospectively. During clinical recalls at 3 months, 1 year, and 5 years, changes in gingival margins were recorded with clinical photographs and recorded in millimeters. Forty-seven patients each received a single implant (19 central incisors, 28 lateral incisors) and were followed for 5 years. Implants and restorations had a 100% survival rate during the study. The mean gingival margin changes (recession) were 0.17 mm at the time of definitive restoration, 0.27 mm at 3 months, 0.30 mm at 1 year, and 0.30 mm at 5 years. After 5 years, 24 of the 47 implant crowns had no significant gingival recession. All central incisor sites received 4.3-mm-diameter implants and had a mean change in tooth length of 0.03 mm at 5 years. Lateral incisor sites (n=28) received either a 3.5-mm-diameter implant (n=20) or a 4.3-mm-diameter implant (n=8). Lateral sites with the 3.5-mm implant had a mean change in gingival margin height of 0.08 mm of tooth length at 5 years; lateral sites with a 4.3-mm platform displayed a mean change of 0.82 mm of tooth length. This study suggests that implant diameter, gingival biotype, surgical technique, and/or the reason for tooth loss can influence the amount of gingival recession occurring over 5 years. Most recession occurred within the first 3 months, between implant placement/provisionalization and definitive restoration. The use of a customized anatomic provisional abutment can reduce the amount and frequency of recession.

A novel technique for inferior rectus recession.

PurposeTo introduce a novel technique of inferior rectus recession operation to allow larger amounts of recession without causing lower lid retraction and to compare this method with the results obtained in standard inferior rectus recession.Material and methodsThis study included 20 patients operated on in the authors’ clinic. The median age of the patients was 24.5±18.6 (4–73) years and the median follow-up was 9.3±11.8 (3–43) months. Ten patients operated on with the standard method were labeled Group 1 and ten patients operated on with the new method were labeled Group 2. Without exceeding 4 mm, inferior rectus recession to the whole muscle was performed in Group 1 patients. Inferior rectus recession was also performed on patients in Group 2 following the new method. Using a spatula, approximately 10% of the muscle surface fibers were detached intact as a thin layer, and the remaining 90% of deeper fibers were recessed 4–8 mm as planned. Patients’ preoperative deviations and lower lid positions were recorded. The same parameters were checked in the first and third month postoperatively. Both groups were evaluated retrospectively by screening their files, and the Mann–Whitney U test was used for statistical evaluation.ResultsLower lid retraction was seen in four patients of Group 1. There was no retraction in Group 2. While there was a need to perform additional vertical muscle procedures for vertical deviations and lower lid retractions in Group 1, it was observed that there was no need for additional procedures in Group 2 patients. There was a statistically meaningful difference between the two procedures (P<0.05).ConclusionThis novel technique was found to be an effective surgical method for permitting more recession without the risk of lower lid retraction.

Stability of Y-splitting procedure combined with hang-back recession of the rectus muscle in rabbit eyes

The Y-splitting procedure has been used both to treat up-shoots and down-shoots in Duane syndrome, and as a substitute for posterior fixation suture. The Y-split is often performed in conjunction with a hang-back recession when a large amount of recession or an adjustable suture is necessary. Herein, we evaluated the stability of Y-splitting hang-back recession in the rectus muscle. Under general anesthesia, a 5-mm hang-back recession of the superior rectus muscle (SR) with Y-splitting was performed in ten eyes from ten rabbits (hang-back group). A conventional recession was performed in the SR of the fellow eye (control group). Six weeks after the procedure, the distance between the original insertion and the recessed SR (recession amount) and the width between the nasal and temporal halves of the SR were measured. These values were compared to the measurements taken at the time of surgery. The hang-back group had a significantly larger forward displacement than the control group (P < 0.001 for both the nasal and temporal halves). The width change between the nasal and temporal halves was also significantly larger in the hang-back group (4.94 ± 1.32 mm) than in the control group (1.14 ± 0.60 mm, P < 0.001). Additionally, the Y-configuration appeared to be more collapsed in the hang-back group than in the control group. Y-splitting of the rectus muscle may be unstable when it is combined with a hang-back recession. Surgeons should consider this possibility when performing Y-splitting procedures.

Change in the location of the equator and recessed muscles in young rabbit eyes

To study the changes in the location of the equator and the new insertion of extraocular muscle after recession surgery in a rabbit model. An experimental study was performed in ten eyes of five rabbits. Eyes were divided into two groups according to the amount of recession. In right eyes, 5 mm superior recti (SR) muscle recession, approximately 2 mm posterior to the equator, was performed (5 mm recession group), while in the left eyes, 3 mm recession was performed to the location of the equator (3 mm recession group). We measured the distance of the equator from the limbus, as well as the distance between the superior rectus insertion and the equator. The preoperative measurements were compared with the results 2 months after the surgery. The change in location of the superior rectus and the equator was compared between the two eyes. The recessed SR muscle did not show any significant change in location in both groups (p = 0.18 and 0.16 respectively). However, the location of the equator of rabbit eye showed movement of about 1 mm posterior to the initial location with the growth of the eyeballs (p = 0.04 and 0.03, respectively). The location of the equator moved posteriorly at 2 months postoperatively in young rabbit model while the insertion of the recessed SR did not show any significant movement.

