Dimensional changes of maxillary sinuses and pharyngeal airway in Class III patients undergoing bimaxillary orthognathic surgery

Maxillary sinus volume changes in individuals with different craniofacial skeletal patterns: CBCT study

BACKGROUND

The maxillary sinus, which is crucial for craniofacial growth, is the largest and earliest sinus to develop among the paranasal sinuses. Our study aimed to evaluate the maxillary sinus volume (MSV) in individuals with different sagittal skeletal patterns via cone beam computed tomography (CBCT).

MATERIALS AND METHODS

In this study, CBCT images of 106 retrospectively selected patients (62 females and 42 males) were included. The ANB and SNA angles were measured to determine the skeletal pattern and position of the maxilla in the sagittal direction. Patients were divided into three groups according to ANB angle: Class I (ANB 2°±2°), Class II (ANB˃4°), and Class III (ANB < 0°). The position of the maxilla in the sagittal direction was divided into three groups according to the SNA angle: normal (SNA 82°±2°), retrognathic (SNA < 80°) and prognathic (SNA˃84°). The MSV was measured by two observers and the data obtained were statistically analyzed.

RESULTS

The mean age of the participants was 22.5 ± 4.32. The mean MSV was 28.598 ± 7.9 cm3 in females and 34.231 ± 8.93 cm3 in males. The difference between the sexes was statistically significant in terms of MSV (p < 0.001). When the MSV was compared according to different skeletal patterns and positions of the maxilla, no statistically significant difference was detected between the SNA groups (p = 0.650) and the ANB groups (p = 0.905).

CONCLUSIONS

Different skeletal patterns and positions of the maxilla in the sagittal direction do not significantly change the MSV, but compared with sex, the MSV is greater in males than in females. The outcomes of this study may be beneficial in the context of dental interventions such as orthodontics and maxillofacial surgery.

CLINICAL TRIAL NUMBER

Not applicable.

Evaluation of Minimum Axial Airway Area and Airway Volume in Orthognathic Surgery Patients

The aim of this study was to compare preoperative and postoperative linear, planar, and volumetric measurements in the pharyngeal airway in orthognathic surgery patients. Preoperative and postoperative cone beam computed tomography (CBCT) images of 60 patients, who underwent maxillary advancement with mandibular setback (Group I, n=25) and bimaxillary advancement (Group II, n=35), were compared. The airway was divided into 3 regions as nasopharynx, oropharynx, and hypopharynx. Linear and planar measurements were made on the reference sections of each region. The minimum axial airway area, the volume of 3 regions, and total airway volume were also measured. Regarding the linear, planar, and volumetric measurements, while there was a statistically significant increase in the measurements for all three regions in Group II, in Group I only the measurements in the nasopharyngeal region demonstrated a statistically significant increase postoperatively ( P <0.05). There was an increase in minimum axial airway areas in both groups; however, it was only statistically significant in Group II ( P <0.05). There was a statistically significant increase in total airway volumes in both groups ( P <0.05). A positive and good correlation was found between the percent increase in the minimum axial area and the percent increase in the total volume ( P <0.05). While bimaxillary advancement surgery results in a significant increase in the pharyngeal airway, mandibular setback with maxillary advancement caused an increase in the total airway. Changes that may occur in the airway should be considered while planning orthognathic surgery.

Maxillary sinus volume and facial asymmetry after unilateral zygomaticomaxillary complex fracture reduction with 2, 3, and 4 fixation points: CBCT-based investigation

PURPOSE

This study aimed to assess the maxillary sinus volume (MSV), Chronic Sinusitis incidence, and asymmetry of the zygomaticomaxillary complex (ZMC) following ZMC fracture surgery with various numbers of fixation points.

MATERIALS AND METHODS

In a prospective non-randomized cohort, 50 adults with unilateral ZMC fractures who treated by open reduction and internal fixation (ORIF) between November 2019 and October 2021 were assigned to accomplish this study. They distributed into three groups as per fixation points (2, 3, or 4 Points). Preoperative (T1), Immediate postoperative (T2), and follow-up (T3) cone beam computed topography were analyzed using the Mimics software. The main measures were MSV and asymmetry indexes (ASI) of six paired bilateral anatomical landmarks (Orbital, Suprajugal, Jugale, Zygon, Maxillozygion 1, and Maxillozygion 2).

RESULTS

MSV decreased significantly on the affected sides postoperatively in 2P and 3P groups, both in T2 and T3. Further, the T2-T3 comparisons showed a significant MSV change (p = 0.001). ASI reduced considerably to clinically tolerated levels (<3 mm) on landmarks near the fixation sites postoperatively. The ASI on the Zygon and Maxillozygion 1 landmarks showed significant changes among the three groups in both T2 and T3. Interestingly, only five cases had reported postoperative sinusitis symptoms.

CONCLUSIONS

Although the MSV was changed among the different fixation point groups, the incidence of chronic sinusitis was uncommon. Bilateral asymmetry affected by number and position of the fixation points, fixation with 4 points provide more symmetry.

Evaluation of maxillary sinus volumes and pathologies in children with and without cleft lip and palate using cone beam computed tomography

OBJECTIVE

The aim of this study is to evaluate the maxillary sinus (MS) volume and pathologies, nasal septum (NS) deviation, and MS septa formation in children with and without cleft lip and palate (CLP); also to investigate the possible causes of MS pathologies.

MATERIALS AND METHODS

Cone Beam Computed Tomography (CBCT) images of 200 (100 CLP, 100 control) children (5-18 years old) were evaluated from the computer database of Marmara University Faculty of Dentistry. Children with a history of maxillofacial trauma, diseases that affect bone metabolism, orthognathic surgery, extrinsic pathologies of the MS, and accompanying syndromes were excluded. NS deviation, MS septa formation, volume, and pathologies evaluated using Mimics® software. In statistical evaluations; Student t test, paired sample t test, Chi-Square test, Fisher's Exact Chi-Square test, Continuity Correction, Chi-square analysis in one-eyed layout, McNemar test, and logistic regression analysis were used.

RESULTS

Total MS volume was smaller in the CLP group (21 232 mm3) than in control children (23 763 mm3) (P:0.026). NS deviation and MS pathology were more frequent in the CLP. In logistic regression analysis, there was no significant relation between the presence of NS deviation and pathology in MS. The presence of CLP increased the risk of MS pathology by 2.6 times.

CONCLUSION

We found that children with CLP have less MS volume and an increased rate of NS deviation and MS pathology compared to the control group. Further radiological and clinical studies are needed to explain the predisposing factors of MS pathology in children with CLP.

Nasal and maxillary sinus volume change in patients with obstructive sleep apnea after bimaxillary advancement surgery

The airway complex is modified by bimaxillary advancement surgery performed in patients suffering from obstructive sleep apnea (OSA). The aim of the present study is to analyse the volume of nasal and maxillary sinus after bimaxillary advancement surgery in patients suffering from OSA. The maxillary sinus and nasal complex of eighteen patients with OSA was measured through cone-beam computed tomography (CBCT) before and after they were treated with bimaxillary advancement surgery. Digital planning software was used to effectively measure the upper volume changes, as well as, statistical analysis of the results was performed.Methods Eighteen patients were diagnosed with OSA the severity of which was measured by the apnea hypopnea index and were selected and submitted to preoperative and postoperative CBCT scans. Afterwards, datasets were uploaded into therapeutic digital planning software (Dolphin Imaging) to measure the volume of the right and left maxillary sinus and nasal and maxillary sinus complex. Statistically analysis between preoperative and postoperative measures was performed by Student t-test statistical analysis.Results The paired t-test showed statistically significant volumetric reductions in the left maxillary sinus (p = 0.0004), right maxillary sinus (p < 0.0001) and nasal and maxillary sinus complex (p = 0.0009) after bimaxillary advancement surgery performed in patients suffering from OSA.Conclusion The results showed that bimaxillary advancement surgery reduces the maxillary sinus volume as well as, the fossa nasal and sinus complex volume.

