BaS analysis: a new cephalometric study for craniofacial malformations

Cephalometric Evaluation of Anterior Cranial Base Slope in Patients with Skeletal Class I Malocclusion with Low or High SNA and SNB Angles

Objective

In the cephalometric analyses, it is observed that both SNA and SNB angles are higher or lower than normal for some skeletal Class I patients. The aim of this study was to assess the correlation between low or high SNA, SNB angles, and anterior cranial base (ACB) slope.

Methods

One hundred and seventeen skeletal Class I patients (45 males with a mean age of 14.5 years, 72 females with a mean age of 14.4 years) were evaluated in three groups. Group 1(n=40): Control group, individuals with normal SNA(82°±2°), and SNB(80°±2°) values. Group 2 (n=37): Patients with SNA>84° and SNB >82°, Group 3 (n=40): Patients with both SNA and SNB values lower than 78°. On the cephalometric radiographs, three angulars (SN/FH; anterior cranial base, Ba-S/FH; posterior cranial base, SN-Ba; total cranial base) and seven linear (S-FH, N-FH, Δ, Ba-S, Ba-N, Ba-A, Ba-B) measurements were performed to analyze the vertical and horizontal positions of the S and N points and thereby the ACB slope. One-way ANOVA and Kruskal Wallis tests were used for statistical analysis.

Results

The ACB slope was observed to be relatively flatter in Group 2, and steeper in Group 3 (p<0.05). The location of the S and N points in the sagittal plane did not significantly affect the SNA and SNB. However, the vertical position of the S and N points was a factor determining the inclination of the ACB, therefore the SNA and SNB.

Conclusion

ACB slope directly affected SNA and SNB measurements. ACB might lead to misleading results when used as a reference plane.

Imaging in craniosynostosis: when and what?

PURPOSE

Currently, the interest on craniosynostosis in the clinical practice is raised by their increased frequency and their genetic implications other than by the still existing search of less invasive surgical techniques. These reasons, together with the problem of legal issues, make the need of a definite diagnosis for a crucial problem, even in single-suture craniosynostosis (SSC). Although the diagnosis of craniosynostosis is primarily the result of physical examination, craniometrics measuring, and observation of the skull deformity, the radiological assessment currently plays an important role in the confirmation of the diagnosis, the surgical planning, and even the postoperative follow-up. On the other hand, in infants, the use of radiation or the need of sedation/anesthesia raises the problem to reduce them to minimum to preserve such a delicate category of patient from their adverse effects.

METHODS, RESULTS AND CONCLUSIONS

This review aims at summarizing the state of the art of the role of radiology in craniosynostosis, mainly focusing on indications and techniques, to provide an update not only to pediatric neurosurgeons or maxillofacial surgeons but also to all the other specialists involved in their management, like neonatologists, pediatricians, clinical geneticists, and pediatric neurologists.

Corrected Cephalometric Analysis to Determine the Distance and Vector of Distraction Osteogenesis for Syndromic Craniosynostosis

Background:

The purpose of this study was to confirm the utility of a corrected cephalometric analysis to facilitate the planning of distraction osteogenesis with Le Fort III osteotomy for syndromic craniosynostosis.

Methods:

This prospective study involved 4 male and 2 female patients (mean patient age, 8 years 9 months; age range, 4 years 6 months to 13 years 2 months) with Crouzon syndrome who were treated with Le Fort III maxillary distraction using our previously described system of analysis of a corrected cephalogram and who underwent clinical follow-up. Lateral cephalograms were obtained immediately after device removal.

Results:

Distraction of orbitale moved the vector downward to the adult profile, but there was slightly less elongation than the adult profile for the distraction distance. The desired and real mean angles after distraction of point A were 29.2 ± 7.9° and 6.1 ± 8.5°, respectively, and the desired and the real mean distances after distraction of point A were 30.6 ± 12.7 mm and 29.4 ± 4.1 mm, respectively.

Conclusions:

Using the corrected cephalometric analysis, the distance and vector of distraction osteogenesis with Le Fort III osteotomy could be determined in patients with syndromic craniosynostosis. The distraction system brought the patients' facial bones to the planned position using controlling devices.

External craniofacial osteodistraction in complex craniosynostoses

PURPOSE

The use of distraction osteogenesis is the first option in the treatment of craniofacial hypoplasia. Both internal craniofacial distractor devices (ICDD) and external craniofacial distractor devices (ECDD) can improve visual and respiratory functions in patients with craniofacial synostosis significantly. They also improve the cosmetic outcome.

DISCUSSION

We reviewed the pertinent literature concerning the use of ECDD in complex craniostenosis. Surgical data as well as quality of life notes were analyzed and compared with those reported for ICDD.

CONCLUSION

The advantage of ECDD compared with ICDD is the easier application and postoperative management as compared with ICDD, with comparable results for extent and quality of distraction osteogenesis. The disadvantage is the quality of life which most authors report is worse if compared to ICDD during the distraction osteogenesis period.

Correlations between the abnormal development of the skull base and facial skeleton growth in anterior synostotic plagiocephaly: the predictive value of a classification based on CT scan examination

BACKGROUND

Anterior cranial plagiocephaly, depending on the early hemicoronal suture fusion, is the most relevant form of plagiocephaly in terms of clinical implications. Its estimated incidence ranges between 0.4 and 1 per 1,000 live births. In the present report, we aim at validating the classification of Di Rocco and Velardi, proposing a scheme based on basicranium analysis using CT scans and its predictive value by evaluating the developmental characteristics of a population of adult subjects affected by anterior plagiocephaly who had underwent the surgical correction in the first months of life.

MATERIALS AND METHODS

The group of patients here considered was retrieved from among all patients operated upon for craniostenosis in the pediatric neurosurgery unit of Policlinico Gemelli in Rome between January 1, 1980 and December 31, 1989. The study group consisted of 13 patients, seven females and six males, affected by anterior synostotic plagiocephaly ranging in age between 20 and 32 years (mean 25.54 years). We also formed a group of unaffected patients in order to control for normal variability in the population. The subjects of the study group were evaluated using CT scan exams and cephalometric analyses were performed using three-dimensional reconstruction.

DISCUSSION AND CONCLUSION

In this study, we were able to associate a facial phenotype to confirm the predictive value of the classification proposed. It is highly probable that the different outcomes depend on the different degrees of involvement in the synostotic process by the various skull base sutures which were essentially unaffected by the surgical procedures.