Effect of 3D printed replicas on the duration of third molar autotransplantation surgery: A controlled clinical trial.

BACKGROUND/AIM: This study aimed to develop a protocol that combines cone-beam computed tomography (CBCT), software, and 3D printing to design 3D replicas for tooth autotransplantation. The goal was to evaluate the impact of this approach on the extraoral time of the donor teeth and the total surgical time, thereby enhancing surgical efficiency and outcomes. MATERIALS AND METHODS: A non-randomized trial (protocol 10.1186/ISRCTN13563091) was conducted at Riga Stradins University, enrolling 46 patients (13-22 years old) who required molar extraction and possessed a non-erupted third molar. The patients were sequentially assigned to a 3D replica group (24 patients) or a control group (22 patients). The primary outcome measured was the extra-alveolar time of the donor tooth, and the secondary outcome was the total duration of surgery. Both were assessed using a sample size capable of detecting a 10-min difference. A generalized linear model adjusted for various factors was used to test for significant time differences (p < .05) between the groups. RESULTS: Forty-six patients were included in this analysis. The effect of using 3D replicas was not statistically significant and was associated with a decrease in the extraoral time of the donor tooth in seconds (ß = -9.35, 95% CI [-40.86, 22.16]). For the total surgical time in minutes, the use of 3D replicas had a statistically significant impact, reducing the operation duration in minutes (ß = -13.42, 95% CI [-24.50, -2.34]). No early complications were observed in either group, with all teeth present at 3-4 weeks post-surgery. CONCLUSIONS: The integration of 3D printing technology can enhance the efficiency of autotransplantation surgeries, primarily by reducing surgical time.

The Facial Characteristics of Individuals with Posterior Crossbite: A Cross-Sectional Study.

Facial morphology is known to be influenced by genetic and environmental factors. Scientific evidence regarding facial parameters in patients with posterior crossbite is lacking. This study aimed to investigate the association between posterior crossbite and facial parameters. This cross-sectional study included 34 adolescents with and 34 adolescents without posterior crossbite in the age range from 13 to 15 years. Facial surface scans were acquired with a 3dMD imaging system, and landmark-based analysis was performed. Data were analyzed using the Mann-Whitney U test and Spearman's correlations. Individuals in the control group had lower face heights (females: p = 0.003, r = 0.45; males: p = 0.005, r = 0.57). The control group females presented with smaller intercanthal width (p = 0.04; r = 0.31) and anatomical nose width (p = 0.004; r = 0.43) compared with the crossbite group females. The males in the control group had wider nostrils. In the control group, significant correlations among different facial parameters were more common, including the correlations between eye width and other transversal face measurements. On the contrary, the facial width was correlated with nasal protrusion (r = 0.657; p < 0.01) and the morphological width of the nose (r = 0.505; p < 0.05) in the crossbite group alone. In both groups, the philtrum width was linked with the anatomical and morphological widths of the nose. Conclusions: Patients with posterior crossbites have increased face height and different patterns of facial proportions compared with individuals without crossbites.

The association between dental and facial symmetry in adolescents.

INTRODUCTION: Facial aesthetics have become one of the most important objectives of orthodontic treatment. The correction of dental arches should be performed in accordance with the face. This study explored the association between occlusal and facial asymmetries in adolescents, particularly emphasizing a Class II subdivision. METHODS: Eighty-one adolescents (43 males, 38 females) with a median age of 15.9 (interquartile range, 15.17-16.33) years were enrolled. Of these patients, 30 had a Class II subdivision (right side, n = 12; left side, n = 18). Three-dimensional facial scans were analyzed using surface- and landmark-based methods. Chin asymmetry was determined using the chin volume asymmetry score. Three-dimensional intraoral scans were analyzed to assess occlusal asymmetry. RESULTS: The surface matching scores were 59.0% ± 11.3% for the whole face and 39.0% ± 19.2% for the chin. Chin volume was larger on the right side than on the left side in most patients (n = 51, 63%), and it was associated with a dental midline shift to the corresponding subdivision side. A correlation between dental and facial asymmetries was noted. In addition, the dental midline shifted to the left in patients with a Class II subdivision, regardless of the side, and to the right in those with a symmetrical Class II subdivision. However, several patients did not possess asymmetrical occlusal traits sufficient for statistical analysis. CONCLUSIONS: Dental asymmetry was weak but significantly correlated with facial asymmetry.

