A comparison of ANB, WITS, AF-BF, and APDI measurements

Comparison of Diagnostic Validity of Cephalometric Analyses of the ANB Angle and Tau Angle for Assessment of the Sagittal Relationship of Jaw and Mandible

BACKGROUND

Cephalometric analysis is an essential tool used in orthodontic diagnosis and treatment planning. The aim of this study was to evaluate the reliability and repeatability of new cephalometric points introduced in Tau angle analysis, in contrast to the gold standard, which is the analysis of the ANB angle. For this purpose, an attempt was made to assess the repeatability and reliability of the introduction of anthropometric points by evaluating both inter- and intraobserver parameters, as well as the agreement among the orthodontists participating in the study.

METHODS

Repeatability and reliability assessments for all six anthropometric points (N, A, B, T, M, G) used in the analysis of the ANB and Tau angles were conducted individually by 29 orthodontists. This assessment was performed in triplicate on the day of the study, on the day following the first study, and on the seventh day after the second study. Measurement errors for the ANB and Tau angles were evaluated using the Dahlberg formula and intraclass correlation coefficients (ICCs).

RESULTS

The orthodontists in the study measured sagittal discrepancy significantly more accurately using the ANB angle compared to the Tau angle (p < 0.001). The Dahlberg error for measuring the Tau angle was three times greater than that for the ANB angle (p < 0.001). Additionally, the ICC for the Tau angle was more than 3.5 times smaller than that for the ANB angle, while the R&R error for Tau measurement was more than three times greater than that for the ANB angle (p < 0.001).

CONCLUSIONS

The results of ANB angle measurements exhibit fewer errors in comparison to Tau angle measurements.

Assessment of the Relation Between Craniofacial Tissue Profile-Morphology and Dermatoglyphics

This study aims to evaluate the relationship between the convexity angle of facial tissue and fingerprint types by analyzing the connection between dermatoglyphic prints and facial structure. A total of 65 adults (24 females, 41 males) participated in the study. Each participant's fingerprint was analyzed using conventional methods of observation upon the index finger of the dominant hand. Fingerprints were classified into 3 fundamental types: arch, whorl, or loop. Craniofacial profiling was performed with measurements of hard tissue (Gl'-A-Pg') and soft tissue facial convexity (Gl-Sn-Pg) and total facial convexity (Gl-Prn-Pg) angles between 3 anthropological points determined on the lateral direct radiographs of the participants. Soft tissue convexity facial angle (Gl-Sn-Pg) values were found to be an average of 166.83° in females and an average of 162.05° in males. (Gl-Prn-Pg) values were found to be an average of 138.54° in females and 135.27° in males. The soft tissue profile of males showed a significantly convex structure compared with females. Also, the "whorl" type of fingerprint was found to be dominant in both sexes. There is no statistically significant difference in terms of soft tissue profile convexity in individuals belonging to the 3 different fingerprint groups. No statistically significant difference in soft tissue profile angular values between right-hand thumb and index fingerprint type groups were found among and between sexes. However, a comprehensive analysis of the relationships between the nose, lips, mouth, ear, and eyes and fingerprints of the same person may prove to be beneficial.

Three-dimensional evaluation of condylar position in skeletal Class I and Class II malocclusions along with vertical facial morphology

Objectives:

This study aimed to three-dimensionally evaluate and compare anatomic condylar position to glenoid fossa in skeletal Classes I and II malocclusions along with vertical facial morphology (VFM).

Material and Methods:

Full skull 50 cone-beam computed tomographies (CBCTs) were taken with teeth in maximum intercuspation of patients aged 18–45 years who were grouped as skeletal Classes I and II, 25 each based on ANB angle and the patient’s right condyle was analyzed on CareStream-3D viewing software. The VFM was categorized based on the Jarabak ratio. Statistical analysis was performed using Mann–Whitney and Chi-square test.

Results:

In skeletal Class II when compared to Class I, the condyle in the glenoid fossa was anteriorly positioned with reduced anterior (P = 0.006) and increased posterior (P = 0.04) distance showing eccentric position. The condyle was also positioned lower suggesting an increased distance in the upper joint space (P = 0.04). The reduced height of the articular eminence indicated the condylar path and its position. The angle of articular eminence (P = 0.44) was decreased. Statistically, significant difference was not found between the various vertical facial morphologies.

Conclusion:

CBCT provides precise diagnostic values of joint spaces in skeletal Classes I and II to differentiate ideal condylar position from non-ideal according to different skeletal patterns, VFM, and also to notice minor discrepancies in joint spaces quantitatively. Depending on increased or decreased distances in the joint spaces, one can identify any temporomandibular joint-related discrepancies.

Assessment of Dentofacial Characteristics and Pharyngeal Airway in Children with Class II Malocclusion and Mouth Breathing

Background In growing patients with skeletal discrepancies, early diagnosis, evidence-based explanation of etiology, and assessment of functional factors can be vital for the restoration of normal craniofacial growth and the stability of treatment needs.

Aims The aim of the study was to assess dentofacial characteristics as well as upper and lower pharyngeal airway in children with skeletal class II malocclusion with mouth breathing, and to investigate possible significant relationships and correlations among the studied cephalometric variables and the airway morphology in these children.

Materials and Methods Sixty untreated children, aged 9 to 13 years, were divided into three groups according to clinical findings and cephalometric analysis of dentofacial characteristics as well as the presence of mouth breathing habit: Group I (20 children with normal jaw relation/class I), Group II (20 children with skeletal class II), and Group III (20 children with skeletal class II with confirmed mouth breathing habit). Cephalometric variables and upper/lower airway widths were recorded. Intergroup comparison of all measurements was performed by post hoc Tukey test, and Pearson's correlation was used to determine the correlation among the variables.

Results Significant changes existed in more than half of the dentofacial measurements among the three groups. Significantly greater skeletal anteroposterior jaw discrepancy and mandibular retrognathism were found in both groups II and III as determined by specific anteroposterior determinants. Children in group III showed significantly increased angle between Sella-Nasion and mandibular plane (SN-MP) angle, y-axis, and a vertical growth pattern. Significant increases in dental measurements, namely upper incisor to Nasion- point A (NA), lower incisor to Nasion - point B (NB), and overjet, were found in group II and group III, while overbite showed a significant decrease. Upper pharyngeal airway width was found to be significantly decreased in group III followed by a smaller though significant decrease in group II. No significant differences were found in lower pharyngeal airway width between the groups. There were statistically significant dentofacial characteristics that showed fair to good correlation with the upper airway width.