Evaluation of Maxillary Sinus Volume of Class III Individuals with Different Jaw Positions by Cone-Beam Computed Tomography

Objective

To compare maxillary sinus volumes and surface areas among individuals with Class III skeletal patterns, with different sagittal positions of maxilla and Class I patients with normal jaw positions using cone-beam computed tomography (CBCT).

Methods

CBCT images of 168 patients were analyzed retrospectively. The calculated surface areas and sinus volumes of 58 patients with Class I, normal mandibular and maxillary position (0SNA>80, 82>SNB>78) were compared with 61 patients with Class III retrognathic maxillary and normal mandibular positions (MRs) (ANB<0, SNA<80, 82>SNB>78) and 49 patients with Class III normal maxillary and prognathic mandibular positions (MP) (ANB<0, 84>SNA>80, SNB>82). Also, volume differences between genders and sides were investigated. One-way ANOVA and t-test were used to compare age, gender, skeletal patterns, and maxillary sinus measurements.

Results

CBCT images of 94 females and 74 males were examined. There was no statistically significant difference in the right and left maxillary sinus volume and surface area measurements among Class I, Class III MR, and Class III MP groups (p>0.05). When the maxillary sinus volume and surface area were evaluated according to gender, the right maxillary sinus surface area and volume of males were found to be statistically significantly higher than those of females (p=0.012 and p=0.024). Similarly, the left maxillary sinus surface areas and volumes of males were also found to be significantly higher than those of females (p=0.000 and p=0.002).

Conclusion

Different sagittal positions of the maxilla do not appear to affect maxillary sinus volume, and males tend to have greater maxillary sinus volume than females. CBCT images can be used to calculate intrabony air spaces.

Three-Dimensional Evaluation of Upper Airway Changes After Bimaxillary Surgery of Skeletal Class 3 Patients

The aim of this study was to evaluate the 3-dimensional changes in upper airway space of class 3 patients after surgery with sleep-related breathing disturbance. This is a retrospective cohort study included 25 patients who had undergone bimaxillary orthognathic surgery with maxillary advancement and mandibular setback for skeletal class 3 deformity. The changes in minimum axial area, nasopharyngeal and oropharyngeal airway volume were determined by cone-beam computed tomography images, as well as the sleep parameters by polysomnography preoperatively and postoperatively. The impacts of mandibular setback and maxillary advancement amounts on the airway structures were evaluated and compared with other parameters. The results show that pharyngeal volume measurement means were found to be significantly increased postoperatively ( P <0.05). No significant difference was observed in the mean values of minimum axial area and sleep parameters after the operation ( P> 0.05). A positive relationship was determined between the oropharyngeal volume and minimum axial area changes at a rate of 60% ( r : 0.600). No relationship was revealed between airway volume changes and polysomnographic parameters. An increase in the total airway volume and no postoperative sleep-related disturbance symptoms were observed in the patients treated by maxillary advancement and mandibular setback surgery.

Morphological Changes in Total and Inferior Part of Maxillary Sinus After Le Fort I Osteotomy, as Determined by Cone-Beam Computed Tomography

To investigate morphological changes of the total and inferior part of the maxillary sinus following Le Fort I osteotomy. 21 skeletal class II and 49 skeletal III patients who underwent orthognathic surgery were enrolled in this retrospective study. Cone-beam computed tomography taken before (T1) and 6 to 24 months after (T2) orthognathic surgery were imported into Mimics 20.0 software to analyze morphological changes of the total and inferior part of the maxillary sinus. Volume of the whole maxillary sinus was significantly reduced after surgery ( P ≤0.008), while the volume of the inferior part of the maxillary sinus was significantly greater than before surgery ( P ≤0.004). Maxillary sinus floor moved occlusally after Le Fort I osteotomy. Movement in the pitch direction of the posterior maxilla affected the state of the maxillary sinus mucosa after orthognathic surgery. Le Fort I osteotomy exerts a significant impact on the morphology of the total and inferior part of the maxillary sinus.

Three-dimensional evaluation of the maxillary sinus in patients with different skeletal classes and cranio-maxillary relationships assessed with cone beam computed tomography

The objective was to evaluate the relationship between the dimensions of the maxillary sinuses (MSs) and various cephalometric parameters. MS volume (MSV), MS surface (MSS), linear maximum depth (LMD), linear maximum width (LMW), and linear maximum height (LMH) were calculated on CBCT scans of 99 adults. Two sets of two-way (ANOVA) assessed the influence respectively of ANB and SNA angles and of the gender on MS dimensions. Pearson's correlation was calculated between MS dimensions and different cephalometric variables. Reliability and accuracy of the proposed method was tested with intra-operator and inter-operator intraclass correlation coefficient (ICC). Two-way ANOVA showed no statistically significant difference in MSV, MSS and LMH between ANB groups, whilst males were associated with bigger sinuses. LMW showed statistically significant difference in both ANB and gender groups. LMD showed no statistically significant difference. The second Two-way ANOVA showed significantly larger MSV, MSS and LMD in patients with increased or reduced SNA angle but not between genders. LMW and LMH also showed a significant difference between genders. All linear measurements showed a significant interaction of the two factors. The intra-observer and inter-observer ICC scored high for all the tested measurements. MSV and MSS showed a positive correlation with S-N, PNS-A, S-Go, N-Me, N-Ans and the distance between Mx points. LMW had a negative correlation with Ba-S-N angle and N-Me, LMH with Ba-S-N angle, S-Go and Mx r-Mx l and LMD with N-Me and N-ANS. LMW had a positive correlation with Mx r-Mx l, LMH with S-N, S-N^Ans-Pns, N-Me, N-Ans and LMD with S-N, Ba-S-N, PNS-A, S-Go and distance between Mx points. In conclusion, MSV and MSS did not differ between the three skeletal classes, males showed significantly larger MS than in females. Concerning the influence of the cranio-maxillary relationship (SNA) and gender on MS dimension, subjects with a retrusion (SNA < 80°) or protusion (SNA > 84°) of the maxillary alveolar bone had larger MSV, MSS, LMW, LMH and LMD than subjects with a normal cranio-maxillary relationship (SNA 82 ± 2°). A statistically significant high positive correlation was observed between S-N, Pns-A, S-Go, Mx-R/Mx-r and MS dimension. Further studies that evaluate similar outcomes in different races may be able to enrich our knowledge on this topic.

Is the volume of the maxillary sinus altered after LeFort I orthognathic surgery? A systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to investigate anatomical changes in the maxillary sinus after LeFort I osteotomy.

METHODS

The study protocol was developed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols, and it was registered with the International Prospective Register of Systematic Reviews under registration number CRD42021236412.

RESULTS

Our search strategy yielded 64 articles. Of these, 31 were duplicate studies, and 33 were independently reviewed by two authors for eligibility. Of these 33 studies, 24 were excluded as they did not meet the inclusion criteria. Finally, nine studies met the criteria for inclusion, and they were critically reviewed.

CONCLUSION

This systematic review and meta-analysis revealed that maxillary sinus volume decreases after one-piece and multisegment osteotomies in both skeletal class II and class III male and female patients, with one-piece LeFort I osteotomy technique showing a greater reduction in the sinus volume than the multisegment osteotomy technique. The maxillary sinus thickness remained constant postoperatively.