Comparative analysis of panoramic radiography and cone-beam computed tomography in treatment planning of palatally displaced canines.

INTRODUCTION: The objective of this research was to compare the predictive value of panoramic radiographs (PRs) and cone-beam computed tomography (CBCT) scans for the estimation of root resorption, spontaneous eruption of a canine, and time for orthodontic traction. METHODS: CBCT scans and PR images of 88 patients (27 male and 61 female; aged between 11 and 44 years) with 106 palatally displaced maxillary canines were retrieved from a database. Predictive values of several radiographic parameters, including the 3-dimensional angle of the canine, were analyzed using the area under the curve and multiple regression analysis. RESULTS: The angle to the midline and canine position category had a discriminative ability for root resorption of the central incisors with area under the curve values of 0.63 (95% confidence interval, 0.56-0.79) and 0.83 (95% confidence interval, 0.75-0.91), respectively. PR measurements were not reliable predictors of resorptions, except severe resorptions, of the lateral incisors and the premolars. The measurements describing the position of the canine in relation to the midline could predict spontaneous eruption of the canine, regardless of the imaging method. The canine angle to the midline assessed on CBCT was significantly associated with traction time of the canine, producing the following equation: canine traction time = 49.6 - 0.24 × canine angle to the midline (r2 = 0.360). CONCLUSIONS: Only severe resorptions of roots can be predicted with PRs. The use of CBCT is indicated in cases of impacted canines.

Exploring the midline soft tissue surface changes from 12 to 15 years of age in three distinct country population cohorts.

INTRODUCTION: Several studies have highlighted differences in the facial features in a White European population. Genetics appear to have a major influence on normal facial variation, and environmental factors are likely to have minor influences on face shape directly or through epigenetic mechanisms. AIM: The aim of this longitudinal cohort study is to determine the rate of change in midline facial landmarks in three distinct homogenous population groups (Finnish, Latvian, and Welsh) from 12.8 to 15.3 years of age. This age range covers the pubertal growth period for the majority of boys and girls. METHODS: A cohort of children aged 12 were monitored for facial growth in three countries [Finland (n = 60), Latvia (n = 107), and Wales (n = 96)]. Three-dimensional facial surface images were acquired (using either laser or photogrammetric methods) at regular intervals (6-12 months) for 4 years. Ethical approval was granted in each country. Nine midline landmarks were identified and the relative spatial positions of these surface landmarks were measured relative to the mid-endocanthion (men) over a 4-year period. RESULTS: This study reports the children who attended 95 per cent of all scanning sessions (Finland 48 out of 60; Latvia 104 out of 107; Wales 50 out of 96). Considerable facial variation is seen for all countries and sexes. There are clear patterns of growth that show different magnitudes at different age groups for the different country groups, sexes, and facial parameters. The greatest single yearly growth rate (5.4 mm) was seen for Welsh males for men-pogonion distance at 13.6 years of age. Males exhibit greater rates of growth compared to females. These variations in magnitude and timings are likely to be influenced by genetic ancestry as a result of population migration. CONCLUSION: The midline points are a simple and valid method to assess the relative spatial positions of facial surface landmarks. This study confirms previous reports on the subtle differences in facial shapes and sizes of male and female children in different populations and also highlights the magnitudes and timings of growth for various midline landmark distances to the men point.

Reproducibility of Natural Head Position assessed with stereophotogrammetry.

OBJECTIVE: The aim of this study was to assess the stability of Natural Head Position (NHP) over time using the 3dMDface System. SETTING AND SAMPLE POPULATION: This was an experimental study. Three-dimensional facial images of 40 students were captured on two different occasions, with an interval of at least two weeks. MATERIALS AND METHODS: The images were taken using a stereophotogrammetric device (3dMD). The mirror positioned NHP was obtained in a standing position and then replicated in a sitting position for capturing. The self-balanced NHP was taken in a sitting position. Rapidform 3D software was used for position angle calculations. The angle changes between the positions were calculated for rotations around the x-, y- and z-axes. RESULTS: The differences between NHP in the self-balanced and mirror positions recorded on the first and second occasions were 2.43 and 1.75 degrees, respectively, around the x-axis. The average changes in NHP around the x-axis between the self-balanced and mirror balanced positions exceeded 3 degrees at the two-week interval. The differences were smaller for the rotations around the y- and z-axes. Some subjects consistently tended to hold their heads in a more extended position when self-balanced, while others did this when mirror balanced. There was no difference in the reproducibility of NHP between men and women. CONCLUSION: The reproducibility of NHP for consecutive stereophotogrammetric captures is generally acceptable. The reproducibility of NHP using the mirror position was slightly better compared with NHP in the sitting self-balanced position.

