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Introduction: A standardized procedure was proposed to control involuntary motion and other factors during the capture of structural light scanning that could influence the morphology of 3-dimensional facial models; interoperator reproducibility was evaluated., Methods: Twenty subjects volunteered for facial scanning. Three researchers scanned each volunteer 3 times on the same day using the FaceScan structural light scanning system (Isravision, Darmstadt, Germany) and after the proposed procedure. Captures were done at 5-minute intervals. The 3 facial scans acquired by the same researcher were compared by reverse engineering software (Geomagic; 3D Systems, Rock Hill, SC). Six facial regions, including forehead, nose, paranasal, upper lip, lower lip and chin, and cheek, were divided. With the first scan as a reference, the other 2 scans were registered, and surface-to-surface distance maps were acquired to calculate the mean, standard deviation, and root mean squares (RMS) between 2 surfaces. The reproducibility between 3 researchers was then evaluated by a 1-way analysis of variance., Results: The mean of 6 facial regions was close to 0. The RMS of lip regions were largest (0.48-0.53 mm), the forehead was smallest (0.21 mm), and the others ranged 0.37 mm to 0.42 mm. The standard deviation was slightly smaller than RMS and had the same trend of change. There was no significant difference in RMS among the 3 researchers (P >0.05)., Conclusions: With the constraint of the standardized procedure, the morphologic reproducibility of facial models in 6 regions was satisfying., (Copyright © 2021 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The purpose of this study was to evaluate the correlation between cephalometric measurements and patients' perception of nasal changes in those with Class III malocclusion who had undergone orthognathic surgery., Methods: Eighty-five patients (36 men and 49 women) who received maxillary advancement with (group 1) or without (group 2) maxillary impaction were included in this study. Lateral cephalometric radiographs taken before and at the end of the treatment were analyzed. The patients were given an esthetic evaluation form and asked to evaluate their own noses on the Likert scale (subjective perception), while at the same time, they were asked to evaluate profile silhouettes without knowing that it was their own profile (objective perception). The changes and correlations between the cephalometric measurements and the scores obtained from the esthetic perception questionnaire were evaluated statistically., Results: Postoperative nasal tip inclination and rotation, nasofacial angle, and sagittal position of pronasale had increased significantly (P <0.05), whereas nasal tip protrusion, nasofrontal angle, and vertical position of pronasale had decreased (P <0.05). The change in the nasolabial angle and vertical position of pronasale was statistically different between the 2 surgical groups (P <0.05). In the end, a significant increase was observed in the patients' objective nasal esthetic scores (P <0.05)., Conclusions: Soft tissues are affected by the vertical and sagittal surgical movements of the maxilla. There was a moderate correlation between patients' perception of nasal changes and cephalometric measurements. The subjective evaluation of the nose was similar among patients after surgery, but in the objective assessment, patients found their noses more esthetic., (Copyright © 2021 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: Children with unilateral cleft lip and palate (UCLP) exhibit snoring and mouth breathing. They are also reported to show obstructive sleep apnea syndrome. However, their upper airway ventilation condition is not clearly understood. Therefore, this study was performed to evaluate upper airway ventilation condition in children with UCLP with the use of computational fluid dynamics., Methods: Twenty-one children (12 boys, 9 girls; mean age 9.1 years) with UCLP and 25 children (13 boys, 12 girls; mean age 9.2 years) without UCLP who required orthodontic treatment underwent cone-beam computed tomography (CBCT). Nasal resistance and upper airway ventilation condition were evaluated with the use of computational fluid dynamics from CBCT data. The groups were compared with the use of Mann-Whitney U tests and Student t tests., Results: Nasal resistance of the UCLP group (0.97 Pa/cm 3 /s) was significantly higher than that of the control group (0.26 Pa/cm 3 /s; P < 0.001). Maximal pressure of the upper airway (335.02 Pa) was significantly higher in the UCLP group than in the control group (67.57 Pa; P < 0.001). Pharyngeal airway (from choanae to base of epiglottis) pressure in the UCLP group (140.46 Pa) was significantly higher than in the control group (15.92 Pa; P < 0.02)., Conclusions: Upper airway obstruction in children with UCLP resulted from both nasal and pharyngeal airway effects., (Copyright © 2019 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The aim of this retrospective study was to assess the influence of presurgical nasoalveolar molding (NAM) on skeletal development in patients with operated unilateral cleft lip and palate at 5 years of age., Materials: Lateral cephalometric radiographs of 26 unilateral cleft lip and palate patients who had undergone presurgical NAM (NAM group) and 20 unilateral cleft lip and palate patients who did not have any presurgical NAM (non-NAM group) were analyzed. The radiographs were digitally traced using Quick Ceph Studio software (version 3.5.1.r (1151); Quick Ceph Systems, San Diego, Calif). Independent samples t tests were performed for statistical analysis., Results: No significant differences were observed in sagittal and vertical skeletal measurements between the NAM and non-NAM groups., Conclusions: NAM resulted in no significant difference in skeletal development in unilateral cleft lip and palate patients compared with those without NAM in early childhood., (Copyright © 2018. Published by Elsevier Inc.)

