Lower Incisor Inclination Research Articles

Comparative evaluation of Tweed's analyses in Class I, Class II, and Class III participants of Central India: A pilot study

Objective: Comparative evaluation of Tweed's analyses in Class I, Class II, and Class III participants of Central India in two different age groups. Materials and Methods: Sample size comprised 240 participants belonged to Central India. Participants were divided into two main groups: Group I comprised 120 young children in the age group of 12–16 years and Group II comprised 120 young adults in the age group of 18–22 years. Tweed's analysis was performed from the collected sample. Results: The lower incisor inclination (incisor-mandibular plane angle [IMPA]) in Central India participants was higher (100.13°) compared to the original Tweed norm of IMPA 90°. Statistically higher value of IMPA was found in young male children compared to young female children in Class II div 1 and Class II div 2 participants and opposite trend was seen in Class III young adults. The Frankfort-mandibular plane angle was found to be significantly more in young adult females (24.93°) than males (18.07°) in Class III participants. Angle IMPA was found to be significantly higher in Class I compared to Class III participants and significantly higher in Class III compared to Class II div 2 participants. Conclusion: The differences of Tweed's parameters in this pilot study indicate that Caucasian norms cannot be truly adhered to Central India participants during orthodontic treatment. Lower incisors were normally more proclined in Central Indian participants and their over retraction during orthodontic treatment would cause prominent chin. Proclination of lower incisor was more in young male children compared to young female children in Class II div 1 and Class II div 2 participants and opposite trend was seen in Class III young adults. Class III female adults show tendency toward vertical growth pattern compared to males. Proclination of lower incisor was found to be more in Class I compared to Class III participants and more in Class III compared to Class II div 2 participants.

Correlation in changes in the upper and lower incisor inclinations toward the nasolabial angle and mentolabial angle in non-extraction Class I malocclusion orthodontic treatment

Non-extraction orthodontic treatment in borderline cases is reported, according to some authors, to lead to upper and lower incisor inclination changes affecting patients’ soft tissue profiles. Here, we aim to determine the correlation, in non-extraction Class I malocclusion cases, between the upper and lower incisor inclination changes toward the nasolabial angle and the mentolabial angle before and after orthodontic treatment. (We took before and after lateral cephalometric radiographs on 26 patients with non-extraction Class I malocclusion orthodontic treatment.) We measured the I-SN, IMP, nasolabial, and mentolabial angles. For statistical analysis, we used the non-parametric Wilcoxon test and the Spearmen correlation test. There was no significant difference between the I-SN and nasolabial angles, but a significant difference between the IMP and mentolabial angles, before and after treatment. The correlation test showed very weak negative and positive correlations between the change in the I-SN angle and the change in the nasolabial angle, and the change in the IMP angle and the change in the mentolabial angle, respectively. The decrease in the I-SN angle was followed by an increase in the nasolabial angle, even though the correlation was very weak. The increase in the IMP angle was followed by an increase in the mentolabial angle, which was also very weakly correlated.

Evaluation of lower anterior dental changes in patients treated with self-ligating brackets

The aim of this study was to evaluate and compare changes in linear distance and inclination of lower incisors and canines and intercanine distance after a 30 months orthodontic treatment with self-ligating appliances. Seven patients were treated orthodontically with a Roth prescription passive self-ligating bracket. To perform the measurements and comparisons, CBCT scans were taken before the start of the orthodontic treatment (T1) and after a period of 30 months treatment (T2). The following measurements were performed: (1) the lower incisors and canines inclination in relation to the mandibular plane, (2) intercanine linear distance in millimeters and (3) linear distance in millimeters of the incisal and apical part of lower anterior teeth to a plane (POGM) passing through pogonion point and perpendicular to the mandibular plane. No significant difference were observed between T1 and T2 for canine inclination (p=0.835), incisors inclination (p=0.149), canine incisal distance to POGM (p=0.423) and incisors incisal distance to POGM (p=0.966), however canine apical distance (p=0.049) and incisors apical distance (p=0.002) to POGM was lower at T1 than at T2. The intercanine distance was significantly lower (p=0.022) at T1 when compared to T2. The use of passive self-ligating brackets in orthodontic treatment to solve 4mm tooth crowding were able to produce dental arch expansion by bodily tooth movement.

