Evaluation and quantification of airway changes in Class II division 1 patients undergoing myofunctional therapy using twin block appliance.

BACKGROUND: The purpose of the present study was to determine the airway changes in skeletal class II division 1 malocclusion patients with mandibular retrognathism, treated with Twin-Block (TB) appliance. METHODS: Airway assessment was carried for twelve patients (mean age 11.7 ± 1.1 years) who underwent myofunctional therapy using TB appliance for correction of skeletal class II division 1 malocclusion with mandibular retrognathism. Acoustic pharyngometry (AP) was used to assess and quantify the comparative changes in the upper airway, pretreatment and posttreatment. RESULTS: Data acquired was subjected to appropriate statistical analysis. The paired 't' test was used to compare pre-treatment (T0) and after the positive pterygoid response (T1). TB appliance increased mean minimum airway area by 0.28 ± 0.25 cm2 and mean airway by 0.47 ± 0.44 cm2 with 95% CI. Posttreatment minimum airway and mean area changes were found to be statistically significant (P-value<0.01). CONCLUSION: TB appliance therapy has a positive effect on upper airway and is beneficial for the treatment of sleep-related disorders associated with Class II division 1 malocclusion for achieving positive functional changes, esthetics, and healthier quality of life.

Management of skeletal class II malocclusion using bimaxillary skeletal anchorage supported fixed functional appliances : A novel technique.

AIM: To evaluate the treatment effects in growing skeletal class II patients subjected to a novel treatment technique, i.e., bimaxillary miniplates supported fixed functional appliance. The null hypothesis was that there is no statistically significant difference in skeletal changes of patients with class II malocclusion treated with bimaxillary skeletal anchorage supported fixed functional appliance and those who were not provided any intervention. METHODS: The sample comprised 32 skeletal class II subjects (17 males and 15 females) with a Cervical Vertebrae Maturity Index (CVMI) demonstrating peak of pubertal growth spurt. Sixteen patients (12.37 ±1.09 years of age) were treated with bimaxillary skeletal anchorage supported fixed function appliance, while 16 well-matched subjects (12.06 ± 1.34 years of age) were included as controls. For both groups, cephalograms (T1, T2) were taken with a matched observational interval of about 7.5 months; 17 linear and 10 angular measurements were recorded. The intraclass correlation coefficient (ICC) was used to determine reliability of measurements recorded. Student t test was carried out to determine the changes produced by the treatment relative to control. RESULTS: When compared with the control group, the treatment group demonstrated significant maxillary retrusion. No significant changes were seen in mandibular growth pattern, whereas mandibular length increased significantly more than in the control group (B-VP: 3.05 mm; Co-Gn: 2.65 mm). Treatment mechanics had minimal effects on maxillary dentition. Mandibular incisors proclined by an average of 3.06°. Maxilla-mandibular relation improved significantly (ANB: -4.29°; NA-Pog: -3.76°). CONCLUSION: The new bimaxillary skeletal anchorage supported fixed functional appliance technique was found to be highly effective in the treatment of class II malocclusion with significant skeletal changes.

Factors associated with abutment screw loosening in single implant supported crowns: A cross-sectional study.

BACKGROUND: Implant restorations are considered an ideal treatment option for replacement of missing teeth in partially edentulous patients. Abutment screw loosening is one of the frequently observed technical complications of implant-supported prosthesis. This study aimed to determine the prevalence and factors associated with the abutment screw loosening in cement-retained single-implant crowns. METHODS: Enrolment criteria included partially edentulous patients who have been rehabilitated with one or more cement-retained single-implant crowns with minimum postcementation period of 1 year. They were recalled and evaluated for the presence or absence of screw loosening both clinically and radiographically. They were further evaluated for the presence or absence of factors associated with screw loosening such as parafunctional habits, wider occlusal table, steep cuspal inclines, non-axial loading and cantilevering of the pontic. RESULTS: Twenty-six cement-retained single-implant crowns out of 280 showed screw loosening, making the overall prevalence rate of 10.77%. Among the factors evaluated, parafunctional habits were associated with three cases, wider occlusal table in four, steep cuspal inclines in three, non-axial loading in nine and cantilevering of the pontic in three cases. Exact reasons could not be ascertained in four cases. CONCLUSION: Abutment screw loosening seems to be a significant prosthetic complication of cement-retained single-implant crowns. Factors evaluated significantly affect the functional durability of the prosthesis. These factors should be considered while restoring to enhance the longevity of such restorations.

Rate of intrusion of maxillary incisors in Class II Div 1 malocclusion using skeletal anchorage device and Connecticut intrusion arch.