Introduction: The aim of this study was to examine the effects of orthodontic treatment with and without extractions on the anatomic characteristics of the upper airway in adults., Methods: For this retrospective study, the pretreatment and posttreatment cone-beam computed tomography scans of 74 adult patients meeting defined eligibility criteria were analyzed. Imaging software was used to segment and measure upper airway regions including the nasopharynx, the retropalatal, and retroglossal areas of the oropharynx, as well as the total airway. The Wilcoxon signed rank test was used to compare volumetric and minimal cross-sectional area changes from pretreatment to posttreatment., Results: The reliability values were high for all measurements, with intraclass correlation coefficients of 0.82 or greater. The volumetric treatment changes for the extraction and nonextraction groups were as follows: total airway, 1039.6 ± 3674.3 mm 3 vs 1719.2 ± 4979.2 mm 3 ; nasopharynx, 136.1 ± 1379.3 mm 3 vs -36.5 ± 1139.8 mm 3 ; retropalatal, 412.7 ± 3042.5 mm 3 vs 399.3 ± 3294.6 mm 3 ; and retroglossal, 412.5 ± 1503.2 mm 3 vs 1109.3 ± 2328.6 mm 3 . The treatment changes in volume or minimal cross-sectional area for all airway regions examined were not significantly (P >0.05) different between the extraction and nonextraction groups., Conclusions: Orthodontic treatment in adults does not cause clinically significant changes to the volume or the minimally constricted area of the upper airway. These results suggest that dental extractions in conjunction with orthodontic treatment have a negligible effect on the upper airway in adults., (Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The purposes of this study were to evaluate and compare the dentoskeletal changes concurrent with 4-point bone-borne and tooth-borne rapid maxillary expanders in growing children., Methods: The study was conducted with 20 growing girls (ages, 12 ± 0.6 years) with posterior crossbite. They were divided into 2 equal groups; patients in one group were treated with a tooth-borne maxillary hyrax expander (TBME), and those in the other group received a bone-borne maxillary hyrax expander (BBME) anchored directly to the palatal bone. Changes were assessed using cone-beam computed tomography. Images were taken before and immediately after expansion., Results: Superimpositions of the 3-dimensional palatal images showed significant increases in skeletal widths at the canine, first premolar, and first molar areas in both groups. The TBME group had greater nasal width expansion. Regarding the transverse dentolinear measurements, significant increases were seen in both groups, whereas the TBME group showed a greater increase than the BBME group. Significant increases in the dentoangular measurements were seen in the TBME group only and were significantly greater than in the BBME group at the first premolars., Conclusions: There were significant increases in facial and maxillary widths for the BBME group and in nasal width for the TBME group. Both expanders produced basal bone expansion at the level of the hard palate. The TBMEs produced more dental expansion, buccal rolling, and a greater increase in nasal width than did the BBMEs., (Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: Two-dimensional maxillary superimposition techniques have been routinely used in clinical practice, but a 3-dimensional plane has yet to be introduced and validated. The purposes of this study were to propose a new plane for regional superimposition of the maxillary complex and then to validate it through clinical data., Methods: Pretreatment and posttreatment palatal expansion records were used. The magnitudes of the transverse expansion at the levels of the first premolars and the first molars were assessed using the proposed superimposition plane and then were compared with the gold standard plaster model measurements. Descriptive statistics and agreement testing were performed to compare the methods., Results: When comparing the superimposition and plaster measurement methods, the mean errors for intermolar and interpremolar distances were 0.57 and 0.59 mm, respectively. Both the intraclass correlation coefficient and the Bland-Altman plot demonstrated high agreement between the 2 methods (intraclass correlation coefficient greater than 0.9)., Conclusions: The proposed maxillary superimposition plane yields clinically suitable results when compared with the gold standard technique, with a mean error of less than 0.6 mm for typical intra-arch measurements. This new landmark-derived maxillary plane for superimposition is a promising tool for evaluating maxillary dentoalveolar changes after treatment., (Copyright © 2014 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The purpose of this study was to evaluate the concept that the affected and contralateral sides do not grow at the same rate in patients with hemifacial microsomia. Changes in the cranial base, maxilla, mandible, and occlusal plane were evaluated on 3-dimensional images from cone-beam computed tomography data in untreated patients., Methods: Six patients were classified as having mandibular Pruzansky/Kaban type I, IIA, or IIB hemifacial microsomia. Cone-beam computed tomography (MercuRay; Hitachi, Tokyo, Japan) scans were taken before orthodontic treatment during both growth and postpuberty periods., Results: The cranial base as defined by the position of the mastoid process was in a different position between the affected and contralateral control sides. The nasomaxillary length or height was shorter on the affected side for all 6 patients with hemifacial microsomia regardless of its severity, and it grew less than on the contralateral control side in 5 of the 6 patients. The occlusal plane angle became more inclined in 4 of the 6 patients. The mandibular ramus was shorter on the affected side in all patients and grew less on the affected side in 5 of the 6 patients. The mandibular body grew slower, the same, or faster than on the control side., Conclusions: The cranial base, position of the condyle, lengths of the condyle and ramus, and positions of the gonial angle and condyle can vary between the affected and contralateral control sides of patients with hemifacial microsomia, with the ramus and nasomaxillary length usually growing slower than they grow on the control side. These results suggest that many factors affect the growth rate of the craniofacial region and, specifically, the mandible in patients with hemifacial microsomia., (Copyright © 2014 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.)