Dental and skeletal long-term side effects of mandibular advancement devices in obstructive sleep apnea patients: a systematic review with meta-regression analysis.

Mandibular advancement devices (MAD) are effective in reducing apnea episodes and they are frequently used as first-line therapy in obstructive sleep apnea (OSA) patients. The MAD must be used every night for a lifetime and since it performs its function discharging the forces on dental elements the aim of this systematic review was to identify the dental and skeletal long-term side effects of MAD therapy and to evaluate the influence of time on them in OSA or snoring patients. An electronic search was performed in MEDLINE, Cochrane Database, Google Scholar Beta, Scopus, and LILACS. Studies until 4 April 2018 were analysed, without language restrictions. Randomized controlled trials and cohort studies investigating dental and/or skeletal side effects on adult patients wearing MAD for OSA or snoring treatment with at least 2 years follow-up were included and independently evaluated by two investigators. The quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) and the risk of bias by means of Cochrane's tools. For each study included and for each dental and/or skeletal parameter, the difference in means and 95% CI was calculated between baseline and follow-up. Twenty-one studies with follow-up between 2 and 11 years were included. The side effects reported were a reduction in overjet, overbite, and in the upper incisor inclination, and an increase in lower incisor inclination, A point-Nasion-B point, and anterior facial height. The meta-regression analysis showed that the side effects were influenced by the therapy duration for all parameters (P < 0.05). The quality of evidence was low/moderate. MAD therapy produces time-related dental and skeletal side effects. After a long period of treatment, the dental side effects are clinically relevant and therefore the clinician should inform the patients about this issue. Since the side effects are progressive, patients need to be continuously monitored over time. The study protocol was not registered.

Residents' journal review

The position of the lower incisors to the underlying mandibular symphysis should be maintained in a healthy relationship throughout orthodontic treatment. The aim of the current study was to analyze and determine if there is a statistically significant correlation between facial growth pattern, Holdaway ratio, symphyseal morphology, and lower incisor position, as well as validate a previous analysis performed by Aki et al. A sample of 100 white adult patients was randomly selected from the University of Seville in Spain. Manual measurements were made from the pre-treatment cephalograms at four different time points by two separate operators. The operators assessed symphyseal height/width (H/A) ratio using the Aki analysis, symphyseal morphology (constructed by point B–menton line and the mandibular plane), and facial growth pattern (determined using the Jarabak-MSE analysis retro-occlusion variable). Facial growth pattern, the Holdaway ratio, and H/A were found to be statistically significant (P < 0.05). The study concluded that anterior mandibular bone support and lower incisor position differs among patients, and that symphyseal morphology is related to both facial growth pattern and lower incisor inclination. Dolichofacial patterns trend towards a narrower symphysis, while broader symphyses are indicative of brachyfacial patterns. These facial patterns can then be further related to lower incisor position using the Holdaway ratio and symphyseal H/A ratio, which showed that larger degrees of lower incisor proclination are associated with dolichofacial patterns and a narrow symphysis, and more upright lower incisors are associated with brachyfacial patterns and a wider symphysis. Therefore, orthodontists must understand the limitations on lower incisor movements depending on each patient's symphyseal morphology and facial growth pattern.

A cephalometric comparison of treatment effects and predictors of chin prominence in Class II Division 1 and 2 malocclusions with Forsus fatigue-resistant fixed functional appliance

BackgroundThe aim of this study was to cephalometrically evaluate and compare a treatment protocol in patients with Class II Division 1 (II/1) and Class II Division 2 (II/2), and to pursue predictors of the change in chin prominence. MethodsThis retrospective study included 30 patients with Class II/1 and 25 patients with Class II/2 treated with the Forsus appliance, in combination with fixed appliances. Pre- and posttreatment lateral cephalometric radiographs were collected, and 28 measurements were recorded. A two-sample t test was used for the pretreatment comparison among the two Divisions. Paired t tests were used to evaluate the treatment changes within each group. Analysis of covariance was used to compare the treatment changes between the Divisions after adjusting for the baseline value, age, gender, treatment duration, and time with the Forsus appliance. The Simes multiple testing procedure permitted adjustment for multiple comparisons. Regression analysis was performed to identify predictors explaining the change in chin prominence. ResultsClass II correction occurred in both Divisions, mainly through dentoalveolar effects. There were no significant cephalometric differences found in the mean treatment changes between the Divisions. The pretreatment Gonial angle, molar eruption, lower incisor inclination, mandibular body length, and soft tissue chin thickness had a significant impact on the treatment changes in chin prominence. ConclusionsTreatment with the Forsus in combination with preadjusted fixed appliances leads to a favorable treatment outcome and produces similar treatment changes in both Class II Divisions.

