Posteroanterior Cephalometric Radiographs Research Articles

The Determinants of Successful Distraction Osteogenesis of the Mandible in Hemifacial Microsomia From Longitudinal Results

The purpose of this study was to investigate sagittal, vertical, asymmetric skeletal characteristics that could determine successful distraction osteogenesis (DO) of the mandible in patients with hemifacial microsomia using longitudinal follow-up data. Lateral and posteroanterior cephalometric radiographs before DO (T0), after DO (T1), and after retention (T2) were analyzed to investigate initial skeletal characteristics, DO effect, and retention. From the measurements at T2, patients were classified into group 1 (good retention results, N = 10) and group 2 (poor results, N = 9). Sagittal, vertical, dental, and asymmetric variables were measured. The differences at each stage and during T0-T1 and T1-T2 between two groups were compared by Mann-Whitney u test, Wilcoxon signed rank test and ANOVA test. Pruzansky type significantly influenced the success or failure of DO. At T0, group 2 showed more retrognathic mandible, smaller ramus height, larger gonial angle, more inward ramus inclination of the affected side, and more chin point deviation to the affected side than did group 1. The major effects of DO on group 1 were lengthening of the ramus height, forward positioning of the mandible, increase of gonial angle, counterclockwise rotation caused by a decrease of the articular angle, increase of ramus inclination of the affected side, and improvement of occlusal canting and chin point deviation. However, by DO, group 2 showed clockwise rotation of the mandible, and less increase of the ramus height than did group 1. After retention, group 2 showed counterclockwise rotation of the mandible and little growth of the ramus height. Group 1 showed reverse tendency. These factors could contribute to the difference in long-term results between two groups.

The effect of head rotation on cephalometric radiographs

The aim of this study was to identify the potential projection errors of lateral, postero-anterior (PA) and submentovertex (SMV) cephalometric radiographs due to head rotation in the vertical z-axis. For this investigation, a complete human dry skull of an adult was used. The skull was rotated from 0 to +/-14 degrees at 2 degree intervals. A vertical axis, the z-axis, was used as the rotational axis to expose 15 lateral and 15 PA cephalometric radiographs. The skull was tilted on each side, again at 2 degree intervals, to expose the 15 SMV films. A series of linear and angular measurements was carried out on all cephalograms. The results revealed that horizontal linear and angular measurements between the horizontal planes on lateral cephalograms were subject to changes from 16.1 to 44.7 per cent with a 14 degree rotation of the head position. For PA cephalograms, again horizontal linear measurements, particularly mandibular length, were subject to a projection error of up to 34.9 per cent with head rotation. On the other hand, projection errors were within the 3-4 per cent limit for SMV radiography. The findings indicate that: (1) linear measurements and the measurement of angles between the horizontal planes are likely to be affected by head rotation in lateral cephalograms, (2) angular measurements demonstrate smaller variations with changing rotation of the head in PA cephalograms, (3) SMV radiographs are less vulnerable to head rotation. Vertical linear measurements of lateral cephalograms and angular measurements of PA radiographs are more reliable in minimizing the projection errors associated with head rotation.

Dentoskeletal treatment changes in Class II subdivision malocclusions in submentovertex and posteroanterior radiographs

The objective of this study was to evaluate the dentoskeletal changes consequent to orthodontic treatment in subjects with Class II subdivision malocclusions, treated with asymmetric extractions, compared with a normal-occlusion control group. The sample consisted of 3 groups, with 30 subjects in each: normal-occlusion subjects (group 1), untreated Class II subdivision subjects (group 2), and Class II subdivision patients treated with asymmetric extractions (group 3). All subjects had a full complement of permanent teeth at the beginning of treatment. The average ages of the subjects were 22.42, 15.76, and 18.57 years, respectively, in groups 1, 2, and 3. Measurements of relative differences in the spatial position of dental and skeletal bilateral landmarks were obtained from the submentovertex and posteroanterior cephalometric (PA) radiographs. The t test for independent samples was used to compare group 1 with groups 2 and 3 at different times. Results from the submentovertex radiograph showed that asymmetric extractions in Class II subdivision malocclusions will maintain the differences in the anteroposterior positions of right and left, maxillary and mandibular first molars, as would be expected with the treatment protocols used. There were no significant skeletal changes that could be attributed to the treatment approaches investigated or transverse collateral effects with the asymmetric mechanics used. It was also demonstrated that treatment of Class II subdivision malocclusions with asymmetric extractions produced corrections of maxillary and mandibular dental midline deviations with the midsagittal plane, without canting the occlusal plane or any other investigated horizontal plane, as seen in the PA radiograph. Treatment of Class II subdivision malocclusions with asymmetric extractions constitutes a beneficial approach to this problem.