Introduction: To correct dentofacial deformities, a combination of orthodontic treatment and orthognathic surgery is needed. Prediction software packages are beneficial in treatment planning and achieving improved outcomes, but before using any software, its reliability and reproducibility must be assessed. The aim of this study was to evaluate the accuracy of 2-dimensional Dolphin (version 10; Dolphin Imaging & Management Solutions, Chatsworth, Calif) and 3-dimensional Maxilim (Medicim, Sint-Niklaas, Belgium) softwares in predicting the soft-tissue profiles of patients who had Le Fort I osteotomies., Methods: The presurgical and postsurgical cone-beam computed tomography synthesized lateral cephalograms of 13 patients were collected. Using the Dolphin and Maxilim softwares, the postsurgical profiles were predicted. The positions of the soft-tissue landmarks in profile views were compared with landmarks in the postsurgical photographs. The data were analyzed with the coefficient of reliability and paired-sample t tests., Results: The alpha values of the interclass correlations for each landmark in the x and y planes were between 0.96 and 0.99, except for stomion superior in Maxilim (0.83). The 95% confidence interval and the absolute mean of the error showed that errors in the Dolphin software were greater than those in the Maxilim software, but the differences were not significant (P >0.05), except for soft-tissue A-point. The greatest errors were seen in the chin region. The prediction errors of the nasolabial and mentolabial angles were greater; the prediction error in the Dolphin software was 9°, which has clinical significance., Conclusions: The Dolphin and Maxilim softwares are both appropriate for clinical use. Their inaccuracies in the prediction of the chin region should be considered in complicated surgical planning., (Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.)

