Association of anterior and posterior occlusal planes with different Angle and skeletal classes in permanent dentitions : A lateral cephalometric radiograph study

Analysis of Neurosensory Changes in Orthognathic Surgery Using Saw or Piezoelectric Devices: A Scoping Review

Orthognathic surgery is a successful surgical method for correcting facial deformities, and the piezoelectric system can be used in place of or in addition to traditional tools like the reciprocating saw to perform osteotomies. This study assesses how using a reciprocating saw or a piezoelectric device exclusively affects neurosensory impairment. A review was performed following the PRISMA-ScR recommendations. A search was conducted until December 2024 in PubMed, Embase, and Web of Science. Clinical trials and quasi-experimental studies in English and Spanish were included. A total of nine articles were obtained for full-text review using inclusion and exclusion criteria. The selected articles included a total of 731 subjects. The age range of the studies included was between 18 and 49 years. Three of the six analyzed state that piezoelectric surgery positively correlates with neurosensory recovery, showing less surgical time and a less painful and faster postoperative recovery than the use of a saw. However, only two reported no significant statistical difference in sensitivity recovery between the saw and piezoelectric instruments. Despite the methodological heterogeneity among the studies included, the sample size, and the variability of factors, using a piezoelectric system typically shows a better postoperative recovery of sensitivity compared to using a saw.

Occlusal Plane, Mandibular Position and Dentoalveolar Changes during the Orthodontic Treatment with the Use of Mini-Screws

This study aimed to describe the changes produced on the occlusal plane (OP), the mandibular position and the dentoalveolar compensations of patients with distalization of the maxillary/mandibular arch assisted by mini-screws (MS). A descriptive case-series study was performed using the digital lateral cephalograms (DLC) of nine patients who underwent orthodontic treatment and required the use of MS for a complete distalization of the maxillary/mandibular arch. Records were collected at three different times (T1-T2-T3) and digitally analyzed (variables: Skeletal diagnosis; maxillary occlusal plane; position of the maxilla/mandible; and dentoalveolar changes of the distalization arch tracing the longitudinal axis of incisors/molars regarding the palatal/mandibular plane). Findings show that the OP varied from T1-T2-T3 in all cases, indicating its stepping or flattening. ODI, APDI, SNA, SNB, and ANB changed minimally in all cases, without variations in the mandibular position or in the skeletal diagnosis. Dentoalveolar measurements also showed differences between T1-T2-T3. In summary, conventional orthodontic treatment modified the OP during the first phase of treatment. Moreover, the distalization mechanics with MS changed the OP and produced dentoalveolar changes, mainly in the inclination of incisors and molars. Other measures considered in the study did not change substantially.

The correlation analysis between incisal guidance angle and occlusal plane angles and temporomandibular joint morphology

OBJECTIVES

The correlations between the incisal guidance angle (IGA) and occlusal plane angles and temporomandibular joint (TMJ) morphology were investigated in adults with skeletal Class II division II malocclusion.

MATERIALS AND METHODS

CBCT images of 37 patients were analyzed. It included 19 cases of skeletal Class II division II malocclusion with low angle (study group) and 18 cases of skeletal Class I average angle (control group). The Invivo Dental 5 software was employed to acquire the data of the incisal guidance angle (IGA), occlusal plane angle (FH-OP), anterior occlusal plane angle (FH-AOP) and the TMJ measurement items.

RESULTS

The results of IGA, FH-AOP angle and FH-OP angle showed the study group > the control group (P < 0.05). There were statistically difference in the condylar mediolateral diameters, articular eminence inclination and height, and posterior joint spaces between two groups. No differences were revealed in the condylar anteroposterior diameters, the condylar inclination angle, condylar head width and height, condylar length, glenoid fossa depth and width between two groups. In the study group, IGA showed a moderate correlation with FH-AOP, a weak correlation with FH-OP and condylar mediolateral diameters. Meanwhile, there was a correlation between FH-AOP, FH-OP, and TMJ indicators.

CONCLUSIONS

The IGA was not only related to FH-AOP and FH-OP, but also to the condylar mediolateral diameters. In addition, there was a correlation between the occlusal plane angles and TMJ morphology in skeletal Class II division II low angle malocclusion.

CLINICAL RELEVANCE

For patients with skeletal Class II division II low angle malocclusion, adjusting the IGA and the occlusal plane angles could improve the esthetic appearance of the anterior teeth, occlusal function, and TMJ morphology.

