scholarly journals Lip-to-incisor Relationship and Postorthodontic Long-term Stability of Cover-bite Treatment

2006 ◽  
Vol 76 (6) ◽  
pp. 942-949 ◽  
Author(s):  
Bernd G. Lapatki ◽  
Dirk Baustert ◽  
Jürgen Schulte-Mönting ◽  
Sibylle Frucht ◽  
Irmtrud E. Jonas

Abstract Objective: To investigate the impact of a persisting high lip line and other potential relapse-inducing factors on long-term stability of orthodontic correction of retroinclined maxillary central incisors. Materials and Methods: Thirty-one cover-bite (“Deckbiss”) patients with retroinclined maxillary central incisors and a deep frontal overbite were evaluated. The maxillary central incisor inclination was determined odontometrically with study models made pretreatment, posttreatment, and at a follow-up examination (mean posttherapeutic interval: 9.0 years). The lip-to-incisor relationship, the interincisal angle, and the anteroposterior maxillary central incisor position were measured on lateral cephalograms taken after active treatment. Results: The relapse tendency of the orthodontic correction of the retroinclined maxillary central incisors displayed great interindividual variability with a range of posttherapeutic inclination change of −6.75° to +8.00°. Multiple regression analysis revealed an increased tendency for relapse in patients with (1) a high posttherapeutic (dorsal) lip line level combined with the maxillary central incisor and lower lip contact only in the incisal crown area (P < .01) and (2) a marked therapeutically induced inclination change of the maxillary central incisors (P < .05). Interrelations between the relapse of the corrected maxillary central incisors and other evaluated parameters were not statistically significant. Conclusions: For maximum treatment stability, the elimination of an excessive overlap of the upper incisors by the lower lip should be regarded as one of the most important therapeutic objectives when treating this malocclusion.

2015 ◽  
Vol 26 ◽  
pp. 340-344 ◽  
Author(s):  
Ute Zschieschang ◽  
Konstantin Amsharov ◽  
Martin Jansen ◽  
Klaus Kern ◽  
Hagen Klauk ◽  
...  

2019 ◽  
Vol 42 (2) ◽  
pp. 200-205 ◽  
Author(s):  
Bernardo Quiroga Souki ◽  
Michele Nieri ◽  
Chiara Pavoni ◽  
Helena Maria Pavan Barros ◽  
Tarcisio Junqueira Pereira ◽  
...  

Summary Aim To develop and validate a prediction model to forecast long-term stability of early treatment with rapid maxillary expansion (RME) and facemask (FM) in a large sample of Class III growing patients. Methods The Brazilian Group (BG) consisted of 73 consecutively treated Caucasian Class III patients (41 females and 32 males). Mean age at T0 (before treatment) was 7.1 ± 1.6 years, while mean age at T1 (long-term follow-up) was 21.8 ± 3.2 years. The Italian Group (IG, validation cohort) comprised 28 consecutively treated Caucasian Class III patients (14 females and 14 males, mean age at T0 9.0 ± 1.3 years and mean age at T1 18.2 ± 1.4 years). Cephalometric analysis was performed on lateral cephalograms at T0. Gender and cephalometric variables, chronologic age, and dentition phase at T0 were used as predictors for long-term unsuccessful treatment at T1. All predictors for unsuccessful treatment in the BG were subjected to bivariate logistic regression. Only those statistically significant predictors in the bivariate logistic regression entered mixed stepwise logistic regression with P = 0.05 to enter and to leave. The validity of the prediction model derived from the BG was then tested on the IG. Results The prediction model consisted of only one cephalometric variable: the angle between the Condylar Axis and the Mandibular Plane (CondAx–MP) (odds ratio: 1.52, 95% confidence interval: 1.25–1.85, P < 0.0001). Unsuccessful treatment at T1 was predicted for values of CondAx–MP at T0 greater than the cut-off value of 147.8 degrees. BG patients predicted incorrectly were 3 out of 22 for the unsuccessful cases and 1 out of 51 for the successful cases. Therefore, accuracy was 0.95, sensitivity 0.86, specificity 0.98, and positive and negative predictive values were 0.95 and 0.94. When the predictive model was applied on IG, all five unsuccessful cases were predicted correctly, while only 1 out of 23 successful patients was predicted incorrectly. Conclusion CondAx-ML was identified as a reliable predictor for long-term stability of early Class III treatment with RME and FM.


2013 ◽  
Vol 67 (1) ◽  
pp. 55-59 ◽  
Author(s):  
Muiruri Macharia ◽  
Andre P Kengne ◽  
Diane M Blackhurst ◽  
Rajiv T Erasmus ◽  
Tandi E Matsha

2020 ◽  
Author(s):  
Robert Nißler ◽  
Larissa Kurth, ◽  
Han Li ◽  
Alexander Spreinat ◽  
Ilyas Kuhlemann ◽  
...  

