Shape of the craniofacial complex in patients with Klinefelter syndrome.

Many authors have studied the correlation of cranial base flexure and the degree of mandibular prognathism and classification of malocclusion. This indicates that the cranial base flexure may or may not have an effect on the degree of mandibular prognathism and classification of malocclusion. This study evaluates the correlation of the pretreatment cranial base angle and its component parts to other dental and skeletal cephalometric variables as well as treatment time. The sample consisted of 99 Angle Class II and Class I malocclusions treated in the mixed dentition with cervical headgear and incisor bite plane. Thirty of the patients required full appliance treatment. Treatment duration averaged 4.3 years (SD, 1.5 years). Only the starting cephalograms were used to acquire linear, proportional, and angular cranial base dimensions using Ba-S-N (total cranial base), Ba-S/FH (posterior cranial base), and SN/FH (anterior cranial base). Pearson product moment correlation coefficients were computed and used to assess the association of the following skeletal and dental variables: N-Pg/FH, MP/FH, Y-axis/FH, U1/L1, L1/MP, A-NPg mm, A-Perp, B-Perp, and treatment time with the cranial base measurements. Significance was determined only when the confidence level was P < .05. Although there was no significant correlation of BaSN or SN/FH with NPg, the angular BaS/FH, linear BaS mm, and proportional length of BaS %BaN were all statistically negatively correlated to the facial angle. This indicates that the posterior cranial base leg is the controlling factor in relating the cranial base to mandibular prognathism.

Background: The cranial base has pivotal role in development of craniofacial structures. Both anterior and posterior cranial bases and the angle between the two affect the position of maxilla and mandible. Objectives: To evaluate the effect of cranial base angle and posterior cranial base length in various vertical facial types. Methodology: The study sample consisted of pre-treatment lateral cephalogram of 135 subjects (63 males and 72 females, age 14-21 years) with skeletal class I pattern. These were divided into three groups of normodivergent, hypodivergent and hyperdivergent facial types with 45 subjects in each group. Two angular parameters i.e Saddle angle (NSAr) and Articular angle (SArGo) and one linear parameter Posterior cranial base length (SAr) were used in cephalometric analysis. Inter-group comparison of means of all measurements were studied using ANOVA with Bonferroni’s correction for multiple group comparison. Results: Saddle angle and articular angle did not show significant difference across three study groups. Highly significant difference in posterior cranial base length was observed between hypodivergent and hyperdivergent groups. Saddle angle and Posterior Cranial base length showed significant positive correlation in hypodivergent whereas Saddle angle and Articular angle showed significant negative correlation in hypodivergent and hyperdivergent groups. Conclusion: The cranial base angle does not affect the vertical facial patterns but posterior cranial base length does affect the hyperdivergent and hypodivergent facial types. Cranial base angle found to correlate with posterior cranial base in hypodivergent facial pattern whereas Saddle angle correlated negatively with articular angle in both hyperdivergent and hypodivergent facial types.

In order to clarify the role of sex chromosome constitution in craniofacial growth control, we compared craniofacial morphology of men with sex reversal syndrome (46, XX) with the morphology of normal men, Klinefelter's syndrome and normal women, using cephalometric measurements. Due to physical resemblance between men with 46, XX karyotype and men with 47, XXY karyotype, cephalometric analysis comprised parametres which had already been found to be specific for Klinefelter's syndrome, i.e. cranial base length and flexion, maxillary and mandibular base length, jaw position in relation to cranial base and sagittal jaw relationship. Linear measurements showed reduction of about 10% in maxillary base length in 46, XX men in relation to normal men. Mandibular base in men with sex reversal syndrome was also shortened for about 10% in relation to both normal men and Klinefelter's syndrome. Cranial base flexion in men with Klinefelter's syndrome and in men with sex reversal syndrome showed similarity. The basal angle was found to be more acute, for about 4 degrees , in comparison to individuals with normal karyotype. Unlike in men with Klinefelter's syndrome, mandibular and maxillary prognathism were not registered in men with sex reversal syndrome.

