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.

Influence of Orthognathic Surgery on Oral Health and Quality of Life.

ABSTRACT: Orthognathic surgery is a common treatment modality for moderate to severe dentofacial deformities. This study aimed to determine the early postoperative changes in quality of life (QoL) after orthognathic surgery.Twenty patients were evaluated preoperatively (T0), postoperatively after 1 month (T1), and postoperatively after 3 months (T2). Short Form Oral Health Impact Profile and Orthognathic Quality of life Questionnaire were used as generic oral health-related and condition-specific QoL measures.Oral Health Impact Profile -14 and Orthognathic Quality of life Questionnaire scores significantly decreased from T0-T2. Physical pain, psychological disability, social disability, and handicap scores significantly decreased during this interval. Facial esthetic, function, awareness of facial deformity, and social aspects of deformity were also found to significantly improve. No significant difference was found between age groups; female patients had significantly greater preoperative Oral Health Impact Profil-14 scores than did male patients.Orthognathic surgery not only enhances the skeletal and facial relations, but also has significant positive effects on the patients' QoL, oral health, and psychological status.

Comparing different software packages for measuring the oropharynx and minimum cross-sectional area.

INTRODUCTION: Several imaging software packages report the ability to measure the oropharynx and minimum cross-sectional area (MCA). This study aimed to compare 4 imaging software packages for measuring the oropharynx volume and MCA. METHODS: Twenty-eight randomly selected cone-beam computed tomography scans had oropharynx volume and MCA calculated by 2 experienced operators using 4 different programs: Dolphin 3D (version 11.95.8.64; Dolphin Imaging & Management Solutions and Management Solutions, Chatsworth, Calif), InVivo Dental (version 6; Anatomage Inc, San Jose, Calif), OnDemand3D (version 1.0.10.7510; CyberMed, Seoul, South Korea), and ITK-SNAP (version 3.8.0; www.itksnap.org). The measurements were repeated after 2 weeks, and intraclass correlation coefficients were used for the reliability tests. Analysis of variance with the Tukey post-hoc test was used to compare the measurements of oropharynx and MCA with different software programs. Paired t tests were used to compare measurements of both investigators and software programs. Bland-Altman analysis was used to assess interexaminer reliability and agreement between the software programs. RESULTS: The intraclass correlation coefficients revealed excellent repeatability for the 4 programs for both investigators. Analysis of variance showed no statistically significant difference between programs when comparing the oropharynx and MCA. There were no significant differences in software programs when measuring the airway. Bland-Altman showed the maximum difference as 4.1 cm3 for volume and 35 mm2 for MCA. Those differences were below the standard deviations of 5.33 cm3 for volume and 73.75 mm2 for MCA. CONCLUSIONS: The use of 4 different software packages to measure the airway for oropharynx volume and MCA showed high intraoperator and interoperator reliability, no statistically significant difference when using analysis of variance, Tukey post-hoc, paired t tests, and variations within one standard deviation when using Bland-Altman.

The Effects of Maxillary Movements on Nasal Aesthetics Following Orthognathic Surgery.

Improvement of the harmony between facial subunits is the ultimate goal of orthognathic surgery and surgeons must accurately make soft tissue projections for planned bony movements. Yet, few studies have examined the effects' of orthognathic surgery on aesthetic parameters of nasolabial area on a thorough basis.This retrospective study included 61 patients that underwent orthognathic surgery. Demographic data, evaluation period, and surgical details were analyzed. Superficial topographical analysis of intercanthal distance, alar width, nasal height, nasal length, nasal tip protrusion, upper lip height, nasal bone angle, supratip break angle, nasal dorsum angle, nasal tip angle, columellar-lobular angle, columellar-labial angle, upper lip angle, and tip-to-midline angle was recorded before and after surgery. Postoperative changes in these parameters and their correlation to maxillary movements were analyzed.Alar width, upper lip height, columellar-labial angle, supratip break angle, nasal dorsum angle, and upper lip angle increased postsurgery, whereas tip-to-midline angle decreased. Upper lip height and columellar-labial angle were significantly correlated with clockwise/counter-clockwise rotation and anterior re-positioning. Columellar-labial angle increased 2° for each 1 mm of anterior movement and decreased 4° for each 1 mm of counter-clockwise rotation. Novel parameters, such as columellar-lobular angle and tip-to-midline angle, were not associated with any maxillary movement postsurgery.Orthognathic surgery primarily affected the lower third of the nose and changed alar width, upper lip height, supratip break angle, nasal dorsum angle, columellar-labial angle, upper lip angle, and tip-to-midline angle in this region; however, only columellar-labial angle and upper lip height were found to be correlated solely with maxillary movements.