Conclusion Children with skeletal class II malocclusion with and without mouth breathing showed significant differences in dentofacial measurements and a significantly narrower upper pharyngeal airway as compared with children with normal jaw/class I relation.

Evaluation of Salivary Leptin Levels and Its Correlation with Class I, Class II, and Class III Facial Skeletal Pattern: A Prefatory Study

Objective The aim of this study was to assess and compare the salivary leptin hormone levels between different classes of facial skeletal pattern (Class I, II, and III).

Materials and Methods A sample of 62 patients were selected prior to the orthodontic treatment from a population that attended the International Islamic University Malaysia Specialist Orthodontic Clinic. Based on the lateral cephalometric analysis, the subjects were grouped into Class I, Class II, and Class III facial skeletal patterns, according to Eastman and Wits appraisal. Subsequently, unstimulated saliva samples were taken and purified to undergo leptin enzyme-linked immunosorbent assay analysis to determine the levels of leptin hormone. Statistical analysis using the Kruskal–Wallis test was used to analyze the data obtained.

Results The results showed that there was a significant difference between the levels of leptin hormone between Class I and Class II skeletal patterns and between Class I and Class III facial skeletal patterns. No statistical difference was noted between the levels of leptin of Class II and Class III facial skeletal patterns.

Conclusion Salivary leptin hormone levels are higher in patients with Class II and Class III facial skeletal patterns compared with Class I.

MKG Angle: A True Marker for Maxillomandibular Discrepancy

Aim: To evolve a new cephalometric estimation called the MKG angle using three skeletal landmarks—point key ridge (KR), point M, and point G to evaluate the sagittal relationship between the maxilla and mandible.

Materials and methods: A total of 60 pretreatment lateral cephalograms were selected and segregated into classes I, II, and III groups on the basis of ANB angle, Wits appraisal, and W angle. The MKG angle was constructed between the lines drawn from point M to point KR and point KR to point G. The MKG angle was measured to calculate the mean and the standard deviation.

Results: After using the one-way analysis of variance and the Newman–Keuls test and running ROC curves, the results showed that an MKG angle in the range 51º–59º can be considered to have a class I skeletal pattern. The MKG angle more than 59º indicates a class II skeletal pattern and less than 51º indicates class III skeletal pattern.

Conclusion: The MKG angle can be used as a dependable marker to assess sagittal jaw discrepancy.

Efficiency of ODI and APDI of Kim's cephalometric analysis in a Latin American population with skeletal open bite

Objective:

The objective of this research was to demonstrate the efficiency of the overbite depth indicator (ODI) and the anteroposterior dysplasia indicator (APDI) from Kim’s cephalometric analysis, regarding the determination of the vertical and sagittal patterns of Latin American individuals.

Methods:

Two hundred lateral cephalometric radiographs were selected and divided into four study groups, with 50 radiographs each, for carrying out a cross-sectional study. The control group included radiographs of balanced individuals, and the other three groups had lateral cephalometric radiographs of subjects with Class I, II and III malocclusions and with skeletal open bite. After the pilot test was performed to calibrate the investigator, the ODI and APDI were measured. Descriptive statistics were performed and the one-way ANOVA with post-hoc Tukey HSD, or Kruskal-Wallis and Mann-Whitney U-test were used. Also a multiple linear regression was employed.

Results:

Statistically significant differences were found for the ODI of all groups (p< 0.001), except between Class I group (65.87 ± 4.26) and Class II open bite group (67.19 ± 3.58), both with similar values to each other. For APDI, statistically significant differences were also found for all groups (p< 0.001). However, no statistically significant differences were found between the balanced group (83.18 ± 1.71) and Class I group with skeletal open bite (81.78 ± 2.69).

Conclusions:

ODI and APDI are reliable indicators to evaluate the sagittal and vertical patterns of an individual, demonstrating their efficiency when a Latin American population was evaluated.

Sagittal discrepancies of the jaw in a Bangladeshi cohort: three-dimensional computed tomography analysis

Objectives

In orthodontic diagnosis and treatment planning, the assessment of skeletal jaw relationships is an essential step. This study aimed to evaluate skeletal jaw relationships in a Bangladeshi cohort by using traditional (ANB angle and Wits appraisal) and newly described (Beta angle, W angle, and Yen angle) sagittal measurements in three-dimensional (3D) computed tomography (CT).

Methods

The radiology department conducted CT scans of Bangladeshi patients. Mimics 3D imaging software (Materialise) was used to process the CT images and evaluate 3D sagittal measurements. SPSS software (IBM) was used to assess significant differences in the data at a confidence level of 5%. Independent-samples t-tests were used to evaluate sexual dimorphism for the measured values.

Results

In total, 85 men and 32 women were included in this study. All measurements were equivalent to the existing standards. There were no significant differences in the acquired values between men and women. Measurements were consistent with Class I normal classification.

Conclusions

This study established 3D CT standards for ANB, Wits appraisal, Beta angle, W angle, and Yen angle in Bangladeshi patients.

Objective assessment of the fetal facial profile at second and third trimester of pregnancy

OBJECTIVE

To investigate the intraobserver and interobserver reproducibility of a novel sonographic parameter named facial maxillary angle (FMA) and to establish nomograms of FMA, inferior facial angle (IFA), frontal nasal-mental angle (FNMA), maxilla-nasion-mandible angle (MNMA), and fetal profile line (FPL) in Chinese fetuses.

METHODS

In this prospective cross-sectional study, FMA, IFA, FNMA, MNMA, and FPL were measured in 592 normal fetuses between 16 and 36 gestational weeks. FMA was measured twice by the same and another operator with a blinded method on the first 50 cases. The reference interval was defined as ±2SD. The efficacy of five sonographic markers was tested in 10 fetuses with micrognathia retrieved from the database of our unit.

RESULTS

The intraclass correlation coefficient (95% CI) of intraobserver and interobserver reproducibility of FMA was 0.937 (0.890-0.964) and 0.891 (0.809-0.938), respectively. FMA, FNMA, and IFA increased slightly from 16 weeks till 28-31 weeks and decreased minimally thereafter. FMA and FNMA made correct diagnosis in all affected fetuses; MNMA and IFA identified nine and eight cases respectively, and FPL only detected five cases.

CONCLUSION

A fixed cutoff of 66° for FMA and 136° for FNMA may be adopted as simple screening criteria of micrognathia.