Twin Block appliance with acrylic capping does not have a significant inhibitory effect on lower incisor proclination.

To investigate the effect of acrylic capping, treatment duration, overjet, and lower incisor inclination on the posttreatment tooth position in patients treated with 2 Twin Block (TB) appliance versions. Cephalograms of 56 patients with Class II malocclusion (21 boys, 35 girls; mean age before treatment [T1] = 12.5 years; standard deviation, 0.7) treated with a TB appliance with either acrylic capping or ball-ended clasps on lower incisors were retrospectively collected and traced. Lower incisor inclination (L1-GoGn, L1-GoMe, L1-MP) was measured at T1 and after TB appliance removal (T2). Regression analysis was performed to evaluate the effect on the lower incisor inclination of appliance type, overjet, lower incisor inclination at T1, and treatment duration after adjusting for baseline measurements. Appliance design was not a significant predictor for either incisor inclination measurement (P< .05). Pretreatment lower incisor inclination was the only factor significantly associated with final tooth inclination (L1-GoGn: β = 0.57, 95% confidence interval [CI] = 0.30, 0.84, P < .001; L1-GoMe: β = 0.56, 95% CI = 0.28, 0.84, P < .001; L1-MP: β = 0.46, 95% CI = 0.17, 0.75, P = .003). There was weak evidence that treatment duration excluding L1-MP (95% CI = -1.85, -0.02; P = .045) and overjet might be associated with inclination of lower incisors at T2. TB appliance design with acrylic capping on lower incisors appears not to significantly control incisor proclination. Pretreatment lower incisor inclination may be significantly associated with tooth inclination after active TB treatment and should be considered in treatment planning.

Effects of hybrid-Hyrax, Alt-RAMEC and miniscrew reinforced heavy Class III elastics in growing maxillary retrusive patients. A four-year follow-up pilot study

Abstract Introduction The aim of this study was to evaluate the short- and long-term effects of hybrid-Hyrax, Alt-RAMEC and applied, miniscrew reinforced, heavy intermaxillary elastics on a modified lingual arch in growing skeletal Class III patients. Methods Fifteen subjects (seven male, eight female) were included, with an average age of 12.52 ± 0.94 years, of cervical vertebrae maturation (CVM) stage CS2-CS4 and skeletal Class III malocclusions due to a retrognathic maxilla. Nine weeks of Alt-RAMEC were followed by eight to nine weeks of maxillary protraction with heavy 400 gm Class III elastics worn 24 h/day. Treatment was finalised with orthodontic fixed appliances. Cone beam computed tomographic (CBCT) scans were taken initially (T1), at the end of maxillary protraction (T2) and four years after active orthopaedic treatment (T3). Cephalometric measurements were performed on reconstructed lateral cephalograms and the differences between time intervals were calculated using an analysis of variance (ANOVA). Results A positive overjet was achieved in all but one subject. From T1 to T2, A point advanced 3.12 ± 3.42 mm and from T2 to T3 advanced a further 2.21 ± 3.49 mm. Significant initial increases in SNA of 1.05° ± 1.10° (p = 0.004), ANB of 2.71° ± 1.01° (p = 0.00), Wits of 4.49 ± 2.21 mm (p = 0.00) and overjet of 4.90 ± 1.66 mm (p = 0.00) were accomplished and maintained without significant changes in the vertical dimension. Upper and lower incisor inclinations were not affected by the protraction protocol but significantly increased (U1-PP: 8.39° ± 5.59°) between T2 and T3. SNB decreased initially by 1.67° ± 1.34° (p = 0.00) but relapsed due to residual mandibular growth and a counterclockwise rotation of the mandibular plane. Conclusion The hybrid-Hyrax Alt-RAMEC combined with miniscrew reinforced heavy Class III elastics resulted in a favourable and stable Class III correction.

