Evaluation of the Correlation of Ramus Height, Gonial Angle, and Dental Height with Different Facial Forms in Individuals with Deep Bite Disorders

Determination of Mandibular Morphology in a Turkish Population With Bipolar I Disorder Using Panoramic Radiography

ABSTRACT

The presence of specific craniofacial deviations may be evidence of abnormal early brain development in bipolar disorder (BD). This study aimed to compare mandibular morphology in patients with BD versus nonpsychiatric controls using panoramic radiography. A total of 215 recorded images, 70 patients with BD and 145 controls, were evaluated. Seven mandibular parameters of the ramus height (RH), condylar height (CH), gonial angle (GA), antegonial angle (AGA), antegonial notch depth (AND), ramal notch depth (RND), and bigonial width (BGW) were measured in a blinded manner. Group analysis was conducted separately for males and females. The univariate comparisons showed increased values in RH, CH, AND, RND, and BGW and decreased values in GA in males with BD compared with male controls. In addition, females with BD had higher RH, CH, RND, and BGW values in comparison to female controls. The differences were statistically significant. Data from multivariate analyses revealed that increases in RH and BGW values in both sexes were significant predictive variables that distinguished patients with BD from controls. Moreover, deeper AND was the most prominent predictor that distinguished male patients with BD from male controls. The identification of subtle changes in mandibular measurements is consistent with the notion of impaired neurodevelopment in BD.

Mandibular morphology in schizophrenia patients compared with non-psychiatric controls using digital panoramic radiography: a retrospective cross-sectional study from Istanbul, Türkiye

BACKGROUND

Schizophrenia is a chronic severe mental disorder characterized by impairment in cognition, emotion, perception, and other aspects of behavior. In light of the association of craniofacial dysmorphology with schizophrenia, mandibular morphology may provide clues about the role of neurodevelopment in the pathophysiology of schizophrenia. This retrospective cross-sectional study aimed to compare the mandibular morphology of patients with schizophrenia with controls using digital panoramic radiography (DPR).

METHODS

302 recorded diagnostic panoramic images obtained from 143 schizophrenia patients (98 males, 45 females), and 159 controls (73 males, 86 females), aged 18-45 years, were evaluated. Seven mandibular measurements consisting of ramus height, condylar height, gonial angle, antegonial angle, antegonial notch depth, ramal notch depth and bigonial width were measured from the DPRs in a double-blinded manner. Bivariate comparisons were carried out using the Independent t-test and Mann-Whitney U test. Logistic regression analysis was used for multivariate comparisons.

RESULTS

Linear measurements were higher while angular measurements were lower in schizophrenia patients. Regression analyses indicated that female patients had greater ramus height (OR = 1.243; P = 0.001), condylar height (OR = 1.463; P = 0.048) and bigonial width (OR = 1.082; P < 0.001); male patients had greater ramus heights (OR = 1.216; P = 0.001) and bigonial width (OR = 1.076; P < 0.001) as well as lower antegonial angle (OR = 0.908; P = 0.012) compared to their respective controls.

CONCLUSION

Quantitative differences in mandibular morphology in schizophrenia patients versus controls deserve attention and corroborate with the concept of abnormal neurodevelopment in schizophrenia.

Morphological characteristics of coronoid process and revisiting definition of coronoid hyperplasia

The aim of this study was to assess the morphological characteristics of the coronoid process (CP) and define coronoid hyperplasia (CH) using cadaveric mandibles of a Caucasian population. A sample of 151 adult dry cadaveric mandibles (302 CPs) was acquired. Three distances were measured, which included the width, height, and length of CP. The surface area measurements involved area A: above the width distance line; area B: between incisura mandibulae-Alveolar ridge line and width distance line; area C: between distance lines of width and height. Finally, angulations of the CP and gonial angles were identified. Both length and surface area A + B acted as hyperplastic indicators. Based on the selection criteria, a sample of 197 CPs was included. The hooked shape (59%) was most commonly observed. No significant difference existed between left and right sides (p > 0.05). The mean values of length and surface area A + B were 2.2 ± 0.3 cm and 3.3 ± 0.8 cm2, and any values above 2.7 cm (n = 5 CPs- 2.5%) and 5.0 cm2 (n = 9 CPs- 4.6%) were described as hyperplastic, respectively. The presented data could act as quantitative reference for differentiating between normal and hyperplastic conditions.

Does Mandibular Gonial Angle Influence the Eruption Pattern of the Lower Third Molar? A Three-Dimensional Study

Lower third molars (M3M) are the most frequent impacted teeth. The aim of this study was to evaluate the correlation between M3M position and gonial angle. A retrospective cross-sectional study was conducted. The study population included patients with unilateral or bilateral M3M and underwent Cone Beam Computed Tomography. A morphometric analysis of the mandible was performed after three-dimensional reconstruction, recording gonial angle (GA), ramus high, ramus width, ramus divergency, and retromolar space. GA was the primary predictor variable. The primary outcome variable was the position of M3M analyzed in sagittal, axial, and coronal planes. Descriptive, bivariate, and multiple regression statistics were performed (p < 0.05). Study sample included 172 patients (mean age: 26.3 ± 4.6 years); 266 M3Ms were analyzed. The average GA was 122.6° ± 4.8°. A reduced GA value was significantly associated with a deeply impacted M3M in the ramus. With a progressive decrease of GA, M3M assumed a more horizontal position closer to the mandibular canal (p < 0.05). A lower GA showed a reduced retromolar space with more complex impacted M3M (p < 0.05). The results confirm a statistically significant correlation between GA and the position of M3M. Higher incidence of impacted M3M was related to a reduction of the GA value.