Cephalometric Floating Norms for the β Angle and MMBP-Wits

The importance of an accurate measurement of sagittal jaw relationship, that is, skeletal class, is critical to orthodontic treatment planning. The ANB angle, β angle, and MMBP-Wits are among indices of sagittal jaw relationship. All of these indices are subjected to geometrical distortion, especially from facial divergence, making the use of floating (individualized) norms necessary. This study thus provides floating norms for the ANB angle and for the first time for the β angle and MMBP-Wits. Lateral head films were obtained from 119 subjects (74 females and 45 males; mean age, 11.2 ± 1.5 years; range, 8.2–14.0 years) with well-balanced and pleasant profile and a near-ideal occlusion. Multiple regression models were employed to quantify the association of the ANB angle, β angle, and MMBP-Wits each with other four angular cephalometric parameters including SNA, SN/PP, SN/MP, and NSBa angles. The β angle and MMBP-Wits were associated with the SNA and SN/MP angles; the ANB angle was associated with all the four other cephalometric variables. Floating norms for the β angle and MMBP-Wits (but not ANB angle) have been cross-tabulated according to the SNA angle (from 74° to 90°) and SN/MP angle (from 24° to 44°). While the ANB angle is subjected to significantly more geometrical distortion as compared to the β angle and MMBP-Wits, floating norms may be used to individualize the reference values for both the β angle and MMBP-Wits.

Three dimensional reliability analyses of currently used methods for assessment of sagittal jaw discrepancy

Background

The objective of this study was to analyse three dimensionally the reliability and correlation of angular and linear measurements in assessment of anteroposterior skeletal discrepancy.

Material and Methods

In this retrospective cross sectional study, a sample of 213 subjects were three-dimensionally analysed from cone-beam computed tomography scans. The sample was divided according to three dimensional measurement of anteroposterior relation (ANB angle) into three groups (skeletal Class I, Class II and Class III). The anterior-posterior cephalometric indicators were measured on volumetric images using Anatomage software (InVivo5.2). These measurements included three angular and seven linear measurements. Cross tabulations were performed to correlate the ANB angle with each method. Intra-class Correlation Coefficient (ICC) test was applied for the difference between the two reliability measurements. P value of < 0.05 was considered significant.

Results

There was a statistically significant (P<0.05) agreement between all methods used with variability in assessment of different anteroposterior relations. The highest correlation was between ANB and DSOJ (0.913), strong correlation with AB/FH, AB/SN/, MM bisector, AB/PP, Wits appraisal (0.896, 0.890, 0.878, 0.867,and 0.858, respectively), moderate with AD/SN and Beta angle (0.787 and 0.760), and weak correlation with corrected ANB angle (0.550).

Conclusions

Conjunctive usage of ANB angle with DSOJ, AB/FH, AB/SN/, MM bisector, AB/PP and Wits appraisal in 3D cephalometric analysis provide a more reliable and valid indicator of the skeletal anteroposterior relationship. Clinical relevance: Most of orthodontic literature depends on single method (ANB) with its drawbacks in assessment of skeletal discrepancy which is a cardinal factors for proper treatment planning, this study assessed three dimensionally the degree of correlation between all available methods to make clinical judgement more accurate based on more than one method of assessment. Key words:Anteroposterior relationships, ANB angle, Three-dimension, CBCT.

Comparison of popular sagittal cephalometric analyses for validity and reliability

Background

The analysis of skeletal relationships of jaws in the sagittal plane is of utmost importance in orthodontic diagnosis for which numerous lateral cephalometric analyses have emerged. None of the analyses is without flaws. Current study compares ANB, Wits appraisal, Beta angle, Yen angle and W angle for their validity and reliability in diagnosis of skeletal classes.

Methods

Pretreatment cephalograph of 209 orthodontic patients comprised of 92 males and 117 females were selected from orthodontic archives. Radiographs were traced for ANB, Wits appraisal, Beta angle, W angle and Yen angle measurements. Patients were divided into three skeletal classes i.e. class I, II and III based on measurements and incisor classification and profile recorded from their files. ANOVA was applied to check the validity of performed analyses and Cramer’s correlation was performed to find out the correlation between analyses and skeletal classes.

Results

All performed analyses showed statistically significant difference in the values for all three skeletal classes p < .05. All measured analyses were found equally reliable in diagnosis of skeletal discrepancies.

Conclusion

All five-skeletal cephalometric sagittal analyses are reliable and can be used in orthodontic diagnosis as alternative to each other.

Dental Age in Orthodontic Patients with Different Skeletal Patterns

Objective. To evaluate the difference between chronological and dental age, calculated by Willems and Cameriere methods, in various skeletal patterns according to Steiner's ANB Classification. Methods. This retrospective cross-sectional study comprised the sample of 776 participants aged between 7 and 15 years (368 males and 408 females). For each participant, panoramic images (OPT) and laterolateral cephalograms (LC) were collected from the medical database. On LC ANB angle was measured; on OPT dental age (DA) was calculated while chronological age (CA) and sex were recorded. The sample was divided into three subgroups (Class I, Class II, and Class III) with similar distribution based on the chronological age and ANB angle. CA was calculated as the difference between the date of OPT imaging and the date of birth, while DA was evaluated using Willems and Cameriere methods. ANB angle was measured on LC by two independent investigators using the cephalometric software. Differences between sexes and the difference between dental and chronological age were tested by independent and paired samples t-test, respectively; one-way ANOVA was used to test differences among ANB classes with Tukey post hoc test to compare specific pairs of ANB classes. Results. The significant difference was found between Class III and other two skeletal classes in males using both dental age estimation methods. In Class III males dental age was ahead averagely by 0.41 years when using Willems method, while Cameriere method overestimated CA for 0.22 years. Conclusion. In males with Class III skeletal pattern, dental development is faster than in Classes I and II skeletal pattern. This faster development is not present in females.

Evolution of ANB and SN-GoGn angles during craniofacial growth: A retrospective longitudinal study

Objective

The aim of this study is to describe the evolution of the ANB and SN-GoGn angles throughout development, in a longitudinal sample of Caucasian patients.

Materials and Methods

Historical cephalometric records from North American individuals available at the American Association of Orthodontists Foundation Craniofacial Legacy Growth Collection website were used to carry out an exploratory longitudinal study. Lateral cephalometric radiographs of orthodontically untreated males and females were included. Individuals with three or more longitudinal cephalometric records at pre- and post-pubertal stages, with at least one postpubertal radiograph available in vertebral cervical maturation stage (cervical vertebral maturation) 5 or 6, were selected. Seventy-one individuals met the inclusion criteria. ANB, SNA, SNB, and SN-GoGn angles were measured. Individuals were classified according to the latest postpubertal ANB angle available and grouped by CVM. Descriptive statistics were obtained for the cephalometric variables, and differences between genders were analyzed.

