[Computerized method for calculating cervical vertebral maturation]. / Méthode informatisée pour le calcul de l'âge osseux vertébral.

For Helm, "the rhythm of facial growth often governs the course of orthodontic treatment". The moment of treatment is an important dimension for our therapy to last a minimum of time with a greatest chance of success and stability. This notion of processing time is a daily requirement in our practices. The radiographs of the wrists will gradually disappear according to the ALARA principle, since we can in a single irradiation, via the profile radiography, have sufficient information to situate the patient on its growth curve. The vertebral stages are good biological indicators of individual skeletal maturity but their interpretation remains difficult. In this work, a computerized method was used to determine the stage of vertebral maturation in a reliable and reproducible manner. In this study, 15 young boys and 15 young girls (total 30 patients) were included, 12,2 years old on average with a standard deviation of 2,6 years. To determine the skeletal age of these patients, the practitioner made an hand-wrist x-ray and, for diagnostic reasons, he also made a profile radiography the same day. The patients who didn't made an hand-wrist x-ray were excluded. The vertebral computerized method seems to be a reliable method to be used in orthodontic practices. Other studies would allow to use this method for average ages, gender-appropriate.

Attempted validation of a method to locate entry and exit foramens of the branches of the trigeminal nerve; benefits for an original cephalometric analysis technique.

INTRODUCTION: Trigeminal analysis focuses on the skeletal entrance and exit orifices of the sensitive fibers of the trigeminal nerve. The aim of this study was to validate the techniques used to locate these landmarks as described by the creator of trigeminal analysis of the face. MATERIALS AND METHOD: This descriptive study was performed on a dry human skull. Two tin balls forming markers R1 and R2 were fixed at random on the skull in a median sagittal position. Two headfilms of the skull were made. The first showed tin balls fixed at the entrance and exit foramens of the sensitive fibers of the trigeminal nerve. The second showed the foramens without the tin balls. The position of the reference point corresponding to the entrance and exit points of the trigeminal fibers was entered on a tracing made from the headfilm (without the balls on the foramens) by 16 operators using an ad hoc guide supplied by Crocquet. A comparison was made between the points as positioned by these operators and the true points as revealed by the X-rays of the balls on the first image (Gold Standard) by calculating the difference between their coordinates on an axis connecting R1 et R2 (X-axis) and the line perpendicular to it passing through R2 (Y-axis). Trigeminal cephalometric analysis was then performed on each of the tracings. The angles and linear values were compared. The validity of the positioning of the points and of the values provided by the analysis was demonstrated by the existence of a difference of less than 2units (mm or degrees). RESULTS: No difference in the means between the trigeminal points found by the operators and the Gold Standard points represented by the X-rays of the balls placed on the foramens exceeded 2mm in absolute value on the Y-axis. On the X-axis, the differences greater than 2mm in absolute value related to: the supra-orbital notch (ESO) and the foramen ovale (FO) (2.12 and 8.19mm, respectively). The angles (ESO-TGR-TO) and (TGR-ESO-TSO) were the only ones to display differences exceeding 2° in absolute value between the two images. CONCLUSION: The detection method advanced by Crocquet for the positioning of the eight points of reference used for analyzing the entrance and exit foramens of the trigeminal nerve is valid apart from the TO and ESO points. Consequently, the validity of the angle measurements involving these points is affected. Further research is required to confirm these findings. If necessary, new recommendations should be devised in order to improve the localization of the TO and ESO cephalometric points.

Evaluation of dentoskeletal parameters in Senegalese subjects using orthodontic architectural analysis.

INTRODUCTION: The aim of this study was to determine the morphological characteristics of a Senegalese population based on an architectural cephalometric analysis. PATIENTS AND METHODS: One hundred and five lateral cephalograms of Senegalese patients were assessed in a cross-sectional study. All lateral cephalometric films were traced on a transparent cellulose acetate sheet by the same operator. Danguy architectural analysis was performed with 11 measurements (seven linear and four angular). T-test was used to assess differences in cephalometric variables between subjects grouped according to gender (male and female) and age bracket (<12 years and ≥12 years). Significance was set at p≤0.05. RESULTS: This study shows that this Senegalese sample had a skeletal class II tendency associated with backward mandibular rotation. The divergence of masticatory corner appears to be greater than in Caucasians with more vertical facial growth. No statistically significant differences were found between men and women. As compared to the under 12 years subgroup, the over 12 years subgroup shows significant increase in maxillary and mandibular lengths whereas skeletal divergence evidenced the opposite tendency and the difference with the under 12 subgroup was significant. Lastly, the first molar underwent significantly greater mesial drift in the 12 and over sub-group. CONCLUSION: Danguy architectural analysis provides a good reliable comparative assessment of facial structures and offers an addition to conventional dimensional or typological analytical methods.

[Value of trigeminal nerve foramina-based approach in the cephalometric study of sagittal morphology of Senegalese subjects]. / Intérêt d'une approche téléradiographique basée sur les entités trigéminales dans l'étude de la morphologie sagittale de sujets sénégalais.

INTRODUCTION: The aim of this study was to determine the morphological characteristics of a Senegalese population based on an original cephalometric analysis using landmarks corresponding to the bony entrance or emergence of sensory fibers of the trigeminal nerve. MATERIALS AND METHODS: One hundred and five lateral cephalograms of Senegalese patients were assessed in a cross sectional study. The landmarks used were based on cranial foramina i.e. ovale (TO), rotundum (TGR), supraorbital (ESO), infraorbital (TSO), incisive (CPA), lesser palatine (CPP), mandibular (IM) and mental (TM). Seven angular measurements were determined on each cephalogram. t test was used to assess differences in cephalometric variable between subjects grouped according to sex (male and female) and age bracket (< 12 years and > or = 12 years). The Pearson's correlation coefficient was used to analyze the relationship between the cephalometric trigeminal and conventional variables. The significance was set at p < 0.05. RESULTS: The Senegalese mesoface appear to be more retrusive and more divergent when compared with European standard. Regarding sexual differences, TRG-ESO-CPA angle shows significant sexual dimorphism, the maxillary mesofacial prognathism is more important for boys (p = 0.04). When compared to the < 12 years subgroup, the > 12 years subgroup shows significant increase in the mesofacial prognathism and a decrease in the mesofacial divergence but the difference was not significant. Maxillary and mandibular mesofacial prognathism were positively correlated respectively with SNA (r = 0.22; p = 0.021) and SNB (r = 0.28; p = 0.004). The latter were in addition negatively correlated with the mandibular angle Ar-Go-Me (r = - 0.20; p = 0.041). Lastly, the mesofacial divergence angle is positively correlated with the mandibular angle (r = 0.20; p = 0.044) and negatively correlated with SNB (r = - 0.22; p = 0.027). CONCLUSION: The trigeminal analysis based on true anatomical skeletal points provides a good way to assess facial structures and could allow proper forecasting of the dento-alveolar compensation and complement reliably conventional cephalometric analysis.