Hemostatic effects of adrenaline and Ankaferd (blood stopper) during orthodontic attachment bonding

Background/aim: Moisture prevention during the bonding of orthodontic attachments on impacted teeth is crucial for accomplishment. It was aimed to compare the hemostatic effects of adrenaline and Ankaferd Blood Stopper (ABS) during the surgical exposure of the impacted maxillary canine. Materials and methods: The study consists of 20 patients, whose orthodontic treatments were outlined with the surgical exposure of maxillary impacted canine. Patients were divided into groups of 10; where each group was treated with one of the two medicines to control bleeding. Group A was treated with adrenaline, and group B was treated with Ankaferd Blood Stopper (ABS). The bleeding period was recorded as the time from the exposure of the crown until the inception of bonding. Results: It was observed that both the bleeding period and the cumulative duration were significantly shorter in group B (the ABS group) than in group A (the adrenaline group) (P < 0.05), but no significant deviation in bonding times was recorded. Conclusion: ABS is a good alternative hemostatic agent for the prevention of bleeding at the surgical exposure of impacted teeth without affecting the bonding.

Implant-Site Related and Patient-Based Factors With the Potential to Impact Patients' Satisfaction, Quality of Life Measures and Perceptions Toward Dental Implant Treatment.

OBJECTIVES: The present study aimed at evaluating both the implant site-related and patient-based factors with the potential to affect the extent of patients' satisfaction and also their perceptions regarding dental implant treatment. Potential differences between the esthetic evaluations of dental patients and dental specialists were also considered. MATERIALS AND METHODS: Implant-supported fixed prosthesis (n = 164) in 264 anterior esthetic implant sites were included. Patients' satisfaction, esthetic considerations, and perceptions toward dental implants, were evaluated by both Oral Health Impact Profile-14 (OHIP-14) questionnaire and visual analog scale. Pink Esthetic Score/White Esthetic Score were used for the professional esthetic evaluations of dental specialists. RESULTS: Overall patient satisfaction was high (87.42 ± 11.86). Compared with implant supported single-tooth restorations, patients with implant-supported bridges had lower OHIP scores (P = 0.001) and were relatively less satisfied with particular aspects of dental implant treatment (eg, cleanability, phonetics, surgical discomfort, and pretreatment information). Generally, type of prosthesis, history of soft/hard tissue augmentation, and reason for tooth loss had a clear impact on the extent of patients' satisfaction, esthetic considerations regarding treatment outcome, and their perceptions toward dental implant treatment (P < 0.05). CONCLUSIONS: Fixed implant-supported restorations generally provide with high levels of satisfaction and oral health-related quality of life.

An airway study of different maxillary and mandibular sagittal positions.

The aim of this study was to evaluate the oropharyngeal (OP) and nasal passage (NP) volumes along with various airway variables of patients with normal nasorespiratory functions having different dentofacial skeletal patterns and to evaluate the correlations between different variables and the airway. One hundred and one patients (57 males and 44 females, aged 14-18 years) having pre-treatment cone beam computed tomography images and complete medical records were selected. The patients were divided into five groups as Class I (CI, 81 ≥ SNA ≥ 77; 80 ≥ SNB ≥ 76; 3 ≥ ANB ≥ 1), Class II maxillary protrusion (CIIMaxP, SNA > 81; 80 ≥ SNB ≥ 76; ANB > 3), Class II mandibular retrusion (CIIMandR, 81 ≥ SNA ≥ 77; SNB < 76; ANB > 3), Class III maxillary retrusion (CIIIMaxR, SNA < 77; 80 ≥ SNB ≥ 76; ANB < 1), and Class III mandibular protrusion (CIIIMandP, 81 ≥ SNA ≥ 77; SNB > 80; ANB < 1). Posterior airway space, area of the most constricted region at the base of the tongue (minAx), and OP volume were significantly higher for the CIIIMandP group, whereas CIIMandR subjects had the lowest values. The only significant difference for the NP volume was between CI and CIIMandR groups where a smaller volume for the CIIMandR group was observed. The minAx was the variable that presented the best correlation with the OP airway volume. It seems that a detailed analysis of airway may prove to be a valuable diagnostic addition in orthodontics.

