Evaluation of Dimensional Changes in Maxillary and Frontal Sinus in Adult Patients With Anterior Open Bite and Normal Overbite: A Retrospective Cone Beam Computed Tomography (CBCT) Study

INTRODUCTION

An anterior open bite is a form of vertical discrepancy that presents as a lack of contact between maxillary and mandibular segments. The treatment modalities usually involve either intrusion of posterior teeth or extrusion of anterior or a combination of both. The anatomical relationship between the apex of the maxillary molar roots to the inferior wall of the maxillary sinus floor is crucial in planning posterior intrusion. The paranasal sinuses influence the growth of the facial structures that eventually get altered in various malocclusions. Studies have proven that the height of the sinus gets modified in anterior open bite owing to pneumatization. This study aims to evaluate the distance from the root apex of maxillary first molars (mesiobuccal, distobuccal, and palatal roots) to the maxillary sinus floor to evaluate the significance of the vertical pneumatization of the sinus on planning for true intrusion in anterior open bite and to assess the correlation between frontal and maxillary sinuses in an anterior open bite.

METHODS

This retrospective study evaluated 30 pre-treatment cone beam computed tomographies (CBCTs) of patients out of which 15 were with anterior open bite and 15 with ideal overbite. Linear measurements were carried out using care stream software in CBCTs.

RESULTS

There was a significant correlation between the distance of the palatal root and the distobuccal root of the maxillary first molar to the maxillary sinus floor bilaterally in the anterior open bite (p<0.04). A significant moderate positive correlation of the maxillary and frontal sinus height in anterior open bite (p<0.006). A significant moderate negative correlation between the distance from the palatal root to the maxillary sinus floor and maxillary sinus height in anterior open bite (p<0.001).

CONCLUSION

Vertical pneumatisation of the maxillary sinus has caused a significant negative correlation between the apex of the palatal root of the maxillary first molar tooth and the maxillary sinus floor in the anterior open bite. The palatal root being the closest to the sinus floor, and the distobuccal root being second nearest. There is a significant correlation between the height of the sinuses in the anterior open bite.

Evaluation of pharyngeal airway volume three-dimensionally in various sagittal skeletal patterns - Systematic review

To investigate the pharyngeal airway volume in different anteroposterior skeletal malocclusions. This study was prepared according to the Cochrane criteria for creating a systematic review and meta-analysis and confirms the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement. This search was conducted to answer the patient/population, intervention, comparison and outcomes (PICO) question: To evaluate (outcome) and compare (comparison) whether there is a difference in airway volume in patients (participants) with different skeletal malocclusions diagnosed using 3D data (intervention).The first two authors extracted the data from the included studies and assessed the risk of bias in the individual studies using the Newcastle-Ottawa scale. Meta-analysis was done using STATA version 16, which compared various three-dimensional pharyngeal airway parameters in skeletal Class II and skeletal Class III malocclusions with that of skeletal class I malocclusion. Out of 370 articles from the initial search, 17 articles were included in the systematic review. Out of 17 studies, 12 eligible studies were included in the quantitative synthesis. The nasopharynx, oropharynx, hypopharynx, and total airway volume were increased in skeletal Class I malocclusion compared to that of skeletal Class II malocclusion and decreased in comparison to skeletal Class III malocclusion. The moderate quality of evidence indicates the total airway volume, oropharynx, and hypopharynx are largest in skeletal Class III compared to Class I and Class II skeletal malocclusion.

Management of Class II Hyperdivergent Mandible by Surgically Altering Occlusal Plane Pattern through Counterclockwise Rotation of Mandible

AIM AND OBJECTIVE

To evaluate the facial esthetic of class II hyperdivergent mandible by altering the high mandibular plane angle into an orthognathic mandibular plane angle by counterclockwise (CCW) rotation of the mandible.

MATERIALS AND METHODS

Five patients with class II hyperdivergent mandible were selected for this study. Initially, preorthodontics was done by aligning the teeth. Then, surgically, bilateral sagittal split osteotomy (BSSO) advancement with CCW rotation of mandible with a posterior open bite of 4 mm was done. Eleven linear and 11 angular measurements were taken. Pre- and postsurgical values were evaluated by composite cephalometric analysis, and the changes in the occlusal plane and facial height were statistically analyzed by using paired t-test. Jarabak ratio was calculated for facial height measurements. Further finishing will be done by postsurgical orthodontic procedures to get functional occlusion.

RESULTS

Change in occlusion to class I is seen in values of Jarabak ratio and Go-Gn. Jarabak ratio shows an increase in posterior and decreases in anterior facial height. Go-Gn, which implies the CCW movement of the mandible, has reduced the anterior open bite and created a posterior open bite of 4 mm for the supraeruption of teeth.

CONCLUSION

BSSO with CCW rotation of mandible with a posterior open bite has conservatively involved in single-jaw surgery, thereby improving the facial esthetics of all the patients taken this study.

CLINICAL SIGNIFICANCE

This innovative method of CCW rotation of mandible with open bite mainly prevents the bi-jaw surgery, improves the stability, and gives an esthetically good appearance.