The contributions of craniofacial growth to clinical orthodontics

The aims of this study were to investigate the relationships between the cranial base and maxillofacial morphology in Japanese crania, and to examine the differences between Class I and Class II samples. Data were obtained from 46 male Japanese crania from the collection of the Jikei University School of Medicine (Tokyo). The sample represents populations which would have lived during the last 100 years. A principal component analysis of linear and angular measurements showed that the anterior and posterior cranial base, and the cranial base angle were associated in different ways with different aspects of maxillofacial morphology. Variation in the anterior cranial base was associated with differences in facial height, lower facial height, bicondylar breadth, ramal height, and ramal width, while posterior cranial base length was correlated with bizygomatic breadth. The cranial base angle was negatively correlated with SNA (r = -0.46) and SNB (r = -0.59), and positively correlated with the palatal and occlusal plane angles. There were significant differences between Class I and Class II specimens in palatal width, SNA, ANB, and the palatal plane angle, but no significant difference in cranial base length or angle. The evidence suggested that cranial base shape and size was related to facial length, inclination of the maxilla, and both maxillary and mandibular prognathism.

The purpose of this investigation is to re-evaluate an existing sample of Caucasian individuals, of mostly Northern European ancestry and undefined ethnic origins, who have been characterized as having excellent occlusions and balanced facial proportions (from a subjective assessment). The focus is the emergence of sexual dimorphism in the skeletal and dental relationships. Serial lateral cephalograms of 51 subjects were obtained from the Bolton-Brush Study at ages 6, 9, 12, 14, 16 and 18 yrs. At each age, the records of 16 males and 16 females were selected. Cephalometric evaluation indicated that the length of the anterior cranial base was larger in males but the cranial base angle was similar for both sexes at all age intervals studied. The effective lengths of the maxilla and mandible were similar in both sexes up to 14 years; thereafter in females this length remained relatively constant while in males it increased. The direction of facial growth was similar for both sexes, with a tendency towards a more horizontal growth pattern in females.

Background: The purpose of this study is to evaluate and compare the cephalometric hard and soft tissue cephalometric for orthognathic surgery (COGS) norms for East Indian subjects and to compare with the Caucasians. Materials and Methods: 200 adults of East Indian population (100 males and 100 females), with an age range of 18-30 years were selected for the study. The subjects included had well-balanced pleasing facial profile, no craniofacial abnormality, Angle's Class I molar relationship on both sides with minimum to moderate anterior crowding, and no previous history of orthodontic treatment. The COGS analysis values for the East Indian population was established and compared with the Caucasians. Results: All the cephalometric parameters except the anterior cranial base, facial convexity angle, maxillary protrusion, lower anterior face height, upper posterior dental height, chin depth; maxillary length, and mandibular body length were comparable among both the groups. The COGS soft tissue parameters such as the mandibular prognathism, upper lip protrusion, and lower lip protrusion were higher in the East Indian subjects as compared to the Caucasians. Conclusion: The cephalometric parameters in the East Indian population are significantly different than those of the Caucasian population. These racial differences which are evident in this study should be kept in mind while charting out plan for orthognathic surgery for the East Indian population.

This study evaluated the proportion of the external chin (protuberantia mentalia) in relation to the total symphyseal area in normal jaws and those with a diverse morphology. A sample of 60 cases was randomly selected and divided into three groups of 20 each on the basis of normal growth, horizontal growth and vertical growth with an open bite. Tracings of lateral dn frontal radiographs were used to describe general mandibular form and to determine the percentage of external/total symphyseal area. Dental casts were also examined to determine a basal arch form ratio. The results of this study indicate that the amount of bony chin present is related to certain morphologic features of the mandible. The most significant findings illustrate: 1. The chin increases in size as the mandibular type varies from a vertical type, to a normal type, to a horizontal type of growth pattern. 2. With dental "hypofunction" in combination with an exaggerated vertical development of the mandible, a smaller proportion of the protruding chin is present. 3. The chin increases in size as the mandibular basal arch form varies from a tapered shape for the vertical cases to a more square form in the horizontal cases. 4. The degree of lateral ramal flair does not appear to influence the proportion of protruding chin present. Several models have been presented which attempt to explain protuberantia mentalia variation. The evidence in this study supports the concept that mandibular morphology is the result of the action of compensative adaption in a developing structure. There appears to be an implied polygenic influence on symphyseal morphology operating from the cartilaginous cranial base and mandibular basilar bone. This may be manifested in the relative proportion of mandibular basal bone to cranial base width, and to the vector of cranial base growth. The ultimate proportion of the bony chin is viewed to be the result of mandibular adaption to a functional musculoskeletal balance in the craniofacial complex. The extreme variability of chin form in man may be considered to be the result of compensative growth developing in response to the most structurally efficient jaw form, the contiguous soft and hard tissue environment, and the intrinsic genotype of the mandible.