Transverse craniofacial features and their genetic predisposition in families with nonsyndromic unilateral cleft lip and palate.

The purpose of this study was to evaluate the transverse craniofacial form in families with nonsyndromic cleft lip and palate (NSCLP). It was hypothesized that affected as well as noncleft NSCLP family members are characterized by a common array of craniofacial features that differ from the general population. This was a prospective cross-sectional investigation that included affected children with NSCLP and their noncleft parents and siblings. A total of 114 subjects (14 affected girls, 17 affected girls, 15 unaffected male siblings, 10 unaffected female siblings, 29 unaffected biological mothers, and 29 unaffected biological fathers) were included. Subject records comprised of posteroanterior cephalometric radiographs obtained from all 114 subjects. The width of midfacial structures, including the orbit and nose, was increased in NSCLP families, compared with published norms. Interestingly, the face was disproportionally wider in relation to total facial height. The transverse craniofacial form of children with or without clefts significantly correlated with that of their parents. Mothers displayed strong correlation with their affected and unaffected sons, whereas fathers correlated to their daughters, suggesting a possible sex-linked developmental influence. Better understanding of the genetic inheritance of craniofacial features associated with cleft lip and palate may ultimately contribute to the development of cleft risk assessment methods.

Orthopedic intrusion of premaxilla with distraction devices before alveolar bone grafting in patients with bilateral cleft lip and palate.

Surgical repositioning of the downward displaced premaxilla in bilateral cleft lip and palate patients remains a controversial and perplexing issue because of its detrimental effects on the growth of the premaxilla. The purpose of this prospective clinical study was to introduce and evaluate the treatment results of an innovative technique for nonsurgically intruding the downward displaced premaxilla. Eight consecutive cases of bilateral cleft lip and palate at the age of mixed dentition were included for the correction of their premaxillary deformities. A pair of intraoral tooth-borne distraction devices was used for the orthopedic intrusion. Serial lateral and posteroanterior cephalometric radiographs were taken periodically for evaluating the growth of the premaxilla 1 year before the intrusion, changes during the intrusion, and growth/relapse up to 1 year after the intrusion. There was no overgrowth of the premaxilla or overeruption of the maxillary incisors during the 1-year observing period before the orthopedic intrusion. The treatment results revealed that the downward displaced premaxillae were all corrected within 1 month. Cephalometrically, 46 percent of the correction resulted from a true orthopedic intrusion and another 54 percent from a dentoalveolar effect in which the maxillary incisors were intruded and the premaxillary dentoalveolus was shortened. The cephalometric evaluations also implied that what occurred during the orthopedic intrusion was mostly the sutural contraction osteogenesis/osteolysis in the vomeropremaxillary suture combined with slightly mechanical upward displacement of the vomeronasal septum complex and nasal bones. The orthopedic intrusion of the premaxilla with distraction devices is an effective nonsurgical method for correcting the downward displaced premaxilla before alveolar bone grafting in patients with bilateral cleft lip and palate, and the results remained stable after 1 year.

Morphologic characteristics of the dentition and palate in cases of skeletal asymmetry.

The purpose of this study was to clarify the three-dimensional morphological characteristics of the dentition and palate in skeletal asymmetry in patients with skeletal Class III malocclusion using a newly defined palatal reference plane in a dental cast. Twenty patients (5 males and 15 females) who had skeletal Class III malocclusion with facial asymmetry were selected. Pretreatment posteroanterior cephalometric radiographs and maxillary dental casts were used. The lateral deviation of Me was measured as the distance from a line perpendicular to Lo-Lo' that passed through CG. The angle between the Lo-Lo' plane and the J-J' plane was measured. Each maxillary dental cast was measured using a three-dimensional surface-scanning system, and the newly defined palatal reference plane was calculated. The right/left difference in the radius of curvature of the palate and right/left differences in the vertical and mesiodistal positions of the first molars were analyzed. Linear correlation and regression techniques were used. Our findings demonstrate that the lateral deviation of the mandible is closely related to the morphology of the alveolar process and to the vertical height of the dentition. In this study, the three-dimensional application of a new palatal reference plane is very useful in morphological research, and the results provide detailed information on the characteristics of facial asymmetry.

