Cephalometric Hard and Soft Tissue Norms for Sudanese Adults

Introduction: Cephalometric norms of various populations show differences between diverse ethnic and racial groups. Thus, numbers of cephalometric norms have been established for different ethnic groups. Objective: To assess skeletal, dental and soft tissue features in a sample of well-balanced face of Sudanese university students. Materials & method: Lateral cephalographs were taken from 18-25 years old 35 male and 38 female Sudanese university students with balanced facial profile and Class I occlusion with no previous orthodontic treatment. Fourteen angular and five linear measurements, and facial index were recorded according to Husund analysis. Male and female mean values were compared statistically using Student t-test. Result: Statistically significant differences were noted between both genders especially in skeletal variables SNA ̊, SNB ̊, SNPg ̊, MLNSL ̊, NL-NSL ̊, UFH, LFH and dental variable I -Ī. Holdaway angle showed no significant difference between the genders. Skeletally, maxilla and mandible of the Sudanese sample were more prognathic compared to Caucasians and Arabs but less prognathic than the Africans. Dentally, maxillary and mandibular incisors were more proclined compared to Arabs and Caucasians. Soft tissue analysis showed more lip protrusion in Sudanese adults. Conclusion: The study offered normative cephalometric standards for Sudanese adults, which were specific for each gender group. The normative values showed that the Sudanese sample lied between African and Arab values which might suggest that the studied sample had an Afro-Arabian mixture.

1][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] Saudis have been shown to have features of more facial convexity than the Caucasians with fuller lips than the Whites. 12Another investigation demonstrated no differences between Saudi males and females except that the males showed straighter profiles than females. 13Jordanians had a reduced lower face height and proclined upper and lower incisors in comparison with the British sample. 14According to a study, Emiratis had no gender dimorphism except SNpalatal plane, which was in the female sample with more bimaxillary protrusion when compared to Caucasians. 15 another study, Emirates' males showed greater facial height and longer mandibular length than females. 160][21][22] Zimbabweans were found to have a greater ANB angle and lower interincisal angle. 23[26] When compared with Caucasians, they had larger antero-posterior facial dimensions, lower vertical facial dimensions with straighter bilabial inclination. 24e purpose of this study was to establish cephalometric norms among a Sudanese adult sample.according to Hasund analysis 7 (Table 1) were recorded and analyzed.

MATERIALS AND METHOD
Descriptive statistics were computed for each cephalometric variable using the SPSS program.
Comparison was made between male and female values using independent sample student t-test.The level of significance was set at 5% (<0.05) level.
Fifteen cephalographs were retraced after four weeks interval by the same operator to determine the error of the method.Dahlberg's formula and paired t-test were used to estimate the error of the method. 27

RESULT
The mean and standard deviation of fourteen angular, five linear measurements and a facial index for Sudanese male and female samples according to Hasund analysis are presented in Table 2.The mean age of the subjects examined was 22.5+3 years with no significant difference between male and female samples.
Antero-posteriorly, males were found to have more prognathic maxilla and mandible than females as indicated by the significant increase in SNAº, SNBº and SNPgº angles.Regarding the vertical inclination, females showed significant increase in maxillary and mandibular inclinations to the base of the skull compared to males.
Table 2 reveals that males had increased upper and lower facial heights than the females (p< 0.01).
Although there was no significant difference in the upper and lower incisors to the maxillary and mandibular bases respectively; the females showed significant decrease in inter-incisal angle indicating greater bimaxillary proclination of the incisors in females compared to males (p<0.05).3).
The highest error in the measurement (0.26) undertaken in the current study was in determining the angle of the cranial base flexure measurement (NSBa).It could be attributed to the difficulty of locating Basion point as it is one of the most difficult points to identify in lateral cephalograph. 28e present study revealed that there was gender dimorphism for SNA, SNB, SNPg angles (p<0.01) with the males having greater values.9][20][21][22] The mean values of maxilla and mandible to cranial base in the current study were larger than those of Saudi 12 Jordanians 14 and Emirati 15 but lesser than those of the Zimbabweans. 23e present study exhibited no statistical difference between males and females regarding the ML-NL; although males showed more anteriorly inclined maxillae and mandibles (NL-NSL and ML-NSL) than females (p< 0.01).The average ML-NL angle in the present study showed higher values than those of the Zimbabwean population 23 indicating a steeper mandible, while it was less compared to the Jordanians 14 and Emiratis populations. 15e present study revealed that there was significant gender difference in upper and lower anterior facial heights.Males had increased upper and lower anterior facial height than the females (p<0.01).The mean value for the upper and lower anterior facial height of the present investigation for both genders was found to be similar to the Egyptian sample. 4The present study males showed more prominent chin in males than females though not statistically significant.
Nigerian and Kenyan were found to have a low value Orthodontic Journal of Nepal, Vol. 5, No. 2, December 2015

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hundred and ninety Sudanese dental students were examined in the university orthodontic clinic.Out of which, 96 fulfilled the criteria of selection, however, many refused to participate in the study and were excluded.Thus lateral cephalometric radiographs were obtained from 73 Sudanese adults including 35 males and 38 females aged between 18-25 years.The study was conducted after obtaining ethical approval was from the University Research Committee and consent from the participants.All subjects were selected among the dental students on the basis of: • Sudanese nationality with up to great grandparents born in Sudan • Balanced facial profile with competent lips • Without any obvious asymmetry and craniofacial deformities • Full permanent dentition (except for the third molars) • Class I molar, incisor and canine relationship • Normal overjet and overbite • Normal transversal occlusion • Aligned or mildly crowded teeth (up to 2 mm) • No previous orthodontic treatment All cephalometric radiographs were taken with the teeth in centric occlusion and lips in repose.Each subject's head was kept in the natural head position by looking at own eyes in a mirror placed two meters away.The radiographs were exposed at 73KV, 10mA for 1.2 seconds.The right side of the patient was facing the cassette.A 150 cm tube target distance to the midsagittal plane was used with 20 cm midsagittal plane to the film distance resulting in 13% enlargement.Cephalograph tracings were done manually on 0.003 matte acetate cephalometric tracing papers using 0.5 mm lead pencil.Fourteen angular, five linear measurements and facial index (Figure 1)