Tooth Mobility and Glucose Metabolism

E. Cheraskin is Professor and Chairman of the Division of Oral Surgery and Oral Medicine, University of Alabama School of Dentistry, and Assistant Professor, Department of Medicine, Medical College of Alabama. Dr. Cheraskin received his M.D. from the University of Cincinnati College of Medicine and his D.M.D. from the University of Alabama School of Dentistry. He is a diplomate of the American Board of Oral Medicine, a Fellow of the American College of Dentists and a member of numerous professional organizations. His contributions to the literature have been many and varied. Dr. Cheraskin is Chairman of the Editorial Board of Practical Dental Monographs.

Introduction

The dental practitioner is daily perplexed by the cause of clinical tooth mobility. The gravity of such a finding is generally well known, for, untreated, it is very likely that the tooth will become so loose that it will exfoliate spontaneously or will necessitate extraction. It follows, then, that the detection of the cause(s) of tooth mobility in the earliest phase is important. This is the stage–probably the last one–at which the process may still be reversed.

The present therapeutic approach to clinical tooth mobility is one of eliminating all local irritating factors (e.g., occlusal trauma). This treatment plan frequently results in lessened tooth mobility; and, because of such relative success with local therapy, it is sometimes felt that clinical tooth mobility is largely or exclusively due to local, presumably mechanical, factors.

The present study will attempt to analyze the relationship.of systemic factors to clinical tooth mobility. Specifically, the research which will be reviewed in this report deals with glucose metabolism and clinical tooth mobility. This paper is designed to try to find the answer to one question: What is the relationship of glucose metabolism and clinical tooth mobility?

Review of the Literature

In order to comprehend the design and results of this study, it is necessary to review briefly: (1) clinical tooth mobility and (2) the present basis for the so-called “normal” glucose tolerance pattern.

Clinical Tooth Mobility

A number of different technics are available for measuring tooth mobility. However, it is generally agreed, among clinicians and in the standard writings, that the simplest and most practical method is that of determining digitally the degree of tooth movement. Usually, measurement is indicated on a three-point scale: the value zero (0) is assigned when there is no obvious clinical tooth mobility; the value 1 is used when tooth mobility is slight (generally less than 1 mm.); and the value 2, when tooth mobility is more marked (greater than 1 mm.).

Rudy and Cohen,^1,2 Kaplan,³ Rutledge⁴ and Martinez⁵ have all reported loosening of the teeth in diabetic patients. However, none of these reports attempts to quantitate tooth mobility and carbohydrate imbalance. Sheridan and his group⁶ have demonstrated, in a study of 100 routine dental patients, that 29% and 47% of those found to be diabetic demonstrated tooth mobility less than, and greater than, 1 mm., respectively. In other words, of those patients found to be suffering with diabetes mellitus, 3 out of 4 showed clinical tooth mobility. In contrast, Sheridan and his associates⁶ found that only one third of those who were unequivocally nondiabetic demonstrated clinical tooth mobility.

It appears, from these limited studies, that there is a relationship between carbohydrate metabolism and clinical tooth mobility. The conclusion to be drawn is that diabetic patients are more prone to demonstrate clinical tooth mobility than nondiabetic subjects; and the implication derived from these limited reports is that the blood glucose and tooth mobility pattern is linear–the higher the blood glucose, the greater the clinical tooth mobility.

Normal Glucose Tolerance Pattern

There are two general approaches for establishing normal values:⁷ statistical analysis and physiologic analysis.

Statistical Analysis–The present values for the normal glucose tolerance pattern have been largely derived from an examination of presumably healthy persons. In most cases, the subjects have been regarded as well if they seemed relatively asymptomatic on superficial interrogation and examination. Mosenthal and Barry⁸ have published a set of values which are generally regarded as representative of the normal, true glucose tolerance pattern. Their conclusions have been derived from the findings in 50 ambulatory hospital workers. On the basis of their observations, these two investigators suggest that the normal glucose tolerance curve is represented by (1) a fasting venous true glucose level of 100 mg./100 ml. or less, (2) no venous true glucose level greater than 150 mg./100 ml. and (3) a return of the venous true glucose level to 100 mg./100 ml. or less at the end of 2 hours.