Association of nasomaxillary asymmetry in children with unilateral cleft lip and palate and their parents.

It has been suggested previously that increased width of midfacial structures is associated with the development of palatal clefting. The aim of this study was to evaluate the association of transverse craniofacial asymmetry between children with unilateral cleft lip and palate (UCLP) and their parents. Specifically, we hypothesized that parental transverse craniofacial asymmetry is a risk factor associated with the development of asymmetry in children with UCLP. Retrospective cross-sectional investigation including affected children and their noncleft parents. A total of 64 children-parent sets of data (32 child-biological mother + 32 child-biological father) were included. Subject records included posteroanterior cephalometric radiographs obtained from 29 Costa Rican families with UCLP. The side of parental nasal asymmetry was significantly associated with the side of cleft in their children. For the majority of parents with children suffering from a left cleft, nasal width was larger on the left, compared with the right side. Similarly, in the majority of parents with children suffering from a right cleft, nasal width was larger on the right, compared with the left side. The results suggest that unilaterally increased nasomaxillary width in parents may play a key role in the development of ipsilateral palatal clefting in their offspring, therefore underscoring the importance of craniofacial form as a genetic etiologic factor in the genesis of clefting. Better understanding of the role of craniofacial form in cleft development will ultimately allow for the assessment of risk for cleft lip and palate.

Association of Nasomaxillary Asymmetry in Children With Unilateral Cleft Lip and Palate and Their Parents

Abstract Objective: It has been suggested previously that increased width of midfacial structures is associated with the development of palatal clefting. The aim of this study was to evaluate the association of transverse craniofacial asymmetry between children with unilateral cleft lip and palate (UCLP) and their parents. Specifically, we hypothesized that parental transverse craniofacial asymmetry is a risk factor associated with the development of asymmetry in children with UCLP. Design: Retrospective cross-sectional investigation including affected children and their noncleft parents. Patients, Participants: A total of 64 children-parent sets of data (32 child-biological mother + 32 child-biological father) were included. Subject records included posteroanterior cephalometric radiographs obtained from 29 Costa Rican families with UCLP. Main Outcome Measures: The side of parental nasal asymmetry was significantly associated with the side of cleft in their children. For the majority of parents with chil...

Comparison of radiographic and photographic measurement of mandibular asymmetry

This study compared measurement of mandibular asymmetry by digitization of mandibular outlines from standardized facial photographs and posteroanterior cephalometric radiographs. Four ratios were used in calculating asymmetry: area (relative size of right and left mandibular segments), perimeter or length of outlines, compactness (shape), and moment. The records of 28 patients with varying degrees of asymmetry were used. A significant relationship was found for 3 of the ratios (area, compactness, and moment) between measurements from photographs and radiographs. A further comparison showed that measurements from the radiographs correlated more closely with those from photographs when the mastoid processes were used as a baseline, rather than latero-orbitale. Repeatability of mandibular outline digitization proved satisfactory. Although digitization from standardized photographs is the preferred approach, the results indicated that posteroanterior cephalometric radiographs can be used similarly. Unlike other cephalometric analyses for mandibular asymmetry, this method avoids problems of landmark identification, thus presenting a clinically useful method of quantifying asymmetry, eg, in auditing the surgical-orthodontic correction of asymmetry or monitoring change over time. (Am J Orthod Dentofacial Orthop 2003;123:167-74)

Maxillary morphology in obstructive sleep apnoea syndrome.

The aim of this case-control study was to test the hypothesis that maxillary morphology differs between obstructive sleep apnoea (OSA) patients and non-snoring, non-apnoeic subjects. Forty randomly selected patients [36 M, 4 F; mean age 49 +/- 2 (SEM) years] with varying degrees of OSA (mean Apnoea/Hypopnoea Index 32 +/- 4/hour) were compared with 21 non-snoring, non-apnoeic control subjects (18 M, 3 F; mean age 40 +/- 2 years). An intra-oral assessment of the occlusion was carried out, particularly for the presence or absence of posterior transverse discrepancies. Maxillary dental arch width was assessed by standardized lateral inter-tooth measurements (inter-canine, inter-premolar, and inter-molar) from dental models. Palatal height and maxillary depth were also measured. The maxillary dental arch was described by a 4th order polynomial equation. The ratios of maxillary to mandibular width (max/mand) and maxillary to facial width (max/facial) were determined from standardized postero-anterior cephalometric radiographs in a subgroup of patients (n = 29) and all controls. Twenty patients (50 per cent) had evidence of posterior transverse discrepancies compared with one control subject (5 per cent; P < 0.01). All patients had significantly reduced inter-canine, inter-premolar, and inter-molar distances (P < 0.05). The maxillary depth was also shorter (P < 0.05), but palatal height was not different. The quadratic coefficient of the polynomial equation was greater in the patients than in the controls (P < 0.05), indicative of greater arch tapering. Patients had smaller maxillary to mandibular and maxillary to facial width ratios (P < 0.01). These results suggest that OSA patients have narrower, more tapered, and shorter maxillary arches than non-snoring, non-apnoeic controls. Further work is required to determine the relevance of these findings in the pathophysiology of OSA.