Semiconducting single wall carbon nanotubes (SWCNTs) fluoresce in the near infrared (NIR) and the emission wavelength depends on their chirality (n,m). Interactions with the environment affect the fluorescence and can be tailored by functionalizing SWCNTs with biopolymers such as DNA, which is the basis for fluorescent biosensors. So far, such biosensors were mainly assembled from mixtures of SWCNT chiralities with large spectral overlap, which affects sensitivity as well as selectivity and prevents multiplexed sensing. The main challenge to gain chirality pure sensors has been to combine approaches to isolate specific SWCNTs and generic (bio)functionalization approaches. Here, we created chirality pure SWCNT-based NIR biosensors for important analytes such as neurotransmitters and investigated the impact of SWCNT chirality/handedness as well as long-term stability and sensitivity. For this purpose, we used aqueous two-phase extraction (ATPE) to gain chirality pure (6,5)-, (7,5)-, (9,4)- and (7,6)- SWCNTs (emission at ~ 990, 1040, 1115 and 1130 nm). Exchange of the surfactant sodium deoxycholate (DOC) to specific singlestranded (ss)DNA sequences yielded monochiral sensors for small analytes (dopamine, riboflavin, ascorbic acid, pH). DOC used in the separation process was completely removed because residues impaired sensing. The assembled monochiral sensors were up to 10 times brighter than their non-purified counterparts and the ssDNA sequence affected absolute fluorescence intensity as well as colloidal (long-term) stability and selectivity for the analytes. (GT)40-(6,5)-SWCNTs displayed the maximum fluorescence response to the neurotransmitter dopamine (+140 %, Kd = 1.9 x10-7 M) and a long-term stability > 14 days. Furthermore, the specific ssDNA sequences imparted selectivity to the analytes independent of SWCNT chirality and handedness of (+/-) (6,5)-SWCNTs. These monochiral/single-color SWCNTs enabled ratiometric/multiplexed sensing of dopamine, riboflavin, H2O2 and pH. In summary, we demonstrated the assembly, characteristics and potential of monochiral (single-color) SWCNTs for multiple NIR fluorescent sensing applications.


2021 ◽  
Vol 11 ◽  
pp. 229-234
Author(s):  
Mansi Radia ◽  
Kalyani Trivedi ◽  
Alap Shah ◽  
Tilak Parikh ◽  
Hemangi Panchal

Objectives: The objectives of the study were to assess the long-term stability of the curve of Spee leveled with continuous archwire in subjects with two different retention protocols. Materials and Methods: The study sample consisted of 20 patients (mean age 18 ± 2 years) presenting with curve of Spee depth of =/> 3 mm. For each subject, lateral cephalograms and dental casts were available before treatment (T1), at the end of orthodontic therapy (T2), and 1 year after the end of treatment (T3). All subjects were divided into two groups according to their retention protocol – fixed retainer group (Group-1) and Essix retainer group (Group-2). Cephalometric parameters were used to evaluate the dental movements after treatment. Curve of Spee depth was measured on standardized digital images of casts. Results: In multicomparison table, it shows that there was a statistically significant difference (P = 0.032) between Spee-T2 and Spee-T3 and there was no statistical difference (P = 0.159) between L1MP-T2 and L1MP-T3 in fixed retainer group. In Essix retainer group, no changes were observed from L1MP-T2 to L1MP-T3 and there was a non-significant difference found between Spee-T2 and Spee-T3. Conclusion: In Group-1 (fixed retainer), there is some amount of relapse or extrusion of lower incisor. In Group-2 (Essix retainer), there was not any change in the position of the lower incisor, which suggests that occlusal coverage of the Essix retainer does not allow any extrusion and retains the curve of Spee.


2020 ◽  
Author(s):  
Robert Nißler ◽  
Larissa Kurth, ◽  
Han Li ◽  
Alexander Spreinat ◽  
Ilyas Kuhlemann ◽  
...  

Semiconducting single wall carbon nanotubes (SWCNTs) fluoresce in the near infrared (NIR) and the emission wavelength depends on their chirality (n,m). Interactions with the environment affect the fluorescence and can be tailored by functionalizing SWCNTs with biopolymers such as DNA, which is the basis for fluorescent biosensors. So far, such biosensors were mainly assembled from mixtures of SWCNT chiralities with large spectral overlap, which affects sensitivity as well as selectivity and prevents multiplexed sensing. The main challenge to gain chirality pure sensors has been to combine approaches to isolate specific SWCNTs and generic (bio)functionalization approaches. Here, we created chirality pure SWCNT-based NIR biosensors for important analytes such as neurotransmitters and investigated the impact of SWCNT chirality/handedness as well as long-term stability and sensitivity. For this purpose, we used aqueous two-phase extraction (ATPE) to gain chirality pure (6,5)-, (7,5)-, (9,4)- and (7,6)- SWCNTs (emission at ~ 990, 1040, 1115 and 1130 nm). Exchange of the surfactant sodium deoxycholate (DOC) to specific singlestranded (ss)DNA sequences yielded monochiral sensors for small analytes (dopamine, riboflavin, ascorbic acid, pH). DOC used in the separation process was completely removed because residues impaired sensing. The assembled monochiral sensors were up to 10 times brighter than their non-purified counterparts and the ssDNA sequence affected absolute fluorescence intensity as well as colloidal (long-term) stability and selectivity for the analytes. (GT)40-(6,5)-SWCNTs displayed the maximum fluorescence response to the neurotransmitter dopamine (+140 %, Kd = 1.9 x10-7 M) and a long-term stability > 14 days. Furthermore, the specific ssDNA sequences imparted selectivity to the analytes independent of SWCNT chirality and handedness of (+/-) (6,5)-SWCNTs. These monochiral/single-color SWCNTs enabled ratiometric/multiplexed sensing of dopamine, riboflavin, H2O2 and pH. In summary, we demonstrated the assembly, characteristics and potential of monochiral (single-color) SWCNTs for multiple NIR fluorescent sensing applications.


