Fadil Elamin

Malnutrition has no effect on the timing of human tooth formation.

The effect of nutrition on the timing of human tooth formation is poorly understood. Delays and advancements in dental maturation have all been reported as well as no effect. We investigated the effect of severe malnutrition on the timing of human tooth formation in a large representative sample of North Sudanese children. The sample (1102 males, 1013 females) consisted of stratified randomly selected healthy individuals in Khartoum, Sudan, aged 2-22 years using a cross-sectional design following the STROBE statement. Nutritional status was defined using WHO criteria of height and weight. Body mass index Z-scores and height for age Z-scores of ≤−2 (cut-off) were used to identify the malnourished group (N = 474) while the normal was defined by Z-scores of ≥0 (N = 799). Clinical and radiographic examination of individuals, with known ages of birth was performed including height and weight measurements. Mandibular left permanent teeth were assessed using eight crown and seven root established tooth formation stages. Mean age at entry and mean age within tooth stages were calculated for each available tooth stage in each group and compared using a t-test. Results show the mean age at entry and mean age within tooth stages were not significantly different between groups affected by severe malnutrition and normal children (p>0.05). This remarkable finding was evident across the span of dental development. We demonstrate that there is little measurable effect of sustained malnutrition on the average timing of tooth formation. This noteworthy finding supports the notion that teeth have substantial biological stability and are insulated from extreme nutritional conditions compared to other maturing body systems.

Comparison of the Bacterial Composition and Structure in Symptomatic and Asymptomatic Endodontic Infections Associated with Root-Filled Teeth Using Pyrosequencing

Residual microorganisms and/or re-infections are a major cause for root canal therapy failure. Understanding of the bacterial content could improve treatment protocols. Fifty samples from 25 symptomatic and 25 asymptomatic previously root-filled teeth were collected from Sudanese patients with periradicular lesions. Amplified 16S rRNA gene (V1-V2) variable regions were subjected to pyrosequencing (FLX 454) to determine the bacterial profile. Obtained quality-controlled sequences from forty samples were classified into 741 operational taxonomic units (OTUs) at 3% dissimilarity, 525 at 5% dissimilarity and 297 at 10% dissimilarity, approximately corresponding to species-, genus- and class levels. The most abundant phyla were: Firmicutes (29.9%), Proteobacteria (26.1%), Actinobacteria (22.72%), Bacteroidetes (13.31%) and Fusobacteria (4.55%). Symptomatic patients had more Firmicutes and Fusobacteria than asymptomatic patients, while asymptomatic patients showed more Proteobacteria and Actinobacteria. Interaction of disease status and age was observed by two-way ANOSIM. Canonical correspondence analysis for age, tooth restoration and disease status showed a correlation of disease status with the composition and prevalence of different members of the microbial community. The pyrosequencing analysis revealed a distinctly higher diversity of the microbiota compared to earlier reports. The comparison of symptomatic and asymptomatic patients showed a clear association of the composition of the bacterial community with the presence and absence of symptoms in conjunction with the patients’ age.

Combining radiographic and histological data for dental development to compare growth in the past and the present

Abstract Background: Being able to estimate the age at death of fossil hominins enables meaningful comparisons of both dental and general growth, past and present. Aim: The aim of this study was to use data for modern permanent canine formation derived from separate histological and radiographic studies to estimate the age at death of an early African Homo erectus specimen (KNM-WT 15 000) with a developing permanent maxillary canine. Methods: Ground sections of 18 sexed modern human canines were used to reconstruct growth in tooth height along the enamel–dentine junction (EDJ) and onwards into root formation along the cement–dentine junction (CDJ). Daily rates of enamel and dentine formation were used to put a time scale to cumulative fractions of tooth height. Results: Age estimates for KNM-WT 15 000 averaged 7.89–8.8 years of age (range = 6.6–10.3 years) and were close to previous histological estimates for this individual (7.6–8.8 years). Conclusions: Stages of dental development in KNM-WT 15 000 were easily accommodated within this age distribution of a modern sample. However, body mass and stature estimates for KNM-WT 15 000 fell well beyond those reported for a modern sample of 438 Sudanese children aged between 7.0–10 years.