A 3-dimensional airway analysis of an obstructive sleep apnea surgical correction with cone beam computed tomography.

PURPOSE: The purpose of this case report is to present cephalometric changes in the craniofacial region and volumetric changes in the oropharyngeal region of a patient diagnosed with obstructive sleep apnea syndrome after maxillomandibular advancement and genial tubercle advancement surgeries. MATERIALS AND METHODS: Cone beam computed tomographic images were used to evaluate cephalometric changes in the craniofacial region and linear changes in the oropharyngeal region of the patient. RESULTS: A patient with obstructive sleep apnea was treated successfully with maxillomandibular advancement and genial tubercle advancement surgery. Airway analysis showed a significant increase in the volume of the patient's oropharynx after surgery. CONCLUSION: Cone beam computed tomographic images are recommended for 3-dimensional airway evaluation in the treatment of obstructive sleep apnea syndrome.

Airway volume for different dentofacial skeletal patterns.

INTRODUCTION: Our objective was to evaluate the nasal passage (NP) and oropharyngeal (OP) volumes of patients with different dentofacial skeletal patterns. METHODS: The study sample consisted of 140 patients (70 boys, 70 girls), divided into 3 groups as Class I (1 ≤ ANB ≤ 3), Class II (ANB > 3), and Class III (ANB < 1), and then further divided into 4 groups as SNA angle ≥ 80°, SNA angle <80°, SNB angle ≥78°, and SNB angle < 78° to evaluate how the positional changes in the maxilla and the mandible affect the OP and NP variables. Differences between groups were determined by using the Kruskal-Wallis test. Correlations between the variables were tested with the Spearman correlation coefficient. The linear multiple regression test was applied to create a model for the airway volumes separately. RESULTS: The OP volume of the Class II subjects (n = 50) was significantly lower when compared with that of the Class I (n = 46) and Class III subjects (n = 44). The only statistically significant difference for NP volume was observed between the Class I and Class II groups. The mean OP airway volume of subjects with retruded mandibular positions was statistically significantly smaller when compared with the subjects with higher SNB angles. The area of the most constricted region at the base of the tongue (minAx) had a high potential in explaining the OP volume, whereas the NP volume models were not as successful as the OP counterpart. However, minAx was also entered into the NP volume equations as an explanatory variable. CONCLUSIONS: The OP airway volumes of Class II patients were smaller when compared with Class I and Class III patients. It was observed that mandibular position with respect to cranial base had an effect on the OP airway volume. The only significant difference for the NP volume was between the Class I and Class II groups, with a smaller volume observed for the Class II group.

Skeletal and dental stability after maxillary distraction with a rigid external device in adult cleft lip and palate patients.

PURPOSE: To evaluate skeletal and dental stability in adult cleft lip and palate patients treated with a rigid external distraction system at the end of distraction and during the postdistraction period. PATIENTS AND METHODS: Lateral cephalograms of 7 patients were obtained before distraction, at the end of distraction, and during the postdistraction period. The mean age before distraction was 21.56 +/- 4.73 years. The mean follow-up was 37.3 +/- 12.4 months. RESULTS: The assessment of findings showed that skeletal maxillary sagittal movement was achieved in a superoanterior direction. The maxillary depth angle and effective maxillary length increased significantly (2 degrees and 9 mm, respectively) after distraction, whereas the palatal plane angle increased by 8 degrees , resulting in an anterior movement of the maxilla with a counterclockwise rotation. The lower facial height showed no significant changes after distraction. The sagittal movement of the upper incisors and the angulation of the upper first molars increased significantly (4.5 mm and 5.5 degrees , respectively). During the postdistraction period, the maxilla showed a slight relapse (22%). The effective maxillary length decreased by 2 mm. The palatal plane angle almost returned to its original position, showing 7 degrees of clockwise rotation. The lower facial height remained stable. The upper incisors moved anteriorly and the upper first molars showed a significant mesioangular change during follow-up. CONCLUSIONS: After distraction, significant maxillary advancement was achieved with a counterclockwise rotation. The upper incisors moved labially, and the upper first molars angulated mesially. After 3 years, a 22% relapse rate was seen in the maxilla. The counterclockwise rotation of the maxilla was returned to its original position. The upper incisors moved more anteriorly.