Evaluation of the posterior maxillary teeth movements during Class II correction: 3-dimensional superimposition of casts.

AIM AND OBJECTIVES: The aim of this study was to analyze the changes of the posterior dentition during Class II correction with the crown Herbst appliance (cHerbst) and intermaxillary Class II elastics. SAMPLE: Class II patients were divided into 2 groups: those who were treated with the cHerbst appliances (n=40, mean age 14.1±1.3) and those who were treated with fixed appliances and Class II elastics (n=20, mean age 16.7±2.7). MATERIALS AND METHODS: The scans of pre- and post-treatment casts the patients were superimposed and registered using the freeware Blender 2.67. The linear measurements in the anteroposterior, transversal and vertical planes along with the rotation angles of the first molars were assessed. RESULTS: In the cHerbst group clinically significant derotation (13.8±5.0°) and distalization (3.2±1.2 mm) of the upper first molars were recorded compared to the intermaxillary Class II elastics group (4.2±5.5°, -0.3±1.5, respectively). In the cHerbst group the second and first premolars followed the distal movements of the upper first molars. The premolars expanded slightly more than the molars in both groups. The posterior teeth extruded in both groups, except the molars in the cHerbst group. CONCLUSIONS: The crown Herbst appliance is significantly more effective in molar derotation and distalization than intermaxillary Class II elastics.

The influence of craniofacial morphology on the upper airway dimensions.

OBJECTIVE: To evaluate the influence of craniofacial morphology on the upper airway dimensions in healthy adult subjects. MATERIALS AND METHODS: The records of 276 healthy 17- to 27-year-old patients were extracted from the cone-beam computed tomography image database of the Institute of Stomatology, Riga Stradins University. Dolphin 11.7 software was used to evaluate craniofacial anatomy and semiautomatic segmentation of the upper airway. Measurements of oropharyngeal airway volume (OPV), minimal cross-sectional area (CSAmin), and nasopharyngeal airway volume (NPV) were obtained. The presence of adenoid tissues was recorded. Associations between variables were analyzed by Spearman's correlation coefficients, and multivariate linear regression analysis was used to identify factors that had a possible influence on upper airway dimensions. RESULTS: The following factors were identified as influencing the variability of NPV (23%): SNA angle, gender, and presence of adenoids. Statistically significant, although weak, correlations were found between SNB angle and OPV (r  =  0.144, P < .05) and CSAmin (r  =  0.182, P < .01). CONCLUSION: The results suggest that craniofacial morphology alone does not have a significant influence on upper airway dimensions.

The upper airway dimensions in different sagittal craniofacial patterns: a systematic review.

OBJECTIVE. Upper airway changes caused by orthognathic surgery operations have been a topic of a concern in the orthodontic literature because of a possible development of obstructive sleep apnea. Diverse response of the airway patency could be expected if the dimensions of the airway differ among various malocclusions already before orthognathic treatment. However the associations between facial morphology and the upper airway dimensions have not been clarified. The purpose of this systematic review was to elucidate whether the upper airway dimensions differ among various sagittal craniofacial patterns. MATERIAL AND METHODS. MEDLINE and the Cochrane Library were searched up to November 2012. Reference lists of relevant articles were checked for further possible studies. Strict inclusion and exclusion criteria were applied when considering the studies to be included. Screening of eligible studies and data extraction were conducted independently by two reviewers. RESULTS. 758 studies were identified and 11 of these were recognized as suitable for further analysis. 75% of studies did not find differences in the nasopharyngeal dimensions among craniofacial patterns. The findings for the oropharyngeal dimensions were controversial as 5 of 11 investigations found these to be smaller in Class II subjects, and 6 of 11 concluded that oropharynx size is larger in Class III pattern. The vertical growth type of the subjects was not considered in five investigations, and 45% of the included studies used lateral cephalometry as only tool for airway assessment. CONCLUSIONS. Currently there is insufficient evidence that the upper airway dimensions differ in various sagittal skeletal patterns.

Mechanisms of Class II correction induced by the crown Herbst appliance as a single-phase Class II therapy: 1 year follow-up.

