3D evaluation of the morphological and volumetric changes of the tongue and oral cavity before and after orthognathic surgery for mandibular prognathism: a preliminary study

Evaluation of Changes of Extraoral, Intraoral, and Tongue Posture After Maxillomandibular Surgery in Skeletal Class III Patients: A Retrospective Volumetric CT Study

Objective

To evaluate the extraoral volume, intraoral volume, and tongue posture in pre- and post-LF1 and B.S.S.O maxillomandibular surgery for skeletal Class III patients, and establish a correlation between them.

Method

A retrospective study that evaluated 8 pre- and post-maxillomandibular surgical CT records of patients fulfilling the inclusion criteria. Borders were demarcated for volumetric measurement. The volume assessment was carried out using Materialise Mimics version 12.0 software.

Results

The mean difference in intraoral volume was 8476 ± 6099 mm3, which was statistically highly significant. The mean difference in extraoral volume was 15005 ± 13704 mm3, which was statistically significant. The mean difference in tongue posture was 2.31 ± 0.63 mm3, which was statistically very highly significant. A strong positive correlation is between the mean differences in tongue-to-palate distance and intraoral volume. A weak negative correlation is between the mean differences in extraoral and intraoral volume and pre- and post-operative maxillomandibular surgery.

Conclusion

There was a significant decrease in the extraoral, intraoral volume, and tongue-to-palate distance following maxillomandibular surgery in skeletal Class III patients.

Assessment of the correlation between the volume of tongue, oral cavity, tongue/oral cavity volume ratio and the upper airway in unilateral cleft subjects: A CBCT study

OBJECTIVES

The current study was conducted to assess the volume of the tongue, oral cavity, and tongue/oral cavity and their correlation with the volume of the upper airway in cleft subjects compared with the control group.

METHODS

The study population included 60 CBCT images from dental school. The sample comprised 30 unilateral cleft patients and 30 sex and age-matched healthy subjects. The CBCT images were imported to the Mimics software in DICOM format. Then, the segmentation process was done in order to create distinct masks for the upper airway, oral cavity, and tongue. The software calculated the volume of the created masks.

RESULTS

The volume of tongue, oral and upper airway were significantly lower in cleft patients than in the control group (P value < 0.05 taken as statistically significant). There was a weak but statistically significant correlation between the U.A.W.V and T.V in both cleft and non-cleft subjects. Additionally, there was a statistically significant correlation between the O.C.V and the U.A.W.V in cleft subjects.

CONCLUSIONS

Except than the proportion of tongue/oral cavity volume, other volumetric measurements were significantly lower in cleft subjects than control group. This reveals that clefts are not necessarily more susceptible to obstructive sleep apnea. Also, the positive correlation between the volume of the tongue and oral cavity with the upper airway confirms that early expansion of the maxillary region in clefts helps significantly in increasing their upper airway volume.

Correlation between oral cavity volume and upper airway changes in skeletal Class III patients undergoing bimaxillary orthognathic surgery: a pilot cone-beam computed tomography study

OBJECTIVES

To evaluate changes of the upper airway and oral cavity volumes in patients with skeletal Class III malocclusion undergoing bimaxillary orthognathic surgery, and to analyze the correlation between postoperative upper airway decrease and the amount of jaw movement and oral cavity volume reduction.

MATERIALS AND METHODS

Thirty patients (16 males and 14 females) undergoing bimaxillary surgery were included. Three-dimensional reconstruction of the upper airway and oral cavity were performed using preoperative (T0) and postoperative (T1) (6 months) cone-beam computed tomography scans.

RESULTS

The volume, sagittal area and minimum cross-sectional area of the upper airway were diminished (P < .001). The decrease in volume and minimum cross-sectional area in the oropharyngeal region of the upper airway were weakly correlated with B-point posterior movement (P < .05). Total oral cavity volume was decreased, with maxillary oral volume increasing and mandibular oral volume decreasing (P < .001). Upper airway decrease was highly correlated with total oral volume reduction and mandibular oral volume reduction, with the most significant correlation being with total oral volume reduction (P < .001).

CONCLUSIONS

Class III bimaxillary surgery reduced the volume, sagittal area, and minimum cross-sectional area of the upper airway as well as oral cavity volume. Upper airway changes were weakly correlated with anterior-posterior mandibular movement but significantly correlated with oral cavity volume changes. Thus, oral cavity volume reduction is a crucial factor of upper airway decrease in patients with skeletal Class III malocclusion undergoing bimaxillary orthognathic surgery.