Results

Forty-five individuals were classified as skeletal Class I at the end of growth, 17 as Class II, and 9 as Class III. ANB values decrease as growth occurs in every group (average ANB decrease between the stages CVM 1 and 6: Class I - 1.5°, Class II - 0.7°, and Class III - 3.1°). For SN-GoGn angle, a constant reduction was observed as skeletal maturation increased (Average SN-GoGn decrease between the stages CVM 1 and 6: Class I - 4°, Class II - 2.5°, and Class III - 4.9°).

Conclusions

ANB and SN-GoGn angles decrease during growth. The magnitude varies depending on individual sagittal characteristics, Class III individuals displaying the greatest reduction, and Class II individuals the least.

Cephalometric comparison of cesarean and normal births

Objective:

The aim of this study was to compare cephalometric variables of subjects with normal and cesarean births.

Materials and Methods:

Ninety age- and gender-matched patients, who were treated in Gaziantep University, Faculty of Dentistry Orthodontics Department were equally divided into normal and cesarean groups according to the birth methods reported by their mothers. To eliminate the negative effects of being different in terms of age and gender among parameters, control, and patient groups were matched in the present study. Pretreatment cephalometrics radiographs were used. Six measurements representing sagittal and vertical relationships were evaluated from pretreatment cephalograms using Dolphin Imaging Orthodontics Software was used in this issue by an orthodontist. Kolmogorov–Smirnov test, Student's t-test, and Mann–Whitney U-test were used for statistical comparisons.

Results:

A point-nasion-B point angle (ANB) and Wits values were higher in the normal group, while sella-nasion-A point angle, sella-nasion-B point angle, Frankfort horizontal-mandibular plane angle, and gonion-gnathion-SN plane angle values were higher in the cesarean group. However, the groups showed no significant differences (P > 0.05). ANB angle and Wits values showed high correlation.

Conclusions:

Within the study limitations, the results suggest that the birth method may not have a considerable effect on the development of the craniofacial skeletal system.

Cephalometric study to test the reliability of anteroposterior skeletal discrepancy indicators using the twin block appliance

Background

The objectives of this study were to check the reliability of the five angular and two linear parameters for sagittal maxillo-mandibular discrepancy and to compare and correlate angular parameters with the ANB angle, and the linear parameter with Wits analysis.

Methods

The pre-treatment and post-functional lateral cephalograms of 25 subjects (17 males, 8 females) with class II division 1 malocclusion treated with twin block functional appliance were selected. Five angular (ANB, β angle, APDI, YEN angle, W angle) and two linear (Wits analysis, App-Bpp) parameters were traced on both sets of cephalograms. Paired Student’s t-test, one-way ANOVA, post hoc test, and Karl Pearson correlation statistical analysis were performed.

Results

All the parameters considered in our study showed highly significant difference in pre-treatment and post-functional values, suggesting their reliability (p < 0.0001). When ANB angle was compared with the other angular parameters, a highly significant change in the mean value of the difference in pre-treatment (T1) and post-functional (T2) values was noted (p < 0.001). No significant change was seen when comparing the mean value of the difference in T1 and T2 between linear parameters (p = 0.949).

Conclusions

All the parameters used in the study can be reliably used to assess anteroposterior skeletal discrepancy. Whenever limitations of the ANB angle and Wits analysis are foreseen, the W angle and App-Bpp, respectively, can be reliably used. The YEN angle may reliably predict the post-functional change with the use of twin block appliance.

Cephalometric investigation of first cervical vertebrae morphology and hyoid position in young adults with different sagittal skeletal patterns

The aim of this retrospective study was to examine hyoid bone position and C1 (atlas) morphology in males and females and analyze these parameters with respect to different sagittal skeletal patterns via cephalometry, with the goal of identifying cephalometric norms. Lateral cephalometric radiographs from 120 individuals (average age: 21.1 ± 2.9 years) were classified according to their ANB angle (Class I, II, or III) and used to assess 14 parameters. Class I and II patients showed significant differences in Hy-NSL, Hy-PD, Hy-CVT, Lum, and a-p measurements. These parameters were consistently larger in males than in females. Intergroup comparisons among males showed significant differences in the SNA, ANB, Hy-CVT, X, and Z measurements. The hyoid was positioned more inferiorly and anteriorly and was more prominent in males than in females in all groups. Among participants exhibiting a Class I skeletal pattern, C1 was also larger in the anterior-posterior direction in males than in females. In the sagittal plane, the hyoid was positioned similarly in males with either Class I or III skeletal patterns but was positioned posteriorly in males with a Class II skeletal pattern. In addition, the vertical position of C1 varied with sagittal skeletal pattern in males.

Comparison of Wits appraisal among different ethnic groups

Objectives:

The Wits values for various ethnic groups are different and the applicability of the norms described in these analyses to different populations is difficult. The objectives of this study were to establish the normal values of Wits appraisal in a sample from the western region of Saudi Arabia and to evaluate the existence of gender dimorphism. Also, to compare the results with previously published Wits values.

Materials and Methods:

A total of 66 lateral cephalometric digital radiographs of Saudi patients from the western region (25 males and 41 females, mean age 19.32±8.16 years and 20.88±8.77 years, respectively). All subjects had angle class-I occlusion, well-balanced faces, all premolars had erupted and in occlusion, and no history of orthodontic treatment. Tracing was performed using the VistadentOC^® software.

Results:

Wits mean values were greater in males (−0.73±2.48) than females (1.79±2.06), with significant gender difference (P<0.001). Comparisons with previously published showed that there is a significant differences between ethnic groups, especially in females’ data.

Conclusion:

Wits appraisal appears to be gender-specific and ethnicity-specific for female values.

Dentoalveolar compensation according to skeletal discrepancy and overjet in skeletal Class III patients

INTRODUCTION

This study was designed to investigate dentoalveolar compensation in untreated skeletal Class III patients with either positive or negative overjet.

