4rchs oral Lhol. Vol. 22. pp. 55 10 57. Pergamon
Press
1977. Printed
in Great Britain.
A COMPARISON BETWEEN MEDIAEVAL MODERN BRITISH MANDIBLES School of
AND
SANDRA E. FRAKEand D. H. GOOSE Dental Surgery, University of Liverpool, Pembroke Place, P.O. Box 147, Liverpool, L69 3BX, England
Summary-A recently excavated site near Liverpool, yielded skeletal remains of a mediaeval population. It was possible to measure 36 mandibles, all of which were male. They were similar in size to those from a comparable Mediaeval site in Scarborough but generally larger in linear dimensions than a British 17th-18th Century sample. The mandibular angle was smaller.
INTRODUCTION
Brash (1930) suggested the hypothesis that overcrowding of teeth, common in modern Western European populations, is due to the intermingling of people from dissimilar stocks. This theory as far as Britain is concerned implies mixture with groups from the European Continent with smaller dental arches. There is, however, no evidence for this; in fact, clinical observation suggests palate size is considerably larger in many Europeans. Between 14th-17th Century, when the arch reduction was occurring, there were no major population movements into Britain. Hooton (1946) postulated that reduction of jaw size in recent times is due to a speeding up of the existing evolutionary tendency. In fact several investigators have noted that maxillary arches appear to be narrower in recent times compared to the mediaeval period (Goose, 1962; Goose and Parry, 1974; LundStrom and Lysell, 1955; Lysell, 1958). Very few studies have been carried out on the mandible, presumably because of the difficulty of sexing isolated mandibles in museum material. Moore, Lavelle and Spence (1968) described measurements on 517 mandibles from Neolithic times onwards. They noted reductions throughout the whole period in bicondylar width, projective length of the body, height at the symphysis, and projective height of the ramus and also between mediaeval and modem samples. Unfortunately the majority of their material was pooled for both sexes and therefore it is uncertain whether some of the effect was due to variation in the proportions of males and females in different groups. Later, however, Lavelle (1974) measured male mandibles from the Anglo Saxon and modern periods and found that various ramus dimensions decreased between the Saxon period and 16th-18th Century. MATERIALS AND METHODS
Norton Priory near Liverpool was founded by a group of Augustinian monks in 1133 A.D. and was used as a place of worship and labour until 1536 A.D. Today only the undercroft of the West range is left standing. Excavations in 197s-1973 recovered 92 skeletons or remains of skeletons, the majority of which were 55
buried in shallow earth graves. Some were buried in stone coffins and these were probably the graves of higher officials of the community, or local patrons. Of the total number of individuals fou’nd, 72 were sexed as male, and 9 female, by employing standard morphological and metrical techniques on both cranial and postcranial bones, two being impossible to assess. Nine were children. Measurements were possible on 36 male mandibles of adult individuals, some being incomplete, however, and not allowing all measurements to be made. Morant (1936) in his classical work on the mandible describes various standardized measuring techniques using callipers and a mandible board. In agreement with Moore, Lavelle and Spence (1968), only six of Morant’s measurements were attempted; however in most instances the symphyseal height could not be recorded ‘owing to post mortem damage and this measurement has therefore been omitted. All measurements were made with the mandible in the standard horizontal position defined by Morant when the mandible is placed on a horizontal surface with the teeth uppermost. T’he following dimensions of the mandible were measured: (1) Bicondylar width-the maximum breadth outside the condyles, measured between the lateral poles of the right and left condyles. (2) Minimum antero-posterior breadth of ramusmeasured at any inclination to the horizontal at about the level of the molar teeth. Morant suggested that the measurements for ramus breadth be made on the left side of the mandible, but if this was defective the right side could be used and this has been carried out in the present study. (3) Projective height of ramus-from the most superior point on the left condyle to the standard horizontal plane (i.e. the base of the measuring board), measured in the vertical plane. (4) Projective length of body-from the most anterior point in the symphyseal region to the intersection of the standard horizontal and rameal planes (i.e. the hinge-point of the inandible board), measured in the horizontal, mid-sagittal plane. (5) Mandibular angle--the angle between the standard horizontal and rameal planes.
56
Sandra E. Frake and D. H. Goose
Table 1. A comparison of the present mediaeval results with that of another mediaeval sample from Scarborough (Moore) and a modern series, Farringdon Street (Cleaver, 1937)
n Bicondylar width Minimum breadth of ramus Projective height of ramus Projective length of body Mandibular angle
11 36 12 13 13
Norton Priory X SD. 119.96 31.82 60.87 76.69 119.11
n
5.79 1.91 4.69 3.66 6.52
14 19 19 19 19
Scarborough x S.D. 120.00 31.90 58.70 72.30 118.42
5.61 2.62 5.67 6.10 6.45
n
Farringdon x
23 40 36 40 40
117.7 30.9 62.2 74.9 121.7
Street S.D. 3.75 2.60 3.54 3.76 5.67
Linear dimensions in mm, angle in degrees. S.D. standard deviations.
Measurements (1) and (2) were made with dial callipers calibrated to 0.05 mm. Measurements (3), (4), and (5) were made using a mandible board. All linear dimensions are recorded in millimetres, and the mandibular angle was determined to the nearest 0.5”. RESULTS
As a test of the repeatability of measurements, five mandibles were taken at random and each measured four times at daily intervals. An analysis of variance showed that the inconsistencies of measurement were insignihcant compared to the difference between mandibles. Table 1 gives a comparison with male data from Scarborough (12th-16th Century) which was obtained from Dr W. J. Moore (personal communication). This was the only material available which was sexed as male and therefore comparable with the present lindings. There is fairly close agreement and r-tests showed there were no significant differences with the exception of the projective length of the body which was larger in the Norton Priory group (p
Press
1977. Printed
in Great Britain.