Orthodontic camouflage versus orthognathic surgery for class III deformity: comparative cephalometric analysis

The objective of this study was to compare different cephalometric variables in adult patients with class III malocclusions before and after treatment, in order to determine which variables are indicative of orthodontic camouflage or orthognathic surgery. The cases of 156 adult patients were assessed: 77 treated with orthodontic camouflage and 79 treated with orthodontics and orthognathic surgery. The following cephalometric variables were measured on pre-treatment (T1) and post-treatment (T2) lateral cephalograms: sella–nasion–A-point (SNA), sella–nasion–B-point (SNB), and A-point–nasion–B-point (ANB) angles, Wits appraisal, facial axis angle, mandibular plane angle, upper and lower incisor inclination, and inter-incisal angle. There were statistically significant differences in cephalometric variables before and after treatment between the two groups. The percentage of normal pre-treatment measurements in the camouflage orthodontics group was 30.7%, which worsened slightly to 28.4% post-treatment. However in the group receiving surgery, this was 24.5% pre-treatment, improving to 33.5% after surgery. SNA, SNB, Wits appraisal, lower incisor inclination, and inter-incisal angle showed differences between the two groups before and after treatment. Wits appraisal, lower incisor inclination, and inter-incisal angle were indicative of one or other treatment. Upper and lower incisor decompensation in both groups did not reach ideal values, which impeded complete skeletal correction in 52% of surgical cases.

Lower incisor inclination in relation to facial biotype in skeletal Class I patients

The lower incisor and its position in the arch are considered of vital importance when planning orthodontic treatment due to its effects on aesthetics and treatment stability. Facial biotype plays an important role in diagnosis and orthodontic treatment planning. Objective: of this study was to compare the lower incisor inclination of each facial biotype in patients whose maxillomandibular sagital relationship was class I as assessed by Ricketts lateral cephalometry. Material and methods: 100 lateral headfilms of class I skeletal patients were selected and classified according to VERT’s facial biotype and the lower incisor inclination to the A-Pog plane was measured. Results: showed that incisor inclination between dolichofacial and mesofacial patients is not different, but among brachyfacial and dolichofacial there were statistically significant differences, as it happens between mesofacial and brachyfacial. In dolichofacial patients, there is more incisor inclination than in brachyfacial patients. Conclusion: that dental inclinations vary according to facial biotype, so diagnosis is essential in order to make the correct choice of appliances. When treating brachyfacial patients a reduced lower incisor inclination should be considered compared to dolichofacial patients.

Appraising Lower Incisor to Mandibular Plane Angle in Different Facial and Sympheal Morphology

Background:: In orthodontic diagnosis and treatment planning assessment of an individual’s facial skeletal pattern in vertical, sagittal and transverse direction is prevalent. Dental compensation is the reverse of skeletal disharmony. Objectives:: This study has correlated the position of mandibular incisors inclination with different facial types and with the mandibular symphyseal morphology. Materials and Methods:: The sample consisted of 100 Pakistani patients of two different age groups i.e. adolescents up to 12 years and audlts up to 22 years on which R–angle, Li–MP, B–MP, Li–MP, symphyseal width (W) and depth (D) were measured. Results:: No correlation was found between Li–MP and R–angle, B–MP, Li–MP, and W except with the D i.e. symphyseal depth. Conclusions:: No significant association observed between lower incisor inclination, different facial types, and symphyseal morphology except with the depth of the symphysis. Slight correlation of differential jaw growth and dental changes with age are coincidental events with no relationship.

Assessment of Anterior Alveolar Bone Dimensions in Adolescents and Adults with Class I Normal Occlusion