METHODS

The positive overjet groups consisted of 104 adults, divided into group 1 (angle between sella-nasion to mandibular plane (SN-MP) > 38°, n = 30), group 2 (30° < SN-MP < 38°, n = 43), and group 3 (SN-MP <30°, n = 31). The negative overjet groups (groups 4-6) consisted of 90 adults who were closely matched to the positive overjet groups with regard to the ANB and SN-MP angles. Twenty-two cephalometric measurements were compared between the matched groups. In the positive overjet groups, correlation analysis was performed between the skeletal and dental measurements, and regression analysis was performed to determine the incisor-mandibular plane angle.

RESULTS

The maxillary incisors were more proclined and the occlusal plane was more flattened in the positive overjet groups than in the negative overjet groups; however, there was no statistically significant difference between them with regard to mandibular incisor inclination. The inclinations of the maxillary and mandibular incisors were correlated with both the sagittal and vertical skeletal measurements. Eight regression equations for the incisor-mandibular plane angle were calculated with the highest coefficient of determination of 0.547.

CONCLUSIONS

Proclination of the maxillary incisors and flattening of the occlusal plane contributed to a positive overjet. Mandibular incisor inclination was more closely associated with sagittal and vertical skeletal discrepancies and was not affected by the incisal relationship.

Study between anb angle and Wits appraisal in cone beam computed tomography (CBCT)

Objectives: To analyse the ANB and Wits values and to study correlations between those two measurements and other measurements in diagnosing the anteroposterior maxilo-mandibular relationship with CBCT. Study Design: Ninety patients who had previously a CBCT (i-CAT®) as a diagnostic register were selected. A 3D cephalometry was designed using one software package, InVivo5®. This cephalometry included 3 planes of reference, 3 angle measurements and 1 linear measurement. The means and standard deviations of the mean of each measurement were assessed. After that, a Pearson´s correlation coefficient has been performed to analyse the significance of each relationship. Results: When classifying the sample according to the anteroposterior relationship, the values obtained of ANB (Class I: 53%; Class II: 37%; Class III: 10%) and Wits (Class I: 35%; Class II: 56%; Class III: 9%) did not coincide, except for the Class III group. However, of the patients classified differently (Class I and Class II patients) by ANB and Wits, a high percentage of individuals (n=22; 49%), had a mesofacial pattern with a mandibular plane angle within normal values. A correlation has been found between ANB and Wits (r=0,262), occlusal plane angle and ANB (r=0,426), and mandibular plane angle and Wits (r=0,242). No correlation was found between either Wits or ANB in relation with the age of the individuals. Conclusions: ANB and Wits must be included in 3D cephalometric analyses as both are necessary to undertake a more accurate diagnosis of the maxillo-mandibular relationship of the patients.

Key words:Cone beam computed tomography, ANB, Wits, cephalometrics.

Does the Eastman correction over- or under-adjust ANB for positional changes of N?

Cephalometric analyses are useful for planning and provision of orthodontic treatment. A and B points are used to resemble the anterior part of maxilla and mandible and N represents the anterior part of the cranial base. The position of N may influence measurements of SNA, SNB, and ANB and changes of N in the antero-posterior plane are thought to have a larger influence on the above measurements than vertical ones. Several methods have been proposed to address this issue, such as the Wits appraisal, the 'Individualized ANB', and the 'Eastman correction'; the latter is mainly used in the UK. This study used a geometrical model of a lateral cephalogram with standard Caucasian average values for SN length, position of A and B points for male and female patients. Linear and angular measurements were digitized using Dolphin™ Imaging software. N was moved in antero-posterior and vertical planes and subsequent changes of SNA, SNB, and ANB were measured and the Eastman correction applied. The correction overestimated the SNA and ANB values in the opposite direction to the directly measured SNA and ANB when N moved posteriorly towards S: The directly measured values tended to show a Class II relationship but the correction indicated a Class III skeletal base. As N moved anteriorly, the Eastman correction overestimated the measured Class III skeletal relationship; SNA did not fall below 81 for correction in the opposite direction. Vertical positional changes had little impact on the underlying ANB and correction was not indicated clinically.

Ethnic differences in dentofacial relationships of Turkish and Saudi young adults with normal occlusions and well-balanced faces

OBJECTIVES

The aims of the present study were (1) to determine ethnic differences in craniofacial dimensions between Turkish and Saudi populations and (2) to identify possible gender differences between males and females, based on a sample of untreated young adult subjects with normal occlusions and well-balanced faces.

METHODS

In total, 163 cephalometric radiographs were traced and evaluated to compare untreated adults of Turkish and Saudi ethnicity. The Turkish group comprised 86 subjects; 45 females and 41 males. The Saudi group comprised 77 subjects; 39 females and 38 males. For statistical evaluation, an independent-samples t-test was performed.

RESULTS

The Turkish sample had a more retrognathic maxilla and mandible (p < 0.001 for SNA and SNB) and a more vertical direction of facial development (p < 0.001), with Turkish males having more retrusive lips (p < 0.001). Distinctive ethnic differences were found in craniofacial structures between Turkish and Saudi young adults.

CONCLUSIONS

It is appropriate to consider these aesthetic differences when a Turkish or a Saudi patient is being evaluated during routine diagnosis and treatment planning.

Prenatal Assessment of the Antero-Posterior Jaw Relationship in Human Fetuses: From Anatomical to Ultrasound Cephalometric Analysis

Objectives

We wished to develop an ultrasound cephalometric analysis, particularly of the antero-posterior jaw relationship, to increase the accuracy of prenatal diagnosis of retrognathism during the routine midterm test.

Methods

Anatomical cephalometric analysis was performed in 18 formalin-fixed human fetuses (between 16 and 39 gestational weeks), and ultrasound cephalometry was prospectively carried out in 52 pregnant women (21 to 25 gestational weeks). The same landmarks were used in the anatomical and ultrasound median sagittal planes for comparison. Four cephalometric angles were measured relative to the anterior cranial base: alveolar projection of the maxilla and the mandible, chin projection, and facial angle. The antero-posterior jaw discrepancy was calculated.

Results

The projection of the maxilla was similar in the two cephalometric analyses (IC [–3.39, 0.23]), whereas the values of the projection of the mandible were lower in the ultrasound sample. The slope of the regression line of the antero-posterior jaw discrepancy on fetuses' age did not show significant differences (IC [–0.05, 1.54]) between anatomical and ultrasound cephalometry, although a difference of 3.23° ± 0.78° (IC [1.69, 4.77]) was observed. Despite this variability, the projections of mandible and chin were well determined by the projection of the maxilla both in the anatomical and ultrasound sample.

