Behice Durgun

The association between cervical rib and sacralization.

Study Design. After determining the normal reference values for the length of the transverse processes of the seventh cervical vertebra, the association between the presence of cervical rib and sacralization was investigated. Objective. To determine the length of cervical rib and search for any association between cervical rib and sacralization. Summary of Background Data. Both cervical ribs and sacralization have been noted in some patients in the authors’ clinical practice. Methods. The cervical rib is a supernumerary rib arising from a cervical vertebra, or it might be simply an elongation of the transverse process of the seventh cervical vertebra. However, there is no consensus about a specified length of this process. For reference values, anteroposterior cervical radiographs of 210 normal individuals (112 male, 98 female, mean age 33.9 ± 10.1 years, range 19–61 years) were taken, and elongation of the transverse processes beyond 2 standard deviations (30 mm) was considered as cervical rib. In the guide of the reference values, 324 outpatients (165 male, 159 female, mean age 42.0 ± 14.6 years, range 17–85 years), having cervical ribs or sacralization detected by plain radiographs, were taken as the study group. As control 729 volunteers (364 male, 365 female, mean age 41.7 ± 14.3 years, range 15–76 years) were studied. Results. In 1053 patients, of 471 patients having cervical ribs, 345 (73.2%) had also sacralization; of 536 patients with sacralization, 345 (64.4%) also had cervical ribs. Significant associations were found between cervical rib with or without articulation and sacralization [&khgr;2 = 52.284, P < 0.001, odds ratio 5.097 (3.156–8.234); &khgr;2 = 139.473, P < 0.001, odds ratio 5.204 (3.922–6.905), respectively]. Conclusion. Presence of cervical rib might be a clue to the existence of sacralization or vice versa. In patients with cervical or lumbar pain, this association may be helpful for differential diagnosis before applying sophisticated diagnostic techniques.

Assessing the Relationship Between Hand Dimensions and Manual Dexterity Performance for Turkish Dental Students

The objectives of this study included: (i) a determination of whether there is a difference in manual dexterity as a function of gender and dentistry curriculum and (ii) an assessment of hand anthropometric characteristics on manual dexterity test performance. In total, 155 dental students (86 males and 69 females) in their first, second, third, fourth, and fifth years of a five-year undergraduate program took part in the study that involved a simple manual dexterity test. We used a paired sample t-test to compare differences between males and females and among students of different years. Pearson’s correlation coefficients were computed as a measure of association between parameters. The results demonstrate that anthropometric data of both hands have small but significant effects on test performance, and that small hands are associated with better test performance.

The Human Nervous System as a Model for Function Allocation in Human-Automation Interaction

The purpose of this presentation is to discuss structure and function of the human nervous system from the view point of the distribution of authority, sharing responsibility and controlling ways as a best model for designing of human-automation interaction. The cognitive view of function allocation was also discussed. The broad scope of ergonomics led to the most transparent, predictable and controllable automation system design. Function allocation is an ergonomic method to decide whether a particular function will be accomplished by a human, by an automation system or by human-automation interaction. Investigation of the human nervous system from integrative perspective provides the better understanding of the basis of automation and designing a better function allocation. High cognitive demands in human-automation interface can also influence the function allocation in man-machine system. It is expected that this presentation will offer the overview of this emerging area, as well as the new and future areas of its application.

Reply: Sacralization is not associated with elongated cervical costal process and cervical rib

We read the article by Tague (2011) entitled ‘‘Sacralization is not associated with Elongated Cervical Costal Process and Cervical Rib’’ with great interest. In the article, Tague reports anthropological observations regarding the association between the costal process length and sacralization. According to the author, ‘‘This study addressed three hypotheses— costal process length among individuals with sacralization differs from that among individuals without sacralization for: (1) only the seventh cervical vertebra, (2) only transitional presacral vertebrae (seventh cervical, twelfth thoracic, and fifth lumbar), because each of these vertebrae took on the characteristics of their immediately succeeding vertebra, and (3) presacral vertebrae in general. The author also concluded that this issue is derived from three perspectives: First, Erken et al.’s (2002) study, second, Schinz et al.’s (1952) theoretical model, and third, sacralization and cervical rib/elongated costal process of the seventh cervical vertebra are part of a systemic elongation of costal processes in the vertebral column.’’ The embryological explanation of Erken et al.’s (2002) study was different from Schinz et al.’s (1952) theoretical model. Schinz et al. (1952) proposed a model—Cranial Variation—to explain that presacral, transitional vertebrae can undergo posterior homeotic transformation as a group and develop the costal process length of their immediately succeeding vertebrae—seventh cervical vertebra forms a rib like that of the first thoracic vertebra; twelfth thoracic vertebra’s rib is shortened, being similar to the costal process of the first lumbar vertebra, and the fifth lumbar vertebra is sacralized. In contrast, Erken et al.’s (2002) study gives support to the view of bidirectional ossification of the vertebral column, rather than a simple craniocaudal direction of ossification progress. Three hypotheses suggested by Tague derived from two different views can not be combined to verify the results of Erken et al.’s study (2002). In the other words, in Erken et al.’s (2002) study, drawing a conclusion for embryological explanation was based on their findings, but Tague (2011) designed the study and analyzes according to the embryological explanation of Schinz et al. In addition, in the Tague’s study, correlational analysis comparing costal and transverse process lengths of vertebra 7 with costal process length of the last lumbar vertebra for individuals with and without sacralization (Table 4) shows whether sacralization and cervical rib/elongated costal process of the seventh cervical vertebra are part of a systemic elongation of costal processes in the vertebral column (different view for embryological explanation in Erken et al.’s (2002) study). Actually, because of limited number of samples of Tague’s study (18 costal processes and 47 transvers processes for individuals with sacralization), the correlational analysis in Table 4 is not enough to suggest that the developmental determinant for costal process length of the last lumbar vertebra does not influence costal or transverse process length of vertebra 7. Besides, the statistical significance was set at P < 0.01 in Tague’s study and it was different from that of Erken et al.’s study (P < 0.05). This typically leads to the erroneous conclusion that there is no association between two variables. The article also provided Table 3 with the author’s interpretation regarding the association between cervical rib and sacralization. Unfortunately, this table does not demonstrate whether the individuals with sacralization have conjoint elongation of only the seventh cervical vertebra. Rather, it demonstrate whether this elongation is more systemic among vertebrae. Table 3 compares individuals with and without sacralization in their costal process lengths for all 12 vertebrae (3–7 cervicals, 11 and 12 thoracics, and 1–5 lumbars). Sixty-nine seventh cervical vertebras were measured (43 without sacralization, 26 with sacralization). As explained in Table 3, five indi-