Assessment of Maxillary Sinus Variations Post-LeFort: A Systematic Review

Background

The purpose of this article was to systematically review maxillary sinus changes after LeFort. We examined and analyzed the anatomical abnormalities that occurred following LeFort I osteotomy, as well as the abnormalities of maxillary sinus volume (MSV) before and after the operation.

Methods

A systematic search was conducted on various databases, such as Google Scholar, PubMed, and Scopus. The articles used were in English and original. This study was conducted until September 2023, and after reviewing the articles, several keywords, such as "Maxillary sinus" and "LeFort I osteotomy", were employed. The obtained data were evaluated based on the PICO framework.

Results

Findings from 15 studies showed that the amount of MSV decreased before and after the operation (considering the three dimensions of the sinus, the measurement was performed linearly). These reduction values differed between men and women, with men having a greater reduction. As is the case with other operations, there were some side effects associated with this type of operation that some patients experienced postoperatively.

Conclusion

In both male and female patients, the MSV was reduced after one-piece and multi-segment osteotomies. Nonetheless, one-piece LeFort I osteotomy showed a higher reduction in MSV than the multi-segment osteotomy method, according to this systematic review and meta-analysis.

Does unilateral surgically assisted rapid maxillary expansion (SARME) lead to perinasal asymmetry?

OBJECTIVE

True unilateral posterior crossbite (TUPC) requires unilateral expansion to prevent nonocclusion at the noncrossbite (NC) side. The recommended osteotomies for TUPC after sutural closure are anterior, lateral, and posterior osteotomies only on the crossbite (C) side and median osteotomy of the midpalatal suture, i.e., unilateral surgically assisted rapid maxillary expansion (SARME). The goal was to assess airway and perinasal soft tissue outcomes after SARME.

METHODS

Data from 16 patients (8 males, 8 females; mean age 18.38 ± 1.45 years) were retrospectively assessed after unilateral SARME. The expansion (twice daily: 0.5 mm/day) and retention periods comprised 3 weeks and 6 months, respectively. Stereophotogrammetric images were used for soft tissue assessment; cone beam computed tomography (CBCT) was used to evaluate the anterior nasal airway. Statistical analyses were performed.

RESULTS

Using linear measurements, soft tissue distances of the alar base and alare to midsagittal plane (MSP) were significantly increased on the C side. A significant decrease was observed for the distance from the lower nostril point to the MSP on the NC side compared to a significant increase on the C side. Comparing the C and NC sides, the changes were significantly higher on the C side for all parameters except the upper nostril point to the MSP distance. Cheek volume was significantly higher on the C side. Volume changes of the anterior nasal airway (ANA) were significantly increased on the C side, but volume changes between NC and C were not significantly different.

CONCLUSIONS

Unilateral SARME led to significant expansion of ANA on the C side, but did not lead to asymmetry in the nasal region or have adverse effects on the airway or perinasal soft tissues. Thus, this novel treatment method may be useful in the treatment of patients with TUPC.

Structural and functional changes of nasal cavity and maxillary sinus in patients with skeletal class III malocclusion 1 year after bimaxillary surgery

PURPOSE

This study aimed to analyse changes in the nasal cavity and maxillary sinus structure and function in patients with skeletal class III malocclusion 1 year after bimaxillary surgery.

MATERIALS AND METHODS

In this study, cone-beam computed tomography (CBCT) images of 20 patients (10 men and 10 women; mean age 24.3 ± 3.4 years) with skeletal class III malocclusion who underwent Le Fort I osteotomy and bilateral sagittal split osteotomy were obtained before and 1 year after the surgery. CBCT data were stored opened with element 3D (E3D) to establish a nasal airway model (the paranasal sinus includes only the maxillary sinus). Ansys (ANSYS) software is used for simulation and analysis.

RESULTS

The maxillary sinus and nasal cavity volumes decreased significantly 1 year after the surgery. After surgery, the volume of nasal cavity decreased by 13.5%, and the average volume of maxillary sinus decreased by 7.8%. There was no significant difference in the degree of deviation of the septum and nasal cavity resistance, and air distribution in the maxillary sinus did not change. The nasal cavity wall shear stress change was similar to that before surgery.

CONCLUSIONS

The maxillary sinus volume and nasal cavity volume of patients with skeletal class III malocclusion changed significantly after bimaxillary surgery, but there was no significant change in nasal ventilation function 1 year after surgery.

Sinus mucosal healing pattern according to pterygomaxillary disjunction type after Le Fort I osteotomy

OBJECTIVES

During Le Fort I osteotomy, the separation of the pterygomaxillary junction (PMJ) is a difficult procedure for most surgeons because it is invisible. In this process, damage to the posterior structures constituting the sinus or those adjacent to it, including the maxillary sinus posterior wall and pterygoid plate, may occur. We would like to investigate the effects of this on the inside of the maxillary sinus after surgery and whether there are complications.

MATERIALS AND METHODS

One-hundred patients who underwent Le Fort I osteotomy from 2013 to 2020 using cone-beam computed tomography images were classified into two groups (clean-cut type and fractured type) according to the PMJ cutting pattern. In addition, the mucosal thickness in the maxillary sinus was divided into preoperative, postoperative three months, one year, and the change over the course of surgery was evaluated retrospectively.

RESULTS

Of the total 100 cases, the clean-cut type numbered 28 cases and the fractured type totaled 72 cases. Among the fracture types, part of the sinus wall and the pterygoid plate were broken in 69 cases, and the maxillary sinus posterior wall was detached in three cases. There was no statistically significant difference in sinus mucosal thickening between the clean-cut type and fractured type of the PMJ, three months and one year after surgery between the two groups. However, there was a significant difference in sinus mucosal thickness at postoperative one year in the case where a partial detachment of the maxillary sinus posterior wall occurred compared to not.

CONCLUSION

Even if there is some damage to the structures behind the PMJ, it may not be reasonable to spend some time on the PMJ separation process considering the overall postoperative complications, if there is no significant difference inside the sinus, or increased probability of postoperative complications.

Maxillary Sinus Volume in Patients with Canted Occlusal Plane: A Cone‐Beam Computed Tomography Study

OBJECTIVES

To compare the maxillary sinus volume between both sides in adult patients with upper occlusal canting (>2 mm cant) and a control group (≤2 mm cant) using cone-beam computed tomography scans.

MATERIALS AND METHODS

This retrospective study included a total of 84 scans (42 scans per group) according to predetermined selection criteria. OnDemand 3-D™ software was used for volumetric and linear measurements of the maxillary sinus. Maxillary occlusal canting was determined at the level of the maxillary first molars. It was defined as the vertical difference between right and left sides relative to the Frankfort horizontal plane. Non-parametric tests were applied.

RESULTS

The median difference in the maxillary sinus volume between the sides was statistically significant between the control and cant groups (P < 0.001). Also, the median difference in the maxillary sinus craniocaudal height and apex sinus distance between the sides was statistically significant between the control and cant groups (P < 0.05 and P < 0.001, respectively).

CONCLUSION

In adult patients, maxillary occlusal canting of more than 2 mm was associated with asymmetric maxillary sinus volumes. In the cant group, maxillary first molars on the canted-down side were in close proximity to the sinus floor, which suggests a limited leeway for molar intrusion.