Morphometry of the soft tissues of the orbital region in Northern Sudanese persons

The orbital region plays a predominant role in the evaluation of the craniofacial complex. No current normative data exist for Northern Sudanese subjects. In the current study information about normal sex- and age-related dimensions of the orbital region was provided. The three-dimensional coordinates of ten landmarks on the orbital soft tissues were obtained using a hand-held laser scanner in 654 healthy Northern Sudanese subjects aged 4-30 years. From the landmarks, biocular and intercanthal widths, paired height and inclination of the orbit relative to both the true horizontal (head in natural head position) and Frankfurt plane, length and inclination of the eye fissure, the relevant ratios, were calculated, and averaged for age and sex. Comparisons were performed by factorial analysis of variance. All analysed linear soft-tissue orbital dimensions, except intercanthal width and left orbital height, were significantly larger in men than in women (p<0.01). A significant sexual dimorphism was found also for the height-to-width ratios (larger in women in most age groups), the orbital inclinations vs. the true horizontal and Frankfurt plane (both measurements were almost always larger in men than in women), and the right side inclination of the eye fissure vs. the true horizontal (larger in women than in men), while no sex-related differences were observed for the left side inclination of the eye fissure vs. the true horizontal. All measurements but the right side inclination of the eye fissure vs. the true horizontal underwent significant modifications as a function of age, with several significant age×sex interactions. Biocular and intercanthal widths, orbital height, length of the eye fissure, all increased from childhood to young adulthood; in the second decade of life all age-related increments were larger in men than in women. Overall, when compared to literature data for African and Caucasoid subjects, several differences were found, pointing to the necessity of ethnic-specific data. Data collected in the present investigation could serve as a database for the quantitative description of human orbital morphology during normal growth and development. Forensic applications (evaluations of traumas, craniofacial alterations, teratogenic-induced conditions, facial reconstruction, ageing of living and dead people, personal identification) may also benefit from age- and sex-based data banks.

Three-dimensional assessment of nose and lip morphology in North Sudanese subjects with Down syndrome

OBJECTIVE To detail the nasolabial morphologic characteristics of North Sudanese subjects with Down syndrome (DS). MATERIALS AND METHODS Nasolabial morphology was assessed three-dimensionally in 64 North Sudanese subjects with DS aged 4 to 34 years and in 682 sex- and age-matched controls. Three-dimensional facial coordinates were collected using a laser scan, and selected distances, angles, areas, and volumes were computed. Subject and reference data were compared by computing z-scores and Students t-tests. RESULTS The nose was significantly smaller (area) in subjects with DS than in reference subjects, and it had a different shape (more flat angle of alar slope, more acute nasal tip angle). The vertical (nasal bridge length, nose height) and anteroposterior (nasal tip protrusion) dimensions were reduced, while the horizontal dimensions (alar base width, inferior widths of the nostrils) were increased. The nasolabial angle was increased. The cutaneous lip volume was significantly smaller, while the vermilion lip area was larger in the subjects with DS. The mouth and philtrum widths were significantly reduced, while the vermilion height was significantly increased. CONCLUSION Analyzed subjects with DS had a hypoplastic nose and different upper and lower lips than did reference, normal subjects.

Morphometry of the ear in north Sudanese subjects with Down syndrome: a three-dimensional computerized assessment.

Down syndrome (DS) is the most frequent live-born autosomal aneuploidy in humans. Scanty data on the craniofacial phenotype of African subjects with DS have been published so far. We wanted to detail the morphologic characteristics of the ears in north Sudanese subjects with DS.The three-dimensional coordinates of 13 soft-tissue landmarks on the ears were obtained using a laser scanner in 64 north Sudanese subjects with DS aged 4 to 34 years and in 682 sex- and age-matched control subjects. From the landmarks, left and right linear distances (ear width and length), ratios (ear width-to-ear length), areas (ear area), angles (angle of the auricle vs the facial midplane), and the three-dimensional symmetry index were calculated. Distances, angles, areas, and ratios were computed. Subject and reference data were compared by computing z scores and calculating Student t tests. Ear width, length, and area were significantly (Student t test, P < 0.001) smaller in the subjects with DS than in the reference subjects. On the right side of the face, the subjects with DS had larger ear width-to-ear length ratios and larger angles of the auricle versus the facial midplane than the reference subjects. The three-dimensional symmetry index was significantly larger in the reference subjects. In conclusion, ear dimensions, position, and shape significantly differed in subjects with DS when compared with sex-, age-, and ethnic group-matched control subjects.

Parturition lines in modern human wisdom tooth roots: do they exist, can they be characterized and are they useful for retrospective determination of age at first reproduction and/or inter-birth intervals?

