Application of the Kvaal method with cone beam for the determination of a local formula for the age estimation of adult African melanoderma subject, Côte d'Ivoire.

BACKGROUND: Age estimation by invasive dental methods is a destructive, costly and time-consuming approach, whereas, age estimation methods using dental radiographs are simple, non-destructive and provide reliable information. Age estimation by the Kvaal radiographic method has proven to be a reliable method, but possible ethnic variations may limit its uses in other populations. The objective of this study was to reproduce the original Kvaal method with CBCT for the estimation of the age of the adult melano-African subject in Côte d'Ivoire, in order to propose an age estimation formula, specific to our study population, by taking into account the measurements of tooth and pulp ratios. METHODS: A cross-sectional study used 102 radiographic data from a CBCT Planmeca® examination in a private dental clinic in Abidjan. It was data from subjects of at least 18 years of age. Dental measurements in length and width of the entire tooth, root and pulp were performed on maxillary central incisors and the different ratios were calculated according to the Kvaal method. The correlation between age and ratios was also assessed. Age estimated using the Kvaal formula was compared to the chronological age. A linear regression equation was developed using ratios and age predictive factors to evaluate the accuracy of the Kvaal formula. RESULTS: In all, a total of 102 radiographs of 102 subjects, of whom 55 (53.9%) were females, were analyzed. The median age was 51 years (inter-quartile range [IQR] 41- 58). Using the Kvaal formula, the Standard error of the estimated age was higher in the African melanoderma population compared to the Kvaal population. The new formula derived from that of the Kvaal formula was developed and applied to our study population (Age = 84.7- 114.2 (M) - 29.4 (W - L) gave more than double the standard error of estimated age by Kvaal (26.03). CONCLUSION: Our study showed that the measurements made by Kvaal are reproducible with CBCT and there is a correlation between age and the dental parameters studied. However, the age estimation formula determined by Kvaal et al. is not valid for African melanoderma subjects living in Côte d'Ivoire.

[Cephalometric characteristics of black African children 3-6 years of age with nasal obstruction]. / Caractéristiques céphalométriques chez l'enfant mélano-africain âgé de 3 à 6 ans avec obstruction du cavum.

OBJECTIVE: To determine the cephalometric craniofacial characteristic of the child with chronic rhinopharyngeal obstruction. MATERIAL AND METHODS: It is about a comparative cross-sectional study with etiologic aiming including children of the 2 sexes, old from 3 to 6 years. The pathological subjects are represented by those presenting a chronic rhinopharyngeal obstruction due to the presence of hypertrophied tonsils (n = 29) and the "normal" subjects, those without any rhinopharyngeal obstruction (n = 30). Lateral cephalometric radiographs were obtained for each subject. The conventional landmarks were determined with the subject's head in neutral position. The two groups underwent cephalometric measurements. The cephalometric analysis was made starting from conventional landmarks resulting from soft tissues and osseous structures. Various statistical tests (test t of student, test of Kruskal Wallis, test of Mann-Whitney) were used for the exploitation of the cephalometric data. RESULTS: On the skeletal level, the length of the posterior cranial base was shorter at the pathological subjects than at the healthy subjects. Concerning the mandible, the height of the ramus and the length of the mandibular corpus are also weaker at the pathological subjects than at the witnesses. The hyoid bone is further away from the 3rd cervical vertebra and the craniocervical angle is more open at the pathological subjects, representing a modification of the slope of the cervical column. On the level of the rhinopharyngeal space, the average distances from the posterior nasal spine at the posterior edge of the rhinopharyngeal space and between the posterior nasal spine and the posterior base of the base of cranium are respectively of 19,43 +/- 4,78 mm and 37,56 +/- 2,95 mm. These measurements are not significantly different from those described in the literature. CONCLUSION: Our study highlighted skeletal modifications in children presenting a rhinopharyngeal obstruction. Even if they do not justify all the symptoms met, these modifications can represent a readjustment of the pharyngeal corridor aiming at facilitating the flow of airflow.

[Cranio-cervical posture and hyoid-mandibular-pharyngeal equilibrium in the presence of factors related to respiratory dysfunction]. / Posture crânio-cervicale et equilibre hyo-mandibulo- pharyngien en présence de facteurs liés a la dysfonction respiratoire.