Measuring the airway in 3 dimensions: a reliability and accuracy study.

INTRODUCTION: The aim of the study was to compare the reliability and accuracy of 3 commercially available digital imaging and communications in medicine (DICOM) viewers for measuring upper airway volumes. METHODS: Thirty cone-beam computed tomography scans were randomly selected, and the upper airway volumes were calculated for both oropharynx and nasal passage. Dolphin3D (version 11, Dolphin Imaging & Management Solutions, Chatsworth, Calif), InVivoDental (version 4.0.70, Anatomage, San Jose, Calif), and OnDemand3D (version 1.0.1.8407, CyberMed, Seoul, Korea) were compared with a previously tested manual segmentation program called OrthoSegment (OS) (developed at the Department of Orthodontics at Case Western Reserve University, Cleveland, Ohio). The measurements were repeated after 2 weeks, and the ICC was used for the reliability tests. All commercially available programs were compared with the OS program by using regression analysis. The Pearson correlation was used to evaluate the correlation between the OS and the automatic segmentation programs. RESULTS: The reliability was high for all programs. The highest correlation found was between the OS and Dolphin3D for the oropharynx, and between the OS and InVivoDental for nasal passage volume. A high correlation was found for all programs, but the results also showed statistically significant differences compared with the OS program. The programs also had inconsistencies among themselves. CONCLUSIONS: The 3 commercially available DICOM viewers are highly reliable in their airway volume calculations and showed high correlation of results but poor accuracy, suggesting systematic errors.

Effects of 2 types of facemasks on condylar position.

INTRODUCTION: The aim of this study was to compare Delaire and Grummons protraction facemasks with a new articulator system (Amtech MG1, American Technologies, Brazil) that can record condylar positions. METHODS: Thirty-four patients treated with protraction facemask therapy were divided into 2 groups; 18 were treated with the Delaire facemask (DFM) and 16 with the Grummons facemask (GFM). The observation periods were 8.5 months for the DFM group and 10 months for the GFM group. Mandibular position indicator (MPI) recordings were taken with the new articulator system and evaluated before and after the protraction facemask therapies. RESULTS: MPI recordings in the sagittal plane showed forward and downward movement from centric relation to maximum intercuspal position for both condyles at the beginning of treatment for most patients. After treatment, the discrepancy between centric relation and maximum intercuspation was less in the DFM group than in the GFM group. However, more compressive movement of the condyles through the glenoid fossa was observed in the DFM group. CONCLUSIONS: Although the centric slide amount decreased more with the Delaire facemask compared with the Grummons facemask, patients treated with the Delaire facemask must be monitored for signs and symptoms of temporomandibular joint disorder.

Strategies for Managing the Risk of Mucogingival Changes During Impacted Maxillary Canine Treatment.

Gingival recession is a frequent mucogingival defect in the adult population. It affects the esthetics and is related to hypersensitivity and a high risk of periodontal attachment loss. The connection between orthodontic treatment and periodontal health has been debated for a long time. A healthy periodontium can be preserved during safe orthodontic tooth movement even in patients with poor mucogingival anatomy. This article aimed to review the strategies around managing the risks of mucogingival and apical root changes owing to maxillary canine impaction, with a special focus on gingival recession and impacted maxillary canine treatment. Maxillary canines are the second most frequently impacted teeth after the third molars. They can be located in the labial or buccal aspect of the alveolar bone. If interceptive procedures fail, the next step is the challenging and time-consuming comprehensive orthodontic-surgical treatment. Determining the exact impacted canine location, its relation to the adjacent teeth and structures, the least invasive surgical approach, and the best path for traction are all a part of the standard diagnostic process. It has also been suggested that orthodontists should evaluate periodontal risks to achieve the best possible results. Clinical examination and cone beam computed tomography provide valuable information for the treatment plan that yields good results with a healthy periodontium.

Reliability of cone-beam computed tomography for temporomandibular joint analysis.

