Novel Parameter in Pre-Surgical Orthodontic Preparation: A Retrospective Study on the Role of the Upper Incisor Position and a Morphological Evaluation of the Anterior Nasal Spine

The position and inclination of the incisors play a crucial role in achieving optimal outcomes in orthodontic and orthognathic surgical treatment, given their impact on facial aesthetics. Background/objectives: Due to numerous distorting factors that affect the reliability of the ANB angle, the aim of the present work is to evaluate a more constant parameter over time, the anterior nasal spine (ANS), and explore whether aligning the incisal margin of the upper incisors with the anterior nasal spine could be a reliable indicator for achieving appropriate labial support in pre-surgical orthodontic preparation. Methods: From a pool of 500 cone beam computed tomography (CBCT) scans, 50 CBCT examinations displaying a Class 1 skeletal pattern (ANB = 2° ± 2°) with an intermediate (3.2-4 mm) or mixed (4-6 mm) sagittal maxillary position (MX), as determined by the 3D multiplanar total face approach (TFA), were selected and compared with CBCT examinations randomly chosen from the initial pool. Moreover, 12 landmarks were identified, and measurements were automatically obtained, using software, and recorded. Mean and standard deviation values were calculated for each sample. A comparison was made between the two samples, aligning the results with the morphological analysis of the anterior nasal spine and the sagittal position of the upper maxilla. Results: In Class 1 subjects, the distance between the incisal margin and the plane passed in relation to the anterior nasal spine should range between -1 mm and 1 mm, aligned with or slightly ahead of the anterior nasal spine or slightly ahead of this limit. Conclusions: The anterior nasal spine can serve as a reliable reference point for planning the position of the upper incisors, with excessive proclination or retroclination from this reference point deemed unacceptable.

Sagittal Jaw Relationship of Different Types of Cleft and Non-cleft Individuals

To investigate whether the craniofacial sagittal jaw relationship in patients with non-syndromic cleft differed from non-cleft (NC) individuals by artificial intelligence (A.I.)-driven lateral cephalometric (Late. Ceph.) analysis. The study group comprised 123 subjects with different types of clefts including 29 = BCLP (bilateral cleft lip and palate), 41 = UCLP (unilateral cleft lip and palate), 9 = UCLA (unilateral cleft lip and alveolus), 13 = UCL (unilateral cleft lip) and NC = 31. The mean age was 14.77 years. SNA, SNB, ANB angle and Wits appraisal was measured in lateral cephalogram using a new innovative A.I driven Webceph software. Two-way ANOVA and multiple-comparison statistics tests were applied to see the differences between gender and among different types of clefts vs. NC individuals. A significant decrease (p < 0.005) in SNA, ANB, Wits appraisal was observed in different types of clefts vs. NC individuals. SNB (p > 0.005) showed insignificant variables in relation to type of clefts. No significant difference was also found in terms of gender in relation to any type of clefts and NC group. The present study advocates a decrease in sagittal development (SNA, ANB and Wits appraisal) in different types of cleft compared to NC individuals.

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.

A Study on the Evaluation of Pharyngeal Size in Different Skeletal Patterns: A Radiographic Study

AIM

The aim of this study was to evaluate the upper and lower pharyngeal airway dimensions were affected by different skeletal malocclusions.

MATERIALS AND METHODS

Lateral cephalograms of 120 subjects were used to measure the pharyngeal airway and were divided into three groups (each group included 40 subjects) according to ANB angle: Class I (ANB angle 2° ≤ ANB ≤ 4°), Class II (ANB angle(ANB ≥ 6°), and Class III (ANB angle ≤ 0°). Various linear cephalometric airway measurements (14 measurements) were used to evaluate pharyngeal airway at various levels. Statistical analyses were performed Using the ANOVA and student t-test.

RESULTS

PNS-ppwl (p < 0.001) and McNamara' lower pharynx dimension (p < 0.05) showed a statistically significant difference between the groups. Two out of 14 variables ie Ba-PNS and t-ppw showed a statistically significant difference between male and female. In both measurements, the difference is significant only in the Class II group with the level of significance being (p < 0.001) in Ba-PNS measurement, and (p < 0.05) in t-ppw measurement. In both measurements males have statistically significant higher mean values than the females.

CONCLUSION

The dimensions of pharyngeal structures were not affected by the changes of the ANB angle. The sagittal skeletal pattern does not seem to influence the variations in the upper airway dimension. There was no significant difference in the dimensions of pharyngeal structures among males and females.

CLINICAL SIGNIFICANCE

The upper and lower pharyngeal airway dimensions are affected by different skeletal malocclusions can significantly aid in Orthodontic treatment planning.

Comparison of Beta and ANB Angles for Evaluation of Sagittal Skeletal Discrepancy: A Cephalometric Study

AIM

Diagnosis in orthodontic cases and treatment planning is a precise assessment of sagittal jaw relationship. A number of angular and linear measurements have been used to attain correct diagnosis. The present study is done to compare beta angle and A point-nasion-B point (ANB) angle for sagittal skeletal discrepancies.

MATERIALS AND METHODS

A total of 105 subjects were included in between the age group of 18 and 24 years and were categorized based on the skeletal patterns as class I, class II, and class III having a sample of 35 in each group. Based on the ANB angle and patients' profile, the sample was divided into different skeletal groups. Beta angle is the angle amid the perpendicular from C to B line through point A and the A-B line. Analysis of variance (ANOVA) and post hoc Scheffe's test were applied to analyze dependent variables. The level of significance was set at p-value 0.05.