Introduction: Orthodontists rely heavily on soft-tissue analysis to determine facial esthetics and treatment stability. The aim of this retrospective study was to determine the equivalence of soft-tissue measurements between the 3dMD imaging system (3dMD, Atlanta, Ga) and the segmented skin surface images derived from cone-beam computed tomography., Methods: Seventy preexisting 3dMD facial photographs and cone-beam computed tomography scans taken within minutes of each other for the same subjects were registered in 3 dimensions and superimposed using Vultus (3dMD) software. After reliability studies, 28 soft-tissue measurements were recorded with both imaging modalities and compared to analyze their equivalence. Intraclass correlation coefficients and Bland-Altman plots were used to assess interexaminer and intraexaminer repeatability and agreement. Summary statistics were calculated for all measurements. To demonstrate equivalence of the 2 methods, the difference needed a 95% confidence interval contained entirely within the equivalence limits defined by the repeatability results., Results: Statistically significant differences were reported for the vermilion height, mouth width, total facial width, mouth symmetry, soft-tissue lip thickness, and eye symmetry., Conclusions: There are areas of nonequivalence between the 2 imaging methods; however, the differences are clinically acceptable from the orthodontic point of view., (Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.)

Introduction: The aim of this prospective, longitudinal study was to evaluate changes to the external shape and form of the nose after surgically assisted rapid maxillary expansion and orthodontic treatment. The changes were registered using a 3-dimensional computer tomography technique, based on superimposition on the anterior base of the skull., Methods: The subjects comprised 35 patients (mean age, 19.7 years; range, 16.1-43.9 years). Low-dose, helical computerized tomography images were taken at treatment start and after orthodontic treatment, about 18 months postsurgery. The 3-dimensional models were registered and superimposed on the anterior cranial base., Results: There were in general significant widening and overall anterior and inferior displacement of the nasal soft tissues. The changes varied in size and direction. No correlation was found between the initial and final widths of the nose, or between the initial and final widths of the nostrils., Conclusions: After surgically assisted rapid maxillary expansion, the most obvious changes to the external features of the nose were at the most lateral alar bases. The difference in lateral displacement profoundly influenced the perception of a more rounded nose. Patients with narrow and constrained nostrils can benefit from these changes. The 3-dimensional superimposition applied in this study is a reliable method, circumventing projection and measurement errors., (Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.)

Introduction: In this study, using a cone-beam computed tomography system, we evaluated the airways of 30 adults., Methods: The shapes of the 3-dimensional volume of the airway were analyzed and compared among the subjects by using surface superimposition software techniques., Results: The airway had the greatest variability in the hypopharynx, in the region below the epiglottis, and above the vocal folds. Moderate variation was apparent at the nares, behind the soft palate, and at the base of the tongue. Conservation of form was seen at the central portion of the nasal airway surrounding the inferior turbinate., Conclusions: The potential for comparing the shape of the airway among subjects is possible., (Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.)

Introduction: The purposes of this study were to detect, locate, and examine the changes in transverse nasal width, area, and volume from bone-borne, surgically assisted rapid maxillary expansion (SARME) with the Dresden distractor by using computer tomography (CT)., Methods: Sixteen patients (average age, 28.7 years) underwent axial CT scanning before and 6 months after SARME. They also underwent CT fusion on specific bony structures. The nasal bone width was examined in the coronal plane. The cross-sectional images of the nasal cavity were taken of the area surrounding the apertura piriformis, the choanae, and in between. We calculated cross-sectional areas and nasal volume according to these data., Results: All but 2 patients had an increase in nasal volume of at least 5.1% (SD, 4.6%). The largest value of 35.3% (SD, 45.8%) was measured anteriorly on the nasal floor, decreasing cranially and posteriorly. This correlated with the V-shaped opening of the sutura palatina. There was no significant correlation between increase in nasal volume and transversal expansion., Conclusions: Because most of the air we breathe passes over the lower nasal floor, SARME is likely to improve nasal breathing., (2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.)