AIM: The goal of this study is to know the modifications of the cranio-cervical posture which accompany the functional anomalies by the nasal breathe of black African children. MATERIAL AND METHOD: The study consists of a cephalometric comparison. Sixteen parameters measured on cephalograms of 98 schoolboys from 6 to 15 years were used. The children were divided into two groups according to their usual mode of breathing: 50 mouth-breathing children and 48 nasal breathers. The mode of breathing used three clinical tests: the mirror test, Rosenthal test and nasal reflex. RESULTS: The results show a significant difference of slope the cervical column between the two groups of children (t student). The oral breathers have the rhinopharyngeal airway dimensions more narrowed. The hyoid bone is more distant of the epiglottis and the mandible is more divergent. However, factor analysis of cephalometric variables suggested that craniocervical angulation (C2C4/SN) is independent of the other variables in oral breathers. Its dependence with is clear in nasal breathers. CONCLUSION: The children with predominantly mouth breathing exhibent a cranio-cervical hyperextension which could not closely be associated hyo-mandibulo-pharyngeal equilibrium.

Comparative cephalometric study of three different ethnic groups of black Africa with normal occlusion.

INTRODUCTION: The aim of this study was to investigate if there are differences or not between African ethnic groups in order to determine any ethnic and regional differences in the facial morphology. MATERIAL: Lateral cephalograms of 53 young Ivorians, 50 young Senegalese and 62 young Chadians, obtained under the same conditions in each country, were measured. Ten skeletal, eleven dento-skeletal and twelve soft tissue variables were investigated. RESULTS: The comparison of all these parameters (test t student) showed multiple differences between these groups. But, those from Senegal presented with a high degree of protrusion of the upper lip and incisors. Moreover they were strongly hyperdivergent compared to those from Côte d'Ivoire and Chad. The latter showed the least convex soft tissue profile. CONCLUSIONS: There were certain differences in dental, skeletal and soft-tissue facial morphology between the three African populations compared. This study provided a better knowledge of facial morphology in this area of Africa and consequently a better adaptation of the treatment planning of cases requiring orthodontics and orthognathic surgery.

[Three-dimensional imaging of root axes in patients from X-ray computed tomography slices]. / Visualisation tridimensionnelle des axes radiculaires des dents chez les patients explorés en coupes TDM.

The authors propose to materialize the corono-radicular axes of the teeth starting from their centre of gravity. This last is calculated with the data of the matrix of inertia resulting from the segmentation from tomodensitometric cuts (TDM). The sample is composed of 37 subjects (16 women and 21 men) old from 15 to 65 years, pertaining to a orthomorphic population. The helicoid acquisition of the data is carried out by an apparatus CT Twin Flash (Elscint Haïfa, Israel) on the subjects in decubitus dorsal under 120 kV with 100 mAs. The software C2000 allows the building of the maxillo-facial frame 8 points which becomes the absolute reference mark of the study. The same software allows by thresholding the selection of the teeth on the native cuts. The calculation of their axis of inertia makes it possible to materialize their barycentre. It becomes thus possible to visualize the position and the orientation of each tooth inside the maxillo-facial frame and the intra-reports/ratios and inter-arcades. The observations which result from this introduce interrogations as for the relevance of certain dogmas occlusodontic.

Croissance cranio-faciale des sujets masculins melano-africains agés de 8 à 20 ans

Les études téléradiographiques de la croissancesont nombreuses et représentent une contributionau domaine de la connaissance anthropologique desétapes du développement cranio-facial. Cependant, en Afrique noire il y a très peu d'études de ce genre. Danscette étude transversale, nous analysons la croissancede la base du crâne, du maxillaire et de la mandibule chez les jeunes garçons africains mélanodermes.L'échantillon d'étude est constitué de 516 garçons en période de croissance, âgés de 8 à 20 ans, non traitésorthodontiquement, supposées orthomorphiques etayant une téléradiographie de profil en occlusion deconvenance.La mandibule et le maxillaire présentent des rythmes de croissance différents tout en restant actifs jusqu'à 20ans mais la croissance de la base du crâne semble sestabiliser plus tôt, après 11 ans. La prise en compte de ces variations morphologiques sont déterminantes pour la conduite de traitements plus stables et adaptés à nos populations

[Cephalometric study of cranio-facial growth of 902 Black African children and adolescents aged 8 to 20]. / Etude céphalométrique de la croissance crânio-faciale de 902 enfants et adolescents mélano-africains agés de 8 a 20 ans.