A COMPARISON BETWEEN MEDIAEVAL MODERN BRITISH MANDIBLES School of
AND
SANDRA E. FRAKEand D. H. GOOSE Dental Surgery, University of Liverpool, Pembroke Place, P.O. Box 147, Liverpool, L69 3BX, England
Summary-A recently excavated site near Liverpool, yielded skeletal remains of a mediaeval population. It was possible to measure 36 mandibles, all of which were male. They were similar in size to those from a comparable Mediaeval site in Scarborough but generally larger in linear dimensions than a British 17th-18th Century sample. The mandibular angle was smaller.
INTRODUCTION
Brash (1930) suggested the hypothesis that overcrowding of teeth, common in modern Western European populations, is due to the intermingling of people from dissimilar stocks. This theory as far as Britain is concerned implies mixture with groups from the European Continent with smaller dental arches. There is, however, no evidence for this; in fact, clinical observation suggests palate size is considerably larger in many Europeans. Between 14th-17th Century, when the arch reduction was occurring, there were no major population movements into Britain. Hooton (1946) postulated that reduction of jaw size in recent times is due to a speeding up of the existing evolutionary tendency. In fact several investigators have noted that maxillary arches appear to be narrower in recent times compared to the mediaeval period (Goose, 1962; Goose and Parry, 1974; LundStrom and Lysell, 1955; Lysell, 1958). Very few studies have been carried out on the mandible, presumably because of the difficulty of sexing isolated mandibles in museum material. Moore, Lavelle and Spence (1968) described measurements on 517 mandibles from Neolithic times onwards. They noted reductions throughout the whole period in bicondylar width, projective length of the body, height at the symphysis, and projective height of the ramus and also between mediaeval and modem samples. Unfortunately the majority of their material was pooled for both sexes and therefore it is uncertain whether some of the effect was due to variation in the proportions of males and females in different groups. Later, however, Lavelle (1974) measured male mandibles from the Anglo Saxon and modern periods and found that various ramus dimensions decreased between the Saxon period and 16th-18th Century. MATERIALS AND METHODS
Norton Priory near Liverpool was founded by a group of Augustinian monks in 1133 A.D. and was used as a place of worship and labour until 1536 A.D. Today only the undercroft of the West range is left standing. Excavations in 197s-1973 recovered 92 skeletons or remains of skeletons, the majority of which were 55
buried in shallow earth graves. Some were buried in stone coffins and these were probably the graves of higher officials of the community, or local patrons. Of the total number of individuals fou’nd, 72 were sexed as male, and 9 female, by employing standard morphological and metrical techniques on both cranial and postcranial bones, two being impossible to assess. Nine were children. Measurements were possible on 36 male mandibles of adult individuals, some being incomplete, however, and not allowing all measurements to be made. Morant (1936) in his classical work on the mandible describes various standardized measuring techniques using callipers and a mandible board. In agreement with Moore, Lavelle and Spence (1968), only six of Morant’s measurements were attempted; however in most instances the symphyseal height could not be recorded ‘owing to post mortem damage and this measurement has therefore been omitted. All measurements were made with the mandible in the standard horizontal position defined by Morant when the mandible is placed on a horizontal surface with the teeth uppermost. T’he following dimensions of the mandible were measured: (1) Bicondylar width-the maximum breadth outside the condyles, measured between the lateral poles of the right and left condyles. (2) Minimum antero-posterior breadth of ramusmeasured at any inclination to the horizontal at about the level of the molar teeth. Morant suggested that the measurements for ramus breadth be made on the left side of the mandible, but if this was defective the right side could be used and this has been carried out in the present study. (3) Projective height of ramus-from the most superior point on the left condyle to the standard horizontal plane (i.e. the base of the measuring board), measured in the vertical plane. (4) Projective length of body-from the most anterior point in the symphyseal region to the intersection of the standard horizontal and rameal planes (i.e. the hinge-point of the inandible board), measured in the horizontal, mid-sagittal plane. (5) Mandibular angle--the angle between the standard horizontal and rameal planes.
56
Sandra E. Frake and D. H. Goose
Table 1. A comparison of the present mediaeval results with that of another mediaeval sample from Scarborough (Moore) and a modern series, Farringdon Street (Cleaver, 1937)
n Bicondylar width Minimum breadth of ramus Projective height of ramus Projective length of body Mandibular angle
11 36 12 13 13
Norton Priory X SD. 119.96 31.82 60.87 76.69 119.11
n
5.79 1.91 4.69 3.66 6.52
14 19 19 19 19
Scarborough x S.D. 120.00 31.90 58.70 72.30 118.42
5.61 2.62 5.67 6.10 6.45
n
Farringdon x
23 40 36 40 40
117.7 30.9 62.2 74.9 121.7
Street S.D. 3.75 2.60 3.54 3.76 5.67
Linear dimensions in mm, angle in degrees. S.D. standard deviations.
Measurements (1) and (2) were made with dial callipers calibrated to 0.05 mm. Measurements (3), (4), and (5) were made using a mandible board. All linear dimensions are recorded in millimetres, and the mandibular angle was determined to the nearest 0.5”. RESULTS
As a test of the repeatability of measurements, five mandibles were taken at random and each measured four times at daily intervals. An analysis of variance showed that the inconsistencies of measurement were insignihcant compared to the difference between mandibles. Table 1 gives a comparison with male data from Scarborough (12th-16th Century) which was obtained from Dr W. J. Moore (personal communication). This was the only material available which was sexed as male and therefore comparable with the present lindings. There is fairly close agreement and r-tests showed there were no significant differences with the exception of the projective length of the body which was larger in the Norton Priory group (p
