Functional and allometric analyses of the hand of the late Miocene ape Oreopithecus bambolii (Tuscany, Italy) reveal a series of features that reflect an improved grasping capability including firm pad-to-pad precision gripping that apes are unable to perform. Related features such as hand length, relative thumb length, a deep and large insertion area for the tendon of the long thumb flexor, and the form of the metacarpal 2/capitate articulation are not present in extant or fossil apes. In these features, the Oreopithecus hand closely matches the pattern of early hominids, presumably as a response to similar functional demands.

The increase in the proportion of adults in the typical orthodontic practice merits closer scrutiny of the treatment differences involved in adult vis-à-vis adolescent patients. Orthodontic treatment in the adolescent relies heavily on growth; in the adult, the practitioner must reposition teeth within the nongrowing arches. This difference may create the potential for greater postretention relapse in the adult; alternatively, continued growth in the subadult might detract from stability of the case. Two samples of Class II, Division 1 cases, all treated by one specialist, were examined an average of 5 years out of treatment. One group had been treated during adolescence (approximately 12 years of age), the other in adulthood (approximately 28 years). The orthodontic corrections were stable in both groups, but for different reasons: Posttreatment changes in the bony and dental structures of the adults were minimal. Bony changes (i.e., continued midface and mandibular growth) were appreciable in adolescents, and this growth--notably growth of the mandible--compensated for unfavorable drift of the dental elements (primarily mesial shift of the maxillary molar) after treatment. In sum, orthodontic corrections in adults were found to be at least as stable as those in the conventional adolescent patient.

The interest of the adult patient in orthodontics has increased as the demographics of the specialty of orthodontics has changed. There are major intreatment and posttreatment differences in Class II malocclusion correction between the adolescent and the adult. This article outlines the differences--and the similarities--between adolescent and adult Class II malocclusion correction. The differences and similarities are illustrated with case reports of a representative adolescent from the adolescent group and a representative adult from the adult group.

A longitudinal analysis was made of total length changes of the four epiphyseal bones of ray two, the index finger, during adulthood. Matched pairs of standardized hand-wrist radiographs on 37 individuals between earlier (means = 22 years) and later (means = 54 years) adult age-grades show that the distal and middle phalanges continue to increase in overall length; the proximal phalange exhibits no change; and the metacarpal significantly decreases in size. The changes in these normal adults are also discernible in cross-sectional data but are not obvious statistically. Causes of the specific increases and decreases remain speculative.

Attainment of a Class I molar relationship (Angle) is often a prime treatment objective. In addition to considerations of improved function and skeletodental harmonies, a Class I relationship often is deemed the "correct" and stable situation. This study assessed the relative stability of the sagittal molar relationship in orthodontically untreated persons with full dentitions who were followed longitudinally from young (approximately 20 years) to older (approximately 55 years) adulthood. The Class I relationship is indeed most stable; none of 69 cases (sides) starting in a Class I cusp-in-groove relationship moved from that condition. In contrast, Class II relationships naturally became significantly "more" Class II (that is, greater distoclusion), and Class III cases shifted significantly to greater mesioclusion.

Lateral cephalometric radiographs were quantitatively assessed in a series of 15 American black children with fetal alcohol syndrome (FAS). Although none was profoundly affected, FAS had been diagnosed in all the children at birth. Comparisons with age-, sex-, and race-matched controls disclosed a triad of facial profile differences:(1) frontal bossing,(2) palatal plane tipped up in the front with proclined upper incisors and a sharp nasolabial angle acquired from digit habits, and (3) above-average length of the mandibular corpus. Collectively these generate the perception of midface hypoplasia, although the midface actually is unremarkable in size and position. A high prevalence of chronic digit habits (8 of 15) is a secondary consideration in FAS, leading to localized skeletodental problems.