Intraoral distraction osteogenesis of the mandible in hemifacial microsomia

Purpose: Lengthening of the mandible by distraction osteogenesis is the preferred method for treatment of hemifacial microsomia in children. Use of an intraoral distraction technique and horizontal oblique ramus osteotomy in such patients is presented. Patients and Methods: Mandibular ramus lengthening was performed in 11 patients aged 6 to 12 years with hemifacial microsomia. During the age of mixed dentition in hemifacial microsomia patients with a hypoplastic mandible, the unerupted molars buds are located high in the retromolar region and are in danger of being damaged by the osteotomy. Therefore, an intraoral approach exposing the mandibular ramus and angle was performed, and a horizontal oblique ramus osteotomy was made, preserving the inferior alveolar nerve. An intraoral device was placed along the ramus, and distraction was started on the third postoperative day at the rate of 1 mm/d and continued for 2 to 3 weeks or as long as necessary. The device was maintained for retention an additional 6 weeks and was then removed. Results: Clinically, the face became more symmetric. The postdistraction posteroanterior cephalometric radiographs demonstrated elongation of the affected ramus and improvement in facial symmetry. Conclusions: The advantages of this method are that it allows device placement along the ramus, permitting the ramus elongation necessary in treatment of hemifacial microsomia, that it prevents damage to the tooth buds which, during the age of mixed dentition, are in a higher position in the retromolar area, and that it prevents injury of the inferior alveolar nerve. © 2001 American Association of Oral and Maxillofacial Surgeons

Cranial Base and Facial Skeleton Asymmetries in Individuals With Unilateral Cleft Lip and Palate

Abstract Objective: Individuals with unilateral cleft lip and palate (UCLP) manifest a plethora of phenotypic characteristics, including asymmetric development of the middle and lower facial skeleton. The purpose of this study was to retrospectively investigate the development of cranial base asymmetries in patients with UCLP noted on posteroanterior cephalometric radiographs. Methods: Thirty individuals with UCLP and 64 controls participated in this study. Medial and lateral cranial base asymmetries were analyzed on frontal cephalometric radiographs relative to three developmental stages. Furthermore, the development of horizontal and vertical lower facial asymmetry in these patients with UCLP was assessed in relation to cranial base, nasomaxillary, and dentoalveolar structures. Results: Individuals with UCLP demonstrated cranial base asymmetries that did not significantly differ from individuals without cleft. In addition, lower facial asymmetry in patients with UCLP correlated with horizontal lower fac...

Effect of rapid maxillary expansion on skeletal, dental, and nasal structures: a postero-anterior cephalometric study

The purpose of this study was to compare the transverse dimensions of skeletal, dental, and nasal structures of a group of patients with maxillary narrowness before and after rapid maxillary expansion (RME) with an untreated control group using postero-anterior (PA) cephalometric radiographs. The material consisted of PA cephalograms of 25 children with a posterior crossbite (mean age 13 years 4 months), and 25 age- and sex-matched controls (mean age 13 years 11 months). Both groups consisted of 20 females and five males. Thirty-four reference points were digitized using the Dentofacial Planner software program. The 17 variables studied consisted of six skeletal, four dental, and seven intra-nasal linear measurements. Student's t-tests were used to compare the differences between the groups, and the effect of RME on skeletal, dental, and nasal structures. RME produced small, but statistically significant changes in maxillary width, upper and lower molar widths, the width between upper central incisor apices, and intra-nasal width. When compared with previous studies, the changes observed were similar for patients of a similar age group, but less than reported for a younger population. There is some evidence that the pattern of expansion produced by RME will vary depending on the age and maturity of the subject.