Cone-beam computed tomography (CBCT) has become popular, and its many inherent advantages are indisputable. Nevertheless, CBCT is prescribed cautiously because the radiation dosage is higher than that of conventional radiography. When and to what extent should CBCT be prescribed for orthodontic patients? The purpose of this article is to present 4 curious cases in which a considerable discrepancy was found between the conventional panoramic radiograph and the CBCT view. Is it time to spare patients an unnecessary conventional panoramic radiograph and shift to CBCT for all patients?, (Copyright 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.)

Introduction: In this study, we compared the precision of landmark identification using displays of multi-planar cone-beam computed tomographic (CBCT) volumes and conventional lateral cephalograms (Ceph)., Methods: Twenty presurgical orthodontic patients were radiographed with conventional Ceph and CBCT techniques. Five observers plotted 24 landmarks using computer displays of multi-planer reconstruction (MPR) CBCT and Ceph views during separate sessions. Absolute differences between each observer's plot and the mean of all observers were averaged as 1 measure of variability (ODM). The absolute difference of each observer from any other observer was averaged as a second measure of variability (DEO). ANOVA and paired t tests were used to analyze variability differences., Results: Radiographic modality and landmark were significant at P <0.0001 for DEO and ODM calculations. DEO calculations of observer variability were consistently greater than ODM. The overall correlation of 1920 paired ODM and DEO measurements was excellent at 0.972. All bilateral landmarks had increased precision when identified in the MPR views. Mediolateral variability was statistically greater than anteroposterior or caudal-cranial variability for 5 landmarks in the MPR views., Conclusions: The MPR displays of CBCT volume images provide generally more precise identification of traditional cephalometric landmarks. More precise location of condylion, gonion, and orbitale overcomes the problem of superimposition of these bilateral landmarks seen in Ceph. Greater variability of certain landmarks in the mediolateral direction is probably related to inadequate definition of the landmarks in the third dimension.

Introduction: Children with severe congenital absence of teeth present uncommon morphologies and therapeutic challenges. This study was designed to investigate the characteristic skeletal and dental features of this group., Methods: A group of 28 children with at least 10 congenitally missing teeth (excluding third molars) was examined roentgenographically. The data were collected from their intraoral series or panoramic views and lateral cephalograms. The results of their cephalometric analyses were compared with classic cephalometric norms and with local population norms., Results: Specific patterns of incisor, premolar, and third molar absence emerged. The cephalometric parameters of the children with severe absence differed from the classic norms in bimaxillary retrognathism, chin angle, and maxillary incisor inclination. These children differed from the Israeli norms in almost all parameters examined., Conclusions: Patients with severe congenital absence of teeth have unique dental and skeletal patterns.

Introduction: The purpose of this study was to use cone-beam computed tomography to quantitatively evaluate skeletal expansion and alveolar tipping of the maxilla at the maxillary canine (C1), first premolar (P1), second premolar (P2), and first molar (M1) after rapid maxillary expansion (RME). The transverse effects to the maxillary suture, nasal width, and maxillary sinus were also assessed., Methods: Thirty consecutive patients (17 boys, 13 girls; mean age, 13.8 +/- 1.7 years) who required RME with Hyrax appliances as part of their comprehensive orthodontic treatment were studied. Measurements before and after RME of palatal and buccal maxillary widths, palatal alveolar angle, nasal width, nasal floor width, and maxillary sinus width at C1, P1, P2, and M1 were compared by using Wilcoxon signed rank, Kruskal-Wallis, and Wilcoxon rank sum tests. Pearson correlation analyses were also performed (* = .05)., Results and Conclusions: Skeletal expansion of the maxilla had a triangular pattern with a wider base in the anterior region, accounting for 55% of total expansion at P1, 45% at P2, and 38% at M1. Alveolar bending or tipping accounted for 6% of total expansion at P1, 9% at P2, and 13% at M1. The remaining orthodontic (dental tipping) portions of total expansion were 39% at P1, 46% at P2, and 49% at M1. RME produces a statistically significant increase in nasal width and a decrease in maxillary sinus width (P <0.0001). Retention time showed a significant negative correlation to the change in palatal maxillary width at C1, P2, and M1 (P <0.05), the rate of appliance expansion had a significant correlation with palatal maxillary expansion at P1 and P2 (P <0.05), and age had no statistically significant association with any parameter (P >0.05).