Aims: To investigate alveolar bone dimensions in the anterior segment of maxilla and mandible in 2 age group samples; adolescents and adults. Materials and Methods: Cephalometric radiographs of 60 adolescent (30 males and 30 females) and 60 adult subjects (30 males and 30 females) with Class I normal occlusion were included in this study. The anterior alveolar segment was assessed using several parameters that measure the thickness (labial and lingual) and height of alveolar bone surrounding upper and lower incisors. Upper and lower incisor inclination and palatomandibular plane (PMP) angle were also measured. Independent samples t– test and Pearson correlation coefficient were used for data analysis. Results: Sexual dimorphism was noticed in labial and palatal alveolar bone thickness of maxilla for both adolescent and adult subjects. Adult males also demonstrated significantly higher values for lower alveolar height and symphysis width than females. The comparison between 2 age groups revealed no significant difference for most variables and the most evident finding was the significantly higher values reported for upper and lower alveolar heights and symphysis width in adult males compared to adolescent males. The results of correlation analysis showed that upper incisor inclination has positive correlation with upper labial alveolar width and negative correlation with palatal alveolar width indicating that thinner palatal bone thickness is associated with more proclined upper incisors. Labial alveolar bone thickness at apical level of maxilla and mandible showed negative correlation with upper and lower alveolar heights in both age groups and with PMP angle in adults only. While, symphysis width showed positive correlation with the width of lingual alveolar bone and with alveolar heights. Conclusions: No significant differences were found between the 2 age groups, however in both adolescents and adults anterior alveolar dimensions showed sexual dimorphism and correlations with other cephalometric parameters.

Comparing relapse after occlusion using begg and biocryl retainers

Stability of the occlusion after orthodontic treatment is a major goal clinicians set for themselves at the onset of treatment. To achieve this stability, retention becomes a dynamic part of orthodontics. Therefore, this study was conducted to compare and evaluate the effectiveness of Begg (wraparound) and Biocryl retainers in the prevention of relapse. Fifty patients with an Angle's Class I bimaxillary occlusion were selected for the study and randomly divided into two retention groups: Group 1 with Begg wraparound retainers and Group 2 with Biocryl retainers. Dental records, including dental casts, OPGs and lateral cephalograms were collected at pre-treatment (T1), post-treatment (T2) and one year post-retention (T3). The results showed no statistically significant difference between the two retainers, on comparison. However, Biocryl retainers were more effective in maintaining the inclination of lower incisors with respect to NB (Nasion to point B) and lower anterior alignment. Thus, Biocryl retainers are an aesthetic alternative to Begg retainers in the prevention of relapse. Clinical Relevance: Retention is a continuation of orthodontic treatment after removal of the fixed appliance. This study highlighted the importance of retainers in maintenance of orthodontic corrections achieved. In addition it compares two retainers and provides a clinical perspective on the ideal retainer to be used.

Preplanning Contemporary Incisor Positioning using Inclinometer: A Clinical and Cephalometric Study

Introduction: The purpose of the present study is to link the fields of cephalometric assessment of incisor inclination with that of contemporary orthodontic incisor inclination correc tion, in order to enhance the applicability of well-accepted cephalometric standards. Materials and methods: The sample of the study consists of 120 subjects, 53 males and 67 females pretreatment lateral cephalograms and corresponding dental casts with proper inclusion criteria. Upper (U1) and lower (L1) axial incisor inclinations were assessed using inclinometer with reference to the cephalometric lines NA (nasion to point A) and NL (palatal plane), and NB (nasion to point B) and ML (mandibular plane: tangent to the lower border of the mandible) respectively. Sagittal and vertical skeletal relationships were classified using SNA (SNB) and NSL (SN plane)—ML (NSL-NL) angles. Third order angles [U1TA (upper incisor torque angle) and L1TA (lower incisor torque angle)] were derived from direct dental cast measurements using an incisor inclination-recording appliance (inclinometer). Results: Cephalometric assessments of upper incisor inclination showed a range of 31 ± 5.27° for U1NA/degree and 32 ± 5.84° for the U1NL. Lower incisor inclination showed a variation of 28.5 ± 6.58 (L1NB/degree) and 36.75 ± 7.2 to the L1ML respectively. Third-order angles varied between 31° for U1TA and 35° for L1TA. In the upper arch, U1TA assessments underscored U1NA/degree values with a mean of 14.43° and U1NL data at a mean of 104.63°. Conclusion: Third-order measurements using inclinometer device can offer a simple way to get an objective and rapid vision of the incisors inclination and might be a helpful guideline to the choice of low or high torque brackets. Incisor inclination is strongly correlated with skeletal-sagittal data, but little with skeletal-vertical findings. OrIgInal reSearch

Tonsillotomy versus tonsillectomy--a randomized trial regarding dentofacial morphology and post-operative growth in children with tonsillar hypertrophy

