Discomfort, Expectations and Experiences during Treatment of Class II Malocclusion with Clear Block and Twin Block Appliance - A Pilot Survey

BACKGROUND Skeletal class II division 1 malocclusion is an antero posterior discrepancy between maxilla and mandible which is usually treated by functional appliances when the patient is in the growing phase. It has been shown that these functional orthodontic appliances may lead to pressure on the oral mucosa, soft tissue tension, oral constriction, toothache and pain. They may also lead to fatigue or to functional speech and respiratory disorders, and they may affect the appearance of the face. All of these undesired consequences affect the patients’ degree of compliance in a negative manner, and may in turn affect the patients’ perception towards the treatment. This study was conducted to investigate patient perception of treatment need, appliance acceptance, expectations of treatment influence on oral health, value of dental aesthetics and information concerning treatment procedures. METHODS Total 30 samples were selected 15 samples were cases treated with twin block appliance and other 15 samples were treated with clear block appliance. After 8 months of treatment, a questionnaire survey was conducted assessing discomfort, expectations and experiences of all patients being treated with clear block appliance and twin block appliance. RESULTS Clear block seemed to be better with regard to all the parameters used in the study but on statistical analysis the difference between the two groups was insignificant. CONCLUSIONS Clear block appliance was designed to increase the compliance of the patient. However, clear block and twin block appliance have similar effects. KEY WORDS Class II, Clear Block, Twin Block

Management of antero posterior discrepancy using expansion appliances- A case series

Antero-posterior deficiencies are one of the major concerns in adolescents especially when presented with class III malocclusion and anterior cross bite. These discrepancies are generally corrected by protraction of maxilla and expansion during growth period. A 16 year old boy and 12 year old girl presented with midface deficiency with anterior cross bite and Class III malocclusion. Antero-posterior expansion was planned with Hyrax and Jack screw appliances respectively. Anterior cross bite and Class III malocclusion was corrected. Majority of these antero posterior discrepancies can be corrected with antero-posterior expansion, hence are of prime importance.

A “new vista” in the assessment of antero-posterior jaw relationship

Aim The purpose of this investigation was to (1) compare the credibility of four recently introduced cephalometric measurements in assessing the antero-posterior jaw relationship; (2) To assess the correlation between various measurements used for assessment of antero-posterior discrepancy, including Yen linear, Yen angle, W angle and Pi angle. Materials and Methods The sample size for the study consisted of 45 subjects with age group of 15-19 years (mean age 17 ± 2.1) and was subdivided into Skeletal Class I, II and III groups of 15 each based upon the ANB angle derived from the pre treatment lateral cephalogram. Landmarks were located and Yen angle, Yen linear, W angle and Pi angle were assessed for each group. All the lateral cephalograms were traced by a single examiner. Intra examiner reliability was assessed by Intraclass co-efficient correlation (ICC) test. Correlation coefficients were obtained for each of parameters to compare their relationship with other parameters in Class I group. Receiver operating characteristics (ROC) curves were run to examine sensitivity and specificity of all the angles. Results The results showed that ICC for all the groups were ≥0.90 showing good repeatability of the measurements. There was statistically significant correlation between Yen angle and ANB angle, Yen linear and Yen angle for Class I group, between W angle and Yen angle for Class II group, between Yen angle, Yen linear and ANB for Class III group. ROC curves showed that Pi angle had 100% sensitivity and specificity to discriminate a Class II and a Class III group from a Class I and a Class III group from a Class II. Yen linear and W angle showed very low specificity to differentiate a Class II from a Class I group. Interpretation and Conclusion The new parameters considered in the study were found to be equally reliable and are not affected much by local remodeling due to tooth movements or by occlusal or Frankfurt horizontal plane. These parameters measure the antero-posterior discrepancy more consistently and accurately, with Pi angle being the most accurate.