Comparison of Maxillary Central Incisor Labial Crown-Root Angle with Collum Angle in Class I and Class II Division 2 Malocclusion.

To anticipate difficulties with intrusion, extrusion, or torqueing mechanics in certain malocclusions, a thorough understanding of crown-root relationships in the bucco-lingual plane is warranted. This study aimed at examining the collum angle of the maxillary central incisor in Angle’s class I and class II division 2 malocclusion and compare these values with the Labial Crown Root Angle (LCRA). MethodsThis study was conducted on two groups i.e., group 1 comprising of 26 Angle’s Class 1 subjects and group 2 comprising of 26 Class II div 2 subjects. Cephalometric measurements of collum angle and LCRA of maxillary central incisors were recorded for each subject and were compared between the two groups. ResultsThe mean Labial Crown-Root Angle was 28.35 ± 4.01 and 38.51 ± 5.80 for class I and class II division malocclusions respectively. Compared to the LCRA of Angle’s class I malocclusion, the mean LCRA of Angle’s class II division 2 was found to be greater, and is statistically significant. There was no significant gender variation. The mean difference between class I and class II div 2 malocclusion was found to be 9.42 ± 2.23 for collum angle and 10.16 ± 1.79 in LCRA respectively. ConclusionsThe Labial Crown Root Angle and collum angle of Angle’s Class II div 2 malocclusion were greater than the corresponding values in Angle’s Class I malocclusion. Also, the LCRA is a more simplified method for measuring the crown root angle and can be used as an adjunct to collum angle.

Má oclusão Classe II, 2ª divisão de Angle com sobremordida exagerada e discrepância acentuada / Angle Class II, division 2 malocclusion with severe overbite and pronounced discrepancy

Este artigo relata o tratamento de uma jovem paciente, com 13,8 anos de idade, que apresentava uma má oclusão Classe II, segunda divisão de Angle, retenção prolongada de dentes decíduos, mordida cruzada dentária, sobremordida exagerada, dentre outros desvios da normalidade. Inicialmente, a abordagem ortodôntica envolveu uma expansão da maxila, seguida pelo uso do aparelho extrabucal de Kloehn e aparelhagem ortodôntica fixa. O resultado obtido demonstra a importância de um diagnóstico e planejamento criteriosos, bem como a necessidade de colaboração do paciente durante o tratamento ortodôntico. Este caso clínico foi apresentado à Diretoria do Board Brasileiro de Ortodontia e Ortopedia Facial (BBO), representando a categoria livre, como parte dos requisitos para a obtenção do título de diplomado pelo BBO.

This article reports the treatment of a young patient at 13.8 years of age who presented with an Angle Class II, division 2 malocclusion, prolonged retention of deciduous teeth, dental crossbite and severe overbite, among other abnormalities. At first, the approach involved rapid maxillary expansion followed by the use of Kloehn headgear and fixed orthodontic appliance. Treatment results demonstrate the importance of careful diagnosis and planning as well as the need for patient compliance during treatment. This case was presented to the Brazilian Board of Orthodontics and Facial Orthopedics (BBO). It is representative of the free category and fulfills part of the requirements for obtaining the BBO Diploma.

Nonextraction treatment of Class II division 2 in an adult patient using microimplant anchorage (MIA) / 대한치과교정학회지

Maxillary anterior teeth were intruded and lingually root torqued with two maxillary anterior microimplants between the lateral incisors and canines. Overerupted maxillary canines were intruded with two other microimplants between the maxillary canines and first premolars. Maxillary posterior teeth and canines were distalized, then the maxillary incisors were retracted with two maxillary posterior microimplants between the first and second molars. The mandibular anterior teeth were intruded and the mandibular posterior teeth were extruded with conventional method such as anterior bite plane, intrusion arch and Class II elastics. The mandible moved slightly forward after the correction of deep bite and retroclination of the upper incisors. Consequently, microimplant anchorage (MIA) provided absolute anchorage for simultaneous correction of Class II canine and molar relationships and deep overbite.

