Permanent Maxillary Odontometrics for Sex Estimation Based on a 3-Dimensional Digital Method.

BACKGROUND In the field of forensic medicine, sex estimation is a critical step in personal identification. Teeth are the hardest tissue and have high temperature resistance and corrosion resistance. In cases such as an airplane crash or the corpse of an unknown person, teeth often play a crucial role in identification. This study applied 3-dimensional technology to obtain odontometrics of permanent maxillary teeth and to examine the sexual dimorphism, finding suitable discriminant indicators to construct appropriate equations for sex estimation. MATERIAL AND METHODS A total of 204 participants (104 men and 100 women) from the Han population in Kashgar were included. Plaster models of their maxillary dentition were obtained to scan and measure through an accepted and commonly used 3-dimensional digital method. Descriptive statistics, t tests, and discriminant analyses were statistically analyzed using IBM SPSS 23.0 software. RESULTS This study showed high intra- and interexaminer reliability (intraclass correlation coefficient >0.950). There were statistically significant sex-related differences (P<0.05), with male values generally being higher for buccolingual distance, mesiodistal distance, intercanine distance, crown area, crown module, crown index, and maxillary canine index. Compared with other measurements, mesiodistal distance and crown area indicator exhibited distinct sexual dimorphism. In addition, several appropriate equations were constructed through different discriminant analyses that could be used to estimate sex in our specific population. CONCLUSIONS Three-dimensional digital technology offers a promising method for odontometry. Combining mesiodistal distance and buccolingual distance of particular teeth or using maxillary canine index in discriminant functions are acceptable auxiliary tools for sex estimation in the forensic field.

[Distribution of WNT10A gene rs10177996 polymorphism between Han and Uygur populations in Xinjiang area].

PURPOSE: To explore the characteristics of distribution of WNT10A gene rs10177996 polymorphism between Han and Uygur populations in Xinjiang area. METHODS: A cross-sectional survey on 154 Han individuals in Urumqi area and 134 Uygur individuals in Kashgar area was performed. Buccal epithelial cells were harvested using Cotton swab scraping, and DNA was extracted by special kit. After screening, the corresponding SNP segments of qualified samples were propagated by PCR. Dideoxy-mediated chain termination method was used for gene sequencing, and then, genotyping was conducted with corresponding software. Statistical analysis of genetic data was performed by SPSS 23.0 software package. RESULTS: Among Uygur nationality in Kashgar area, the frequencies of CC, CT, TT genetypes in rs10177996 were 8.21%, 30.60% and 61.19%, respectively. The allele frequency of C was 23.51% and T was 76.49%. Among Han nationality in Urumqi area, the frequencies on CC, CT, TT genetypes of rs10177996 were 9.74%, 43.51% and 46.75%, respectively. The allele frequency of C was 31.49% and T was 68.51%. When compared with Han nationality, the frequency of TT was significantly higher in Uygur nationality(P=0.046). When compared with European, the frequency of TT was significantly lower in Uygur nationality (P=0.05). When compared with European, the frequency of TT was significantly lower in Han nationality(P＜0.01). Compared with European, the distribution on C allele frequency was significantly higher, the distribution on T allele frequency was significantly lower in Han nationality (P=0.033). However, there was no significant difference between Han nationality in Urumqi area and Uygur nationality in Kashgar area (P＞0.05), and, between Uygur nationality in Kashgar area and European (P＞0.05). Meanwhile, there was no significant difference in gender between Uygur nationality in Kashgar area and Han nationality in Urumqi area (P＞0.05). CONCLUSIONS: The distributions of WNT10A gene rs10177996 SNP among Han nationality in Urumqi area, Uygur nationality in Kashgar area and the reported European population are obviously different.

Investigation of anterior teeth color of Uygur youth aged15-20years in the Kashi area of Xinjiang Uygur Autonomous Region / 口腔疾病防治

Objective @# To study the distribution range of the color values of the upper anterior teeth of Uygur youth in the Kashi area of XinJiang as a reference for clinical applications.@*Methods@#Based on the International Commission on Illumination (CIE) L*a*b* color system, the colorimetric values of the anterior teeth of 212 Uygur youths in Xinjiang, Kashi, were analyzed by digital camera colorimetry. There were 105 males and 107 females. The length of the neck to the cutting end of the tooth was measured, and the tooth was evenly divided into thirds. To determine the chromaticity values of the incisors, lateral incisors, cuspids, and middle teeth, 1/3 of the cervical, middle and incisal regions and 9 test areas were measured. @*Results @#The color of the cervical, middle and incisal regions of the same tooth position in Uygur youth in the Kashi area showed the following trends: L* value: middle regions > cervical regions > incisal regions; a* value: cervical regions > incisal regions > middle regions; b* value: cervical regions > middle regions > incisal regions, and the differences were statistically significant (P < 0.05). The value of L* gradually decreased, and the value of a* gradually increased (P < 0.05). There were no significant differences in the a* value of male and female maxillary anterior teeth (P > 0.05). However, there was a significant difference in the b* value between the middle teeth and the incisors, the middle and the incisal regions of the upper maxillary incisors, and the cutting end of the upper maxillary incisors (P < 0.05). @*Conclusions @# There was a significant difference in the color of the cervical, middle and incisal of the same tooth. The upper jaw gradually reduced from the incisors to the sharp teeth, and the color gradually became reddish. The maxillary central incisor was brighter in males than in females, and the middle and incisal regions of the maxillary front teeth were more yellow than in males than in females.