RESULTS

The mean scores of ANB for class I skeletal pattern were 2.46 ± 0.460, for class II, 5.64 ± 1.258, and for class III, -1.03 ± 1.618. Similarly, significant differences were observed in beta angle for class I skeletal pattern as 31.71 ± 3.885, for class II, 24.97 ± 2.162, and for class III, 39.26 ± 3.649.

CONCLUSION

Both ANB and beta angle showed significant differences with different skeletal patterns.

CLINICAL SIGNIFICANCE

Both ANB and beta angle are awfully supportive diagnostic measurements to scrutinize sagittal jaw relationship.

Evaluation of Nasal Proportions in Adults with Class I and Class II Skeletal Patterns: A Cephalometric Study

AIM:

The aim of this study was to evaluate sexual dimorphism in nasal proportions of Class I and Class II skeletal malocclusions in adults.

MATERIAL AND METHODS:

The sample comprised 120 patients (females 18 years and above and males 21 years and above), with no history of previous orthodontic treatment or functional jaw orthopedic treatment. They were divided into different groups based on point A-Nasion-point B (ANB) angle and gender. Groups I and II included 30 males and 30 females with skeletal class I malocclusion (ANB 0–4 degrees). Groups III and IV included 30 males and 30 females with skeletal class II malocclusion, respectively (ANB above 4 degrees).

RESULTS:

In regards to the comparison between males and females (Class I + Class II), nasal length (P < 0.001), nasal depth 1 (P < 0.001), nasal depth 2 (P < 0.001), nasobasal angle (P < 0.001), soft tissue convexity angle (P < 0.001), and nasal bone length (P < 0.008) were found to be statistically significant. Nasobasal angle was found to be significantly higher in females than in males (Class I) (P < 0.001). Nasolabial angle was prominent in class I males than in class I females (P < 0.001). Soft tissue convexity angle of Class I participants was significantly lower than that of Class II participants (P < 0.001), whereas nasobasal angle and nasomental angle of Class I participants were found to be significantly higher than that of Class II participants (P < 0.001).

CONCLUSION:

Sexual dimorphism was found in various nasal parameters. Significant amount of differences was found in the nasal proportions of Class I and Class II (male and female) participants.

Airway in Class I and Class II skeletal pattern: A computed tomography study

BACKGROUND AND OBJECTIVES

A normal airway is required for the normal growth of the craniofacial structures. The present study was designed to evaluate and compare the airway in Class I and Class II skeletal pattern and to see if there is any association between the airway and maxillomandibular relationship.

MATERIALS AND METHODS

Peripheral nervous system computed tomography scans of 30 patients were divided into two groups as Class I (ANB ≤ 4.5°), Class II (ANB ≥ 4.5°). The Dolphin three-dimensional version 11 was used to assess the airway.

STATISTICAL ANALYSIS

Correlations between the variables were tested with the Pearson correlation coefficient. Independent sample t-test was performed to compare the averages between the two groups. P < 0.05 was considered as statistically significant.

RESULTS

The ANB angle was negatively correlated with all the airway parameters. The airway area and volume was significantly reduced in Class II subjects compared to Class I.

CONCLUSION

The results suggest a strong association between the airway and skeletal pattern showing a reduced airway in Class II patients with a high ANB angle.

Comparative assessment of sagittal skeletal discrepancy: a cephalometric study

BACKGROUND AND OBJECTIVES

Evaluating the sagittal apical base relationship during orthodontic diagnosis and treatment planning is an important step. This study was aimed at comparison of Beta angle, ANB angle and Wit's appraisal for assessment of sagittal skeletal discrepancy.

MATERIALS AND METHODS

Eighty six young adults (43 female and 43 male) were selected from the patient's reporting to Department of Orthodontics, College of Dental Sciences, Davangere, India. Family lineage was studied to know the nativity of Davangere. The standardized pre-treatment lateral cephalogram of the chosen sample was traced. The sample was divided into three skeletal pattern groups: Class I, Class II and Class III, based on the ANB angle and profile, Beta angle was assessed in each group.

STATISTICAL ANALYSIS

The data was subjected to statistical analysis student's t-test, ANOVA test and correlation and regression analysis, using the software namely SPSS Software version 13. Microsoft word and Excel were used to generate graphs and tables.

RESULTS

In the local Davangere population, Class I skeletal pattern group exhibited Beta angle between 26°-34°, Beta angle less than 27° was found in Class II skeletal pattern, and Beta angle greater than 32° was seen Class III skeletal pattern. The coefficient of variation of Beta angle in all the three groups was significantly homogenous compared to ANB angle and Wits appraisal. The correlation and regression analysis of the total sample indicated a highly significant correlation between Beta angle and ANB angle (p<.001), and between Beta angle and Wits appraisal (p<.01).

CONCLUSION

Beta angle can be used to classify subjects into different skeletal patterns. The Correlation and regression analysis for the total sample suggests a highly significant relation between Beta angle and ANB angle and, between Beta angle and Wits appraisal. It can be more reliably used to assess sagittal jaw discrepancies than ANB angle and Wits appraisal.