Abstract Background: Parturition lines have been described in the teeth of a number of animals, including primates, but never in modern humans. These accentuated lines in dentine are comprised of characteristic dark and light component zones. Aim: The aim of this study was to review the physiology underlying these lines and to ask if parturition lines exist in the third molar tooth roots of mothers known to have had one or more children during their teenage years. Methods: Brief retrospective oral medical obstetric histories were taken from four mothers and compared with histological estimates for the timing of accentuated markings visible in longitudinal ground sections of their wisdom teeth. Results: Evidence of accentuated markings in M3 root dentine matched the age of the mother at the time their first child was born reasonably well. However, the dates calculated for inter-birth intervals did not match well. Conclusions: Parturition lines corresponding to childbirth during the teenage years can exist in human M3 roots, but may not always do so. Without a written medical history it would not be possible to say with confidence that an accentuated line in M3 root dentine was caused by stress, illness or was a parturition line.

Morphometry of the Orbital Region Soft Tissues in Down Syndrome

Abstract The orbital region of subjects with Down syndrome (DS) has been scanty described so far. We wanted to detail the morphologic characteristics of the soft tissue orbital region in Italian and North Sudanese subjects with DS. The three-dimensional coordinates of 10 landmarks on the orbital soft tissues were obtained using computerized anthropometry in 53 Italian and 64 North Sudanese subjects with DS aged 4 to 52 years, and in 461 (Italian) and 682 (North Sudanese) sex- and age-matched controls. From the landmarks, linear distances, ratios, areas, and angles were calculated, z scores computed, and compared by t-tests and analyses of covariance. In North Sudanese DS subjects, intercanthal width and height-to-length ratio were increased; biorbital width, eye height, length, and area were reduced. Eye fissure and orbital inclinations relative to Frankfort plane were reduced, whereas orbital inclinations versus the true horizontal were increased. In Italian DS men, orbital height and height-to-length ratio were increased, eye length was decreased; orbital inclination versus the true horizontal was increased. For almost all measurements, a significant effect of age was found. No effects of sex were found. Ethnic group influenced orbital height, area, and orbital inclination versus Frankfort plane. All paired measurements had similar discrepancies on both sides. The orbital soft tissues of North Sudanese DS subjects differed from those of their reference subjects, but this was only partially true for Italian subjects. The 2 ethnic groups had different alterations in their soft tissue orbital regions that were influenced by age, but not by sex.

Abnormal Variations in the Facial Soft Tissues of Individuals With Down Syndrome: Sudan Versus Italy.

Objective To provide quantitative information about the facial soft tissue of Italian and Northern Sudanese subjects with Down syndrome by using summary anthropometric measurements. Design, Setting, and Patients The three-dimensional coordinates of soft tissue facial landmarks were obtained using a computerized digitizer in 54 Italian subjects with Down syndrome (20 females and 34 males, 13 to 52 years), in 64 Northern Sudanese subjects with Down syndrome (18 females and 46 males, 5 to 34 years), and in 578 Italian and 653 Northern Sudanese reference subjects, matched for sex and age. From the landmarks, 16 facial dimensions were calculated. Data from subjects with Down syndrome were compared with those collected from control individuals by computing z scores. Two summary anthropometric measurements for quantifying craniofacial variations were obtained: the mean z score (an index of overall facial size) and its standard deviation, the craniofacial variability index (an index of facial harmony). Results In subjects with Down syndrome, facial size was significantly smaller and craniofacial variability was significantly greater than in typically developed individuals; 93% of Italian and 81% of Northern Sudanese subjects with Down syndrome had one or both values outside the normal interval. Overall, Italian subjects with Down syndrome differed more from the norm than did those from Northern Sudan. In the Northern Sudanese subjects, the mean z scores and the craniofacial variability index were significantly influenced by age: Older Northern Sudanese subjects with Down syndrome had smaller mean z scores and craniofacial variability index values than younger subjects. Conclusions The two ethnic groups had different alterations in their soft tissue facial dimensions that were partially influenced by age.

The timing of mandibular tooth formation in two African groups

Abstract Background: Ethnic differences in the timing of human tooth development are unclear. Aim: To describe similarities and differences in the timing of tooth formation in two groups of Sudanese children and young adults. Subjects and methods: The sample consisted of healthy individuals from Khartoum, Sudan, aged 2–23 years. The Northern group was of Arab origin (848 males, 802 females) and the Western group was of African origin (846 males, 402 females). Each mandibular left permanent tooth from first incisor to third molar was assessed from dental radiographs into one of 15 development stages. Mean ages at entry for 306 tooth stages were calculated using probit regression in males/females in each group and compared using a t-test. Results: Mean ages were not significantly different in most tooth stage comparisons between ethnic groups for both males (61/75) and females (56/76), despite a tendency of earlier mean ages in the Western group. Mean ages for most tooth stage comparisons between males and females (137/155) were not significantly different within ethnic groups suggesting low sexual dimorphism. Conclusion: The mean ages of most mandibular tooth formation stages were generally not significantly different between ethnic groups or between males and females in this study.