Cephalometric studies of the growth are numerous and represent a contribution to the field of the anthropological knowledge of the stages of the cranio-facial growth and for a better adaptation of the orthodontic treatments. However, in Black Africa people there are very few studies of this kind. The purpose of this investigation is to analyze the growth of the cranial base, the maxillary skeletal region and mandibular skeletal region at the young African subjects. The sample of study consists of 386 girls and 516 boys in period of growth, old from 8 to 20 years, presumedly orthomorphic and having lateral cephalometric radiograph in occlusion. The statistical analysis of the data recorded on the layouts cephalometric (test U of Mann Whitney) announces the existence of a sexual dimorphism which is strongly significant around 9 years, 11 years and 17 years. Maxilla and mandible present different rates of growth while remaining active up to 20 years but the growth of the base of cranium seems to be stabilized earlier, after 11 years. The taking into account of these morphological variations are determining for the conduit of treatments more stable and adapted to our populations.

[Prevalence of rhino-pharyngeal disease in the presence of malocclusion in school children in the village of Abidjan]. / Prévalence des affections rhino-pharyngées en présence d'anomalie orthodontique chez les enfants scolarisés de la ville d'Abidjan.

An epidemiological survey of randomly selected school children led to Abidjan in three public schools made it possible to determine the prevalence of the rhinopharyngeal diseases in presence of malocclusions. It is an exploratory study jointly undertaken by two teams of specialists in ORL and Orthodontics within a sample of African schoolchildren old of 5 to 21 years. The results showed the presence of malocclusions in 73.30% of the cases (N = 220). The rhinopharyngeal diseases account for 38.3% (N = 115). At the subjects carrying a malocclusion the rhinopharyngeal diseases are 48.30% and they are dominated by the allergic chronic rhinitis (40%) followed obstructive hypertrophic tonsillitis (16.5%). However, these states which cause certainly a nasal obstruction involving an oral breathing do not cause inevitably malocclusion. We cannot thus affirm unambiguous a bond between malocclusions and rhinopharyngeal diseases (p > 0.05). They are nevertheless as many indications to question the patient on other symptoms and to refer to an ORL specialist. Our investigation being limited to the occlusal study, it seems essential to us to continue these analyses to detect the possible predisposition of certain patients to develop dento-skeletal anomalies in the presence of rhinopharyngic diseases.

[Treatment of class I malocclusion with severe dento-maxillary dysharmony in the permanent dentition of young black African patients]. / Traitement de la malocclusion de classe i avec dysharmonie dento-maxillaire severe chez le jeune patient Africain melanoderme en denture permanente.

Class I malocclusion with severe dental crowding can constitute a serious psychosocial and functional damage among young patients; from where orthodontic importance of the treatment. In the present study the authors present the treatment of two clinical cases whose initial problems are similar. They are two cases of class I malocclusion but whose certain diagnosed clinical factors have constrained in a case to control to the maximum anchoring on the level of the molars and in the other to control the dental axes. The final results are satisfactory because of the restoration of a physiological occlusion. Concomitantly we obtain a clear improvement of the smile.

[Quantification of initial malocclusion according to the mode of breathing in black African children]. / Quantification de la maloclusion initiale en fonction du mode de respiration chez l'enfant africain melanoderme.

The relations between the mode of breathing and the development of the malocclusions were the subject of many studies causing polemic sometimes (2, 3, 7, 9, 20). In fact the impact of the mode of breathing on occlusion is not clarified yet. The goal of this study is to quantify the dental characteristics, which constitute the malocclusion according to the mode of breathing. 100 African melanoderme children old from 6 to 15 years were subjected to a rhinologic evaluation based on the nostril reflex of GUDIN and the test of ROSENTHAL (12). Of this examination these children were left again in a group of 50 nasal respirators and in another group of 50 mouth breathers. Each child underwent a radiographic examination which was used to make a cephalometric analysis and a meeting of catch of dental prints. The statistical analysis of the data recorded on the dental casts and the layouts cephalometric (test t of student) indicate that the mode of breathing is not associated standard initial malocclusion. But, when the facial divergence, which is characteristic of mouth breathing increases, the initial malocclusion becomes significant.