Conclusions

Cephalometric analysis by prenatal sonography can be performed to study the antero-posterior jaw relationship. We think that this procedure could be useful to improve prenatal diagnosis of retrognathism in high-risk pregnancies. Further studies should address the reproducibility and accuracy of such analysis.

Comparison of Japanese and European overbite depth indicator and antero-posterior dysplasia indicator values

This study evaluated cephalometric differences between 113 Japanese (43 males and 70 females, aged 14.1 ± 5 years) and 106 European subjects (36 males and 70 females, aged 13.5 ± 7.3 years) using two compound angular measurements and their single components: the overbite depth indicator (ODI) for the assessment of vertical skeletal relationships and the antero-posterior dysplasia indicator (APDI) for an evaluation of sagittal dysgnathia. Both populations were assigned to groups representing Angle Classes I, II, and III, and an anterior open bite (AOB) group. Two sample t- and Wilcoxon signed-ranks tests were performed (P < 0.05). The ODI values showed no statistically significant differences between the Japanese and European samples. The Japanese sample showed a significantly smaller APDI but only in the Class II group. In the Japanese Class II and III subjects, the malocclusion patterns were more pronounced than those in the Caucasian sample (overbite, overjet, and APDI).

[Impact of the vertical dimension on the occlusal plane inclination in a Moroccan population]

This study was performed in order to investigate the influence of the vertical dimension on the occlusal plane angle. Cephalometric tracing were made from sideview headfilms from a sample of 150 patients consulting at the consultation and treatment center in Rabat, Morocco. This sample group included 60 males and 90 females. The aims of our research were to study statistically the impact of the vertical dimension on the occlusal plane angle and to check the validity of the Wits (Ao-Bo) by evaluating the impact of the vertical dimension on the Wits and by comparing it with the AF-BF value (Ao-Bo/Frankfurt) proposed by Chang.

Maxillary incisor proclination effect on the position of point A in Class II division 2 malocclusion

OBJECTIVE

To test the hypothesis that the magnitude of alteration in the position of point A is not associated with proclination of the upper incisors in Class II division 2 malocclusion.

MATERIALS AND METHODS

Cephalometric films were taken for 30 Class II division 2 patients (8 males and 22 females; average age, 18.3 years) before and after upper incisor proclination. The total change in the position of point A was measured by superimposing the pretreatment and postproclination lateral cephalograms on the sella-nasion line at the sella. To determine the local effect of alveolar bone remodeling associated with upper incisor proclination on the position of point A, postproclination tracing of the maxilla was superimposed on the pretreatment tracing according to the Bolton template of maxillary superimposition.

RESULTS

The total vertical displacement in Point A position was downward by 0.84 mm (P = .002), and the total horizontal displacement was forward by 0.45 mm (P = .054). Assessment of local changes in point A revealed that the position of point A had moved backward by 0.60 mm (P = .001). No significant change was observed in the value of the sella-nasion-point A angle (SNA).

CONCLUSION

The hypothesis is rejected. The position of point A is affected by local bone remodeling associated with proclination of the upper incisor in Class II division 2 malocclusion, but this minor change does not significantly affect the SNA angle.

Influence of diabetes mellitus on the development and treatment of malocclusions--a case report with literature review

Diabetes mellitus is a metabolic disorder characterized by disturbed glucose regulation, manifesting primarily as chronic hyperglycemia. Today about 6% of the world's population suffers from diabetes mellitus. This metabolic disorder is known to be associated with a large number of concomitant and secondary diseases of the cardiovascular system, as well as of the joint and supporting tissue systems. It is also a recognized fact that diabetes mellitus is closely associated with diverse problems in the oral, facial and jaw regions. These facts suggest that patients with diabetes may respond to orthodontic treatment differently from those without diabetes in how the periodontium and surrounding visceral cranium react to therapy. Beginning with a clinical case report we proceed to present a general overview of the clinical features and pathophysiology of diabetes mellitus, followed by a critical discussion of the results of a systematic literature search for aspects of the disease relevant to orthodontics.

Overjet as a predictor of sagittal skeletal relationships

Skeletal relationships in the sagittal plane do not always correspond with dental relationships. The aim of this study was to determine in which type of malocclusion the correlation between overjet and skeletal sagittal parameters assessed by lateral cephalogram analysis is the highest. The extent to which overjet can predict skeletal relationships in the sagittal plane was also assessed. Eighty-three subjects fulfilled the inclusion criteria (40 males and 43 females, mean age 16.3 +/- 4.3 years). Overjet was measured on study casts and sagittal skeletal relationships were analysed on lateral cephalograms. ANB angle, Wits appraisal, and convexity at point A were determined. Mean values and standard deviations of measured parameters were calculated for Class I, Class II division 1, and Class III malocclusion subjects. Correlation between overjet measured on study casts and sagittal skeletal parameters measured on lateral cephalogram was calculated. Overjet as a predictor of skeletal relationships was assessed by means of linear regression analysis. A statistically significant positive correlation (P < 0.01) was found between the values of overjet and ANB (r = 0.690), overjet and Wits appraisal (r = 0.750), and overjet and convexity at point A (r = 0.608) when assessing the whole sample. When linear regression between overjet and cephalometric parameters was assessed separately in Class I, Class II division 1, and Class III malocclusion subjects, the percentage of variability was statistically significant in just four pairs. The findings show that overjet is a good predictor of sagittal relationship only in subjects with a Class II division 1 malocclusion.

Influence of occlusal plane inclination on ANB and Wits assessments of anteroposterior jaw relationships

INTRODUCTION

Although assessments of anteroposterior relationships are vital for orthodontic treatment planning, they cannot be precisely achieved by current cephalometric and noncephalometric resources. ANB angle and the Wits appraisal are the most popular cephalometric measurements applied in clinical orthodontics, although they have drawbacks. Facial vertical features, especially the occlusal plane angle, play an important role in their assessment, contributing to their unreliability.

METHODS

To further understand the influence of occlusal plane inclination, ANB angle and the Wits appraisal were analyzed in cephalo-lateral radiographs of 122 finished orthodontic patients in 2 groups: high occlusal plane angle and low occlusal plane angle.

RESULTS

There was a tendency for inconsistency between ANB and Wits assessments in the high occlusal plane angle group and a tendency for consistency in the low occlusal plane angle group. Cranial base influences on ANB and Wits assessments were investigated by subdividing the groups. Any of the considered cranial base factors was decisive for lack or presence of consistency between ANB and Wits assessments.

CONCLUSIONS

The clinician should beware of possible misinterpretations when using ANB and Wits to assess the anteroposterior relationship of the jaws, especially in high occlusal plane angle patients.