The long-term stability of the lower incisor axis in Class II division 2 malocclusions / 대한치과교정학회지

The purpose of this study was to evaluate the post-retention stability of the lower incisor axis in Class II division 2 malocclusions. The dental casts and lateral cephalograms from before (T1) and after (T2) orthodontic treatment and long-term post-retention (T3) in 62 Class II division 2 malocclusion cases were included in this study. After several linear and angular measurements at each time were taken, the significance in the amount of change of the lower incisor axis for each gender and extraction versus non-extraction was evaluated. The results showed that the lower incisors that inclined labially during treatment were unstable and relapsed to the original lingual position in Class II division 2 malocclusions (p 0.05). There was no significant difference between male and female groups for the axial change of the lower incisors (p > 0.05). As a result of multiple regression analysis, the cephalometric measurement best predicting the lower incisor position to the A-Pog line post-retention was pre-treatment L1-Apog(mm) and pre-treatment SNGoMe(degrees ). Because of the instability of labially inclined lower incisors after orthodontic treatment, the treatment goal should be the pre-treatment incisor axial position.

A cephalometric investigation on the craniofacial configurations of Class II division 1 and 2 in Korean / 대한치과교정학회지

Numerous studies have revealed the similarities and discrepancies in two divisions of class II malocclusion, since these malocclusion groups have been postulated to be disparate criterion, much as classified under one diagnostic umbrella. This study was undertaken to describe the craniofacial configurations of class II division 1 and 2, and consequently to discriminate the morphologic differences between the two malocclusion groups in Korean sample. Lateral headfilms of 34 class II division 1 and 29 division 2 were employed, while those of 142 adults of normal occlusion served as a control. The landmarks were digitized and 26 variables were statistically analyzed for one way: 1. There manifested no statistically significant difference in maxillary position anteroposteriorly. Normal occlusion group exhibited most anteriorly positioned mandible, whereas class II division 1 showed the most retroposition. Class II division 1 disclosed clockwise rotation tendency of mandible, which resulted in position of the chin posteriorly. 2. Class II division 1 showed greater in SN to MP, SN to PP significantly than other groups. 3. Class II division 2 showed smaller gonial angle and larger mandibular body length than other groups. 4. Class II division 1 revealed greater anterior lower face height than other groups, whereas division 2 dictated significantly greater posterior face height. 5. Class II division 2 expressed the most retroclined lower incisor, while division 1 manifested the most proclination. The largest interincisal angle resided in Class II division 2 group. There were no significant differences in upper molar position anteroposteriorly.

A cephalometric study on the morphologic characteristics of Class II division 2 malocclusion of the Korean Female patients / 대한치과교정학회지

The purposes of this study were to evaluate the cephalometric clv racteristics of Korean female patients with Class II division 2 malocclusion and to compare Korean females with Caucasian females who had same type of malocclusion. All of the samples had Class II division 2 malocclusion with deep overbite (more than 4nun) and fulll permanent dentition. These samples were divided into two groups according to the races: Group 1(N=16; Korean females; average age=18Y 2M) and Group 2 (N=20; Caucasian females; average age=14Y 2M). The pretreatment lateral cephalograms were measured, analyzed and compared by using 38 variables and independent t-test. And the results were as follows: 1. Although there were no differences in Overbite, SN to mandibular plane angle, Palatomandibular plane angle, and FMA between Group 1 and 2, the other vertical relation variables of maxilla and mandible (SN to palatal plane angle, SN to occlusal plane angle, ODD of Group 1 showed more clockwise rotation tendency of occlusal plane and less hypodivergency tendency than those of Group 2. 2. There were no differences in mandibular body length and ramus height between Group 1 and 2 except small upper gonial angle of Group 1. There was less counterclockwise rotation tendency of mandible in Group 1. 3. There were no statistical significant differences in UAFH/LAFH and PFH/AFH between Group 1 and 2. 4. Although there were no differences of overjet and anteroposterior position of mandible between Group 1 and 2, the position of maxilla of Group 1 was more retropositioned than that of Group 2. 5. Except the more protrusion of lower incisor to A-Pog of Group 1, there were no differences of inclination and distance of upper and lower incisors to basal plane between Group 1 and 2. 6. The distance from upper first molar to palatal plane showed no difference between Group 1 and 2. But the distance from lower first molar to mandibular plane of Group 1 was greater than that of Group 2. So it may be partially related to the clockwise rotation of occlusal plane and the less counterclockwise rotation tendency of mandible of Group 1. 7. Group 1 had more protrusive upper and lower lips than Group 2.