Mandibular and maxillary asymmetry in individuals with unilateral cleft lip and palate.

This study was conducted to evaluate the degree of maxillary and mandibular asymmetry in the verticle and transverse planes seen in posteroanterior cephalometric radiographs relative to chronologic age in postoperative complete UCLP patients compared to controls. Mandibular and nasomaxillary asymmetry was retrospectively studied in complete unilateral cleft lip and palate (UCLP) and noncleft individuals (controls) by means of posteroanterior cephalometric analysis. All the UCLP patients available (total 40) and randomly selected noncleft controls (total 142) were included in the study. The UCLP patients had undergone lip and palate reconstruction in Strong Memorial Hospital, University of Rochester, Rochester, New York, and orthodontic treatment in the Department of Orthodontics, Eastman Dental Center, Rochester, New York. The controls were selected based on the age that treatment was initiated and were treated in the department for various malocclusions; none had undergone maxillary expansion or surgical treatment. The asymmetry assessed on mixed longitudinal records of the patients with UCLP was analyzed relative to three chronologic age groups and compared to the controls. In addition, mandibular asymmetry was correlated to maxillary asymmetry in UCLP individuals to investigate possible growth patterns between the two jaws. Mandibular asymmetry in UCLP individuals was found to increase with growth and time and peaked at post-pubertal growth-spurt stages. The cleft subjects were more asymmetric than controls in all stages of growth. Mandibular asymmetry followed the affected maxilla closely, indicating a parallel growth pattern of the jaws. The unilateral cleft lip and palate patients manifested asymmetry of the mandible. This asymmetry develops in a parallel pattern with the affected maxilla, suggesting that early evaluation and treatment of the anomalies in the nasomaxillary skeleton as well as in the mandible is necessary when treating unilateral cleft lip and palate individuals.

Normal eruption of the maxillary canine quantified in three dimensions.

The normal eruption path of maxillary canine teeth was quantified on annual lateral and depressed postero-anterior cephalometric radiographs of 15 females and 15 males aged 5-15 years. The lateral view was rotated so that the horizontal coincided with the Frankfort plane on the depressed views, thus orientating the two views in space. Successive positions of canine cusps were marked on tracings of both views superimposed on the anterior outline of the zygomatic process. All positions of the canine cusps were digitized and the horizontal, vertical and lateral annual differences found by subtraction, taking the first position of the canine as the origin. The chronological data were corrected for enlargement and adjusted to increments of 12 months. Adjustments were also made to take into account varying ages of eruption. Posterior movement occurred between 7 and 13 years (all three years before eruption, the year of eruption and the following year). Vertical movement occurred between 5 and 13 years (all of the six years before eruption, the year of eruption and the following year). Lateral movement tended to be in a palatal direction up to 2 years before eruption followed by significant buccal movement in the year before eruption, the year of eruption and the following year. Data are given for eruption in three planes.

Longitudinal analysis of mandibular asymmetry in hemifacial microsomia.

Reconstruction of the mandible is one of the key elements in the skeletal rehabilitation of patients with hemifacial microsomia. Unfortunately, knowledge about long-term mandibular skeletal growth in these patients is lacking. The purpose of this study was to analyze mandibular skeletal growth longitudinally in unoperated hemifacial microsomia patients from childhood to adolescence. The longitudinal records of 26 patients with unoperated unilateral hemifacial microsomia were utilized. The average age at initial records was 3.1 years, and the average age at final records was 16.7 years. Posteroanterior cephalometric radiographs were utilized to evaluate both horizontal and vertical mandibular asymmetry. Patients also were analyzed according to the grade and side of the mandibular deformity. A paired t-test (p < 0.05) and a two-way ANOVA were used to analyze the data. There were 5 patients with grade I, 14 with grade II, and 7 with grade III. The results indicated that the skeletal mandibular asymmetry in hemifacial microsomia is not progressive in nature and that growth of the affected side in these patients parallels that of the nonaffected side. The grade and the side of the mandibular deformity did not influence these findings. These results should be considered when treatment strategies are developed to reconstruct the asymmetrical mandible in hemifacial microsomia.

