A small skull from Flores dated to the 20th century.

A human skull with mandible from the Ngada District on the island of Flores, Indonesia, is described in order to contribute to the knowledge of variation in cranial architecture, which is important in interpretations of evolutionary cerebralisation. The skull was excavated in 1924 and sent to the National Museum in Copenhagen. The "Copenhagen Flores" (CF) male skull is radiocarbon-dated and of modern age. The cranium is small, but larger than e.g. Liang Bua skull (LB1) in every measurement. The (CT-scan based) cranial capacity of 1258 ml is normal for modern humans, but somewhat lower than values from the middle or upper Palaeolithics. The metric cranial data analysed in FORDISC, characterize the skull as a male Vietnamese rather than a Chinese or White individual. Tooth morphology shows the sundadont pattern and tooth size corresponds to that of teeth from Bali, Java and Malayan Orang Asli. Remarkable are the marked asymmetries in the dentition with rotation of an upper premolar and congenital absence of a third molar. In these respects the CF skull is similar to dentitions belonging to the pygmoid villagers of Rampasasa, a village not far from the Liang Bua cave, and to LB1.

Radix mesiolingualis and radix distolingualis in a collection of permanent maxillary molars.

Two lingual root structures are occasionally found on human permanent maxillary molars. One of these is the normal lingual root, which is always present, the other is a supernumerary structure which can be located either mesiolingually (radix mesiolingualis (RML)) or distolingually (radix distolingualis (RDL)). The available literature refers only to the existence and location of RML and RDL Very small materials have, quite simply, hitherto precluded a more detailed description of these roots. The large collection of extracted teeth at the School of Dentistry in Copenhagen now includes a non-random subcollection of 145 permanent maxillary molars, the root complex of which contains 2 lingual root structures. Based on this material it was possible to undertake a modern, systematic analysis of the macromorphological variation of RMLs and RDLs. In this study, which was mainly non-metric, criteria for the identification of RML and RDL were established. The analysis also showed that the lingual supernumerary roots were only rarely found on the first molar, but with increasing frequency on the second and third molars. Both separate and non-separate RML and RDL were observed. In the material, degrees of separation greater than 0.9 were registered, degrees of divergence up to approximately 45 degrees, an apical bend of approximately 90 degrees, and extreme apical slenderness. Even though the supernumerary roots described here do not occur very often, knowing about them is nevertheless clinically relevant in for example endodontic and surgical contexts.

Radix paramolaris and radix distomolaris in Danish permanent maxillary molars.

The School of Dentistry in Copenhagen possesses a collection of 96 human permanent maxillary molars (M sup) with a root complex, the macromorphology of which includes a facially located supernumerary root known as radix paramolaris (RP) and/or a distally located supernumerary root called radix distomolaris (RD). Systematic analysis of these teeth enabled the authors to establish precise criteria for the identification of RP and RD on M sup; 91.5% out of a total of 70 RP identified occurred on M3 sup, 7.2% on M2 sup, and 1.4% on M1 sup. The corresponding percentages for 29 RD identified were: 96.5% on M3 sup, 3.4% on M2 sup, and 0.0% on M1 sup; 50.0% of the 70 RP were separate in relation to the 2 facial root components and 31.5% non-separate; in 18.6% of the RP observed, it was impossible to establish whether or not they were separate. Corresponding frequencies for the 29 RD in relation to the distofacial and lingual root components were 41.3% separate and 37.9% non-separate; 20.7% of the roots could not be categorized. The following clinically relevant macromorphological variables regarding RP and RD were also observed: degree of separation in relation to the respective neighboring root components, degree of divergence in relation to the same macrostructures, apical bend, apical gracility, and pattern of fusion.

Aspects of teeth from archaelogic sites in Sweden and Denmark.