Physiologic Analysis–At the time of this writing, no published reports are available which attempt to analyze the normal glucose tolerance pattern on the basis of the absence or presence of clinical tooth mobility, although clinical tooth mobility, as shown in the literature, appears to be associated with diabetes mellitus. However, four papers, pending publication,^9-12 attempt such a physiologic comparison. This report represents a summary of the findings in those four unpublished documents.

Method of Investigation

One hundred dental patients were studied in the Section on Oral Medicine at the University of Alabama School of Dentistry. As far as was feasible, the subjects were selected at random. The patients ranged in age from 6 to 69 years and included 22 males and 78 females. Each subject was carefully examined regarding possible clinical tooth mobility. The scoring was made on the basis of a three-point scale: (0) zero, when no tooth mobility was demonstrated by digital pressure; 1, when the teeth showed mobility less than 1 mm.; and 2, when clinical tooth mobility was greater than 1 mm.

A true glucose tolerance test was performed on each patient according to the methods of Somogyi^13,14 and Nelson.¹⁵ No preparatory diet was recommended except for complete fasting for 12 hours before the laboratory examination. A fasting venous true glucose value was determined in the morning. The patient was then given 100 Gm. of glucose to drink. At 30 minutes and at 1, 2 and 3 hours after the fasting, a sample of venous blood was drawn and blood glucose determinations were again made.

Results

The findings in this series of 100 patients will be considered in the form of the answers to six questions:

1. Is there a relationship between tooth mobility and age? If the answer is affirmative, does the correlation extend to the degrees of tooth mobility?
2. Is there a correlation between age and blood glucose? If the answer is yes, does the relationship prevail with age gradations?
3. How are blood glucose and tooth mobility related?
4. What happens to the blood glucose and tooth mobility patterns when the age factor is eliminated?
5. What changes in the relationship of tooth mobility and age occur when the blood glucose is kept constant?
6. What is normal blood glucose? More important, from a practical standpoint–what blood sample or samples would be most representative of glucose metabolism?

Tooth Mobility and Age

Figure 1 shows the percentage of patients in each age group with and without clinical tooth mobility. In the first group, under 9 years of age, the one patient in the series showed no clinical tooth mobility. Therefore, 100% “no clinical tooth mobility” is shown. It is clear from Figure 1 that, in the next age group, 10-29 years, only two thirds of the patients demonstrate no clinical tooth mobility; in other words, approximately 1 out of every 3 of the subjects has acquired clinical tooth mobility with increasing age. It can also be observed from Figure 1 that, in the third age group 30-49 years, half of the subjects are almost equally divided between those with and those without clinical tooth mobility; consequently, another 1 in 5 subjects has acquired tooth mobility. Finally, only 1 in 5 of the subjects in the last age group, 50-59 years, display no clinical tooth mobility. Thus, another 3 out of every 10 patients now demonstrate some degree of looseness of the teeth.

Fig. 1–Comparison of age and clinical tooth mobility.

One can conclude, from these observations, that there is a very definite relationship between tooth mobility and age. More specifically, one can state that, with increasing age, there is increasing tooth mobility. This observation is certainly not new, for it has been observed clinically and reported in many publications. On the basis of these past findings, two rather unfortunate conclusions have been evolved: (1) the implication prevails that some degree of clinical tooth mobility is normal in the adult, especially in the elderly patient; and (2) there is the added inference in clinical practice that age actually causes clinical tooth mobility. The only basis for these assumptions is the fact that most, or at least many, older persons possess clinical tooth mobility; in other words, the cause-and-effect relationship is based purely and simply on the commonness of tooth mobility and age. The absurdity of this conclusion can be shown by any one of a host of common examples. For example, if the terms “ubiquitousness” and “physiologic” are equivalent, then it follows that dental caries is a physiologic state, since 95% of the population is afflicted with dental decay.

Since age and tooth mobility correlate positively, the next question to be answered is whether this relationship extends to the degrees of tooth mobility. The findings in the 100 patients in this regard are shown in Figure 2.

Fig. 2–Comparison of age and degrees of tooth mobility.