Cone beam computed tomography volumetric airway changes after orthognathic surgery: a systematic review

The aim of this systematic review was to provide a structured overview of three-dimensional airway volume changes in relation to various orthognathic surgeries. Clinical human studies performing pre- and postoperative three-dimensional airway volume assessments to investigate volumetric changes of the airway after orthognathic surgery were included. Pre-determined inclusion and exclusion criteria were applied in an extensive search of the PubMed, Embase, and Web of Science electronic databases. The cut-off date was set to January 1, 2022. Forty-one articles reporting retrospective and prospective case-control and case series studies were included. All studies were determined to be of medium quality (moderate risk of bias). The included studies were categorized by type of intervention. Pre- and postoperative volumes were extracted from the available data, and volume changes as a percentage of the preoperative levels were calculated. Isolated mandibular setback surgery generally decreased the airway volume. Isolated maxillary or mandibular advancement, bimaxillary advancement, and surgically assisted maxillary expansion generally increased the airway volume in the total airway and oropharynx, among which the effect of bimaxillary advancement surgery appeared most significant. High heterogeneity exists in the terminology and definitions of the airway and its segments. A more uniform methodology for airway volume measurement is needed to provide an insight into the impact on the airway of specific types of surgical intervention. In conclusion, airway volumes are affected after orthognathic surgery, which may be of clinical significance, especially in patients who are predisposed to obstructive sleep apnoea.

Computed Tomography Assessment of Maxillary Sinus and Inferior Nasal Airway After Le Fort I Osteotomy

PURPOSE

This study aimed to evaluate and predict the factors that affect the postoperative maxillary sinus and inferior nasal cavity conditions after Le Fort I osteotomy.

SUBJECTS AND METHODS

The rate of aerated (healthy) sinus area and the inferior nasal airway area were calculated by preoperative computed tomography measurements and at 1 week and 1 year postoperatively. Factors predicting the rate of aerated sinus area and the ratio of the inferior nasal cavity area after 1-week were examined using these variables.

RESULTS

The subjects consisted of 112 patients (224 sides) who underwent Le Fort I osteotomy with sagittal split ramus osteotomy. The rate of aerated sinus area after 1 week was significantly correlated with sex, age, and amount of blood loss (P < 0.0001). The rate of the inferior nasal cavity area after 1 week was significantly correlated with the anterior impaction amount of the maxilla and the preoperative rate of the inferior nasal airway area (P= 0.0017).

CONCLUSIONS

This study suggests that attention should be paid to females, older patients, and the amount of blood loss to prevent sinusitis, and larger maxillary impaction at the anterior site should be carefully planned to prevent severe nasal obstruction immediately after Le Fort I osteotomy.

'Comparison and correlation of the maxillary sinus dimensions in various craniofacial patterns: A CBCT Study'

Background: To compare and correlate the maxillary sinus dimensions and basal bone height among various facial patterns using CBCT for advanced diagnosis and treatment planning in Orthodontics.

Methods: 66 CBCT images within age group of 18-30 years were divided into horizontal (Group 1), average (Group 2) and vertical (Group 3) facial growth patterns. Maxillary sinus dimensions were compared and correlated in all three groups. The sinus height and basal bone height were recorded at 3 locations-between 1 ^st premolar and 2 ^nd premolar (PM1-PM2), between 2 ^nd premolar and 1 ^st Molar (PM2-M1) and between 1 ^st and 2 ^nd molar (M1-M2).

Results: Overall reduction in sinus height and significantly reduced sinus volume was seen in Group-1. Longest maxillary sinus height in M1-M2 region and shortest in PM1-PM2 region was seen in Group-3. The basal bone height in PM1-PM2 region was significantly longer in Group-3 than in Group-1(p<.05).Shortest basal bone height in M1-M2 region was seen in Group-3. A significant negative correlation was seen between the maxillary sinus height and the basal bone height in Group-1 and Group-3(p<.05).

Conclusion: There is a correlation between the maxillary sinus height and basal bone height with that of facial pattern which needs to be considered during orthodontic treatment planning and while carrying out facial growth modification procedures in younger patients.

A CBCT based analysis of the correlation between volumetric morphology of the frontal sinuses and the facial growth pattern in caucasian subjects. A cross-sectional study

BACKGROUND

The aim of this study was to evaluate the relationship between frontal sinus shape and facial growth pattern.

METHODS

The three-dimensional examination was carried out by means of 80 CBCT scans selected from a sample of 1247 records of patients treated, for different reason, at the Department of Biomedical Surgical and Dental Sciences at University of Milan, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico Milan. The sample (age ranges between 12 and 40 years) was divided according to gender and age in four groups (12-17, 18-20, 21-30, 31-40). Left and right frontal sinus volume (VOL), surface (SUP) and linear maximum width (XMAX), depth (ZMAX) and height (YMAX) were calculated using Mimics Research 17.0 (Materialise N.V., Leuven, Belgium). Cephalometric analysis has been performed for all subjects to categorize the patients depending on their facial growth pattern. Univariate and multivariate regression analysis were performed to investigate any association of frontal sinuses measurements (height, width, depth, volume and surface) and cephalometric variables. P value < 0.05 was considered statistically significant.

RESULTS

A total of 160 frontal sinuses were measures in 80 patients: 40 men and 40 women, average age of 23.5 ±14.6. Globally the frontal sinuses had the following average dimensions: volumes of 9055.8 ± 6505 mm3 and surfaces of 3820.3 ± 2125 mm2. The statistical analysis showed that frontal sinus volume was statistically significant (p=0.003) greater for male (11,425 mm3) than female (6597.5 mm3). Similarly, the surface showed to be greater in men than in women (p=0.005). No correlation between age and frontal sinuses characteristics has been found. A statistically significant (p<0.05) increase of frontal sinus depth, surface and volume was correlated with SNB angle. In addition, frontal sinus volume increased in subjects with greater anterior skeletal dimension values and with a superior length of the cranial base. Furthermore, a decrease of ANB has been found related to an increase in frontal sinus volume (p=0.04).

CONCLUSIONS

The present study showed a correlation between frontal sinuses dimensions and craniofacial aspects, despite the inter-individual variability of their morphology. The results suggested that young adults in whom the frontal sinuses have reached their maximum size, while vertical growth continues, a larger frontal sinus may be associated with future vertical growth.

Comparison of oropharyngeal airway dimensional changes in patients with skeletal Class II and Class III malocclusions after orthognathic surgery and functional appliance treatment: A systematic review

Objective

To compare the dimensional changes in the oropharyngeal airway in patients with skeletal Class II and Class III malocclusion before and after orthognathic surgery and treatment with a functional appliance.

Methods

The protocol was developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) and was registered to the International Prospective Register of Systematic Reviews (PROSPERO) under the registration number CRD42020170901. Furthermore, the reporting of the present SR was performed based on the PRISMA checklist.

Results

The use of removable functional appliances increased the volume of the oropharyngeal airway in patients with skeletal Class II malocclusion. Furthermore, the increase in the volume of the oropharyngeal airway following the removable functional appliance treatment was more than that observed after fixed functional appliance treatment in growing patients. For patients with skeletal Class III malocclusion, who underwent the bimaxillary orthognathic surgery, resulted in no change in the dimensions of the oropharyngeal airway.

Conclusion

Growing patients who receive removable functional appliance treatment have a more favorable long-term prognosis with regard to the oropharyngeal airway when compared with those who receive fixed functional appliance. Alternatively, in patients aged from (18–22) years with skeletal class III malocclusion Bimaxillary orthognathic surgery was found to be the recomended and superior method of treatment.

Effect of orthodontic maxillary posterior en masse intrusion anchored with miniplates on maxillary sinuses volume. Retrospective CBCT study

OBJECTIVE

To evaluate, by means of cone beam computed tomography (CBCT), the volume change of maxillary sinuses in patients that underwent orthodontic maxillary posterior en masse intrusion anchored with miniplates.