Square Face Correction by Gonial Angle and Masseter Reduction

Introduction

The association of mandibular gonial angle, facial height, and jaw relationship in masseteric hypertrophy (MH) has not been adequately described for the typical Indian population. The aim of this study was to report the gonial angle relationship with facial height parameters in cases diagnosed with bilateral MH and its possible influence on the treatment plan.

Materials and Methods

This is a retrospective study based on archival records of bilateral MH cases surgically treated over a 10-year period at the author's center. Patients' records fulfilling inclusion and exclusion criteria were considered for the study. Age, gender, upper anterior facial height (UAFH), lower anterior facial height (LAFH), upper posterior facial height (UPFH), ramus height (also a reflection of the lower posterior facial height), and gonial angle were collected along with the type of bite (open/normal/deep), surgical procedure (debulking with/without bone removal), and concomitant jaw bone corrections (yes/no). These were subjected to statistical analysis using SPSS, and P ≤ 0.05 was taken as statistically significant.

Results

Overall, 21 patients formed the study group comprising 9 females and 12 males. Gender influenced the UAFH, LAFH, UPFH, ramus height, and gonial angle significantly. Males had higher values than females. Normal bite had an obtuse gonial angle than the deep bite, and the difference was statistically significant (P = 0.036). When the gonial angle was acute or square faced, the need for other surgical procedures was high and the difference was statistically significant (P = 00.048).

Discussion and Conclusion

The results are discussed in the light of Indian skeletal anthropometry. The relationship of the gonial angle with facial height parameters in bilateral MH cases in this part of the world is presented.

Is there a relationship between third-molar impaction types and the dimensional/angular measurement values of posterior mandible according to Pell & Gregory/Winter Classification?

OBJECTIVE

The aim of this study was to examine the relationship between ramus height, gonial angle and impaction classifications of mandibular third molars.

METHODS

A total of 829 mandibular third molars in 601 patient's orthopantomography (OPG) and cephalometric radiography records were evaluated. Gonial angle was measured on cephaloametric radiography and ramus height was measured on OPG. Impacted third molars were classified according to Pell & Gregory Vertical/Winter classification on OPG. The relationship between the impaction classifications and ramus height/gonial angle was evaluated.

RESULTS

Statistically significant difference was found in Pell & Gregory Classification types in terms of ramus height/gonial angle (p < 0.001). Significant difference was found in terms of Gonial angle in Winter Classifications (p < 0.001). Ramus height was found to be lower than 3.8 cm in patients with an angle less than 123.8° (sensitivity 78%, specificity 84%).

CONCLUSIONS

Correlation between ramus height/gonial angle and impaction classification types of mandibular third-molar teeth was detected.

The Influence of the Gonial Angle on the Initial Biomechanical Stability of the Plate Osteosynthesis in Polyurethane Mandibles With Angle Fractures

The aim of the present study was to examine the biomechanical stability of the mandibular angle fractures (MAF) fixated with standard titanium miniplates in polyurethane models with different gonial angles (GA). Three custom molds were prepared for 3-dimensional printed mandibles with low, normal and high GA. Twenty polyurethane replicas were cast per group and standard MAFs were created on each sample. Fractures were stabilized with 1 4-hole standard titanium miniplate inserted over the superior alveolar border. Half of the samples were subjected to molar loading and the other half to the incisal loading up until 150 N force magnitude. The load-displacement curves and the horizontal moment arms were recorded and analyzed. The samples with high GA demonstrated greater displacement than those with normal and low GA during molar loading (P < 0.05 for both). After correcting for the effects of the moment arm, the incisal loading also resulted in higher mean displacement in the high GA group than the others (P < 0.05 for both) and the normal GA samples showed higher displacement after 100 N level compared to those in low GA (P < 0.05). Within the limits of this in vitro study, it can be concluded that the MAFs of the polyurethane mandibles with high GA fixated with 1 standard monocortical plate are more likely to demonstrate higher displacement values under the effects of the molar and incisal loadings than do the mandibles with normal and low GA.

Does Mandibular Gonial Angle Predict Difficulty of Mandibular Third Molar Removal?

PURPOSE

Predicting the difficulty of impacted mandibular third molar (IM3M) removal remains a controversial issue because many variables have been associated with increased operation time. Thus, the main objective of this study was to assess the influence of the gonial angle on the surgical difficulty of IM3M extraction.

PATIENTS AND METHODS

A prospective cohort study of patients requiring IM3M removal was conducted. The gonial angle measured with a goniometer was considered the primary predictor variable. The primary outcome variable was operation time. Difficulty also was recorded by surgeons using a 100-mm visual analog scale (VAS). Postoperative complications (pain, swelling, and trismus at 48 hours and 7 days) were registered as secondary outcome variables. A descriptive bivariate statistical analysis, Pearson correlations and scatter plots, and an explanatory multiple linear regression model were performed. Significance was set at P < .05.

RESULTS

The sample comprised 60 participants (17 men and 43 women) with a mean age of 25.2 years (standard deviation, 7.1 years). No significant correlations were found between the gonial angle and operation time, VAS difficulty score, and postoperative complications. Regression analysis confirmed this lack of effect of the gonial angle. The operation time was significantly affected by surgical experience (P = .016) and patient age (P = .009), whereas the 100-mm VAS difficulty score was only related to surgical experience (P = .001).

CONCLUSIONS

The gonial angle is not related to the surgical difficulty of IM3M removal. Moreover, this variable is not associated with the occurrence of postoperative complications. According to the findings in this cohort, surgical experience and patient age are the only variables significantly related to increased operation time.