Morphological features of the craniofacial complex during orthopedic chin cup therapy were investigated in growing patients with mandibular prognathism. Lateral cephalograms of 30 subjects (15 boys and 15 girls, mean age: 9.04 +/- 1.29 years), taken at four different stages during treatment, were analyzed for 14 measurements. These measured values were standardized by use of Japanese controls and then evaluated to investigate longitudinal changes in the craniofacial morphology at the four different stages. Further, factor analysis was used to compare factors describing the craniofacial morphology for the initial and final stages. Dimensional changes of the mandible were not easily produced even if orthopedic treatment was conducted, whereas the maxilla exhibited a tendency to approach the normal range of the controls. Positional changes of the complex, the backward and downward repositioning of the mandible in particular, played an important role in altering a profile from prognathic before treatment to orthognathic at the end of treatment. Craniofacial morphology was similar pretreatment and posttreatment, although the orthognathic factor became more prominent when associated with positional changes of the mandible at the end of treatment.

The literature suggests different views on the correlation between the cranial base morphology and size and saggital intermaxillary relationships. The aim of this study was to investigate the cranial base morphology, including the frontal facial part in patients with mandibular prognathism, to clarify a certain ambiguities, in opposing viewspoints in the literature. Cephalometric radiographies of 60 patients were analyzed at the Dental Clinic of the Military Medical Academy, Belgrade, Serbia. All the patients were male, aged 18-35 years, with no previous orthodontic treatment. On the basis of dental and sceletal relations of jaws and teeth, the patients were divided into two groups: the group P (patients with mandibular prognathism) and the group E (the control group or eugnathic patients). A total of 15 cephalometric parametres related to the cranial base, frontal part of the face and sagittal intermaxillary relationships were measured and analyzed. The results show that cranial base dimensions and the angle do not play a significant role in the development of mandibular prognathism. Interrelationship analysis indicated a statistically significant negative correlation between the cranial base angle (NSAr) and the angles of maxillary (SNA) and mandibular (SNB) prognathism, as well as a positive correlation between the angle of inclination of the ramus to the cranial base (GoArNS) and the angle of sagittal intermaxillary relationships (ANB). Sella turcica dimensions, its width and depth, as well as the nasal bone length were significantly increased in the patients with mandibular prognathism, while the other analyzed frontal part dimensions of the face were not changed by the malocclusion in comparison with the eugnathic patients. This study shows that the impact of the cranial base and the frontal part of the face on the development of profile in patients with mandibular prognathism is much smaller, but certainly more complex, so that morphogenetic tests of the maxillomandibular complex should be included in further assessment of this impact.

Background: Biologic mechanisms of the form-function interaction are one of important component of orthodontic diagnosis. The purpose of this study is to search for the statistical associations between natural postural and craniofacial morphologic variables of the head. Materials and methods: The sample comprised natural head posture (NHP) cephalograms of 90 subjects, aged 18 to 25 years. Interpretation of the facial structure was made by using both intracranial and the extra-cranial reference lines in AutoCAD computer program. Results The measures of anteroposterior maxillary position, SNA showed a low negative correlations with the anterior cranial base angulation to true vertical (SN.Ver) and with the cranio-cervical position of the head (SN.OPT),(SN.CVT) The measures of anteroposterior mandibular position, SNB and SNPog, both showed moderate correlations with the anterior cranial base angulation to true vertical (SN.Ver) and with the cranio-cervical position of the head (SN.OPT),(SN.CVT) . Conclusion Regarding the correlations between the variables indicating the degree of facial prognathism in the NHP, and the postural variables of the cervical column, it can be argued that in subjects with forward cervical inclination, a relative decrease in facial prognathism is expected.