Even though there has been debate over whether a separate premaxilla exists in the human being, it has been suggested that the premaxillary-maxillary suture remains patent into adolescence and provides an explanation for the action of certain orthodontic and orthopedic appliances. To assess whether this suture is pertinent to an understanding of appliance effects, the skulls of 50 subadult subjects were scrutinized to determine patency with regard to age. Remnants of a premaxillary-maxillary suture may be present on the surface of the palate at all ages studied, and often this suture extends deep to the surface. However, in no case was the suture continuous so as to distinguish a distinct premaxilla. These findings disprove the claim that the premaxillary-maxillary suture system provides an explanation for any form of orthodontic or orthopedic therapy.

Two groups of adolescent orthodontic patients, one from the Midwest and one from the Midsouth, were compared to test the clinical impression that the permanent teeth of southern children form and erupt at significantly later ages. Indeed, a marked difference is documented, with the Midsouth series achieving mineralization stages at least 1 1/2 years later on average. This suggests that regional differences are appreciably greater than previously suspected. Clinical consequences revolve on the use of conventional (generally Northeast-based) norms for tooth formation and eruption and predictive models of facial growth. In contrast, the analysis of rates of hand-wrist development (bone age) of these same subjects disclosed no difference; this further confirms the essential independence of development of the dental and osseous tissue systems.

Relative finger lengths, especially the second-to-fourth finger length ratio, have been proposed as useful markers for prenatal testosterone action. This claim partly depends on an association of relative finger lengths in adults with related sex differences in children and infants. This paper reports the results of a study using serial radiographs to test for both sex differences in the fingers of infants and children and for a relationship between sex differences in the children and infant finger and adult finger length ratios. This is the first study using long-term serial data to evaluate the validity of finger length ratios as markers. We found not only that sex differences in finger length ratios arise prior to puberty, but that sex differences in the fingers of children are highly correlated with adult finger length ratios. Our results strongly encourage the further use of finger length ratios as markers of perinatal testosterone action.

OBJECTIVE: Little is known about how specific radiographic features are related to hand strength in osteoarthritis (OA). This study examined associations of radiographic variables with pinch and grip strength among individuals with radiographic hand OA. METHODS: Participants (n = 700, 80% female, mean age 69 years) were part of a study on the genetics of generalized OA. All had bilateral radiographic hand OA. Linear models were used to examine associations of grip and pinch strength with 1) OA in joint groups (proximal interphalangeal, metacarpophalangeal [MCP], carpometacarpal [CMC]), 2) OA in rays (first through fifth), and 3) summed Kellgren/Lawrence (K/L) grades for severity of OA in all joints. Adjusted models controlled for age, sex, hand pain, chondrocalcinosis, and hand hypermobility. Mixed models accounted for clustering within families. RESULTS: In bivariate analyses, all joint groups, all rays, and total summed K/L grades were significantly negatively associated with grip and pinch strength (P < 0.05). In adjusted models, the only joint group significantly associated with grip strength was the CMCs, and only OA in the MCP joint was significantly associated with pinch strength (P < 0.05). The only ray significantly associated with grip strength (P < 0.05) was ray 1, and no individual rays were significantly associated with pinch strength. A higher summed K/L grade was significantly associated with both lower grip strength and lower pinch strength. CONCLUSION: Among individuals with radiographic hand OA, increasing radiographic severity is associated with reduced grip and pinch strength, even when controlling for self-reported pain. Individuals with radiographic OA in specific locations (CMC joints, MCP joints, and ray 1) may be at particular risk for reduced hand strength.