Correlation of "K" plane to occlusal plane and three different ala-tragal lines in dentulous subjects with different skeletal forms: A cephalometric study

Aim

Orientation of the occlusal plane is an important clinical procedure for complete denture fabrication. An attempt had been made to reconstruct the occlusal plane using a different reference plane. The aim of this study was to find the correlation of the "K" plane to the occlusal plane and to assess the angular deviation between the K-plane to the occlusal plane (KO) with different skeletal forms.

Settings and Design

An in vivo observational study was conducted on dentulous subjects having Class I dental occlusion with different skeletal forms undergoing orthodontic treatment.

Materials and Methods

The study was conducted on 54 subjects aged 18-30 years. Metallic balls (3 mm in diameter) were attached to the desired landmarks, and a lateral cephalogram was taken for each subject. Cephalometric analysis was done using the Dolphin Imaging software, and the values obtained were recorded and subjected to statistical analysis.

Statistical Analysis Used

The values obtained were recorded and subjected to statistical analysis using simple descriptive analysis, Shapiro-Wilk test, Mann-Whitney U-test, and Pearson's correlation.

Results

A positive correlation was found between KO with a mean angular deviation of 8.59° ± 3.05°. The angle was found to be steeper in skeletal Class II subjects.

Conclusions

Clinical application of the K-plane to use as a reference plane to orient the posterior occlusal plane can enhance the treatment outcome for a removable prosthesis. The results of this study provide a theoretical foundation for the practical restoration of the occlusal plane in different skeletal forms.

Implications of occlusal plane in diagnosis and treatment of malocclusion

Occlusal plane (OP) is one of the essential factors affecting craniofacial morphology and function. The OP not only assists in diagnosing malocclusion but also serves as an important reference for making treatment plans. Patients with different types of malocclusions have different forms of OP. Compared with patients with standard skeletal facial type, the occlusal plane of patients with skeletal class Ⅱ and high angle is steeper, while that of patients with skeletal class Ⅲ and low angle is more even. In orthodontic treatment, adjusting and controlling the OP can promote the normal growth and development of the mandible in most patients with malocclusion during the early stage of growth, while causing favorable rotation of the mandible in some adults with mild-to-moderate malocclusion. For moderate-to-severe malocclusion, the OP rotation by orthodontic-orthognathic treatment can achieve better long-term stability. This article reviews the evolution of the definition of OP and its implications for diagnosing and the guiding treatment of malocclusion.

Intra- and Interrater Agreement of Face Esthetic Analysis in 3D Face Images

The use of three-dimensional (3D) facial scans for facial analysis is increasing in maxillofacial treatment. The aim of this study was to investigate the consistency of two-dimensional (2D) and 3D facial analyses performed by multiple raters. Six men and four women (25-36-year-old) participated in this study. The 2D images of the smiling and resting faces in the frontal and sagittal planes were obtained. The 3D facial and intraoral scans were merged to generate virtual 3D faces. Ten clinicians performed facial analyses by investigating 14 indices of 2D and 3D faces. Intra- and interrater agreements of the results of 2D and 3D facial analyses within and among the participants were evaluated. The intrarater agreement between the 2D and 3D facial analyses varied according to the indices. The highest and lowest agreements were found for the dental crowding index (0.94) and smile line curvature index (0.56) in the frontal plane, and Angle's classification (canine) index (0.98) and occlusal plane angle index (0.55) in the profile plane. In the frontal plane, the interrater agreements were generally higher for the 3D images than for the 2D images, while in the profile plane, the interrater agreements were high in the Angle's classification (canine) index however low in the other indices. Several occlusion-related indices were missing in the 2D images because the posterior teeth were not observed. Esthetic analysis results between 2D and 3D face images can differ according to the evaluation indices. The use of 3D faces is recommended over 2D images to increase the reliability of facial analyses, as it can fully assess both esthetic and occlusion-related indices.

Orthodontic treatment of an adolescent patient with Class II division 1 malocclusion with consideration of growth pattern and occlusal plane: A case report

Consideration of growth pattern and occlusal plane is critical in orthodontic treatment planning to achieve optimal dentofacial esthetics and long-term stability in adolescent patients, which is illustrated by success in orthodontic treatment of an adolescent Class II division 1 malocclusion with nonextraction.

Preliminary feasibility torque mechanical evaluation for 3D printed orthodontic springs with different parameters: in vitro study

Background

The purpose of the presented investigation is to evaluate the resulting torque on loaded 3D printed springs using different coil thickness and length.