summary Occlusal plane position was analysed cephalometrically in 35 Klinefelter adults (47, XXY) and compared with 60 eugnath control males (46, XY).The significantly smaller angles between the occlusal plane and the cranial base (NSL‐OLs) and between the occlusal plane and the Frankfort horizontal plane (Fr‐OLs) were obtained in 47, XXY males (P &lt; 0.0l), while the angles between the maxillary base and the occlusal plane (NL‐OLs) and between the Camper's line and the occlusal plane (Camp.‐OLs) were not significantly different (P &gt; 0.05) from the control group. Significantly smallelr angles between the occlusal plane and the cranial base (NSL‐OLs) and between the occlusal plane and the Frankfort horizontal plane (Fr‐OLs) in Klinefelter males are attributed to the hereditary influence of an extra X chromosome on the smaller growth of the cranial base and the greater growth of the lower border of the mandible. Although the maxilla was also shifted forward in XXY males in relation to the cranial base it was not enough to compensate for the hereditary influence, due to the greater growth of the lower border of the mandible and the smaller cranial base in 47, XXY males, on the inclination of the occlusal plane to the Frankfort horizontal plane and the cranial base. The forward shift of maxilla was sufficient to compensate for the inclination of the occlusal plane in 47, XXY males to the maxillary base and the Camper's line (P &gt; 0.05).

Background: Antegonial notch is a small concavity at the inferior surface of the mandible. The purpose of this study is to identify the distribution of mandibular antegonial notch depth and its relationship with craniofacial morphology in different skeletal patterns. Materials and method: The sample included 191 pretreatment digital lateral cephalometric radiographs (93 males, 98 females) collected from the Orthodontic Department in the College of Dentistry, University of Baghdad. The sample was divided into three groups according to the skeletal classes, and then each group divided according to depth of mandibular antegonial notch into: shallow, medium, and deep groups. Sixteen angular and thirteen linear measurements were used. Results: Cl I had the highest percentage of medium antegonial notch. Cl II had the highest percentage of deep notch, while Cl III had the highest percentage of shallow notch. Males had significantly deeper notch than females in Cl I and Cl II. Significant difference found between males skeletal Cl II and Cl III. The craniofacial measurements showed significant changes with the increase in antegonial notch depth variably in different classes. Conclusions: Angular measurements of cranial base more concerned with mandibular morphology than linear measurements. The increase in vertical growth pattern and backward rotation of the mandible in association with the increase in notch depth appeared particularly in skeletal Cl II.

Occlusal plane position was analysed cephalometrically in 35 Klinefelter adults (47,XXY) and compared with 60 eugnath control males (46,XY). The significantly smaller angles between the occlusal plane and the cranial base (NSL-OLs) and between the occlusal plane and the Frankfort horizontal plane (Fr-OLs) were obtained in 47,XXY males (P < 0.01), while the angles between the maxillary base and the occlusal plane (NL-OLs) and between the Camper's line and the occlusal plane (Camp.-OLs) were not significantly different (P > 0.05) from the control group. Significantly smaller angles between the occlusal plane and the cranial base (NSL-OLs) and between the occlusal plane and the Frankfort horizontal plane (Fr-OLs) in Klinefelter males are attributed to the hereditary influence of an extra X chromosome on the smaller growth of the cranial base and the greater growth of the lower border of the mandible. Although the maxilla was also shifted forward in XXY males in relation to the cranial base it was not enough to compensate for the hereditary influence, due to the greater growth of the lower border of the mandible and the smaller cranial base in 47, XXY males, on the inclination of the occlusal plane to the Frankfort horizontal plane and the cranial base. The forward shift of the maxilla was sufficient to compensate for the inclination of the occlusal plane in 47, XXY males to the maxillary base and the Camper's line (P > 0.05).

A male (30 years five months) who complained of mandibular prominence and masticatory dysfunction was diagnosed as a mandibular prognathic with acromegaly after cephalometric and endocrine examinations. The level of growth hormone (GH) subsequent to a transsphenoidal hypophysectomy had been controlled by medicines for about five years. Surgical orthodontic correction improved his occlusion and profile, but magnetic resonance imaging detected a recurrent adenoma in the cranial base during the retention period. The recurrence resulted in slight prognathic changes of the patient with a high level of GH. This is a case report of the treatment of an acromegalic patient discussing growth considerations that could influence the orthodontic treatment plan and long-term stability.