Age-related changes in sagittal relationship between the maxilla and mandible

The aim of the study was to assess age-related changes in sagittal jaw relationship during pre-pubertal and pubertal development on the basis of angular [ANB, anteroposterior dysplasia indicator (APDI) and A-B plane angle] and linear (Wits, AF-BF, App-Bpp, and App-Pgpp) measurements. Lateral cephalograms of orthodontically untreated subjects were evaluated at 7, 9, 11, 13 and 15 years of age. Cephalometric standards and age-related changes were determined on the basis of Class I subjects with a good occlusion (n = 18, 10 males and 8 females). With respect to changes related to growth, the main findings were, in both genders, a statistically significant age-related decrease in ANB angle, App-Bpp and App-Pgpp, a significant increase in APDI, but no age-related change in Wits. A reduction of sagittal jaw distance during pre-pubertal and pubertal development was observed arising from a relative dominance of sagittal mandibular growth. For an evaluation of differences concerning jaw relationship in Class II subjects, a group with Class II division 1 malocclusions (n = 17) and a group with Class II division 2 malocclusions (n = 12 were compared with two control groups, i.e. the good occlusion group and a Class I group (n = 37). Conclusions about the sagittal discrepancy in Class II division 1 and Class II division 2 subjects depended on the geometric reference used in the various parameters, and further research is called for with respect to the diagnostic performance of the various measurements. Differences between Class II subjects and controls present at 15 years of age were already established at 7 years of age, but were less pronounced.

Posteroanterior cephalometric norms in Turkish adults

PURPOSE

The aims of this study were to establish cephalometric norms from posteroanterior cephalograms for Turkish adults, identify possible gender differences in these norms, compare Turkish norms with the norms of other groups, and identify possible correlations between all investigated transverse linear measurements.

MATERIAL

The subjects included 46 Turkish men (mean age, 26.06 +/- 2.10 years) and 54 Turkish women (mean age, 24.10 +/- 3.04 years). Each subject had ideal occlusion and a well-balanced face. Nineteen linear measurements were determined on each radiograph. For each variable, the arithmetic mean, the standard deviation, and the minimum and maximum values were calculated. For statistical evaluation, an independent-samples t test was performed. The Pearson product-moment correlation coefficient was calculated to indicate the relationship between all investigated linear dimensions.

RESULTS

Posteroanterior transverse linear norms for Turkish adults were generally similar to Ricketts' clinical norms. Of the 19 craniofacial transverse measurements, 15 showed significant sexual dimorphism. All investigated measures were higher in Turkish men than in women, with the exception of the distance from the intersection of the processus zygomaticus and the processus alveolaris maxillae on the right side and the frontal facial plane. Statistically significant correlations were determined in most measurements.

CONCLUSIONS

These Turkish posteroanterior cephalometric norms can be used in the treatment of Turkish patients.

Craniofacial structure of Anatolian Turkish adults with normal occlusions and well-balanced faces

This study aimed to develop cephalometric standards for Anatolian Turkish men and women. Fifty young men (mean age [+/- standard deviation], 22.61 +/- 1.22) and 55 young women (mean age, 22.14 +/- 1.44 years) were studied. All subjects were born to Turkish parents and grandparents and were 19 to 25 years old. All had Class I occlusions with minor or no crowding, normal growth and development, well-aligned maxillary and mandibular dental arches, all teeth present except third molars, good facial symmetry determined clinically and radiographically, no significant medical history, no history of trauma, no previous orthodontic or prosthodontic treatment, and no maxillofacial or plastic surgery. Twenty-five measurements (14 linear and 11 angular) were analyzed on each radiograph. Arithmetic mean and standard deviation were calculated for each measurement. For statistical evaluation, independent-samples t tests were performed. Our established values were compared with the norms of other investigators who studied facial esthetics. Significant racial differences were found in skeletal measurements (anterior nasal spine [ANS] to menton), dental measurements (maxillary incisor to sella-nasion plane, mandibular incisor to nasion-Point B line, and mandibular incisor to mandibular plane), and soft tissue measurements (H angle, upper lip to E plane, and upper lip to Steiner S line). Significant sex differences were found in the measurements condylion to A point, condylion to gnathion, ANS to menton, and nasion to ANS. It is appropriate to put these cephalometric norms into daily orthodontic practice when an Anatolian Turkish population is being treated.

Determination of Holdaway soft tissue norms in Anatolian Turkish adults

The purpose of this study was to determine Holdaway soft tissue standards for Anatolian Turkish adults. The material included the lateral cephalometric radiographs of 175 patients, 90 men and 85 women, selected from the dental students at Selcuk University, Konya, Turkey. After analyzing these radiographs, 105 subjects (55 men, mean age 22.61, and 50 women, mean age, 22.14) with normal anteroposterior and vertical skeletal relationships were selected for the study. Ten linear and 2 angular measurements were analyzed on each radiograph. The landmarks were located according to the definitions of Holdaway. For each variable, the arithmetic mean and standard deviation were calculated. For statistical evaluation, an independent-samples t test was performed. Except for the measurements of soft tissue chin thickness and basic upper lip thickness, all soft tissue measurements were similar to Holdaway norms. For nose prominence, inferior sulcus to H line, upper lip strain, soft tissue chin thickness, and basic upper lip thickness measurements, statistically significant sex differences were determined. We believe it is appropriate to use these Anatolian Turkish soft tissue norms in daily orthodontic practice.

The reliability of 3 sagittal reference planes in the assessment of Class I and Class III treatment

The objective of this study was to test the reproducibility and validity of 3 sagittal reference planes with the use of the Wits analysis. Measurements made to the functional occlusal plane, the bisected occlusal plane, and the maxillomandibular bisector were compared with each other and with the angular measurement of the ANB angle. The angular relationship of these reference planes to the postmaxillary vertical reference plane was also studied. The data were collected from pretreatment (T1), posttreatment (T2), and 2-year postretention (T3) lateral cephalograms of 35 Class I and 10 Class III subjects. Nonextraction treatment for these patients was performed with full fixed orthodontic appliances in the permanent dentition. Cephalometric data were compared with 39 Class I and 9 Class III control subjects. The serial lateral cephalograms of untreated control subjects that were analyzed were taken at ages approximating those of the treated groups at T1, T2, and T3. The maxillomandibular bisector was determined to be an easily identifiable and reproducible reference plane that exhibited greater stability over time with both growth and treatment than either the functional occlusal plane or bisected occlusal plane. The mean values for the maxillomandibular bisector Wits result for Class I and III populations were distinct and, when combined with previous Class II data, yielded a triphasic distribution that may be a useful clinical tool for patient assessment.