In the age group 10-29 years, approximately 4 patients showed tooth mobility of less than 1 mm. to every 1 patient with severe (greater than 1 mm.) clinical tooth mobility. With increase in age, as demonstrated in the intermediate group (30-49 years), the frequency of slight and severe tooth mobility is almost equal.

One would expect, from the pattern shown in Figure 2, that both degrees of tooth mobility would increase in the last, the oldest, age group; but the graph demonstrates no such progressive increase in the frequency of severe mobility. The explanation for this discrepancy is not apparent in Figure 2. However, it is known that severe tooth mobility is more likely to lead to spontaneous exfoliation or extraction of the teeth. It is also a common clinical observation that tooth mobility is greatest in older individuals. Thus, the discrepancy in Figure 2 is probably due to the fact that edentulous patients were not included.

Age and Blood Glucose

One of the big problems in any study on clinical tooth mobility and glucose metabolism is to establish blood glucose normality. Figure 3 represents the relationship of age to blood glucose fasting at 30 minutes and at 1, 2 and 3 hours after the ingestion of glucose. It can be seen, in this figure, that there is a distinct positive correlation between age and the glucose tolerance patterns. At every point in the procedure, the youngest patients show the lowest blood glucose values; the oldest, the highest scores; and the intermediate patients, intermediate values.

Fig. 3–Comparison of age groups and glucose tolerance patterns.

A number of specific points are worth special consideration. For example, the mean fasting blood glucose in the young group is 77 mg./100 ml., in contrast with 84 and 88 mg./100 ml. for the intermediate and oldest age groups, respectively. It is also of interest that the 3-hour blood glucose value for the youngest age group is below the fasting level (77-71 mg./100 ml.). In the older age groups, this situation is progressively reversed. In other words, the 3-hour blood glucose values are higher than initially. Thus, it appears, within the limits of this testing procedure, that it is in the youngest patients that the blood glucose levels can be best righted after drinking glucose.

One can conclude, from these observations, that there is a relationship between age and glucose tolerance patterns: with increasing age, there are increasing blood glucose values. This observation has been observed clinically and reported in the literature. On the basis of these findings, two rather unfortunate conclusions have been drawn: first, it has been concluded that higher blood glucose is normal in the adult, particularly in the elderly patient; and second, these observations have led some investigators to contend that age actually causes higher blood glucose. The only basis for these assumptions is the fact that most, or at least many, older persons have higher blood glucose scores; that is, the cause-and-effect relationship is based purely and simply on the commonness of age and blood glucose.

Blood Glucose and Tooth Mobility

Thus far, evidence has been presented to demonstrate a distinct positive relationship between tooth mobility and age (Figs. 1 and 2) and between age and blood glucose (Fig. 3). The one other obvious correlation which remains to be analyzed is that between clinical tooth mobility and the glucose tolerance pattern.

Figure 4 shows the relationship between glucose tolerance patterns and clinical tooth mobility. It can be seen in this figure that the group with no clinical tooth mobility has lower blood glucose values at every point in the pattern. In addition, the mean fasting blood glucose finding in the group with no clinical tooth mobility (irrespective of age) is 77 mg./100 ml. Mention should be made, here, that this same mean fasting blood glucose value of 77 mg./100 ml. was observed for the youngest age group (irrespective of clinical tooth mobility) in Figure 3.

Fig. 4–Comparison of tooth mobility and glucose tolerance patterns.

These observations raise the question as to what is fasting blood glucose normality. It would appear, from this presumptive evidence, that fasting values at or near 77 mg./100 ml. are more nearly physiologic than the presently recognized broad range of a fasting blood glucose level less than 100 mg. / 100 ml.

It is also of interest to compare the glucose tolerance curves in groups with different tooth mobility patterns (Fig. 5). In the age category with no mobility, the blood glucose levels are lowest. In contrast, the group with less than 1 mm. and greater than 1 mm. tooth mobility show progressive rises of blood glucose at every temporal point. In other words, it seems that, in the main, those with greater degrees of tooth mobility show greater blood glucose levels than those without clinical tooth mobility.

Fig. 5–Comparison of degrees of tooth mobility and glucose tolerance patterns.

