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Sleep pattern of tooth-grinding: Its relationship to dreaming
DEPARTMENT
OF REVIEWS Edited
AND
ABSTRACTS
by DR. J. A. SALZMANN, New PO?% City
AZZ inquiries regarding informatzon on reviews and abstracts should be directed to the respective authors. Articles or books for review in this department should be addressed to Dr. J. A, Salzmann, 654 Madison Ave., New York $1, NeU: York.
The
Effect
of
Occupational
Exposure
to
By Raymond Xeltser and Philip (Dec. Zl), 1964.
Radiation
E. Xartwell.
on
Mortality
of
Physicians
J. A. M. A. 190: 10.46-1048
The findings of t,his study support the hypothesis that occupational exposure to ionizing radiation has had a life-shortenin, w effect on radiologists and other physicians who use x-rays in their practice. This effect has been at least reduced, and possibly eliminated, in recent years. Not only cancer but other diseases as well have shown an excess mortality among radiologists. Sleep
Pattern
of
Tooth-Grinding:
Its
Relationship
to
Dreaming
By Georges R. Reding, William C’. Rubright, Allan Robert S. Daniels. Science 145: ‘725 (slug. 14), 1964.
Rechtschafen,
and
Simultaneous recordings of brain waves, rye movements, and masticatory muscle potentials throughout t,he night demonstrate a t,emporal relationship between episodes of bruxism and periods ol’ rapid eye movements indicative of dreaming. Twelve subjects in whom bruxism was known IO occur wcrc observed for one or two nights each, for a total of fourteen nights. ho mass&r contractions which occurred during gross body movements wcrc scorotl. Sounds of grinding were clearly unreliable indicators OC bruxism, because massive masscter (Aontracations indicated that noiseless but, vcr,v strenuous tooth-c1(~ncllirLg could o~ur. Masscter contractions of any amplitude WCPCrare during sleep cliaractcrizcd by high-amplitude, slow delta 13EG activit,g (sleep Stages III and IV). Masseter contractions during these stages were usually a c,oncomitant of other body movements and preceded by less than 2 minutes tltc onset of Stage II or of Stage I. Mass&r contractions were infrcqucnt, in Stage II of sleep, but not as infrequent as in Stages 111 ilnd IV. Pilot experiments with four normal subjects showed a similar relationship between sleep stage and massetcr cont,ractions, indicating that symptomatic> bruxism ma,y represent an c’xaggcratioll 0 f a normal phenomenon. Heightened electromyographic activit,? from the masseter leads was observed in conjunction with virtually all large movc~mr~nts ol’ the trunk or limbs. To decrease the possibility that this activity might have represcntcd a. spread of electrical activity from othor muscle groups) an additional measure was used. 708
Reviews and abstracts
709
Two metal plates were fitted onto corresponding upper and lower molar teeth and arranged in a circuit so that a signal was registered on the polygraph tracing whenever the pla,tes came into contact. Because at rest the lower teeth are normally separated from the upper teeth by a space elf a few millimeters, a meeting of the upper and lower teeth could serve as another index of rnassetcr contraction. Virtually all movements of the limbs and trunk were found to bc accompanied by a meeting of the upper and lower teeth as well as by electromyographic signs of masseter contraction. The close temporal association between periods of masseter contractions could be explained on the basis of the anatomic proximity (within the brain stem) of the motor nucleus of the trigeminal nerve, which is directly responsible for the contractions of the masticatory muscles, and the nucleus rcticularis pontis caudalis. Preliminary findings thus hold promise for the hypothesis, suggested by Michel and associates, that the spread of activity frorn the pontine reticular formation may not be confined to the visual syst.ern. Thumb-Sucking
in
an
Adult
By Eugene B. Brody. J. A. M. A.
189: 971 (Sept. al), 1964.