MATERIALS AND METHODS

The sample consisted of pretreatment (T1) and posttreatment (T2) CBCT scans obtained from 14 patients (4 male and 10 female), with a mean age of 32.4 years, that underwent orthodontic maxillary posterior en masse intrusion anchored with miniplates in the zygomatic crest. The mean treatment duration was 20 months and the mean intrusion movement was 2.4 mm. Maxillary sinus volume was measured by means of the software ITK SNAP (version 3.8.0) in T1 and T2 CBCT scans. The changes in sinuses volume were calculated by T1-T2 values. Data were analyzed statistically with Wilcoxon test at 5% of level of significance and the method error was analyzed with Wilcoxon test, intraclass correlation and Dahlberg's formula.

RESULTS

The mean difference (T1-T2) was -242.85 mm³ (p = 0.396) for the right sinus and -32.5 mm³ (p = 0.875) for the left sinus. A slight increase in the volume of the sinuses was shown although these results were not statistically significant.

CONCLUSION

The orthodontic maxillary posterior en masse intrusion anchored with miniplates did not influence significantly the maxillary sinus volume.

Effect of maxillary surgical movement on nasal cavity and maxillary sinus dimensions and function after Le Fort I osteotomy

This study was designed to evaluate the effects of different maxillary movements performed in Le Fort I surgery on the anatomy of the nasal cavity and maxillary sinus, occurrence of rhinosinusitis, and nasal airflow. Patients were divided into three groups: group I underwent pure advancement, group II underwent advancement with yaw rotation, and group III underwent advancement with impaction movements. All evaluations were performed using pre- and postoperative computed tomography images and surveys. Twenty-eight patients were enrolled. The mean pre- and postoperative nasal air volumes in group I were 22.74 ± 6.32 cm³ and 25.17 ± 6.19 cm³, respectively, showing a significant increase (P = 0.041). The mean pre- and postoperative maxillary sinus air volumes were 33.94 ± 13.72 cm³ and 26.28 ± 14.12 cm³ in group II and 35.29 ± 9.58 cm³ and 28.65 ± 8.42 cm³ in group III, respectively, showing significant reductions (P = 0.028 and P = 0.007, respectively). For all movements, the occurrence of septum deviation and nasal airflow impairment was not statistically significant. Pure maxillary advancement movement enhanced nasal cavity air volume. The yaw rotation movement significantly increased quantitative clinical rhinosinusitis symptoms. The risk of airflow impairment following Le Fort I surgery is low.

Postoperative changes in the pharyngeal airway space through computed tomography evaluation after mandibular setback surgery in skeletal class III patients: 1-year follow-up

Background

This study evaluated the pharyngeal airway space changes up to 1 year after bilateral sagittal split osteotomy mandibular setback surgery and bimaxillary surgery with maxillary posterior impaction through three-dimensional computed tomography analysis.

Methods

A total of 37 patients diagnosed with skeletal class III malocclusion underwent bilateral sagittal split osteotomy setback surgery only (group 1, n = 23) or bimaxillary surgery with posterior impaction (group 2, n = 14). Cone-beam computed tomography scans were taken before surgery (T0), 2 months after surgery (T1), 6 months after surgery (T2), and 1 year after surgery (T3). The nasopharynx (Nph), oropharynx (Oph), hypopharynx (Hph) volume, and anteroposterior distance were measured through the InVivo Dental Application version 5.

Results

In group 1, Oph AP, Oph volume, Hph volume, and whole pharynx volume were significantly decreased after the surgery (T1) and maintained. In group 2, Oph volume and whole pharynx volume were decreased (T2) and relapsed at 1 year postoperatively (T3).

Conclusion

In class III malocclusion patients, mandibular setback surgery only showed a greater reduction in pharyngeal airway than bimaxillary surgery at 1 year postoperatively, and bimaxillary surgery was more stable in terms of airway. Therefore, it is important to evaluate the airway before surgery and include it in the surgical plan.

Evaluation of Nasal Function and Upper Airway Morphology After Bi-Maxillary Surgery Using Rhinomanometry and Computed Tomography

PURPOSE

This study was performed to evaluate changes in nasal airflow, nasal airway resistance, nasal cross-sectional area, pharyngeal horizontal area, nasopharyngeal and oropharyngeal volume following Le Fort I osteotomy (L1) impaction with sagittal split ramus osteotomy (SSRO) in classes II and III.

MATERIALS AND METHODS

The subjects consisted of 35 patients (6 males and 29 females, 70 sides) 17 of which were diagnosed as class II and 18 as class III who underwent L1 and SSRO. Nasal airflow and resistance were measured using the rhinomanometry system (GM NR-6 EXECUTIVE) before and at 1 and 6 months after surgery. Nasal, cross-sectional area, and volume were measured using a 3-dimensional computed tomography respectively, before and 1-year after surgery.

RESULTS

Although a significant decrease was found in nasal volume after surgery (P = 0.0042), there was no difference between before and after surgery in the nasal airway resistance in class II.A significant decrease in nasal volume was found after surgery (P = 0.0005) and there were no postoperative changes in both nasal airflow and resistance in class III.

CONCLUSION

The study suggested that L1 impaction with SSRO did not worsen nasal function such as nasal airflow and nasal airway resistance, although nasal volume significantly decreased in both groups.

Upper Airway Changes Following Different Orthognathic Surgeries, Evaluated by Cone Beam Computed Tomography: A Systematic Review and Meta-analysis

PURPOSE

This study sought to assess the upper airway changes following different orthognathic surgeries using cone-beam computed tomography.

METHODS

An electronic search of the literature was conducted in major electronic databases including Medline (PubMed), Web of Science, Scopus, and Open Grey for articles published up to January 20, 2018. Human studies that evaluated the changes in the volume and minimum cross-sectional area of the upper airway or its subdivisions in patients who had undergone orthognathic surgery by use of cone-beam computed tomography were included. Manual search of the bibliographies of the included articles was also conducted. The included studies underwent risk of bias assessment.

RESULTS

A total of 1330 articles were retrieved. After excluding the duplicates and irrelevant articles, 41 studies fulfilled the eligibility criteria for this systematic review; out of which, 30 entered the meta-analysis. The majority of studies had a medium risk of bias. Mandibular setback, and maxillary advancement + mandibular setback decreased the volume of the upper airway (-6042.87 mm3 and -1498.78 mm3, respectively) and all its subdivisions in long-term (>3 months), except for the nasopharynx, the volume of which increased following maxillary advancement + mandibular setback. Mandibular advancement and maxillomandibular advancement both increased the upper airway volume in long-term (7559.38 mm3 and 7967.06 mm3, respectively); however, only the changes after the former procedure were significant. The minimum cross-sectional area increased after maxillomandibular advancement (161.43 mm2), and decreased following maxillary advancement + mandibular setback (-23.79 mm2) in long-term.

CONCLUSION

There is moderate evidence to suggest that mandibular advancement is the only orthognathic movement that provides a statistically significant change in long-term upper airway volume.

An Update of the Possible Applications of Magnetic Resonance Imaging (MRI) in Dentistry: A Literature Review

This narrative review aims to evaluate the current evidence for the application of magnetic resonance imaging (MRI), a radiation-free diagnostic exam, in some fields of dentistry.

BACKGROUND

Radiographic imaging plays a significant role in current first and second level dental diagnostics and treatment planning. However, the main disadvantage is the high exposure to ionizing radiation for patients.

METHODS

A search for articles on dental MRI was performed using the PubMed electronic database, and 37 studies were included. Only some articles about endodontics, conservative dentistry, implantology, and oral and craniofacial surgery that best represented the aim of this study were selected.

RESULTS

All the included articles showed that MRI can obtain well-defined images, which can be applied in operative dentistry.

CONCLUSIONS

This review highlights the potential of MRI for diagnosis in dental clinical practice, without the risk of biological damage from continuous ionizing radiation exposure.