BACKGROUND: The objective of this study is to evaluate the skeletal and dentoalveolar effects of the crown Herbst appliance used alone for a single phase of therapy followed by a 1-year observation period. METHODS: Forty patients (mean age 13.6±1.3 years) with a stable Class I occlusion 1 year following the treatment with the crown Herbst appliance were selected from a prospective sample of 180 consecutively treated Class II patients. No other appliances were used during treatment or during the follow-up period. The dentoskeletal changes were compared with a matched sample of untreated Class II subjects (mean age 13.9±1.6 years). Lateral cephalograms were taken before treatment, after Herbst treatment (1 year), and after 1-year follow-up. Overcorrection was avoided intentionally. RESULTS: Treatment produced an increase in mandibular length, a decrease in ANB angle, and a restriction in the vertical growth of posterior maxilla. The maxillary molars moved backward and tipped distally. The lower incisors proclined markedly, and the upper incisors became retroclined. During the follow-up period, the changes primarily were dentoalveolar in nature, with marked rebound of the upper molars and lower incisors, resulting in some increases in overbite and overjet. CONCLUSIONS: The occlusal correction of Class II malocclusion observed 1 year after the crown Herbst appliance as a single-phase therapy was achieved primary due to the dentoalveolar changes and only limited skeletal change occurred.

Soft tissue response after Class III bimaxillary surgery.

OBJECTIVE: To analyze the impact of surgical change in anterior face height and skeletal relapse on the long-term soft tissue profile. MATERIALS AND METHODS: Cephalometric radiographs of 81 patients taken before surgery and at five time points during a 3-year follow-up period were analyzed. All patients had Le Fort I and bilateral sagittal split osteotomies. The patients were divided into three subgroups according to the change in anterior face height during surgery. Calculations of soft to hard tissue ratios were based on the long-term soft tissue response relative to the surgical repositioning. RESULTS: The horizontal surgical repositioning varied considerably, depending on whether anterior face height was increased or decreased. For upper lip prominence, the pattern of long-term change was the same irrespective of change in face height. In all groups, upper lip thickness decreased in both the short term and the long term, particularly in patients with surgical increase in face height. Lower lip thickness increased in the short term but decreased during the follow-up period. There were significant associations between horizontal soft tissue and corresponding hard tissue changes, except for soft tissue A-point and upper lip, when face height was increased. The ratios were higher for mandibular variables than for maxillary variables, particularly for B-point and pogonion when anterior face height had decreased. CONCLUSION: A change in facial height influences the soft tissue response. The mandibular soft tissues closely follow skeletal relapse beyond 2 months postsurgery. The findings have clinical implications for the relative maxillary and mandibular repositioning when planning surgery.

Immediate post-treatment crowned Herbst effects in growing patients.

OBJECTIVE. The aim of this prospective study was to describe the mechanism of Class II correction in growing patients induced by crown Herbst (cHerbst) appliance as an immediate result of therapy. MATERIALS AND METHODS. Forty patients (mean age 13.6 ± 1.3 years) with stable Class I occlusion 1 year following treatment with the cHerbst appliance were selected from a prospective sample of 180 consecutively treated Class II patients. No other appliances were used during treatment. The immediate dentoskeletal changes after discontinuing cHerbst therapy were compared with a matched sample of untreated Class II subjects (mean age 13.9 ± 1.6 years). Lateral cephalograms were taken before treatment and immediately after one year therapy. RESULTS. Treatment produced significant skeletal changes: increase in mandibular length and SNB angle, decrease of ANB angle, restricted growth of posterior maxilla. Significant dentoalveolar changes: maxillary molars moved backwards and tipped distally, lower first molars moved forward and extruded, lower incisors proclined, upper incisors retroclined, overjet and overbite decreased. CONCLUSIONS. Immediate postreatment results revealed that Class II was mainly corrected due to dentoalveolar changes and only limited skeletal change.

A prospective study on the clinical effectiveness of the stainless steel crown Herbst appliance.