Introduction: In orthodontic treatment, a harmonious soft-tissue profile can be difficult to achieve; the thickness of the soft tissues can vary greatly, and changes with growth and treatment can be difficult to predict. The purpose of this study was to investigate changes in the thickness and the length of the soft tissues of the nose, upper and lower lips, and chin due to growth from 6 to 16 years of age., Methods: Cephalograms of 36 subjects (22 boys, 15 girls) with skeletal Class II malocclusions were analyzed. They participated in the Burlington Growth Study, and longitudinal records had been collected at ages 6, 9, 12, 14, and 16 years. The cephalograms were digitized and analyzed with Dentofacial Planner Plus (version 2.0; Dentofacial Software, Toronto, Ontario, Canada) software. Statistical analysis was performed with the nonparametric Friedman test, and comparisons among means were made with 1-way ANOVA software., Results: All structures showed some growth at all stages. The nose showed the greatest increases in thickness and length in both sexes. There was sexual dimorphism at 16 years, with higher values for boys. Upper lips tended to reduce in the girls. Upper lip length showed slight increases, and base of the upper lip showed small increases for both sexes. The lower lip had moderate increases in all measurements, and its thickness showed sexual dimorphism at almost all ages. The soft tissues of the chin increased in both thickness and length, with no sexual dimorphism.

The objective of this study was to investigate the possibility of enhancing the clinical versatility of the panoramic radiograph, which is an indispensable tool for dental diagnosis. The material of this study consisted of lateral cephalograms and panoramic radiographs obtained from 30 patients. A correlation test was performed between the parametric measurements, and the predictability level of the cephalometric measurements from panoramic radiograms was determined by using regression equations. The equations showed that the Go-Gn/S-N, ANS-PNS/Go-Me (palatal plane/mandibular plane), and Co-Go/Go-Me parameters could be predicted from panoramic radiographs within statistically significant levels, and their predictability levels were 20.6%, 15.6%, and 11.2%, respectively. Statistically significant correlations and predictability levels were also determined for the cephalometric and corresponding panoramic parameters in which Frankfort horizontal plane was used. It can be concluded that even though panoramic radiographs provide information on the vertical dimensions of craniofacial structures, clinicians should be vigilant when predicting skeletal cephalometric parameters from panoramic radiographs, because of their lower predictability percentages.

The purpose of this investigation was to assess the individual reaction pattern and the long-term effect of Herbst appliance treatment on the vertical jaw base relationship, as expressed by the mandibular plane angle (ML/NSL). In the evaluation special reference was given to the pretreatment vertical jaw base relationship (hypodivergent, normodivergent or hyperdivergent). Lateral head films of 80 patients (47 males and 33 females) from before, at start (when the appliance was placed) and at the end of Herbst treatment (when the appliance was removed) as well as 6 months and 4.5 to 5 years posttreatment were analyzed. The ML/NSL angle was on the average unaffected by Herbst therapy. Posttreatment, a continuous decrease in the ML/NSL took place. Male subjects showed a larger angular decrease than female subjects. However, a large interindividual variation existed. No statistically significant differences were found between hypodivergent, normodivergent, and hyperdivergent subjects.