2016 ◽  
Vol 87 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Arturo Vela-Hernández ◽  
Rocio López-García ◽  
Verónica García-Sanz ◽  
Vanessa Paredes-Gallardo ◽  
Felicidad Lasagabaster-Latorre

ABSTRACT Objective: To (1) evaluate the efficacy of build-ups in the correction of anterior open bite in adults, (2) evaluate their efficacy in producing molar intrusion, (3) analyze skeletal and dental changes, and (4) assess the long-term stability. Materials and Methods: The sample consisted of 93 lateral cephalograms from 31 patients with skeletal and dental anterior open bite. The patients had received orthodontic treatment consisting of bonded resin blocks on the maxillary molars combined with Tip-Edge Plus bracket appliances. Cephalometric measurements were performed on radiographs taken before treatment (T1), after treatment (T2), and after a retention period (T3), which were analyzed and compared. Results: Significant dental and skeletal changes were observed after treatment. Molar intrusion averaging 1 mm; 1.44 and 1.57 mm extrusion of mandibular and maxillary incisors, respectively; and a mean of 3.98 mm overbite increase were observed. The mandibular plane angle showed a mean closure of 1.19°, and there was a mean decrease in anterior facial height of 0.7 mm. A mild relapse tendency was observed, but long-term stability was acceptable. Conclusions: Build-ups are an effective treatment alternative for anterior open bite in adults. Outcomes remain significantly stable during the retention period.


2017 ◽  
Vol 88 (2) ◽  
pp. 163-170 ◽  
Author(s):  
Eiman S. Marzouk ◽  
Hassan E. Kassem

ABSTRACT Objectives: To evaluate soft tissue changes and their long-term stability in skeletal anterior open bite adults treated by maxillary posterior teeth intrusion using zygomatic miniplates and premolar extractions. Materials and Methods: Lateral cephalograms of 26 patients were taken at pretreatment (T1), posttreatment (T2), 1 year posttreatment (T3), and 4 years posttreatment (T4). Results: At the end of treatment, the soft tissue facial height and profile convexity were reduced. The lips increased in length and thickness, with backward movement of the upper lip and forward movement of the lower lip. The total relapse rate ranged from 20.2% to 31.1%. At 4 years posttreatment, 68.9% to 79.8% of the soft tissue treatment effects were stable. The changes in the first year posttreatment accounted for approximately 70% of the total relapse. Conclusions: Soft tissue changes following maxillary posterior teeth intrusion with zygomatic miniplates and premolar extractions appear to be stable 4 years after treatment.


2021 ◽  
Author(s):  
Sébastien Merlet ◽  
Pierre Gillot ◽  
Bing Cheng ◽  
Romain Karcher ◽  
Almazbek Imanaliev ◽  
...  

<p>Atom gravimeters based on atom interferometry offer new measurement capabilities, by combining high sensitivities and accuracies at the best level of a few tens of nm.s<sup>−2</sup> with the possibility to perform continuous measurements. Being absolute meters, their scale factor is accurately determined and do not need calibration. Because of their high sensitivity and low drift, superconducting gravimeters are the key instruments for the continuous monitoring of gravity variations. Nevertheless, being relative meters, they need to be calibrated.</p><p>We revisit a 2015 one month long common view measurement of an absolute cold atom gravimeter (CAG) and a relative iGrav superconducting gravimeter, which we use to investigate the CAG long term stability and calibrate the iGrav scale factor. The initial measurement has already been presented at EGU 2016. Here finalized, we present how it allowed us to push the CAG long-term stability down to the level of 0.5 nm.s<sup>−2</sup>. We investigate the impact of the duration of the measurement on the uncertainty in the determination of the correlation factor and show that it is limited to about 3‰ by the coloured noise of our cold atom gravimeter. A 3-days long measurement session with an additional FG5X absolute gravimeter allows us to directly compare the calibration results obtained with two different absolute meters. Based on our analysis, we expect that with an improvement of its long term stability, the CAG will allow to calibrate the iGrav scale factor to better than the per mille level (1σ level of confidence) after only one-day of concurrent measurements during maximum tidal amplitudes.</p>


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