BACKGROUND: Nonsurgical correction of deep bite involves either extrusion of posterior teeth, intrusion of incisors, or combination of both. The introduction of skeletal anchorage device with microimplant provides near absolute anchorage without producing any untoward effects on anchor unit. Connecticut Intrusion Arch (CIA) provided an efficient system of intruding anterior segment without producing much adverse affects on anchor teeth. METHODS: The study comprised of 30 patients of Class II Div 1 malocclusion with overbite of >6 mm and required therapeutic extractions of all first premolars, randomly distributed into two groups. Group 1 was treated using orthodontic microimplants, while Group 2 treated with CIA. Lateral cephalograms were taken pre-intrusion (T1) and post-intrusion at the end of six months (T2). RESULTS: The rate of intrusion was 0.51 and 0.34 mm/month for Group 1 and Group 2 respectively. The average amount of change in centroid point to PP distance and U1-SN angle was significantly higher in Group 1 compared to Group 2 (P < 0.001). The average amount of change in U6 to PP distance did not differ significantly between two study groups (P > 0.05). CONCLUSION: The amount of intrusion is significantly higher in SAD group. Although vertical molar positional change was higher in CIA group than the SAD group, it was not changed significantly in both treatment modalities. SAD group overall had better results and was easier in handling during intrusion.

Prevalence of malocclusion and orthodontic treatment need in schoolchildren - An epidemiological study.

BACKGROUND: To ascertain the prevalence of malocclusion and orthodontic treatment need in schoolchildren dependent on armed forces personnel. To review the overall oral health using DMFT index and to evaluate any relation between increased DMFT index to existing orthodontic problems. METHOD: Five schools were randomly selected among Army/KV/AF schools and a random sample of 1200 children aged 10-15 years old attending these schools dependant on armed forces personnel were selected. A survey form was filled up after the examination of children by the principal worker and need for orthodontic treatment was assessed using index for orthodontic treatment need (IOTN) and overall oral health status by DMFT index and totaled. Frontal intra oral photograph in centric occlusion were taken. Dental Health Component (DHC) of IOTN for all the patients was marked by one set of orthodontists. The most severe occlusal trait was identified by the examiner for any particular patient and the patient was then categorized according to this most severe trait. AC of the IOTN was assessed by second orthodontist, individual and a layperson. RESULTS: It was observed that prevalence of malocclusion in the sample was 53.7%. 32.8% (239 males & 154 females) of samples are in need of orthodontic treatment. 55.1% of samples shown no caries risk, 38.1% had moderate caries risk and 6.8% had high caries risk. CONCLUSION: Significant percentage of the samples are in need for orthodontic treatment. There is significant relation between higher DMFT index and orthodontic treatment need. It was found that IOTN is a reliable and user-friendly index, which can be used for orthodontic surveys.

A comparative evaluation of rate of space closure after extraction using E-chain and stretched modules in bimaxillary dentoalveolar protrusion cases.

BACKGROUND: Aim of this study was to compare the rate of space closure between E-chain mechanics in one side of upper arch and by elastomeric module with ligature wire on the contralateral side in same patient. METHODS: Thirty bimaxillary dentoalveolar protrusion cases were taken up for comprehensive fixed orthodontic treatment after extraction of all first premolars to retract both upper and lower anterior teeth. After initial alignment and levelling, alginate impressions were made for upper and lower arches and models constructed. In the upper arch model a vernier caliper was used to measure the extraction space in both sides from middle point of distal surface of canine to the middle most point of mesial surface of second premolar. This is the amount of space present before the onset of retraction mechanics. During space closure procedure two different retracting components were applied in right and left sides of each case. On right side elastic chain (E-chain) applied in both upper and lower arches and on left side elastomeric module with steel ligature (0.010") stretched double its diameter fixed in both arches. Both the mechanisms produced approximately 250-300 g of force as measured by a tension gauge. After onset of retraction mechanism all patients were recalled after every six weeks for three visits. In all these three visits modules and E-chains were changed. In all three visits impression was made, models constructed, and the remaining available space was measured by a vernier caliper up to 0.1 mm level variations. RESULTS: Mean value for total space closure in case of E-chain was 2.777 mm whereas in case of module with ligature wire the value increased to 3.017 mm. Mean value for rate of space closure in case of E-chain was 0.2143 mm, whereas in case of module with ligature wire the value increased to 0.2343 mm with a standard deviation of 0.001104 and 0.001194, respectively. The standard deviation for total space closure was 0.1305 for E-chain and 0.1487 for module with ligature wire. CONCLUSION: Space closure by elastomeric module with ligature wire is better than the E-chain.

Efficacy of Second Molar to Achieve Anchorage Control in Maximum Anchorage Cases.

BACKGROUND: The aim of the study was to assess the efficacy of inclusion of second molar in treatment at the outset to reinforce anchorage. METHODS: A comparative study comprising of 30 maximum anchorage cases to quantify anchorage loss in two situations was undertaken. Group I consisted of cases in which only first molars were banded and Group II consisted of cases where both first and second molars were banded. A total of seven landmarks were marked and six measurements were recorded on to the pre-treatment and post-treatment lateral cephalogram. RESULT: The difference in pre-treatment and post-treatment values of all the variables were statistically significant (p<0.05) except maxillary central incisor vertical movement (U1 VER), implying a significant post-treatment change. Thus in both the treatment approaches U6 and U1 showed a considerable amount of movement in horizontal and vertical direction and there was rotation which brought about change in angular values. CONCLUSION: The study has successfully quantified the anchorage loss and brought out the advantages of including second molar in treatment at the outset. Not only the anchorage loss is minimized but inclusion of second molar also helps to maximize incisor retraction and helps control angular movement of molar and incisor. Extra time required for second molar banding is well spent, as the benefits are overwhelming.