The purpose of this study was to examine ground sections of primary second molars and permanent first molars from the same jaws. Teeth from 11 individuals were collected from archaeologic sites in Sweden and Denmark. Longitudinal buccolingual sections were examined in a polarization light microscope and in a Philips scanning electron microscope (SEM). The seven teeth from Sweden appeared to have been subjected to environmental influences at their burial site, which had affected both the dentin and the enamel. The teeth from the Danish sites had a normal color, and no disintegration of the dentin was seen. The general morphologic appearance was normal in all primary and permanent teeth. The position of the neonatal line indicated a normal full-term gestational age. The observed accentuated incremental lines in both the primary and permanent enamel suggested periods of dietary changes, possibly related to periods of illness. SEM images of the surface area of the Swedish teeth showed an extremely porous enamel surface with severe changes in the prism structure as an effect of acid penetration. The Danish teeth did not show any marked changes in the enamel.

Root canals in two-rooted maxillary second molars.

The aim of this study was to register the root canal number, root canal position, and root canal cross-section in human two-rooted, permanent maxillary second molars. One hundred and fifty-nine such teeth extracted in Denmark were cross-sectioned at the mid-root level and apically in accordance with precise guidelines. The observations were made in a stereomicroscope, corresponding to the above-mentioned section levels. At mid-root there were two canals present in 11% of the teeth examined; the canals were located mesially and distofacially, mesiofacially and distally, or facially and lingually. Three canals positioned mesiofacially, distofacially, and lingually were observed in 89% of the teeth. At the same level 62% of the canal cross-sections were noncircular, some being, for instance, C-shaped, whereas 38% of the cross-sections were circular. Apically, two canals were found, representing 19% of the teeth, with the canal position as at mid-root; 81% of the teeth were three-canaled with the same canal position as at mid-root. At the apical level 60% of the canal cross-sections were noncircular, whereas 40% of the cross-sections were circular.

Dental conditions and temporomandibular joints in an early mesolithic bog man.

In 1994 parts of a human skeleton were found in the county of Västergötland, Sweden. The remains were probably from a man and estimated according to 14C dating to be about 9800 years old, i.e. from the Early Mesolithic Period. As such old finds are rare and the skull was well preserved a more detailed description is presented in this paper. The facial skeleton was robust and the face shape was rectangular. The remaining teeth, one maxillary and 10 mandibular teeth, exhibited no caries but extensive occlusal wear which in some teeth had exposed the pulp and led to periapical osteitis. Besides these teeth the 4 maxillary incisors and the two canines and one incisor in the mandible had been lost post-mortem, probably because of severe marginal bone loss. Both temporomandibular joints showed remodelling, one also osteoarthrotic changes. The observations are discussed with respect to masticatory function and some background factors.

Mandibular premolar differentiation.

The authors present a method for differentiating between human mandibular premolars: P1 inf and P2 inf. The material with which the method was developed consisted of 260 stone casts. On these, both premolars were present and were intact on at least one side. The study models represented 131 girls and 129 boys, mean age 14.6 yr. In a comprehensive pilot project, a whole range of macromorphologic criteria was tested that, in various combinations, could be expected to be usable for differentiation between P1 inf and P2 inf. On the basis of the pilot study, the total variation was reduced to four criteria-combinations, called types, which, in summary, can be characterized as the following: type 1: flattening of the mesiolingual part of the crown, no lingual lobe; type 2: at least one lingual lobe; type 3: lingual part of the crown symmetrically curved, no lingual lobe; type 4: other characteristics. After definition of the types, their occurrence on P1 inf and P2 inf was definitively registered. Observations were made with a stereomicroscope; 131 premolar pairs from the right side and 129 from the left were registered. Statistical tests showed that there was no significant difference in the distribution of types between variants from the right and left sides, or between girls and boys. These data were therefore pooled for P1 inf and P2 inf, respectively. A subsequent test revealed, as expected, a highly significant difference in the distribution of the four types among 1. and 2. premolar.(ABSTRACT TRUNCATED AT 250 WORDS)

Root canals in one-rooted maxillary second molars.