OBJECTIVE: The aim was to assess the intraobserver and interobserver reliabilities of temporomandibular joint linear measurements and condylar shape classifications performed with cone-beam computed tomography (CBCT). METHODS: CBCT images of 30 patients were measured at two different time points by two orthodontists using the Dolphin 3D program (n = 60). Anterior, posterior, and superior joint space measurements and sagittal joint morphology classification in the sagittal view and medial and lateral joint space and mediolateral width measurements and coronal joint morphology classification in the coronal view were recorded. Intraclass-interclass correlation coefficients (ICC) and kappa statistics were used to assess intraobserver and interobserver reliability for the measurements and morphology classifications, respectively. RESULTS: The ICC values were good for measurements of the posterior joint space by observer I and for measurements of the posterior, medial, and lateral joint spaces by observer II, while the other intraobserver measurements were excellent. Only the mediolateral width measurements showed excellent interobserver ICC values, while the other measurements showed good interobserver ICC values. Intraobserver agreement for the sagittal morphology classifications was moderate (κ = 0.479) and almost perfect (κ = 0.858) for observers I and II, respectively, while the corresponding agreement for the coronal morphology classifications was substantial for both observers. The interobserver agreement values for sagittal and coronal morphology classifications were slight (κ = 0.181) and fair (κ = 0.265), respectively. CONCLUSIONS: Linear temporomandibular joint measurements were reproducible and reliable in both intraobserver and interobserver evaluations. However, interobserver agreement for assessments of condylar shape was low.

Maxillary sinus volume in patients with impacted canines.

OBJECTIVES: To evaluate the maxillary sinus volumes in unilaterally impacted canine patients and to compare the volumetric changes that occur after the eruption of canines to the dental arch using cone beam computed tomography (CBCT). MATERIALS AND METHODS: Pre- (T0) and posttreatment (T1) CBCT records of 30 patients were used to calculate maxillary sinus volumes between the impacted and erupted canine sides. The InVivoDental 5.0 program was used to measure the volume of the maxillary sinuses. The distance from impacted canine cusp tip to the target point on the palatal plane was also measured. RESULTS: Right maxillary sinus volume was statistically significantly smaller compared to that of the left maxillary sinus when the canine was impacted on the right side at T0. According to the T1 measurements there was no significant difference between the mean volumes of the impaction side and the contralateral side. The distance from the canine tip to its target point on the palatal plane were 17.17 mm, and the distance from the tip to the target point was 15.14 mm for the left- and right-side impacted canines, respectively, and there was a significant difference between the mean amount of change of both sides of maxillary sinuses after treatment of impacted canines. CONCLUSIONS: Orthodontic treatment of impacted canines created a significant increase in maxillary sinus volume when the impacted canines were closer with respect to the maxillary sinus.

Tetraploid/diploid mosaicism with generalized aggressive periodontitis.

BACKGROUND: Changes of chromosome number diploid to triploid or tetraploid states are rare in human pregnancies, where the main clinical features of tetraploidy are delayed growth and/or craniofacial abnormalities. The present report describes the oral features of tetraploid/diploid mosaicism. Although the medical literature described the physical manifestations of this genetic abnormality, the oral features of this disorder were not previously described. METHODS: A 13-year-old patient presented because of his severe periodontal conditions. Clinical, radiological, microbiologic, immunologic, and genetic examinations were conducted. RESULTS: Long eyelashes and mandibular micrognathia were noticeable in his extraoral examination. Intraoral examination revealed significant generalized edema of the gingiva and severe sulcular bleeding on probing. Generalized maxillary and mandibular alveolar destruction was determined with radiographic examination. Actinobacillus actinomycetemcomitans was also detected in his subgingival samples. He was diagnosed as generalized aggressive periodontitis. His medical cytogenetic examination revealed 92,XXYY (25%)/46,XY (75%) karyotype indicating tetraploid/diploid mosaicism. He was given initial and advanced periodontal therapy and he is currently under a routine follow-up period. CONCLUSIONS: This report provides information on the oral characteristics of tetraploid/diploid mosaicism and describes periodontal treatment. Severe periodontal conditions such as aggressive periodontitis may accompany tetraploid/diploid mosaicism subjects and these patients should be frequently seen by their dental practitioners. It is suggested that initial and/or advanced periodontal procedures may be a way of treating tetraploid/diploid mosaicism subjects with aggressive periodontitis. The importance of physical examination and medical consultation is also discussed.

Three-dimensional evaluation of upper airway following rapid maxillary expansion: a CBCT study.