Changes in Maxillary Sinus Volume and Mucosal Thickness Post Bimaxillary Advancement Procedures: A Retrospective Study

Background: Bimaxillary surgery is an elemental procedure in the field of cranio-maxillofacial surgery. It allows for the correction of even the most challenging cases of maxillomandibular disorders, malocclusion, facial asymmetry, and disproportion. The osteotomies and maneuvers carried out during the procedure result in changes to the surrounding tissues, including the maxillary sinuses (MS). The aim of this study was to assess the change in the maxillary sinus volume and the thickness of the mucosa after maxillomandibular advancement (MMA) surgeries. Methods: A group of 25 patients who underwent MMA surgery were included in the study. Computed tomography (CT) of the head and neck region was performed 2 weeks preoperatively and 6 months postoperatively. Acquired Digital Imaging and Communications in Medicine (DICOM) files were analyzed using different software programs to calculate the medium MS mucosa thickness and MS volume. Results: A statistically significant reduction in MS volume was observed (p = 0.015). The change in the median thickness of the MS mucosa was not statistically significant. The median sella-nasion-A point angle (SNA angle) value of the group increased from 80.2 to 83.4 degrees. A weak negative correlation between the SNA delta and the MS volume delta was observed. Spearman's rank coefficient: (ρ s = -0.381, p = 0.060). Conclusions: The MMA surgery results in a reduction in the MS volume. The amount of forward movement of the maxilla may be correlated with the extent of the MS volume reduction.

Intraoral volume changes in relation to the hard tissue shape changes in asymmetric patients before and after orthognathic surgery - A retrospective CT study

OBJECTIVES

To evaluate Intraoral volume changes in relation to the hard tissue shape changes in asymmetric patients before and after orthognathic surgery and establish a correlation between them.

MATERIALS AND METHODS

A retrospective study which evaluated 12 asymmetric patients' pre and post-surgical CT records satisfying the inclusion criteria. Borders were defined for the measurement of extraoral, intraoral and tongue volume. The volume assessment was carried out using software from 3D SYSTEMS, Colorado, US, Version 1.0.2.2055.

RESULTS

Predicting changes in volume between extra-oral, intra-oral spaces and tongue, Linear regression modeling of the data revealed that for every mm3 change in post-surgical extra-oral volume the post-surgical intra-oral volume decreased by 0.684 mm3 and for every mm3 change in post-surgical intra-oral volume, the post-surgical tongue volume increased by 0.728 mm3.

CONCLUSIONS

Significant decrease in the extra-oral volume, Intra-oral volume and tongue volume was evident after orthognathic surgery in patients with facial asymmetry. This volumetric approach sheds insight into achieving a muscular equilibrium between intraoral and extraoral structures, which would improve orofacial function and enhance facial aesthetics.

Influence of second premolar extractions on the volume of the oral cavity proper: a control comparative cone-beam computed tomography volumetric analysis study

OBJECTIVES

To compare the pre- and postorthodontic treatment volumetric changes of the oral cavity proper (OCP) in extraction and nonextraction patients and to identify influencing variables.

MATERIALS AND METHODS

Pre- and posttreatment cone-beam computed tomography (CBCT) scans of patients undergoing orthodontic treatment with fixed labial appliances and who satisfied the inclusion criteria were individually landmarked. Linear, angular, and volumetric measurements were determined. Descriptive statistics, repeated measure analyses of variance, correlations, and stepwise regression statistical analyses were applied.

RESULTS

The CBCT scans of 54 patients who underwent the extraction of second premolars and/or extraction of second primary molars associated with agenic second premolars, and 59 nonextraction patients matched for crowding, were assessed. The mean age for both groups was 15 years. There was a statistically significant increase in the volume of the OCP for both the extraction and nonextraction groups, with the nonextraction group demonstrating a larger increase in the volume of the OCP. Gender, age, changes in mandibular and maxillary arch length, and changes in mandibular and maxillary intermolar width all influenced the change in the OCP volume.

CONCLUSIONS

The volume of the OCP increased in growing patients with and without the extraction of the second premolars and/or extraction of second primary molars associated with agenic second premolars. Patients who did not have extractions as part of their orthodontic treatment demonstrated a greater overall increase in OCP volume.

Volumetric measurement of the tongue and oral cavity with cone-beam computed tomography: A systematic review

Purpose

The goal of this systematic review was to compare the use of cone-beam computed tomography (CBCT) with that of computed tomography (CT) for volumetric evaluations of the tongue and oral cavity.

Materials and Methods

A search for articles was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-analyses guidelines. The PubMed, Scopus, ScienceDirect, and SAGE Journals databases were searched for articles published between 2011 and 2021. Articles were screened and assessed for eligibility. Screening involved checking for duplication, reading the title and abstract, and reading the full text.

Results

The initial search retrieved 25,780 articles. Application of the eligibility criteria yielded 16 articles for qualitative analysis. Multiple uses of CBCT were identified. In several studies, researchers assessed the volumetric correlation between tongue and oral cavity volumes, as well as other parameters. Post-treatment volumetric evaluations of the oral cavity were also reported, and the reliability of CBCT was assessed. The use of CT resembled that of CBCT.

Conclusion

CBCT has been used in the evaluation of tongue and oral cavity volumes to assess correlations between those volumes and with the upper airway. It has also been used for volumetric evaluation after surgical and non-surgical procedures and to assess the relationships between tongue volume, tooth position, occlusion, and body mass index. Participants with obstructive sleep apnea and malocclusion have been evaluated, and the reliability of CBCT has been assessed. In the included studies, CT was utilized for similar purposes as CBCT, but its reliability was not assessed.