There are several other features about the curves in Figure 5 which deserve discussion. In the first place, as has been previously stated, the fasting blood glucose value in the patients with no clinical tooth mobility (irrespective of age) is exactly the same as the fasting blood glucose value in the youngest age group (irrespective of tooth mobility) as demonstrated in Figure 3. Secondly, following the ingestion of glucose, the blood glucose levels rise in all three groups. However, the initial rise is less in those subjects without clinical tooth mobility, compared with those with severe tooth mobility. Thirdly, immediately after the initial rise, the blood glucose level begins to decline in those patients without tooth mobility. In contrast, the blood glucose level remains the same, or even rises more, in those with clinical tooth mobility. There is, thus, the possibility that the homeostatic mechanisms in the mobility-free group are more efficient than those in the patients with tooth mobility. Finally, the 3-hour blood glucose level returns to, or drops below, the fasting level in the no-mobility group. The 3-hour blood glucose value in the other two groups is higher than initially. This might be interpreted as further evidence of the more effective homeostatic adjustments in the relatively healthier group (at least as judged by the absence of clinical tooth mobility).

One can conclude from Figure 5 that there is a relationship between blood glucose values and degrees of tooth mobility: the subjects with increasing tooth mobility also show increasing blood glucose values. The implication to be drawn from these observations is that the relationship is linear: the higher the blood glucose, the greater the tooth mobility.

Tooth Mobility and Blood Glucose (Constant Age Factor)

Thus far, a very definite positive relationship has been demonstrated between age, tooth mobility and blood glucose. The question which naturally arises is whether one or another of these three factors is the cause and which one or another may be the effect. In order to attempt an answer to this question, within the limits of the study, it is necessary to eliminate one factor at a time. The analysis which has been carried out in Figures 6-11 is based on maintaining the age factor constant.

It can be seen in Figure 6 that only the patients in the youngest age group, 10-29 years, have been studied. This figure shows that the lowest glucose values at every temporal point prevail in the group with no clinical tooth mobility. Attention should be called to the fact that the glucose tolerance pattern is relatively flat; that is, the fluctuations in glucose levels are less in the group with no clinical tooth mobility.

Fig. 6–Comparison of tooth mobility and glucose tolerance patterns: 10-29-year age group.

A number of other items which appear in this graph deserve consideration. First, it is noteworthy that the fasting blood glucose value is 76 mg./100 ml. This is surprisingly close to the mean fasting blood glucose value for the youngest age group (irrespective of tooth mobility) and the mobility-free group (irrespective of age). Second, the peak blood glucose level is reached sooner in the patients with no tooth mobility. Finally, the return to the original level occurs only in the mobility-free group. All of these findings suggest a more efficient homeostatic mechanism in the healthier group of patients.

With the age factor still constant, Figure 7 shows the relationship of glucose tolerance and degrees of tooth mobility. The first and obvious point to be made is that the greater the tooth mobility, the greater the blood glucose scores. Second, the more severe the tooth mobility, the higher the blood glucose rise after glucose ingestion. Third, the more loose the teeth, the longer the time required to reach a peak glucose level. Fourth, the greater the tooth mobility, the less the return to the original (fasting) level in 3 hours. And last, it is particularly interesting that the distinction between the patients with severe versus slight tooth mobility is greater than between those with slight versus no clinical tooth mobility.

Fig. 7–Comparison of degrees of tooth mobility and glucose tolerance patterns: 10-29-year age group.

A number of interesting conclusions are possible from an analysis of Figures 6 and 7. Certainly, it appears that age is not a factor, or at least not a serious determinant, in the relationship between tooth mobility and glucose values, since the age factor is constant. The correlation between severe clinical tooth mobility and glucose values is obvious. However, the glucose tolerance patterns for the patients with slight and with no clinical tooth mobility are not very different. It is possible that the lack of a clear-cut distinction may be due to one of two reasons. First, it is technically more difficult to discriminate between clinically slight and no mobility than it is to discriminate between severe and no tooth mobility. Second, there is the possibility that time has not been operative long enough to yield a significant difference; in other words, time has not compensated for the mildness of glucose imbalance. In order to answer this question of the time factor, the next age group was also studied.