OBJECTIVES: To evaluate, by using cone beam computed tomography, the skeletal, dental, oropharyngeal (OP) airway volume, and nasal passage (NP) volume changes that occur after rapid maxillary expansion (RME). MATERIALS AND METHODS: Two groups were selected, each with 35 patients (15 males, 20 females), an RME group (mean age, 14.02 ± 1.46 years) and a control group (mean age, 14.10 ± 1.44 years). The RME group consisted of patients with maxillary constriction who were treated with Hyrax palatal expanders, and the control group comprised age- and sex-matched patients who underwent comprehensive orthodontic treatment without the use of a rapid maxillary expander. RESULTS: All of the transverse skeletal (medial orbital width, lateral nasal width, maxillary width, and mandibular width) and interdental (intermolar, interpremolar, and intercanine) parameters were significantly enlarged in the RME group. A statistically significant increase in airway variables was seen in both groups between pretreatment (T0) and final records (T1). The mean increase of NP airway volume for the RME group (1719.9 ± 1510.7 mm(3)) was twofold compared with the control group (813.6 ± 1006.7 mm(3)), and no intergroup significant difference was found for the OP volume. CONCLUSIONS: Rapid maxillary expansion creates a significant increase in nasal passage airway volume but no significant change in the oropharyngeal airway volume.

Evaluation of the soft tissue treatment simulation module of a computerized cephalometric program.

OBJECTIVE: The purpose of this study is to compare the accuracy of the treatment simulation module of Quick Ceph Studio (QCS) program to the actual treatment results in Class II Division 1 patients. DESIGN: Retrospective study. MATERIALS AND METHODS: Twenty-six skeletal Class II patients treated with functional appliances were included. T0 and T1 lateral cephalograms were digitized using QCS. Before applying treatment simulation to the digitized cephalograms, the actual T0-T1 difference was calculated for the SNA, SNB, ANB angles, maxillary incisor inclination, and protrusion and mandibular incisor inclination and protrusion values. Next, using the treatment simulation module, the aforementioned values for the T0 cephalograms were manually entered to match the actual T1 values taking into account the T0-T1 differences. Paired sample t-test were applied to determine the difference between actual and treatment simulation measurements. RESULTS: No significant differences were found for the anteroposterior location of the landmarks. Upper lip, soft tissue A point, soft tissue pogonion, and soft tissue B point measurements showed statistically significant difference between actual and treatment simulation in the vertical plane. CONCLUSION: Quick Ceph program was reliable in terms of reflecting the sagittal changes that would probably occur with treatment and growth. However, vertical positions of the upper lip, soft tissue pogonion, soft tissue A point, and soft tissue B point were statistically different from actual results.

Effects of extraction versus non-extraction treatment on oropharyngeal airway volume.

OBJECTIVE: To compare the effects of extraction vs nonextraction orthodontic treatments on oropharyngeal airway volume. MATERIALS AND METHODS: An existing patient database was screened for pretreatment (T0) and posttreatment (T1) cone beam computed tomography (CBCT) scans and complete medical histories. Twenty patients treated with removal of four premolars (ExtG) and 20 controls (NExtG), were matched for age, gender, ethnicity, height, weight, body mass index, and oropharyngeal (OP) volumes, among other variables. Constructed lateral cephalograms (three skeletal and four dental variables) and OP volumes were measured at T0 and T1 using Dolphin Imaging 11.0. Independent sample t-tests were used to compare the groups at T0 and the outcome variables at T1. Paired sample t-tests were used to compare the mean changes from T0 to T1. Statistical significance was set at P < or = .05. RESULTS: Changes from T0 to T1 were found to be significant in both groups for CoA, CoGn, U1-FH, and IMPA. In the ExtG alone, U1-Na Perp and L1-Na Perp were also significantly different from T0 to T1. Despite the observed differences, no significant differences were found at the end of treatment between the mean OP volumes for either group (12,675.6 +/- 4483.6 for ExtG; 12,002.7 +/- 2857.0 for NExtG, P > .05). Similarly, the mean changes in OP volume (1082.6 mm(3) and 1701.1 mm(3) for ExtG and NExtG, respectively) and increase in mean minimal constricted axial areas (17.4 mm(2) and 1.9 mm(2) for ExtG and NExtG, respectively, P > .05) from T0 to T1 were not significant for the two groups. CONCLUSION: Extraction of four premolars with retraction of incisors does not affect OP airway volume.