The reliability of three sagittal reference planes in the assessment of Class II treatment

This investigation evaluated the reliability and validity of three anteroposterior skeletal measurements using the maxillary-mandibular (MM) Bisector, the functional occlusal plane (FOP), and the bisected occlusal plane (BOP) as reference planes in the assessment of anteroposterior discrepancies. Comparisons were made between these measurements in both treated and control samples of Class II Division 1 patients. The data were collected from pretreatment, posttreatment, and 2 years posttreatment lateral cephalograms of 36 Class II Division 1 subjects whose treatment was nonextraction with low or straight pull headgears. Comparisons were made to an untreated control group of 15 Class II Division 1 subjects. The MM Bisector was found to be a highly reproducible reference plane whose greater stability was demonstrated by a lack of change in its cant during growth or during growth and treatment, compared with the BOP or FOP. With the ANB angle used as a standard, and MM Bisector anteroposterior measure was a more reliable and valid indicator of the skeletal anteroposterior relationship of the jaws, especially longitudinally during growth and treatment, than the Wits appraisals made with either the FOP or BOP.

Comparison between cephalometric classification methods for sagittal jaw relationships

The present study evaluated how 2 widely used cephalometric sagittal analyses, ANB angle and WITS appraisal, classify skeletal classes I, II, and III in a random selection of 497 Finnish boys aged 4-20 years. This distribution was also compared with the visual inspection of cephalometric structures judged by 2 university instructors in orthodontics. The results showed remarkable differences and even sparked controversy concerning classification of the sagittal jaw relationships. The ANB angle and the WITS appraisal emphasized the role of class II based on a failure to distinguish the proportion of class I. The low-angle influence skewed the distribution of the ANB pattern in the class III direction, and the WITS pattern, conversely, towards class II. High- or low-angle influence had only minor effects on the visual inspection of cephalometric structures. This cross-sectional study showed an age-related decreasing mean value for the ANB angle and increasing mean value for the WITS appraisal, thus explaining the remarkable difference in the distribution of sagittal classes. However, the findings of age-related changes makes the use of the fixed norms questionable. For extreme or controversial cephalometric interpretations, visual inspection provides an essential aid in diagnosis and skeletal classification.

A study on the pharyngeal size in different skeletal patterns

In the present study, pharyngeal size was investigated on the lateral cephalometric head films of 90 subjects, 45 males and 45 females, having different ANB angles. All of the subjects were aged 13 to 15 years. The films were taken at natural head position, and all were divided into three groups according to the ANB angle: ANB angles smaller than 1 degree, between 1 degree and 5 degrees, and larger than 5 degrees. In addition, each group was also divided into two subgroups according to sex. The effects of the ANB angle and sex on the pharyngeal size were investigated by means of variance analysis. It has been observed that two measurements, hy-apw4 and oropharynx area measurements, were affected by the change of ANB angle, and two other measurements, t-ppw and hy-apw2 measurements, by the sex; and that hy-apw4 measurement and oropharynx area became smaller with the increase of ANB angle.

Extracranial versus intracranial references in individual cephalometric analysis

This study was undertaken to determine whether angles SNA and ANB genuinely represent both the degree of maxillary prognathism and the intermaxillary relationship in natural head position (NHP). Pearson's r correlation coefficients were used to assess the associations between these angles, and variables based on NHP and extracranial reference lines. A large sample (n = 106) was used, comprising subjects with a variety of facial patterns. This was also divided into subgroups comprising subjects with similar facial configurations, determined by natural head position parameters. For the subgroups, SNA and ANB were not associated with the variables based on NHP, and showed high variations in subjects with similar facial patterns. SNA also showed statistically significant and high correlation with the inclination of the NSL to the true vertical.

The maxillary-mandibular planes angle (MM degrees) bisector: a new reference plane for anteroposterior measurement of the dental bases

A new plane, geometrically derived from the dental base planes, has been tested as an occlusal plane substitute for the measurement of anteroposterior jaw relationships. It lies close to but at an angle and inferior to the traditional occlusal planes and is highly reproducible at all times. Lateral cephalograms of 36 young adults (25 men and 11 women) and 43 10- to 12-year-old children (24 girls and 19 boys) were selected and the Wits technique of anteroposterior measurement was used to compare A-B values measured to the new plane with those measured to the functional occlusal plane (FOP) and to the traditional or bisecting occlusal plane (BOP). Because of the downward cant of the bisector anteriorly, B is projected onto it ahead of A in normal occlusion and coincides with A in skeletal (2) malocclusion. Mean values for normal occlusion were found to be approximately -4 mm for the children (-4.2 mm girls and -4.0 mm boys) and -4.5 mm for the adults (-4 mm women and -4.7 mm men).

Maxillary protraction: different effects on facial morphology in unilateral and bilateral cleft lip and palate patients

Since 1977 patients with anterior/posterior crossbites in the care of the Bergen CLP team have undergone an interceptive orthopedic protraction phase during the deciduous and mixed dentition period. Eighty-seven cases with complete clefts (63 unilateral and 24 bilateral) displaying anterior crossbite (negative overjet) were treated to normal occlusion. A fixed quad-helix appliance was used in combination with a facial mask. In the unilateral complete cleft lip and palate (UCLP) group, mean age at start of treatment was 6 years 10 months and mean duration was 12 months. In the bilateral complete cleft lip and palate (BCLP) group, mean age at start of treatment was 7 years and mean duration 15 months. The protraction force was 700 g. The sagittal changes during protraction in the UCLP and BCLP groups were compared, and related to the growth changes in a group of noncleft children at the same age. Dentofacial treatment effect was different in the UCLP and BCLP groups. Significant increase of maxillary prognathism (angle s-n-ss) was found only in the UCLP group, whereas the treatment effect in the BCLP group was mainly dentoalveolar. However, after protraction there was no longer a significant difference in maxillary prognathism between the two CLP groups, and the sagittal position of the upper molars was normalized in both groups. The upper incisors remained retroclined in both groups, significantly more in the BCLP group. Increase of the upper facial height (n-sp") and clockwise rotation of the occlusal line were significantly greater in the BCLP group. The computerized occlusal line was unsuitable as a reference standard for the evaluation of sagittal dentofacial treatment changes when the occlusal line was rotated during treatment.