Figure 8 is an analysis of tooth mobility and blood glucose levels for the next two decade groups, 30–49 years. It is clear from this chart that the patients with no tooth mobility demonstrate the lowest blood glucose values. A comparison of Figure 6 and Figure 8 (differing only in time, as measured by increasing age) shows, first, that the patterns in the intermediate age group (30-49 years) are more discrete than those in the younger group (10-29 years). These comparisons would tend to suggest that time, as well as blood glucose values, plays a role in tooth mobility. Secondly, it is noteworthy that the patterns for the patients with no mobility in the young and intermediate age groups are strikingly similar. In both instances the fasting blood glucose level is also strikingly similar (76 and 77 mg./100 ml.) and the peak is essentially the same (111 and 112 mg./100 ml.); and the height of the curve in both instances is reached in 30 minutes. Finally, in each situation the blood glucose returns to below the fasting level in 3 hours.

Fig. 8–Comparison of tooth mobility and glucose tolerance patterns: 30-49-year age group.

Figure 9 illustrates the relationship of the glucose tolerance patterns and the degrees of clinical tooth mobility. The first and obvious conclusion is that there is a relationship between glucose tolerance patterns and gradations of clinical tooth mobility. Second, the patterns for the intermediate age group (Fig. 9) are more distinct than those observed in the youngest age group (Fig. 7). This tends to confirm the observation that time, in addition to blood value, is a factor in the tooth mobility pattern. Also, the conclusion can be drawn that the relationship is linear; in other words, the higher the blood glucose and the greater the time factor, the more severe the clinical tooth mobility.

Fig. 9–Comparison of degrees of tooth mobility and glucose tolerance patterns: 30-49-year age group.

The next logical step is to examine the oldest age group (50-69 years) in a similar manner. Since time has been operative even longer, the findings should be even more clear-cut than those observed in the intermediate age category (30-49 years).

Figure 10 depicts this comparison of the glucose tolerance patterns and tooth mobility in the oldest age group (50-69 years). It may be seen in this figure that the relationships between the patterns for those patients with no mobility versus the patterns for those with clinical tooth mobility are not as clear-cut as was shown in Figure 8. Once again, precise reasons cannot be given for this lack of correlation. It is clear from the original data that many patients in the oldest age group who have tooth mobility also show evidence of hypoglycemia rather than hyperglycemia. These data undoubtedly lower the mean glucose pattern for the patients with clinical tooth mobility. Unquestionably, this factor, in part, explains the gradual loss of distinction between the curves. Further, there is the likelihood that, with time, other factors besides glucose metabolism may enter into the genesis of tooth mobility and may play an increasingly important role. Thus, there is the possibility that time can serve in two ways. First, more time multiplied by small variations in blood glucose can equal the same end-result as less time plus greater variations in blood glucose levels. This can be effectively illustrated in a simple equation:

Fig. 10–Comparison of tooth mobility and glucose tolerance patterns: 50-69-year age group.

There is also a second possibility, as has been alluded to earlier. With increasing time (age), more patients suffer with hyperglycemia. However, with increasing time (age) more individuals also suffer with hypoglycemia.

To complete the picture, an analysis was made of glucose tolerance patterns and degrees of clinical tooth mobility in the oldest age group. In Figure 11, one observes a number of interesting factors which deserve consideration. (1) The distinction on the basis of gradations of tooth mobility (as shown earlier in the intermediate age group) is lost. (2) The loss of correlation does not occur, in the main, in the group with no clinical tooth mobility. For example, the fasting blood glucose value for the mobility-free group of old patients is strikingly similar to that observed in the young and intermediate age groups (78, 77 and 76 mg./100 ml., respectively). (3) The return to the initial levels in 3 hours is also strikingly similar for the three groups: 76-66 (-10) mg./100 ml. for the youngest group; 77-73 (-4) mg./100 ml. for the intermediate category; and 79-81 (+2) mg./100 ml. for the oldest group. As a matter of fact, there are, in general, more similarities between the no mobility groups at different ages than there are similarities for the mobility groups at the same ages. This observation would tend to contradict the present thought that glucose levels and tooth mobility are normally higher with advancing age. The patterns observed in Figures 10 and 11 also add weight to the clinical observation that both hyperglycemia and hypoglycemia are associated with clinical tooth mobility.