A comparison of ocular alignment success of hang-back versus conventional bilateral lateral rectus muscle recession for true divergence excess intermittent exotropia

To assess whether hang-back or conventional bilateral lateral rectus muscle recessions were more successful in achieving a satisfactory postoperative ocular alignment in patients with true divergence excess intermittent exotropia. The medical records of consecutive patients with true divergence excess intermittent exotropia who underwent bilateral lateral rectus muscle recession using hang-back or conventional techniques were retrospectively analyzed. All surgeries were performed by a single surgeon using the same standard table of surgical dosage. We compared the preoperative characteristics and motor surgical outcomes between the two groups. Success was defined as alignment within 10(Δ) of intermittent exotropias at distance and near. Any amount of postoperative esotropia was considered a failure. A total of 42 patients were included: 13 in the hang-back group and 29 in the conventional group. The mean age at surgery, mean preoperative deviation at near and distance, mean amount of lateral rectus muscle recession, and mean follow-up duration were not statistically significantly different between groups. At the most recent follow-up, the conventional group had a significantly greater success rate (≤10(Δ) of intermittent exotropia) than the hang-back group (83% vs 31%, P = 0.0009). There was no statistically significant difference in the mean amount of lateral rectus recession between patients with successful and unsuccessful surgical outcomes in both groups. Within the limitations of this study, conventional bilateral lateral rectus recessions were more effective than hang-back recessions in achieving a successful postoperative alignment in patients with true divergence excess intermittent exotropia.

An analysis on the factors responsible for relative position of interproximal papilla in healthy subjects

PurposeThis study examined the factors that can be associated with the appearance of the interproximal papilla.MethodsOne hundred and forty-seven healthy interproximal papillae between the maxillary central incisors were examined. For each subject, a digital photograph and periapical radiograph of the interdental embrasure were taken using a 1-mm grid metal piece. The following parameters were recorded: the amount of recession of the interproximal papilla, contact point-bone crest distance, contact point-cemento-enamel junction (CEJ) distance, CEJ-bone crest distance, inter-radicular distance, tooth shape, embrasure space size, interproximal contact area, gingival biotype, papilla height, and papilla tip form.ResultsThe amount of recession of the interproximal papilla was associated with the following: 1) increase in contact point-bone crest, contact point-CEJ, and CEJ-bone crest distance; 2) increase in the inter-radicular distance; 3) triangular tooth shape; 4) decrease in the interproximal contact area length; 5) increase in the embrasure space size; and 6) flat papilla tip form. On the other hand, the amount of gingival recession was not associated with the gingival biotype or papilla height. In the triangular tooth shape, the contact point-bone crest distance and inter-radicular distance were longer, the interproximal contact area length was shorter, and the embrasure space size was larger. The papilla tip form became flatter with increasing inter-radicular distance and CEJ-bone crest distance.ConclusionsThe relative position of the interproximal papilla in healthy subjects was associated with the multiple factors and each factor was related to the others. A triangular tooth shape carries a higher risk of recession of the interproximal papilla because the proximal contact point is positioned more incisally and the bone crest is positioned more apically. This results in an increase in recession of the interproximal papilla and flat papilla tip form.

Surgical Outcomes of Medial Rectus Recession in Esotropia with Cerebral Palsy

To determine the outcome of a reduced amount of medial rectus (MR) muscle recession in esotropes with cerebral palsy (CP) and to compare the surgical response with that of normal controls. Retrospective cohort study. Thirty esotropes with CP and 60 age-matched esotropes without CP who underwent a unilateral or bilateral MR muscle recession. The surgical amount of MR muscle recession was reduced by 1 mm per muscle in patients with CP. Success rates, surgical response, cumulative probabilities of success, and factors affecting surgical responses evaluated by generalized linear mixed models. In patients with CP, the initial success rate was higher (P = 0.037) and the rate of undercorrection was lower (P = 0.037) compared with patients without CP. At the final visit, success rates were not significantly different between both groups. However, the rate of overcorrection was higher (P = 0.003) compared with patients without CP. The rate of overcorrection per person-year during follow-up was 11% in patients with CP and 2% in patients without CP. Patients with CP showed a greater surgical response than did those without CP, at about 1.3 prism diopters per millimeter of MR muscle recession (P<0.001). Even with the reduced amount of recession, esotropes with CP showed a greater surgical response to MR muscle recession than did those without CP, and the incidence of late overcorrection was significantly higher compared with that of patients without CP.

Predicting shoreline evolution on a centennial scale using the example of the vistula (Baltic) spit

The proposed algorithm comprises three main steps. The first step is the evaluation of the sediment transport and budget. It was shown that the root segment of the Vistula Spit is dominated by eastward longshore sediment transport (up to 50 thousand m3/year). Over the rest of the spit, the shoreline’s orientation causes westward sediment transport (more than 100 thousand m3/year). The gradients of the longshore and cross shore sediment transport become the major contributors to the overall sediment balance. The only exception is the northeastern tip of the spit due to the appreciable imbalance of the sediment budget (13 m3m−1 yr−1). The second step in the prediction modeling is the estimation of the potential sea-level changes during the 21st century. The third step involves modeling of the shoreline’s behavior using the SPELT model [6, 7, 8]. In the most likely scenario, the rate of the recession is predicted to be about 0.3 m/year in 2010–2050 and will increase to 0.4 m/year in 2050–2100. The sand deficit, other than the sea-level rise, will be a key factor in the control of the shoreline’s evolution at the northeastern tip of the spit, and the amount of recession will range from 160 to 200 m in 2010–2100.