OBJECTIVES: To evaluate the clinical performance of the stainless steel crown Herbst (cHerbst) used as a single appliance for a single phase therapy. MATERIALS AND METHODS: A total of 180 consecutive Class II patients were treated with cHerbst for one year and followed up one year after the end of treatment. RESULTS: Class I relationship was achieved in all 175 patients who finished the functional phase of treatment, 58 patients continued treatment with fixed appliances while 21 patients (12%) showed relapse. Seventy two patients (41.1%) obtained and maintained stable Class I relationship one year after treatment with the cHerbst appliance used as a single appliance. Altogether 46 episodes of appliance breakages were observed and most of them could be repaired at the chair side. Patients' questionnaire revealed that in general the appliance was easy to tolerate and did not cause esthetic or functional problems. CONCLUSIONS: The crown Herbst appliance is a viable therapeutical option in patients with Class II malocclusions and it is characterized by low complication rate along with good patient compliance.

Importance of the vertical incisor relationship in the prediction of the soft tissue profile after Class III bimaxillary surgery.

OBJECTIVE: To quantify the relative soft tissue profile response to the skeletal changes resulting from bimaxillary surgery to correct Class III malocclusion in patients with different vertical incisor relationships presurgery. MATERIALS AND METHODS: The sample comprised lateral cephalograms of 80 consecutive patients before and 2 months after surgery. All patients had one-piece Le Fort I and bilateral sagittal split osteotomies. Patients were divided in three subgroups according to their preoperative characteristics, as follows: (1) open-bite patients, (2) patients with positive overbite and the upper lip resting on upper incisors, and (3) patients with positive overbite and the upper lip resting on lower incisors (lip-block). Trimmed means of soft to hard tissue ratios were calculated for the subgroups. Regression analyses were performed to examine factors influencing the soft tissue changes. RESULTS: There were strong correlations between the horizontal movement of upper incisors and upper lip in patients with open bite (r  =  0.77) and in patients with positive overbite and upper lip resting on upper incisors (r  =  0.85). The upper lip followed the maxilla with a ratio of 0.5∶1. In patients with lip-block, the association between maxillary repositioning and upper lip changes was weak. In all groups a strong association between horizontal soft and hard tissue changes was observed for the lower lip and chin, but the pattern differed depending on the vertical movement of the mandible. CONCLUSIONS: In the prediction of soft tissue response it is important to take into account the vertical incisor relationship, particularly in patients with lip-block.

Soft tissue thickness changes after correcting Class III malocclusion with bimaxillar surgery.

UNLABELLED: THE AIM OF THIS STUDY was to evaluate and analyse soft tissue thickness changes after bimaxillary orthognathic surgery. MATERIALS AND METHODS: Eighty three consecutive patients (54 males and 29 females) with Class III malocclusion operated with bimaxillary orthognathic surgery were enrolled in this study. Standardized lateral cephalograms of adequate quality were analysed. RESULTS: The mean upper lip thickness decreased as a result of the surgery and statistically significant differences were recorded (p<0.01). The statistically significant difference in the post surgical tissue thickness of the lower lip also was recorded (p<0.05). Subjects with thick upper lips compared to patients with thin upper lips demonstrated greater (0.7 mm) and statistically significant (p<0.01) increase of vertical nasal projection. Vertical growth pattern had an influence only on B point to lower lip distance, which exhibited greater (2.2 mm; p<0.01) decrease during observation period. CONCLUSION: It was found differences in the soft tissue responses between patients with thick or thin soft tissues after bimaxillary surgery and it should be taken into account while planning operation.

The effect of maxillary advancement and impaction on the upper airway after bimaxillary surgery to correct Class III malocclusion.

AIM: The aim of this study was to evaluate the upper airway changes after simultaneous maxillary advancement/impaction and mandibular setback in skeletal Class III malocclusion. METHODS: The subjects included 76 patients whose treatment included 1-piece LeFort I and bilateral sagittal split osteotomies. Lateral cephalograms were taken before surgery and 2 months and 3 years postoperatively. In order to analyze the effect of maxillary repositioning, the material was divided into subgroups according to whether the maxillary impaction and advancement were clinically significant (≥2 mm) or not. RESULTS: Advancement of the maxilla with or without impaction resulted in a significant long-term increase (P <0.001) in airway dimension at the nasopharyngeal level (13%-21% increase). At the oropharyngeal and retrolingual levels, a decrease took place but was significant (P <0.05) only at the oropharyngeal level when the maxilla was not impacted. When the maxilla was not advanced, there was no significant change, except at the hypopharyngeal level (12% decrease) (P <0.01). CONCLUSIONS: Clinically significant advancement (≥2 mm) of the maxilla significantly increased the airway dimension at the nasopharyngeal level and to some extent compensated for the effect of mandibular setback at the hypopharyngeal level.