The Royal Dental College, Copenhagen, houses an extensive collection of human teeth extracted in Denmark. The collection currently contains 104 one-rooted, permanent maxillary second molars. The root complex on these teeth was sectioned at the junction between the coronal and the apical halves, i.e. mid-root, and at the junction between the middle and the apical thirds, i.e. apically. Using a stereomicroscope we then registered, mid-root and apically, the following variables: canal number, canal position, and canal cross-section. Mid-root there was 1 centrally located root canal in 25.96% of the teeth examined; 2 canals were observed either mesially and distofacially, mesiofacially and distally, or facially and lingually in 34.62%; 3 canals positioned mesiofacially, distofacially, and lingually were found in 39.42%. At the same level 63.51% of the canal cross-sections were non-circular, whereas 36.49% of the canals had a circular cross-section image. The non-circular canal cross-sections could more specifically be characterized as C-shaped, Y-shaped, hourglass-shaped or the root canal had a greater faciolingual than mesiodistal extension or, respectively, a greater mesiodistal than faciolingual extension. Apically there was 1 centrally located root canal in 35.58%; 2 canals were observed with a position either mesially and distofacially, mesiofacially and distally, or facially and lingually in 37.49%; 3 canals located mesiofacially, distofacially, and lingually were found in 26.92%. At the apical level, 64.32% of the root canal cross-sections were non-circular, whereas 35.68% of the canals showed a circular cross-section. The results presented here are aimed at: clinical dentists, endodontists, and dental morphologists.

Radix paramolaris in permanent mandibular molars: identification and morphology.

The Royal Dental College, Copenhagen, houses an extensive collection of human teeth which have been extracted in Denmark. The collection presently includes 203 permanent mandibular molars with a root complex containing a facially-located supernumerary root. This macrostructure is named radix paramolaris (RP). By analyzing the large number of specimens available it was possible to establish uniform and precise criteria for the identification of RP on M1 inf, M2 inf, and M3 inf. The analyses included both separate and non-separate RP. The representation of the RP variants according to tooth type was mapped. Furthermore, the following clinically relevant variables with respect to RP were registered: degree of separation, divergence, apical bend, apical gracility, and fusion. Because of the nature of the material, the study was mostly qualitative and non-metric. The results are aimed primarily at clinical dentists, dental morphologists, and dental anthropologists.

Radix entomolaris: identification and morphology.

The Royal Dental College, Copenhagen, houses an extensive collection of human teeth, extracted in Denmark. At present, the collection includes 398 permanent mandibular molars with a root complex containing a lingually-located supernumerary root. This macrostructure is called radix entomolaris (RE). By analyzing the large number of available specimens it was possible to establish uniform and precise criteria for the identification of RE on M1 inf, M2 inf, and M3 inf. The analyses included separate as well as non-separate RE. The representation of the RE variants according to tooth types was mapped. Furthermore, the following relevant clinical variables with respect to RE were registered: degree of separation, divergence, apical bend, apical gracility, and fusion. Because of the nature of the material, the investigation was mostly qualitative and non-metric. The results should be of interest to clinical dentists, dental morphologists, and dental anthropologists.

[Proximal grooves in Danish mesolythic and neolythic molars]. / Approximale Furchen bei dänischen mesolithischen und neolithischen Molaren.

In 24 out of 350 mesolithic and neolithic sets of teeth from Denmark approximal grooves were found in the side teeth. 30 molars, 15 premolars and one canine tooth showed cervical, horizontally running grooves, i.e. 45 on distal and 21 on mesial tooth surfaces. The grooves lay in the root dentine with slight overlapping on the cervical enamel. They were polished smooth and well demarcated from the surrounding tooth surface. These grooves occurred in wellworn teeth (75%), and were associated with marginal bone absorption (70%) and caries (30%). These grooves could have been caused by toothpicklike bone clasps used for therapeutic and palliative purpose.