A longitudinal cephalometric study of transverse and vertical craniofacial growth

Longitudinal growth changes were studied from posteroanterior cephalometric radiographs of 25 male subjects from 4 to 25 years of age and 25 female subjects from 4 to 20 years of age who had Class I skeletal and dental patterns. Growth for males continued past age 18 years for all skeletal measurements, except for maxillary width. Growth for females was completed by 17 years for all skeletal measurements. At 6 years of age the transverse measurements had a greater percentage of the adult size completed than vertical measurements for both males and females. Gender differences at age 6 years were in the mean widths for the cranium, face, and maxilla. At age 12 years the differences were in cranial width, maxillary width, and maxillary and mandibular intermolar width (6-6). There were gender differences at age 18 years for all the variables, except for nasal width and mandibular intermolar width (6-6). Regression lines provided strong-to-moderate predictive equations to determine the size of most of the measurements at age 18 years, if the value at age 6 years is known. (A M J O RTHOD D ENTOFAC O RTHOP 1993;104:471-83.)

A computer-based assessment of structural and displacement asymmetries of the mandible

The purpose of this article was to assess and quantify the different components that can lead to mandibular asymmetry in a person during or at the end of growth and to investigate the extent to which improvement can be obtained in the different situations. Three boys and 17 girls, 8 to 21 years of age, with facial asymmetry and chin deviation were selected. Posteroanterior cephalometric radiographs were taken in intercuspal position. On each radiograph, three mandibular points (menton, gonion or antegonion, and articular point) were selected to define a mandibular area. A vertical axis of reference was also determined. Computer-aided design was employed to develop two systems (A and B) to assess a symmetry degree of the mandible. With system A, the left mandibular area was rotated around the vertical axis of reference, and the degree of the superimposition between the left and right areas was plotted. With system B, the left area was rotated around an axis that ran through menton and was perpendicular to a line connecting the two articular points of the mandible. Also, in this case, the degree of superimposition between the two areas was plotted. With system A, the degree of superimposition was a function of mandibular position and mandibular symmetry. With system B, it was a function of mandibular symmetry only. Thus through comparative examination of the data, assessment of displacement asymmetry and structural asymmetry was possible. In two patients, only displacement asymmetry was present, whereas 14 patients showed various features of structural asymmetry. The patients were treated with orthopedic splints to keep the mandible in a position of symmetry. Orthodontic treatment followed so that the intercuspal position would finally coincide with the position of symmetry. Computer-aided design analysis was performed again after a mean observation period of 41.1 months. In 11 patients an improvement in symmetry was observed with both systems. The patients in whom no improvement of structural asymmetry was observed showed a relatively high degree of symmetry at the beginning or had a considerably higher age than the mean age of the whole group. The clinical implications of the data are discussed. (A M J O RTHOD D ENTOFAC O RTHOP 1991;100:19-34.)

A biplanar cephalometric stereoradiography technique

A biplanar cephalometric stereoradiography (BCSR) technique was developed for accurate three-dimensional assessment of structures that can be identified by markers or anatomical landmarks that are visible on both lateral closed and posteroanterior cephalometric radiographs. The accuracy and precision of the technique were determined by means of a phantom and clinical radiographs. On the phantom, three-dimensional coordinates were determined by the BCSR technique and were measured directly with an electronic digital caliper. The accuracy of the BCSR technique was found to be within 0.5% of the measured distances. On clinical radiographs, the lengths of plates and screws, used as rigid fixation devices, were measured on two subsequent sets of biplanar radiographs and were found to be within the accuracy of our current digitizer (+/- 0.381 mm). The stability of interosseous wires was tested against implants and other interosseous wires on two subsequent sets of biplanar radiographs through a comparison of the distances between two devices. These comparisons confirmed the stability of interosseous wires. The BCSR technique proved to be an accurate method for measurements in three dimensions.

Asymmetry of the Maxilla in Children With Complete Unilateral Cleft Lip and Palate

Craniofacial asymmetry was analyzed in 31 children with unilateral cleft lip and palate (UCLP) and compared to a group of 24 children with incomplete clefts of the lip (CL). Symmetry was evaluated from 32 variables on posteroanterior cephalometric radiographs. Two types of asymmetry were identified: In the first, there was a positional deviation and a change of arch shape of the maxillary segment on the cleft side. The basal maxillary width was similar in the two groups. At the dentoalveolar level a decrease in width was localized to the cleft side in the UCLP group. Maxillary height of the cleft segment was reduced. The second type was related to the anterior part of the maxilla and the nasal septum. The inferior border of the bony part of the nasal septum deviated towards the cleft side. The anterior nasal spine and the midpoint between the upper central incisors deviated toward the noncleft side, but to a different degree indicating a vertical tilting of the premaxillary region.