OBJECTIVE: To evaluate secular changes in height, sitting height and estimated leg length between 1968 and 2000 in residents in a rural Zapotec-speaking community in Oaxaca, southern Mexico. MATERIALS AND METHODS: Height and sitting height were measured in school children 6-13 years (1968; 1978, 2000), in adolescents 13-17 years (1978, 2002) and adults 19-29 years (1978, 2000). Leg length was estimated as height minus sitting height. The sitting height/ height ratio was calculated. Subjects were grouped by sex into four age categories: 6-9, 10-13, 13-17 and 19-29 years for analysis. The Preece-Baines Model I growth curve was fitted to cross-sectional means for 1978 and 2000. RESULTS: There were no differences between children 6-9 and 10-13 years in 1968 and 1978 with the exception of the sitting height ratio in girls 6-9 years. Children of both sexes 6-13 years and adolescent boys 13-17 years were significantly larger in the three dimensions in 2000 compared to 1978; adolescent girls differed only in height and sitting height. Adult males in 2000 were significantly taller with longer legs than those in 1978, but the samples did not differ in sitting height and the ratio. Adult females in 1978 and 2000 did not differ significantly in the three dimensions. Rates of secular change in height and sitting height between 1978 and 2000 were reasonably similar in the three age groups of male children and adolescents, but the rate for estimated leg length was highest in 10-13-year-old boys. Secular gains were smaller in adult males, but were proportionally greater in estimated leg length. Girls 6-9 and 10-13 years experienced greater secular gains in height, sitting height and estimated leg length than adolescent and young adult females, while secular gains and rates decreased from adolescent girls to young adult women. Ages of peak velocity for height, sitting height and estimated leg length declined in boys, while only ages of peak velocity for height and estimated leg length declined in girls. CONCLUSIONS: There are major secular increases in height, sitting height and estimated leg length of children and adolescents of both sexes since 1978. Secular gains in height are of similar magnitude in boys and girls 6-13 years, but are greater in adolescent and young adult males than females. The secular increase in height of young adults of both sexes is smaller than that among adolescents. Estimated leg length accounts for about 60% of the secular increase in height in children of both sexes. Estimated leg length and sitting height contribute equally to the secular increase in height in adolescent boys, whereas estimated leg length accounts for about 70% of the secular increase in height in young adult males. Sitting height contributes about two-thirds of the secular increase in height in adolescent and young adult females.

Mobility of metacarpophalangeal joints (MP) of the three-phalangeal fingers was measured in university students (52 males and 49 females), senior citizens (30 males and 30 females), and pianists (21 males and 31 females). We consider the student data file to be a control group with hand mobility unchanged by external influence. Extension, flexion, and total abduction in this group are greater in the left than the right hand. Only extensions were greater in females compared to males. In seniors, all types of studied movements are, with the exception of total abduction in females, lesser that in the control group. The difference is more apparent in males than in females. Intersexual difference showing better MP joint mobility in females than males is thus greater in seniors than in students; however, greater mobility of MP joints in left compared to right hand is less noticeable. Compared to students, pianists show greater finger abduction, and--less markedly--also passive and active extensions, while we did not notice difference in finger flexion. Intersexual difference in MP joint mobility in pianists were not recorded, and better mobility on the left hand compared to the right hand was evident only in dorso-palmar movements in males (the exception was total finger abduction, which is greater for the left hand in males as well as in females). In the three studied series we did not register differences in interfinger abduction between the left and right hand or between sexes. Active dorso-palmar MP joint range of motion is greatest in the little finger and smallest in the index finger, smallest in seniors and greatest in pianists. In all three groups, the range is greater in the left than the right hand and in females compared to males.

Sex differences other than the simple dimorphism in size were documented for the metapodials of two primate species. Lengths of metacarpals and metatarsals were obtained from the skeletons of 64 gorillas and 42 chimpanzees. Length ratios were constructed for all possible pairings of the five bones in each individual hand and foot. For both species, several of these length ratios exhibited substantial differences between the sexes. Body size was not the basis for these sex differences; when specimens of similar size were compared, the sex differences remained. In humans, length ratios for the fingers and toes also have previously been demonstrated to exhibit sex differences, and the length ratio for the index and ring fingers (the 2D:4D ratio) has been shown to correlate with various medical conditions. Various facts suggest that length ratios in human digits are associated with androgen exposure, probably during prenatal development. For gorillas, the metacarpal length ratio showing the largest sex difference was 4Mc:5Mc in both hands, and the metatarsal length ratio showing the largest sex difference was 1Mt:2Mt in the left foot. Sex differences in length ratios also existed for chimpanzees, but they were generally smaller than for gorillas. Apparently, both gorillas and chimpanzees are affected by developmental mechanisms, possibly androgenic mechanisms, similar to those in humans. Analyses of previous measurements [Susman, R.L., 1979 Comparative and functional morphology of hominoid fingers. Am. J. Phys. Anthropol. 50, 215-236] revealed that all components of the rays are not affected equally by whatever mechanisms are responsible for the sex differences in length ratios.