How does bimaxillary orthognathic surgery change dimensions of maxillary sinuses and pharyngeal airway space?

OBJECTIVES

To assess changes in the maxillary sinus (MS) and pharyngeal airway space (PAS) after bimaxillary orthognathic surgery using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

The CBCT scans of 48 patients were divided into two groups: group 1: maxillary advancement and mandibular setback (n = 24); group 2: maxillomandibular advancement (n = 24). The CBCTs were acquired 1 to 2 months preoperatively and 6 to 8 months postoperatively. A kappa test was used to determine intra- and interexaminer agreement. Area, volume, and linear measurements of MSs and PASs obtained before and after surgery were compared using a mixed model (P < .05).

RESULTS

All variables of the MS showed significant postsurgical reductions in both groups, except the MS length, which showed a significant increase in group 2. Volume and minimum axial area of PAS showed statistically significant postsurgical increases in both groups (P < .05).

CONCLUSIONS

Despite the reduction in the MS and the increase in the PAS, results indicated that the airway was not negatively affected after maxillomandibular advancement and maxillary advancement with mandibular setback.

Maxillary sinus haziness and facial swelling following suction drainage in the maxilla after orthognathic surgery

Background

We investigated the efficacy of a maxillary Jackson-Pratt (J-P) suction drain for preventing maxillary sinus hematoma and facial swelling after maxillary Le Fort I osteotomy (LF1).

Methods

We retrospectively evaluated 66 patients who underwent LF1 at a single institution. Of these, 41 had a J-P suction tube inserted in the mandible and maxilla (maxillary insertion), and 25 had a J-P drain inserted in the mandible only (no maxillary insertion). Facial CT was obtained before and 4 days after surgery. We compared mean midfacial swelling and maxillary sinus haziness by t test and examined correlations between bleeding amount and body mass index (BMI).

Results

For the maxillary-insertion group, the ratio of total maxillary sinus volume to haziness (57.5 ± 24.2%) was significantly lower than in the group without maxillary drain insertion (65.5% ± 20.3; P = .043). This latter group, however, did not have a significantly greater midfacial soft tissue volume (7575 mm³) than the maxillary-insertion group (7250 mm³; P = .728). BMI did not correlate significantly with bleeding amount or facial swelling.

Conclusions

Suction drainage in the maxilla reduced maxillary sinus haziness after orthognathic surgery but did not significantly reduce midfacial swelling.

Immediate effects of mandibular posterior displacement on the pharyngeal airway space: A preliminary study

Objective

This study aimed to evaluate the immediate effects of mandibular posterior displacement on the pharyngeal airway space (PAS) by using cephalometric evaluations and to investigate how the surrounding structures are schematically involved.

Methods

In this retrospective study, 38 subjects with functional Class III malocclusion and two lateral cephalograms were selected. The first lateral cephalogram was taken with the mandible in the habitual occlusal position, and the second in anterior edge-to-edge bite. Paired t-test was used to analyze changes in the PAS, hyoid bone, tongue, and soft palate, followed by mandibular posterior displacement. Pearson's correlation analysis was used to determine the relationship between the amount of mandibular posterior displacement and other variables.

Results

A statistically significant decrease was observed in the PAS following mandibular posterior displacement. Along with mandibular posterior displacement, the tongue decreased in length (p < 0.001) and increased in height (p < 0.05), while the soft palate increased in length, decreased in thickness, and was posteriorly displaced (p < 0.001). The hyoid bone was also posteriorly displaced (p < 0.05). There was no correlation between the amount of mandibular posterior displacement and the measured variables.

Conclusions

The PAS showed a statistically significant decrease following mandibular posterior displacement, which was a consequence of retraction of the surrounding structures. However, there were individual variances between the amount of mandibular posterior displacement and the measured variables.

Three-Dimensional Evaluation of Maxillary Sinus Changes in Growing Subjects: A Retrospective Cross-Sectional Study

This study aims to evaluate changes of maxillary sinuses in growing subjects. Cone Beam Computed Tomography (CBCT) scans of 146 patients were divided according to gender and age (6–8, 9–11, 12–14 years old). Left, right and total maxillary sinus volume (MSV-R, MSV-L, MSV-Tot) and surface (MSS-R, MSS-L, MSS-Tot), left and right linear maximum width (LMW-L, LMW-R), depth (LMD-R, LMD-L) and height (LMH-R, LMH-R) were calculated using Mimics Research 22. Kruskal–Wallis Test and showed a statistically significant increase in both genders for all variables. Pairwise comparisons in females are always statistically significant in: LMH-R, LMH-R, MSS-Tot, MSV-Tot. All other variables showed a statistical significant increase between 9–11 and 12–14, and between 6–8 and 12–14 age groups, apart from LMSW-R, LMSW-L, LMSD-R, LMSD-L between 6–8 and 12–14 age groups. Pairwise comparisons in males are always and only statistically significant between 9–11 and 12–14, and between 6–8 and 12–14 groups. Symmetrical measurements (right and left) evaluated using Wilcoxon test retrieved no statistical significant difference. Comparisons between measurements on male and female subjects using Mann–Whitney test showed a statistical significant difference in 6–8 years group in MSV-R, MSV-L and MSV-Tot, and in 12–14 age group in MSV-R, MSV-L, MSV-Tot, MSS-r, MSS-l, MSS-Tot, MSW-R, MSW-L, MSD-R, MSD-L. Intraclass Correlation Coefficient (ICC) assessing inter-operator and intra-operator concordance retrieved excellent results for all variables. It appears that maxillary sinus growth resembles the differential peak of growth in male and female subjects. Sinuses starts to develop early in female subjects. However, in the first and last age group female sinuses are statistically significantly smaller compared to male ones. In male subjects, sinus growth occurs mainly between the second and third age group whilst in female subjects it starts between the first and second age group and continues between the second and the last. Sinus has a vertical development during the peak of growth, which is the main reason for its increase in volume.

The Changes in Upper Airway Volume after Orthognathic Surgery Evaluated by Individual Segmentation on CBCT Images

Objectives:The aim of this CBCT study was to evaluate the postoperative volume changes of the rhinosinusal airway space, maxillary sinuses and nasal fossa, that occur after Le Fort I osteotomy, using individual segmentation of 3D virtual models. Material and methods:A number of 16 patients (with Class II and Class III malocclusions) who underwent a CBCT examination for orthognathic surgery at six month-interval between preoperative and postoperative evaluations were included. Patients with thickening of the sinus mucosa, craniofacial syndromes, maxillofacial trauma, rhinoplasty or other maxillofacial pathological conditions were excluded from the study. Individual segmentation of airway volumes was performed by the ITK-SNAP 2.0 software. Paired student t-test was used for the statistical examination of volume changes and Pearson's test for the assessment of intra-rate correlation. Outcomes:A statistically significant decrease in the rhinosinusal volume in Class II (9.36±3.43 cm3) and Class III malocclusions (3.65±2.96 cm3) was found after Le Fort I osteotomy. A decrease in volume was also found for maxillary sinuses (5.63±1.52 cm3 for Class II and 6.72±4.5 cm3 for Class III malocclusion). Nasal fossa decreased in volume (3.79±3.8 cm3) in Class II malocclusion patients and increased (3.07±2.39 cm3) in Class III malocclusion patients. The Pearson correlation revealed a high intra-rate agreement of measurements. Conclusion:Le Fort I osteotomy modifies the postoperative volume of rhinosinusal aerial spaces and individual segmentation on CBCT images is a useful tool to analyze the changes.

3D Airway changes using CBCT in patients following mandibular setback surgery ± maxillary advancement

INTRODUCTION

The aim of this study was to determine the 3D airway changes that occur following mandibular setback surgery alone vs bimaxillary surgery in patients with similar skeletal start forms.