The primary aim of this study was to analyse two different methods of tonsil surgery, tonsillectomy (TE) and tonsillotomy (TT), regarding post-operative dentofacial growth in children with tonsillar hypertrophy. A secondary aim was to analyse these results in relation to cephalometric standards. The study group consisted of 64 subjects (39 boys and 25 girls), mean age 4.8 years ± 4 months. They were randomized to a complete removal of the pharyngeal tonsil, TE, (n = 31) or a partial removal, TT, (n = 33). Pre-operative and 2 years post-operative study material were obtained and analysed. The results were compared with cephalometric standards. Pre-operative, children with hypertrophic tonsils displayed an increased vertical relation (P < 0.05) compared with cephalometric standards. Post-operative, no significant difference could be detected between the two surgical procedures regarding dentofacial growth. Mandibular growth with an anterior inclination was significant (P < 0.001/TE, P < 0.01/TT) for both groups. An increased upper and lower incisor inclination was noted (P < 0.01/TE,TT). The vertical relation decreased (P < 0.001/TE, P < 0.05/TT) as well as the mandibular angle (P < 0.01/TE, P < 0.001/TT). Reduction was also significant for the sagittal intermaxillar (P < 0.001/TE,TT) relation. These post-operative results, together with a more prognatic mandible (P < 0.05/TE,TT) and chin (P < 0.001/TE, P < 0.01/TT), might indicate a more horizontal direction of mandibular growth. TE and TT yielded equal post-operative dentofacial growth in children treated for hypertrophic tonsils. This result should be considered when deciding upon surgical technique.

Control of lower incisor inclination with a completely customized lingual appliance for dentoalveolar compensation of class III malocclusion

Bracket slots and orthodontic archwires offering high dimensional precision are needed for fully customized lingual appliances. We aimed to investigate whether high-precision appliances of this type enable dentoalveolar compensation of class III malocclusion so that lower incisor inclination at the end of treatment will closely match the anticipated situation as defined in a pretreatment setup. This retrospective study included a total of 34consecutive patients who had worn a fully customized lingual appliance to achieve dentoalveolar compensation for class III malocclusion by intermaxillary elastics, or proximal enamel reduction, or extraction of teeth in one or both jaws. Casts fabricated at different points in time were three-dimensionally scanned to analyze how precisely the lower incisor inclinations envisioned in the setup were implemented in clinical practice. Aside from minor deviations of ±3.75°, the lower incisor inclinations were clinically implemented as planned even in patients with major sagittal discrepancies. Treatment goals predefined in a setup of dentoalveolar compensation for class III malocclusion can be very precisely achieved via a customized lingual appliance. Correct planning can prevent undesirable lingual tipping of the lower incisors. This finding should not encourage a more liberal use of dentoalveolar compensation, but it should heighten clinicians' awareness of how essential it is to sufficiently consider the individual anatomy of the dentoalveolar complex during treatment planning.

Mini-implants and the efficiency of Herbst treatment: a preliminary study

BackgroundThe purpose of this study is to present the use of a modified Herbst appliance in association with temporary anchorage devices (TADs) in order to enhance the correction of skeletal class II malocclusions.MethodsTen consecutive adolescents scheduled for Herbst treatment were assigned to two treatment groups. Five cases were treated with a modified miniscrew-supported Herbst appliance (experimental group (EG)) and five cases with a conventional cast Herbst appliance (control group (CG)). In all cases, the Herbst was kept in place for 9 months and was followed by fixed appliances until class I relationships were achieved. The initial (T1) and final (T2) lower incisor inclination on lateral headfilms were analyzed for each case, and the mean increase for the five EG patients and the five CG patients were compared.ResultsThe mean increase in lower incisor inclination at the end of treatment was 1° (range 0° to 2°) for the EG and 7° (range 4° to 10°) for the CG.ConclusionsThe rational association of TADs with the Herbst appliance can optimize treatment efficiency and skeletal response by reducing the occurrence of excessive lower incisor proclination.