Fig. 11–Comparison of degrees of tooth mobility and glucose tolerance patterns: 50–69-year age group.

Hypoglycemia and Tooth Mobility

Thus far, a very definite positive relationship has been demonstrated between tooth mobility and blood glucose. The evidence indicates that, with increasing time, as measured by age, this correlation is seemingly diminished. The two likely possibilities for explaining the contribution of age to this biochemical-clinical relationship are the appearance of more patients with hypoglycemia in the advancing age groups and the introduction of other variables, both local and systemic, in the genesis of tooth mobility. The question which naturally arises is whether hypoglycemia is an important factor in tooth mobility. Figures 12-14 illustrate an analysis of this factor.

In Figure 12 a comparison has been made between fasting blood glucose values and clinical tooth mobility in the youngest age group. It should be recalled that clinical tooth mobility was graded on a three-point scale (0, to indicate no clinical tooth mobility; 1, for less than 1 mm. mobility; and 2, for greater than 1 mm. of tooth mobility). These tooth mobility scores were added, and the mean values at the various blood glucose levels were charted. It can be seen from Figure 12 that mean clinical tooth mobility is least in the group with blood glucose values of less than 79 mg./100 ml. In the groups with higher blood glucose values, the frequency of clinical tooth mobility increases. Of particular interest is the fact that the occurrence of clinical tooth mobility decreases in those patients with initial blood glucose values greater than 99 mg./100 ml. Thus, the relationship between fasting blood glucose values and clinical tooth mobility is not linear, nor is it any other particular pattern. In other words, it is not true that the higher the blood glucose level, the greater the tooth mobility. This, as has already been pointed out, is probably due to two factors: (a) these young patients do not, in general, show very high or very low glucose levels; and (b) young persons have not lived long enough to show the effects of time multiplied by slight glucose imbalance.

Fig. 12–Comparison of fasting blood glucose and tooth mobility: 10-29-year age group

Figure 13 demonstrates the relationship of fasting blood glucose and tooth mobility in the intermediate age group (20-39 years). It is clear from Figure 13 that the pattern is not chaotic (as in Figure 12), nor linear. Rather, one sees a parabola. This is probably due to several factors. In the first place, there are now more patients with hyperglycemia and hypoglycemia than in the youngest group. Secondly, these patients have been suffering with these glucose problems longer (in point of time). Of particular interest is the observation that the least amount of tooth mobility seems to be present in the group of patients demonstrating fasting blood glucose levels of 80-89 mg./100 ml.

Fig. 13.- Comparison of fasting blood glucose and tooth mobility: 30-49-year age group.

In Figure 14 the relationship of fasting blood glucose to tooth mobility in the oldest age group (50-69 years) is demonstrated. It is clear from this chart that the parabola described for the intermediate age group has been lost. This cannot be explained on the basis of the number of hypoglycemic persons, for, in fact, there are many more in the oldest age group than in the intermediate category. The most likely explanation is that other factors (both local and systemic) in the genesis of clinical tooth mobility have been introduced with added time which were not present in the younger age categories.

Fig. 14–Comparison of fasting blood glucose and tooth mobility: 50-69-year age group.

Therefore, one may conclude that blood glucose and tooth mobility are, indeed, related. But the relationship is not linear; that is, it is not true that the higher the blood glucose the greater the tooth mobility. Rather, it appears that there is a small range of blood glucose normality characterized by a relatively small frequency of clinical tooth mobility. As the blood glucose increases, there is increased clinical tooth mobility. Significantly, as the blood glucose decreases, there is once again an increased frequency of clinical tooth mobility. However, with time, other factors enter into the picture which also contribute to the appearance of clinical tooth mobility.

Physiologic Glucose Values

Evidence has been shown that tooth mobility increases with age (Fig. 1) and that, even more specifically, degrees of tooth mobility parallel advancing age (Fig. 2). However, no evidence is available in this report or in any other publication that age, per se, causes tooth mobility. Obviously, there is also no proof that increasing tooth mobility causes advancing age.