SETTING AND SAMPLE POPULATION

The University of Michigan School of Dentistry and Medical Center. A total of 85 patients undergoing mandibular setback with or without simultaneous maxillary advancement.

MATERIALS AND METHODS

A retrospective evaluation of pre- and post-surgical CBCT scans for patients undergoing mandibular setback surgery alone (14) vs bimaxillary surgery (71) was performed. Cross-sectional evaluation at standardized locations, minimum cross section and volumetric analysis were performed (Dolphin Imaging & Management Solutions).

RESULTS

Patients who underwent mandibular setback surgery alone showed a statistically significant average increase of 47.5 mm² in minimum axial area. Patients who underwent bimaxillary surgery showed a statistically significant increase in airway volume, minimum axial area, location of minimum axial area, and axial area at the retropalatal and retroglossal regions.

CONCLUSIONS

The results demonstrate that the mandible can be setback safely without decreasing airway dimensions. In borderline OSA patients, bimaxillary surgery remains the preferred approach due to the larger airway increases observed. Long-term follow-up with polysomnography must be conducted to determine the full functional implications of both procedures.

Is the maxillary sinus volume affected by concha bullosa, nasal septal deviation, and impacted teeth? A CBCT study

PURPOSE

Various mechanisms play an important role in the growth of maxillary sinus cavities. The purpose of this study was to investigate the correlations of maxillary sinus volume (MSV) with nasal septal deviation (NSD), concha bullosa (CB) and impacted teeth using cone-beam computed tomography (CBCT) images.

METHODS

From 55 patients, a total of 110 maxillary sinus images were obtained and examined. Data including age, gender, impacted third molar, canine teeth, NSD, and CB were examined. MSV was measured using the MIMICS software (Materialise HQ Technologielaan, Leuven, Belgium). All statistical analyses were performed using the SPSS (Statistical Package for Social Sciences, version 21) software and p values < 0.05 were considered to indicate statistical significance.

RESULTS

Mean volume of the right maxillary sinus was 13.566 cm³, while the left was 13.882 cm³. The rate of patients with right and left impacted third molar teeth was 49.1% and 47.3%, respectively. The rate of right and left impacted canines was 1.8% and 5.5%, respectively. NSD was found in 56.4% of CBCT examinations and right and left CB were observed in 30.9% and 32.7% of the patients' examinations, respectively. Males had a significantly higher mean sinus volume than females for both sides (p < 0.05). There were no significant correlations between MSV and age (p > 0.05). No significant differences were found between MSV and impacted teeth, NSD and CB (p > 0.05).

CONCLUSION

NSD, CB, impacted teeth, and age were not found to be related to MSV. Gender had an effect on MSV and males had higher mean sinus volume than females.

Three-dimensional evaluation of maxillary sinus volume in different age and sex groups using CBCT

AIM

Sinus maxillaris is an important anatomical formation in many branches of dentistry due to its proximity to the field of work. Various methods have been used in literature to measure the maxillary sinus volume (MSV) such as cadavers, stereology, two-dimensional conventional radiographs, computed tomography (CT), magnetic resonance imaging (MRI). The aim of this study is to evaluate the change of maxillary sinus volume according to age and gender with MIMICS 19.0 (Materialise HQ Technologielaan, Leuven, Belgium) which is one of three-dimensional modeling software.

MATERIALS AND METHODS

This study was performed in 200 patients selected by a retrospective review of the archives of the Dicle University, Faculty of Dentistry, Department of Oral and Maxillofacial Radiology. Patients were divided into five age groups (18-24 years, 25-34 years, 35-44 years, 45-54 years, and ≥ 55 years) and by sex. Cone-beam computed tomography (CBCT) images of the patients were transferred to the MIMICS software and the MSV was measured. All statistical analyses were performed using the SPSS (Statistical Package for Social Sciences, version 21) software.

RESULTS

There was no statistically significant difference between the right and left maxillary sinus volume according to the findings obtained from our study, and maxillary sinus volume in males was found to be significantly higher than that of females. Another finding of our study is that the maxillary sinus volume decreases with age increase. Especially it was also found that the sinus volume in males in the 18-24 age group was statistically significantly higher than females.

CONCLUSION

Consequently, maxillary sinus volume measurements can be made on CT, CBCT, MRI scans using reconstruction software.

Investigation of maxillary sinus volume relationships with nasal septal deviation, concha bullosa, and impacted or missing teeth using cone-beam computed tomography

OBJECTIVES

The aim of this retrospective study was to investigate the correlations of maxillary sinus volume with nasal septal deviation, concha bullosa, impacted teeth, and missing teeth in the maxillary posterior region on maxillary sinus volume using cone-beam computed tomography (CBCT) images.

METHODS

The study cohort comprised 252 CBCT images of 252 patients retrospectively selected from the records in our CBCT archive. All CBCT images were exported to 3D modeling software for calculation of maxillary sinus volumes. Nasal septal deviation cases were grouped as mild, moderate, and severe. Concha bullosa was classified as lamellar, bulbous, and extensive. Maxillary sinus volume differences were evaluated by comparing the bilateral sinus volumes in patients with nasal septal deviation, unilateral concha bullosa, and unilateral impacted or missing maxillary posterior teeth.

RESULTS

The findings revealed that males had a significantly higher mean sinus volume than females (p < 0.01) and that sinus volume tended to decrease with age (p < 0.05). In moderate and severe nasal septal deviation cases, the maxillary sinus volume was significantly smaller on the same side as the deviation than on the contralateral side (p < 0.05). There were no significant correlations between maxillary sinus volume and concha bullosa, unilateral impacted teeth, or unilateral missing teeth (p > 0.05).

CONCLUSIONS

The present findings suggest that maxillary sinus volume is smaller on the same side as the deviation in moderate and severe septal deviation cases and that the maxillary sinus volume tends to decrease with increasing age.

Volumetric changes of the upper airway following maxillary and mandibular advancement using cone beam computed tomography

The objective of this project was to retrospectively evaluate changes in volume of different compartments of the upper airway in response to maxillary, mandibular, and bimaxillary advancement surgeries and to predict the extent of volumetric changes associated with these surgical movements. Pre- and post-surgical cone beam computed tomography scans of 36 patients were evaluated for changes in nasal cavity, nasopharyngeal, oropharyngeal, and hypopharyngeal compartments. The amount of movement for each surgery was measured from skeletal landmarks to reference planes and was correlated with volumetric changes. Maxillary advancement of 4.0±2.2mm increased the oropharyngeal volume significantly (41.40%), and mandibular advancement of 3.8±1.6mm also significantly increased the oropharyngeal volume (21.17%). Bimaxillary advancement of 5.1±1.3mm for the maxilla and 6.4±3.1mm for the mandible significantly increased nasopharyngeal (27.45%), oropharyngeal (66.39%), and hypopharyngeal (52.48%) volumes. Furthermore, for every millimeter anterior movement, oropharyngeal volume increased by 2319.2±771.8mm³. Bimaxillary advancement showed a greater increase than isolated maxillary and mandibular advancement in all pharyngeal compartments. Every millimeter of advancement in the bimaxillary group led to a significant increase in oropharyngeal volume, while every millimeter downward movement showed a significant increase in nasopharyngeal volume.

Gender differences in morphological and functional outcomes after mandibular setback surgery

PURPOSE

The aim of this study was to examine and compare morphological and functional outcomes after either isolated mandibular setback or bimaxillary surgery in males and females.