Mandibular length is measured on cephalographs to depict changes during growth and after orthodontic treatment, and is often defined between condylion (Co, most posterior superior point on the condylar outline) and pogonion (Pog, most anterior point on the chin). The aim of this study was to assess the accuracy of identifying condylar anatomy, thus the validity of using Co-Pog to evaluate mandibular growth. The sample included 34 children from a prospective study on the early treatment of distoclusions. Two lateral head films were taken of each child, the first with the mouth closed (MC), the second with the mouth open (MO). Three examiners, two orthodontists (U.H. and K.H.) and a dental radiologist (R.B.), rated the condyle as identifiable, nonidentifiable, and interpreted. The rating was applied to the left (L) and right (R) condyles, or to only one outline (O) when the R and L structures appeared superimposed and were not distinguished separately. Besides Co-Pog, the orthodontists traced sella-nasion (SN) and incisor tip-menton (I-Me) to evaluate variability in measurements that do not include Co. One operator (J.G.) measured all distances. Agreement among the three examiners was best in rating the MO radiographs (50%): 4.1% identifiable, 5.9% nonidentifiable or interpreted; in the MC films, they agreed in 32.3% of the cases, but only one of the ratings was identifiable (2.9%). The highest agreement was in identifying the left condyle on the MO film (35.3%). Intraclass correlation coefficients for CO-Pog ranged from r = 0.73 (L side) to r = 0.92 (O) for one orthodontist, and for the other from r = 0.76 (O) to r = 0.85 (L). Both orthodontists had high correlations for SN and I-Me between MC and MO (0.94 < r < 0.98). The variability between examiners in recognizing condylar anatomy, particularly on radiographs taken with the mouth closed, suggests that the identification of condylar anatomy must be rated in studies of mandibular growth. Researchers measuring mandibular length in investigations of mandibular growth after orthodontic therapy should differentiate between cases where the condyle is readily identified, and those where condylar anatomy is interpreted.

Antirat nasal septum cartilage antisera (RNS-IgG) produced in rabbits by injection of crude antigens derived from rat nasal septum cartilage was cytotoxic for rat chondrocytes in vitro. The effect of this antisera on rat facial growth was tested by injecting three groups of growing rats at 4-day intervals from birth to 30 days. The treatment group (n = 19) received injections of RNS-IgG, one control group (n = 11) received injections of the IgG fraction of preimmune rabbit sera (PI-IgG) and a second control group (n = 16) received injections of normal saline. All animals were killed at the conclusion of the experiment, and lateral and dorsoventral cephalometric radiographs were taken. Statistical difference between treatment and control groups were found for 15 cephalometric measurements. Specifically, snout length (as measured from the intersphenoidal synchondrosis to the upper incisors (is-i) was reduced in animals treated with RNS-IgG compared with both PI-IgG and saline injected controls (p < 0.06, p < 0.005, respectively). In addition, premaxillary length, premaxillary displacement, and bimaxillary width were significantly reduced (p < 0.05) in RNS-IgG treated animals compared with saline injected controls. Bimolar width was reduced (p < 0.05) between RNS-IgG and PI-IgG groups. These results demonstrate that injection of antinasal septum antisera reduces midfacial dimensions in experimental rats and that nonimmune rabbit antisera may have an effect on the growth process. In summary, the results of this pilot study suggest the possibility for using more specific antinasal cartilage antibodies to effect dose-dependent, tissue specific, modulation of facial growth.

The interaction between airway and tongue structures in a sample of 25 adult men with obstructive sleep apnea was quantified on the basis of a series of preoperative CT slices obtained for each subject. Tracings were completed for tongue, and right and left nasal, nasopharynx, oropharynx, and hypopharynx structures; computer graphics were used to obtain superior and lateral three-dimensional reconstructions of all structures for each subject. In addition, cross-sectional areas of specific sites of airway constriction, surface area, volume, and ratio calculations were completed. The majority of the constrictions occurred in the oropharynx (0.52 +/- 0.18 cm2), but six subjects had two constrictions--one in the oropharynx and one in the hypopharynx. The airway had a mean volume of 13.89 +/- 5.33 cm3, whereas tongue volume ranged from 44.03 to 99.56 cm3 with a mean of 71.96 +/- 13.41 cm3. Subjects with more severe obstructive sleep apnea tended to have larger tongue and smaller airway volumes. The more obese subjects showed larger tongue surface areas and smaller airway surface areas. To determine the structural relationships between airway and tongue variables, a series of logarithmic plots was determined. An isometric relationship characterized tongue surface area and tongue volume. A logarithmic plot of oropharyngeal airway vs. tongue volume showed a negative allometric relationship. Tongue volume increased more rapidly than airway volume in subjects with obstructive sleep apnea. Subjects with large tongue volumes were observed to experience significant complications at the time of surgical treatment. Quantification of the volume of the oropharynx and its relationship to tongue volume provide an overview of the interaction between these structures.