Considerable evidence suggests that digit length and dermatoglyphic asymmetry patterns in the hand are affected by early exposure to androgens. Because androgens play an important role in sexual differentiation of morphological and behavioral traits, digit length patterns often display sex differences. When present, sex differences in digit lengths are more pronounced on the right side as compared to the left side. Moreover, the ratio of the second to fourth digit length (2D:4D) in the right hand is inversely correlated with testosterone (T) in men. Because T is implicated in agonistic behavior, 2D:4D may be used as a marker of androgen exposure and subsequent behavioral variation in adulthood. Consequently, we investigated the relationships among 2D:4D, directional asymmetry of 2D:4D (left hand 2D:4D minus right hand 2D:4D) as a variant of T, and human reactive aggression. One hundred young men (n = 51) and women (n = 49) participated in our experiments (mean age = 20.1 years). Participants called two noncompliant confederates to solicit donations for a fictitious charity organization and selected follow-up letters after the calls. The force exerted when hanging up the phone and the "tone" of the follow-up letters were used to assess reactive aggression. High aggression scores were associated with high directional asymmetry of 2D:4D and masculinized (low) right hand 2D:4D, only in females and under high provocation. Directional asymmetry of 2D:4D was positively correlated with T in males (pooled data, n = 97). Taken together, these data confirm the predominantly right-sided influence of androgens on digit length and suggest that digit length ratios may be associated with female reactive aggression when sufficient provocation is present.

Skeletal tuberculosis (TB) is less common than the pulmonary form. Involvements of the metacarpals and phalanges of the hand are infrequent. The authors report their experience with treatment and outcome of TB of the metacarpals and phalanges of the hand in 7 patients. There were 4 women and 3 men in the study who ranged in age from 3 to 60 years (average age, 22.7 years). The duration of complaints at presentation ranged from 4 to 17 months (average, 9 months). The most common presentation was pain and swelling. The presumptive preoperative diagnoses were bone tumor in 4 patients, spina ventosa in 2, and chronic pyogenic osteomyelitis in 1 patients. The results of the laboratory examination showed a mild increase in the erythrocyte sedimentation rate. No patient had an active tubercular lesion or history of pulmonary disease. The diagnosis was based on the clinical picture and radiographic features, and was confirmed by open biopsy. No patient had bony debridement or arthrodesis to control the infection. The treatment of all patients began with a 4-drug regimen for 2 months, followed by a 2-drug regimen for 10 months. The mean follow-up was 30.28 months (range, 16-52 months). At the time of the last follow-up, all lesions had healed with no recurrence. The functional results were satisfactory in all patients. One patient with thumb metacarpophalangeal TB had joint irregularity and thumb metacarpal shortening. Arthrodesis was not needed in any patient. TB of the metacarpals and phalanges of the hand can be difficult to diagnose during the early stages. TB should be suspected in cases of long-standing pain and swelling in the metacarpals and phalanges. It is necessary to keep TB in mind when making the differential diagnosis of several osseous pathologies.

BACKGROUND: The ratio between the length of the 2nd or index finger and the 4th or ring finger (2D:4D) differs between the sexes, such that males have lower 2D:4D than females, and shows considerable ethnic differences, with low values found in Black populations. It has been suggested that the sex difference in 2D:4D arises early in development and that finger ratio is a correlate of prenatal testosterone and oestrogen. In children, 2D:4D has been reported to be associated with measures of fetal growth, congenital adrenal hyperplasia, developmental psychopathology, autism and Asperger's syndrome. However, little is known of the patterns of sex and ethnic differences in the 2D:4D ratio of children. AIM: To investigate sex and ethnic differences in 2D:4D in Caucasian, Oriental and Black children. STUDY DESIGN: Population survey. METHOD: The 2D:4D ratio was measured from photocopies of the right hand of Berber children from Morocco, Uygur and Han children from the North-West province of China, and children from Jamaica. RESULTS: There were 798 children in the total sample (90 Berbers, 438 Uygurs, 118 Han, and 152 Jamaicans). The 2D:4D ratio was lower in males than in females and this was significant for the overall sample and for the Uygur, Han and Jamaican samples. There were significant ethnic differences in 2D:4D. The Oriental Han had the highest mean 2D:4D, followed by the Caucasian Berbers and Uygurs, with the lowest mean ratios found in the Afro-Caribbean Jamaicans. The sex and ethnic differences were independent of one another with no significant interaction effect. In the overall sample there were no associations between 2D:4D and age and height. CONCLUSIONS: In common with adults, the 2D:4D ratio of children shows sex and ethnic differences with low values found in a Black group. There was no overall association between 2D:4D and age and height suggesting that the sex and ethnic differences in 2D:4D appear early and do not show appreciable change with growth.