Evidence has been presented in Figure 3 that there is a distinct positive correlation between age and the glucose tolerance pattern. However, there is no proof in this report, or in any other published document, that age causes increased blood glucose values. Similarly, there is no indication from any study that the higher blood glucose level causes increased age.

Finally, the data in this study demonstrate a very definite relationship between glucose tolerance patterns and clinical tooth mobility (Fig. 4) and gradations of tooth mobility and glucose levels (Fig. 5). There is no published report indicating that increasing tooth mobility causes higher blood glucose concentrations; but there is some evidence from this study, as well as from other published reports, that higher blood glucose levels might well be one of the causative factors in the production of clinical tooth mobility.

Therefore, the next question which naturally arises is: What criteria should be used for the normal glucose tolerance pattern? Standards have already been set⁸ which are presently being followed as yardsticks of glucose normality. These standards for normality include a fasting blood glucose of less than 100 mg./100 ml. Some investigators prefer to regard a fasting blood glucose of 60-100 mg./100 ml. as more representative of the physiologic carbohydrate state. The present yardsticks indicate that the blood glucose level, at its peak, must be below 150 mg./100 ml. The present requirements demand that, in 2 hours, the blood glucose level return to below 100 mg./100 ml.

It is safe to assume, and there is no report which would negate this assumption, that tooth mobility is not a sign of health. Therefore, it would, indeed, be interesting to develop the normal glucose tolerance pattern for patients with no clinical tooth mobility. Naturally, this glucose tolerance pattern would not be definitive of complete health, since patients may not demonstrate clinical tooth mobility but may still show other symptoms and signs which specifically indicate disease. Nonetheless, it would be interesting to develop the glucose tolerance pattern for the mobility-free group as one step closer to the glucose metabolic picture of healthy man.

Figure 15 depicts these relationships. It shows that the fasting blood glucose value, irrespective of age, varies by only 3 mg./100 ml. (76-79 mg./100 ml.). Although this graphic depiction is not a perfectly straight line, the line is, nonetheless, almost parallel to the abscissa. The mean blood glucose levels for patients without tooth mobility at the 30- and 60-minute intervals increases sharply with age. In contrast, the 2-hour and 3-hour scores at the various age levels are relatively constant, although certainly not so consistent as the fasting determinations.

Fig. 15–Comparison of blood glucose values & age in patients with no clinical tooth mobility.

The statement has already been made that age, in itself, does not produce higher blood glucose levels. However, it is certainly true that older persons do demonstrate higher glucose concentration. This is probably due to the fact that older persons are, in the main, more ill. Therefore, it would seem logical that the ideal glucose tolerance pattern would be that observed for patients without clinical tooth mobility in the youngest age group. Thus, a fasting blood glucose level at or near 76 mg./100 ml., a rise to or about 111 mg./100 ml. and a return to or about 72 mg./100 ml. in 2 hours seems to be the most desirable glucose tolerance pattern.

The last question which arises is whether it is essential that the entire glucose tolerance test be performed. Put another way: Is there one sample, or more samples, which will provide the same or almost the same amount of diagnostic information as the entire glucose tolerance test? Should the answer to this question be in the affirmative, the practical implications are quite clear: then, the practitioner would have need of performing less laboratory testing than is normally required to execute the entire glucose tolerance test.

Figure 15 shows that the most consistent finding is the fasting blood glucose value. The variations, even in the light of the age factor, are only of a magnitude of 3 mg./100 ml. Next most constant are the 3-hour determinations, where, even in the light of the age factor, the values range from 76-77 to 81–a difference of 15 mg./100 ml. Third most consistent are the 2-hour determinations, where the range is 72-90 mg./100 ml. (a difference of 18 mg./100 ml.). The two phases of the glucose tolerance pattern which are least diagnostic are the 30-minute and the 60-minute samples.