MATERIALS AND METHODS

A retrospective study was done on 52 patients, in whom surgical correction for mandibular prognathism was performed either by isolated mandibular setback (30 cases) or by bimaxillary surgery (22 cases). Morphological changes were studied using cephalograms and functional changes studied using impulse oscillometry (IOS) taken before surgery (T0), 3 months (T1) and 1 year after surgery (T2). Also 3% oxygen desaturation index (ODI) was measured at T0 and T2.

RESULT

Posterior airway space decreased significantly in both groups and both sexes but more so in males after mandibular setback surgery and in females after bimaxillary surgery. Changes in supine R20 (central airway resistance at 20 Hz) and supine R5 (total airway resistance at 5 Hz) in IOS statistically significantly increased in the period T0-T1 in males compared with females after mandibular setback surgery (p < 0.05).

CONCLUSION

Gender dimorphism is present according to morphological and functional outcomes, with males at a higher risk for obstructive sleep apnea (OSA) after mandibular setback surgery and females after bimaxillary surgery; however, compensatory changes act as a barrier against this.

Evaluation of upper airways after bimaxillary orthognathic surgery in patients with skeletal Class III pattern using cone-beam computed tomography

Introduction:

It has been suggested that mandibular setback surgery, combined or not with maxillary advancement as a treatment alternative for patients with mandibular prognathism, can induce changes in upper airway space (UAS). Therefore, this study aimed to assess the response of the upper airway in the oropharynx region of patients with Class III skeletal pattern that underwent bimaxillary orthognathic surgery (maxillary advancement and mandibular setback) combined with mentoplasty.

Material and Methods:

The sample comprised 26 cone-beam computed tomography (CBCT) scans of 13 patients. The examination was taken before and after surgery. UAS volume, sagittal area, length and minimal axial area with its width, depth and location, were measured with the aid of Dolphin Imaging^TMsoftware version 11.5 Premium. Data were statistically treated by applying Shapiro-Wilk test and Student's paired t-test, considering as statistically significant the results of which p-value was lower than 0.05.

Results:

No statistically significant differences were found in any measurements evaluated.

Conclusions:

No significant changes were observed in the oropharynx after bimaxillary orthognathic surgery and mentoplasty.

Surgical Maxillary Advancement Increases Upper Airway Volume in Skeletal Class III Patients: A Cone Beam Computed Tomography-Based Study

STUDY OBJECTIVES

Although volumetric changes of the upper airway occur following surgical advancement of the maxilla, few studies investigated these changes using three-dimensional imaging techniques. Thus, the goal of this study was to verify whether the surgical advancement of the maxilla affects the volume of the upper airway and to determine any association of these volume changes with sex and age.

METHODS

Preoperative and postoperative cone-beam computed tomography (CBCT) scans of 14 patients (8 male and 6 female) who underwent maxillary advancement to correct skeletal class III deformities were assessed to determine the postoperative volumetric changes in the upper airway. Preoperative and postoperative airway volume measurements were compared by means of paired t-test, which was also used to compare airway volume between genders. Pearson correlation coefficient was used to verify whether a correlation between age and upper airway volume was present.

RESULTS

Maxillary advancement produced significant upper airway volume increases (mean 20.94%, p < 0.05) on nearly half of our sample. However, sex and age did not seem to influence upper airway volume in our sample of skeletal class III patients.

CONCLUSIONS

Surgical advancement of the maxilla may produce significant volume increases in the upper airway of skeletal class III patients regardless of sex and age.

Impact of different orthodontic treatment modalities on Airway: A literature review

This review focused on airway dysfunctions and orthodontic treatment modalities. A systematic search of the dental literature was performed using PubMed and Web of Science library database. Different combinations of search terms related to airway and orthodontic treatment were used. Any Non-English articles were excluded. Among titles found, abstract and full articles were reviewed. References from all the relevant articles were hand-searched to include more articles. Forty articles which were found relevant were included in the review. Surgical, orthopedic and fixed appliance therapy has been advocated by clinicians to treat patients with airway dysfunctions. These treatment modalities differ from patient to patient and have to be considered based on lot of criterion.

The reviewed studies were not convincing in providing information about the orthodontic treatment modalities; further research regarding the same could be encouraging.

Posterior Pharyngeal Airway in Clockwise Rotation of Maxillomandibular Complex Using Surgery-first Orthognathic Approach

Background:

Because obstructive sleep apnea is known to be an important preexisting factor causing chronic disease, many investigations have been done recently. There have been few reports regarding the posterior pharyngeal airway after clockwise rotation of maxillomandibular complex. Because the 2-jaw surgery in class III patients could cause obstructive sleep apnea or snoring, we investigated the posterior pharyngeal airway change of the clockwise maxillomandibular complex in the surgery-first orthognathic approach for the correction of class III dentofacial deformities.

Methods:

A cephalometric evaluation of 35 patients with skeletal class III deformity was performed preoperatively and postoperatively. Three measurements of the posterior pharyngeal airway space (nasopharynx, oropharynx, and hypopharynx) and hyoid bone positions (the distance from palatal plane to hyoid bone and the distance from mandibular plane to the hyoid bone) were evaluated and correlated with the skeletal movement of the jaws using imaging software (V-Ceph, Osstem, Seoul, Korea).

Results:

The preoperative airway space turned out to be enlarged in class III dentofacial deformities compared with those of normal persons. The preoperative P1, P2, and P3 in our cohort were increased and posterior nasal spine to hyoid bone and mandibular plane to hyoid bone were decreased compared with those of normal person’s data because the cohort consists of prognathic patients where the mandible is located in forward position. After 6 months, most values were nearly normal.

Conclusion:

Orthognathic surgery based on clockwise rotation of maxillomandibular complex did not cause severe posterior airway space changes at 6 months postoperation.

Technical aspects of dental CBCT: state of the art

As CBCT is widely used in dental and maxillofacial imaging, it is important for users as well as referring practitioners to understand the basic concepts of this imaging modality. This review covers the technical aspects of each part of the CBCT imaging chain. First, an overview is given of the hardware of a CBCT device. The principles of cone beam image acquisition and image reconstruction are described. Optimization of imaging protocols in CBCT is briefly discussed. Finally, basic and advanced visualization methods are illustrated. Certain topics in these review are applicable to all types of radiographic imaging (e.g. the principle and properties of an X-ray tube), others are specific for dental CBCT imaging (e.g. advanced visualization techniques).

Gender-related difference in the upper airway dimensions and hyoid bone position in Chinese Han children and adolescents aged 6-18 years using cone beam computed tomography

OBJECTIVE

To investigate the gender-related differences in upper airway dimensions and hyoid bone position in Chinese Han children and adolescents (6-18 years) using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

CBCT-scans of 119 boys and 135 girls were selected and divided into four groups (group 1: 6-9 years; group 2: 10-12 years; group 3: 13-15 years; group 4: 16-18 years). The airway dimensions including the cross-sectional area (CSA), anteroposterior (AP) and lateral (LAT) width, length (L), mean CSA and volume (VOL) of upper airway segmentations and hyoid bone position including 11 linear and three angular measurements were investigated using Materialism's interactive medical image control system (MIMICS) 16.01 software. Gender-related differences were analyzed by two independent sample t-tests.

RESULTS

No gender-related difference was found in values of the facial morphology, airway dimensions and hyoid bone position for group 1 (p > 0.05). The children and adolescents in groups 2, 3 and 4 showed significant gender-related differences in the measurement results of facial morphology, airway dimensions and hyoid bone positions (p < 0.05). What's more, the measurement values of boys were obviously larger than those of girls except some measurements in group 2.

CONCLUSIONS

The measurements of airway dimensions and hyoid bone positions have gender-related differences in children and adolescents aged 10-18 years. These results could be taken into consideration during orthodontic diagnosis and treatment.