The stability of bilateral sagittal ramus osteotomy and vertical ramus osteotomy after bimaxillary correction of class III malocclusion.

INTRODUCTION: The purpose of this retrospective cephalometric study was to compare the stability of bilateral sagittal split osteotomy (BSSO) with extra-oral vertical ramus osteotomy (VRO) after correction of class III malocclusion by means of bimaxillary orthognathic surgery. METHODS: The sample comprised 51 consecutively treated patients, 38 females and 13 males, with a mean age of 19.1 years. All had a one-piece Le Fort I osteotomy with maxillary advancement and mandibular setback. VRO was performed in 30 cases, and BSSO was performed in 21 cases. Lateral cephalograms were obtained before surgery, within 1 week of surgery and 1 year after surgery. RESULTS: The mean forward movement of the maxilla was 5.6 mm in both groups (p<0.001). The mean horizontal surgical change in the VRO group was 4.4 mm (p<0.001), and in the BSSO group it was 5.4 mm (p<0.001). In the VRO group, the horizontal relapse was 1.2 mm (p<0.001), and in the BSSO group, it was 1.4 mm (p<0.001). CONCLUSION: There was no difference in the stability between the BSSO and VRO groups. The average relapse in the whole sample was 26% of the surgical movement.

Three-year follow-up of bimaxillary surgery to correct skeletal Class III malocclusion: stability and risk factors for relapse.

INTRODUCTION: The purpose of this study was to evaluate long-term skeletal and occlusal stability after bimaxillary surgery to correct skeletal Class III malocclusion. METHODS: The sample comprised 81 consecutively treated patients. All subjects had received a combined 1-piece LeFort I and bilateral sagittal split ostotomies with rigid fixation between 1990 and 2003 and were followed for 3 years. Lateral cephalograms were obtained before surgery and at 5 occasions after surgery. RESULTS: The mean setback was 6.9 mm in the mandible, and the maxilla was moved forward 3.7 mm. In most patients, the posterior maxilla was impacted. Relapse of maxillary advancement was insignificant (0.1 mm), whereas relapse at B-point was on average 1.7 mm (P <0.010). After 3 years, mean overjet and overbite amounts were 2.0 and 1.9 mm, respectively. Skeletal relapse of the mandible increased significantly with the surgical setback (P <0.001) and the change in the vertical position of the posterior maxilla (P = 0.010) (multivariate regression analysis). CONCLUSIONS: Bimaxillary surgery resulted in good occlusal stability. Maxillary advancement was stable, whereas relapse of the mandibular setback varied. Risk factors for horizontal relapse of the mandible were large setback and inferior repositioning of the posterior maxilla.

Two- and three-dimensional evaluation of the upper airway after bimaxillary correction of Class III malocclusion.

OBJECTIVE: The aim the study was to evaluate area and volumetric changes in the upper airway after bimaxillary correction of Class III malocclusion by the means of computer tomography (CT), and to compare these to the changes in linear measurements from lateral cephalograms. STUDY DESIGN: This was a prospective clinical trial. Lateral cephalograms and CT scans of 10 Class III patients were evaluated 1 week before and 6 months after surgery. Wilcoxon matched pairs signed ranks test was used to determine the differences in measurements pre- and postoperatively. Spearman's rank correlation was used to test the association between the CT and cephalometric measurements. RESULTS: CT measurements: The oropharyngeal and hypopharyngeal volumes increased by 3.98 +/- 4.18 cm(3) (P = .015) and 2.51 +/- 1.92 cm(3) (P = .021), respectively. The total volume of the posterior airway space increased, but the increase was not statistically significant. After surgery no change in the cross-sectional area of the upper airway was recorded at the retropalatal, oropharyngeal, or hypopharyngeal levels. Cephalometric measurements: The nasopharyngeal space increased 4.08 +/- 5.07 mm (P = .039) and the tongue increased in length by 4.84 +/- 5.93 mm (P = .22). No correlation was found between the measurements on CT scans and corresponding measurements on the lateral cephalograms. CONCLUSIONS: Bimaxillary surgery for correction of Class III malocclusion did not cause decrease of the posterior airway space. Three-dimensional imaging techniques are preferable to 2-dimensional lateral cephalograms for evaluation of the upper airway after orthognathic procedures.