Summary

1. An attempt has been made herein to analyze the present-day thinking in connection with clinical tooth mobility and glucose metabolism.
2. The evidence from the literature suggests that the relationship between glucose metabolism and clinical tooth mobility is linear–that is, the higher the blood glucose, the greater the tooth mobility.
3. The findings in this report substantiate the well-reported observation that clinical tooth mobility and age are correlated. In other words, with advancing age there is increasing clinical tooth mobility. However, there is no evidence to support the idea that age causes tooth mobility.
4. Information derived from this study supports the common observation that there is a distinct correlation between age and blood glucose; in other words, older individuals are more likely to demonstrate higher blood glucose levels. However, one cannot conclude from these observations that age causes hyperglycemia. Probably, older individuals display higher glucose levels because they are, in general, more ill.
5. From this report, it appears that there is a definite correlation between blood glucose and clinical tooth mobility: the patients displaying the highest glucose levels also demonstrate the greatest degrees of clinical tooth mobility.
6. According to the findings in this study, age exerts a role in the disease process by contributing the time factor necessary for minimal or subclinical disease states to become clinically evident.
7. It appears that clinical tooth mobility is associated with glucose metabolism in a parabolic, rather than in a linear, relationship–that is, patients with hypoglycemia and hyperglycemia demonstrate the same clinical finding.
8. One cannot conclude, from the work analyzed in this report, that glucose, per se, causes clinical tooth mobility. A number of factors must be operating to produce this important clinical sign. Moreover, glucose metabolism is only a reflection of the interplay of a host of nutritional, hormonal and psychologic conditions. The final answer must await the identification and evaluation of these many different factors.
9. For the detection of the patient with carbohydrate imbalance, the glucose tolerance test is a very helpful tool. However, in situations where it is not possible to perform the entire procedure, single samples provide diagnostic information. In situations where only one sample can be taken, the fasting determination seems preferable. The 3-hour determination rates second; and the 2-hour determination, third. The values of least diagnostic importance are the 30-minute and the 60-minute determinations.
10. From these studies, it appears that the physiologic fasting blood glucose values may be of a smaller range than is generally considered normal. At the present time, a fasting blood glucose value of 60-100 mg./100 ml. is regarded within normal limits. However, values close to 77 mg./100 ml. are much more representative of physiologic fasting blood glucose values.

References Cited:

1. Rudy, A., and Cohen, M. M.: “The oral aspects of diabetes mellitus,” New England J. Med. 219:503, Oct. 6, 1938.
2. Rudy, A., and Cohen, M. M.: “Oral aspects of diabetes mellitus,” A.D.A. 29:523, April, 1942.
3. Kaplan, N.: “Oral symptomatology of diabetes mellitus,” Pennsylvania D. J. 41:50, 60, November, 1938.
4. Rutledge, C. E.: “Oral and roentgenographic aspects of the teeth and jaws of juvenile diabetics,” A.D.A. 27:1740, November 1940.
5. Martinez, E.: “Diabetes in dental practice,” Abstr. 1:178, March, 1956.
6. Sheridan, R. C., Jr.; Cheraskin, E.; Flynn, F. H.; and Hutto, A. C.: “Epidemiology of diabetes mellitus: II. A study of 100 dental patients,” Periodont, 30: 298, October, 1959.
7. Ivy, A. C.: “What is normal or normality?” Bull. Northwestern Univ. M. School 18:22, Spring, 1944.
8. Mosenthal, H. O., and Barry, E.: “Criteria for and interpretation of normal glucose tolerance test,” Int. Med. 33: 1175, November, 1950.
9. Cheraskin, E., and Moller, P.: “The normal glucose tolerance pattern: The development of blood glucose normality by an analysis of oral signs (dental findings),” West. Soc. Periodont. In press.
10. Moller, P., and Cheraskin, E.: “The relationship of fasting blood glucose to oral signs (dental findings)” (to be published).
11. Moller, P., and Cheraskin, E.: “The relationship of two-hour blood glucose to oral signs (dental findings)” (to be published).
12. Moller, P., and Cheraskin, E.: “The relationship of three-hour blood glucose to oral signs (dental findings)” (to be published).
13. Somogyi, M.: “A new reagent for the determination of sugars,” Biol. Chem. 160:61, September, 1945.
14. Somogyi, M.: “Determination of blood sugar,” Biol. Chem. 160:69, September, 1945.
15. Nelson, N.: “A photometric adaptation of the Somogyi method for the determination of blood sugar,” Biol. Chem. 153:375, May, 1944.