BACKGROUND: In the past few years, competition climbing has grown in popularity, and younger people are being drawn to the sport. HYPOTHESIS: Although the radiographic changes in long-term climbers are known, there are little data available on young climbers. The question arises as to whether climbing at high levels at a young age leads to radiographic changes and possibly an early onset of osteoarthrosis in the finger joints. STUDY DESIGN: Cross-sectional study. METHODS: Nineteen members of the German Junior National Team and 18 recreational climbers were examined clinically and through radiographs. For comparison, radiographs of 12 young nonclimbers (control group) were collected. Radiographs were evaluated using a standard protocol. For evaluation of the physiologic adaptation, the cortical thickness of the middle phalanx and the Barnett Nordin index were analyzed. The results were compared between the 3 groups and against radiographs of 140 long-term, experienced climbers. RESULTS: Six climbers (32%) of the German Junior National Team presented a decreased range of motion for the small finger joints; none of the recreational climbers showed this decrease. In 47% of the German Junior National Team and 28% of the recreational climbers, stress reactions could be found: cortical hypertrophy (26% German Junior National Team, 11% recreational climbers), subchondral sclerosis (47% German Junior National Team, 6% recreational climbers), broadened base of the proximal interphalangeal joint (42% German Junior National Team, 28% recreational climbers), and broadened base of the distal interphalangeal joint (16% German Junior National Team, 0 recreational climbers). Signs of an early stage of osteoarthrosis were seen in 1 climber in each group. The control group showed no radiologic abnormalities. The Barnett Nordin index was 0.49 +/- 0.05 in German Junior National Team, 0.49 +/- 0.07 in recreational climbers, and 0.48 +/- 0.08 in the control group. There was no statistically significant difference on the Barnett Nordin index between the groups (German Junior National Team/recreational climbers: P =.89; German Junior National Team/control group: P =.58; recreational climbers/control group: P =.55). CONCLUSIONS: Intensive training and climbing lead to adaptive reactions; nevertheless, osteoarthrotic changes are rare.

Osteoarthritis (OA) is a progressive disease of the joints and can cause pain, reduced range of motion and strength, and ultimately loss of function at affected joints. Osteoarthritis often occurs at sites where biomechanical stress is acutely severe or moderate but habitual over the course of a lifetime. Skeletal remains from an Umm an-Nar tomb at Tell Abraq, United Arab Emirates (ca. 2300 BC), were recovered and represented over 300 individuals of all ages. The remains were disarticulated, commingled, and mostly fragmented. An analysis of 650 well-preserved adult metacarpal and carpal bones, from the tomb's western chamber, revealed that over 53% of the trapeziometacarpal joint facets showed signs of OA varying from mild to severe. The first and second metacarpals and trapezium bones were sided and evaluated for OA at the trapeziometacarpal joint articulations. Osteoarthritis was detected on 53% of the first metacarpals, 40% of the second metacarpals, and 57% of the trapezium bones. All specimens appeared enlarged, and the first metacarpals were assessed for sexual identification and robusticity. Eighty-five percent of the bones were probable males, and more than 80% of them had a robusticity index of 60 or higher. A strong correlation was found between OA, sex, and robusticity. High levels of OA and robusticity at the thumb suggest that the people of Tell Abraq were habitually involved in biomechanically challenging work with their hands.