Methods

Specimens were designed and printed using the 3D printer MAX (Asiga, Sydney, Australia) with 3D printable, experimental, flexible material (Code:BM2008, GC, Tokyo, Japan). The specimens were divided into three groups according to spring coil design. Control group (n = 18), length group (n = 19) and thickness group (n = 22). Groups were tested using a Sauter Machine for torque calculation (DB, Grindelwald, Switzerland) in conjunction with a universal testing machine (Zwick Z010, Ulm, Germany) for clock-wise and anti-clockwise testing. Statistical analysis was performed using the Steel–Dwass test to compare median values of the three groups in both testing directions (p < 0.001).

Results

The highest torque value was determined in the thickness group for both clockwise and anti-clockwise testing directions, achieving 44.00 N/mm and 39.62 N/mm respectively. The length group ranged from 21.65 to 11.04 N/mm in clockwise direction and from 18.04 to 11.38 N/mm in counter-clockwise testing. The control group ranged from 22.72 to 17.18 N/mm in the clock-wise direction while in the anti-clock wise testing it ranged from 21.34 to 16.02 N/mm.

Conclusions

The amount of torque produced from the computer aided designing/computer aided manufacturing (CAD/CAM) springs is being affected by diameter more than the length design parameter in comparison to the control group. The values of the thickness group are significantly higher than those of the length group (P < 0.001).

Occlusal Plane Changes After Molar Distalization With a Pendulum Appliance in Growing Patients with Class II Malocclusion: A Retrospective Cephalometric Study

Objective

This study aimed to evaluate the skeletal and dental changes after distalization with a pendulum appliance in growing patients with Class II malocclusion, focusing on the occlusal plane (OP).

Methods

The sample included 24 patients with Class II malocclusion (10 boys, 14 girls); their mean age was 12.1 years. All patients underwent molar distalization and had 2 serial cephalograms traced at baseline (T1) and after distalization (T2). Angular and linear dental changes were calculated by taking the sella-nasion (SN), palatal plane (PP), and pterygoid vertical as reference. OP inclination was compared with SN, PP, and mandibular plane. The collected data were computed for all the tested variables, and one-way paired t-test was used to assess the significance of the differences between the time points. α was set at 0.05. Multiple linear regressions were used to predict the OP changes.

Results

The mean total treatment time was 8±2 months to obtain a super Class I molar relationship. In T1-T2 interval, statistically significant incisor buccal tipping of 5°±3.6° (p<0.05), first molar distal tipping of 8.9°±8.3° (p<0.001), and second molar tipping of 8.2°±8.1° (p<0.001) were observed. The maxillary first and second molars moved significantly backward by 2.8±3.2 mm (p<0.05) and 3.7±2.7 mm (p<0.001), respectively. Only the premolars showed a statistically significant anchorage loss of 2.7±3.3 mm (p<0.05); overjet increased significantly at 1.3±1.2 mm (p<0.05). Regarding the OP, none of the tested variables showed any statistically significant changes between T1-T2.

Conclusion

The pendulum appliance showed efficacy in distalizing the maxillary first and second molars at the expense of anterior anchorage loss. The OP did not show statistically significant changes after molar distalization.

Integration of digital maxillary dental casts with 3D facial images in orthodontic patients

OBJECTIVE

To evaluate three-dimensional (3D) accuracy and reliability of nonradiographic dentofacial images integrated with a two-step method.

METHODS

3D facial images, cone-beam computed tomography (CBCT) images and digital maxillary dental casts were obtained from 20 pre-orthodontic subjects. Digital dental casts were integrated into 3D facial images using a two-step method based on the anterior tooth area. 3D coordinate values of five dental landmarks were identified in both dentofacial images and CBCT images. The accuracy of the integration method was assessed with paired t-tests between dentofacial images and CBCT-based reference standards. Intraclass correlation coefficients (ICCs) were assessed for the reliability of dentofacial images and CBCT-based images. Analysis of variance and Kruskal-Wallis tests evaluated the accuracy of the method in different dimensions.

RESULTS

There was no statistical difference between dentofacial images and CBCT reference standards in both translational and rotational dimensions (P > .05). Translational mean absolute errors for full dentitions were within 0.42 mm and ICCs were over 0.998 in x, y, and z directions. Rotational mean absolute errors for full dentitions were within 0.92° and ICCs over 0.734 in pitch, yaw, and roll orientations. Integration errors were significantly greater in the first molar, z-translation, and pitch rotation (P < .05).

CONCLUSIONS

Integrating 3D dentofacial images with the two-step method is precise and acceptable for clinical diagnostics and scientific purposes. Errors were greater in the molar region, z-translation, and pitch rotation.