The inclination of mandibular incisors revisited

To reassess the inclination of lower incisors and evaluate possible associations with gender, age, symphyseal parameters, and skeletal pattern. Twelve hundred and seventy-two (605 females, 667 males) cephalograms of untreated subjects of a craniofacial growth study (age: 8-16 years) were evaluated. Correlations between the angulation of the lower incisors and age, symphyseal distances (height, width, and depth), symphyseal ratios (height-width, height-depth), and skeletal angles (divergence of the jaws and gonial angle) were investigated for all ages separately and for both sexes independently. The inclination of lower incisors increased over age (8 years: girls = 93.9° [95% CI, 92.3°-95.7°], boys = 93.3° [95% CI, 91.8°-94.9°]; 16 years: girls = 96.1° [95% CI, 94.1°-98.2°], boys = 97.1° [95% CI, 95.6°-98.6°]). Inclination of lower incisors correlated with the divergence of the jaws for all ages significantly or highly significantly, except for boys and girls 9 years of age and girls 11 and 12 years of age, for which only a tendency was observed. Similarly, a strong correlation to gonial angle could be observed. No correlation could be found between the inclination of lower incisors and any symphyseal parameters (absolute measurements and ratios), except for symphyseal depth. Lower incisor inclination is linked to the subject's sex, age, and skeletal pattern. It is not associated with symphyseal dimensions, except symphyseal depth. Factors related to natural inclination of lower incisors should be respected when establishing a treatment plan.

Cephalometric Assessment of Lips in Skeletal Class II Patients by Steiner’s Line

Abstract Introduction: Steiner's (S) Line has been used as reference line to assess antero-posterior position of lips cephalometrically and has been an effective diagnostic aid in this era of soft tissue paradigm. Norms for S-line has been established for different populations and it has been used widely to assess treatment outcomes in Skeletal Class II malocclusion, however antero-poste-rior position of lips and determinants of lip position in Skeletal Class II has not been explored. Study Design: This Prospective study was aimed to find out the antero-posterior position of lips on cepha-lograph using S-line in patients with retrognathic pro-file and to establish correlation between determinants of lip prominence. Data was collected using non-pro-bability convenience sampling technique following the selection criteria. Materials and Methods: The study was conducted on 65 subjects, with retrognathic profile as judged by orthodontists in consensus and confirmed by lateral cephalogram (ANB > 4°). S-Line was drawn on lateral cephalograph to assess the prominence of upper Lip and lower lip. SPSS 17.0 was used for statistical evalu-ation. Results: Antero-posterior position of upper and lower lip in patients with retrognathic profile with reference to S-line was 1.96 ± 2.6 mm and 3.09 ± 3.16 mm res-pectively. Moreover it was found that statistically sig-nificant correlation existed between lower lip promi-nence as assessed by S-line and upper lip prominence using the same reference line (r = 0.411), Lower inci-sor inclination (r = 0.535) and Skeletal Class II as as-sessed by ANB angle (r = 0.27). Upper lip prominence as assessed S-line was found to be statistically signi-ficantly correlated with lower incisor inclination and lower lip prominence. Discussion: Results were compliant with the previous studies. Conclusion: In the present study both upper and low-er lips were more prominent in Skeletal Class II patie-nts as compared to Steiner's norms for skeletal class I. Keys: Retrognathic Progile, Skeletal II Class Maloc-clusion, Lip Prominence, S-Line.

Cephalometric norms for orthognathic surgery for North Indian population.

Objective:The objective of this study is to establish the cephalometric hard tissue norm for orthognathic surgery for North Indian subjects.Materials and Methods:A total of 100 young adults which consists of 46 males and 54 females with the age range of 14-24 years with balanced facial profile and minimum arch length discrepancies were chosen for the study. Lateral cephalograms with teeth in occlusion were recorded and analyzed manually to establish the norm. The mean values of various cephalometric hard tissue variables for North Indian males and females were compared with those Caucasians. P < 0.05 was considered to be statistically significant.Results:All the cephalometric parameters for orthognathic surgery except mandibular length and lower incisor inclination were comparable among North Indian males and females. The mandibular length was significantly more among North Indian males than females (P < 0.05) and the inclination of lower incisors was significantly more among North Indian females than males (P < 0.05). However, many of the cephalometric parameters for orthognathic surgery were significantly different among North Indian and Caucasian males and females.Conclusion:The cephalometric norms for orthognathic surgery were established for North Indians and many measurements were different from those for Caucasians.