A physician describes the case of a 19-year-old girl who sucks her t.humb at bedtirne and during the night, despite attcrnpts to break the habit by wearing gloves, painting the thumb with a. bitter-tasting solution, and tying her hand to the bed. In reply to his request for recommendations, it is pointed out that in such a case the thumb-sucking may bc regarded as having some need-gratifying, anxiety-reducing, or conflict-solving function. Therefore, the source of the patient’s anxiety or the nature of the conflict must be deterrnined and dealt with. It is also possible that this is only the presenting aspect of a more extensive disorder, such as an obsessive-compulsive neurosis, a depression, or an early schizophrenia. In any event, a careful history should be taken, with special reference to the patient’s fears and fantasies about sleeping and going to bed. The social situation, particularly the patient’s relations with her family and boy friend (if any), should be explored. Occasionally, although it is rare in a person of this age, some change in a stressful psychosocial situation will be followed by the disappearance or modification of behavior of this kind. Psychiatric consultation, if available, is recommended. Diagnostic0 (Mandibular
Cefalometrico
del
Prognatismo
Inferior
(Cephalometric
Diagnosis
of
Prognathism)
By Guillermo Mayora.1 Her,rero. Rev. Pac. odontol. d.e la Universidad National (Bogot6, Colombia). Xeptember-December, 1963. Routine use of cephalometry by the oral surgeon is indispensable in th? diagnosis of dentofacial anomalies that require surgical treatment. One should establish the differential diagnosis of each case studied, classifying the anomalies in the soft tissues, teeth, jaws, temporomandibular articulation, and occlusion. In each of these groups must be noted the nature of the alterations according to
OF REVIEWS Edited
AND
ABSTRACTS
by DR. J. A. SALZMANN, New PO?% City
AZZ inquiries regarding informatzon on reviews and abstracts should be directed to the respective authors. Articles or books for review in this department should be addressed to Dr. J. A, Salzmann, 654 Madison Ave., New York $1, NeU: York.
The
Effect
of
Occupational
Exposure
to
By Raymond Xeltser and Philip (Dec. Zl), 1964.
Radiation
E. Xartwell.
on
Mortality
of
Physicians
J. A. M. A. 190: 10.46-1048
The findings of t,his study support the hypothesis that occupational exposure to ionizing radiation has had a life-shortenin, w effect on radiologists and other physicians who use x-rays in their practice. This effect has been at least reduced, and possibly eliminated, in recent years. Not only cancer but other diseases as well have shown an excess mortality among radiologists. Sleep
Pattern
of
Tooth-Grinding:
Its
Relationship
to
Dreaming
By Georges R. Reding, William C’. Rubright, Allan Robert S. Daniels. Science 145: ‘725 (slug. 14), 1964.
Rechtschafen,
and
Simultaneous recordings of brain waves, rye movements, and masticatory muscle potentials throughout t,he night demonstrate a t,emporal relationship between episodes of bruxism and periods ol’ rapid eye movements indicative of dreaming. Twelve subjects in whom bruxism was known IO occur wcrc observed for one or two nights each, for a total of fourteen nights. ho mass&r contractions which occurred during gross body movements wcrc scorotl. Sounds of grinding were clearly unreliable indicators OC bruxism, because massive masscter (Aontracations indicated that noiseless but, vcr,v strenuous tooth-c1(~ncllirLg could o~ur. Masscter contractions of any amplitude WCPCrare during sleep cliaractcrizcd by high-amplitude, slow delta 13EG activit,g (sleep Stages III and IV). Masseter contractions during these stages were usually a c,oncomitant of other body movements and preceded by less than 2 minutes tltc onset of Stage II or of Stage I. Mass&r contractions were infrcqucnt, in Stage II of sleep, but not as infrequent as in Stages 111 ilnd IV. Pilot experiments with four normal subjects showed a similar relationship between sleep stage and massetcr cont,ractions, indicating that symptomatic> bruxism ma,y represent an c’xaggcratioll 0 f a normal phenomenon. Heightened electromyographic activit,? from the masseter leads was observed in conjunction with virtually all large movc~mr~nts ol’ the trunk or limbs. To decrease the possibility that this activity might have represcntcd a. spread of electrical activity from othor muscle groups) an additional measure was used. 708
Reviews and abstracts
709
Two metal plates were fitted onto corresponding upper and lower molar teeth and arranged in a circuit so that a signal was registered on the polygraph tracing whenever the pla,tes came into contact. Because at rest the lower teeth are normally separated from the upper teeth by a space elf a few millimeters, a meeting of the upper and lower teeth could serve as another index of rnassetcr contraction. Virtually all movements of the limbs and trunk were found to bc accompanied by a meeting of the upper and lower teeth as well as by electromyographic signs of masseter contraction. The close temporal association between periods of masseter contractions could be explained on the basis of the anatomic proximity (within the brain stem) of the motor nucleus of the trigeminal nerve, which is directly responsible for the contractions of the masticatory muscles, and the nucleus rcticularis pontis caudalis. Preliminary findings thus hold promise for the hypothesis, suggested by Michel and associates, that the spread of activity frorn the pontine reticular formation may not be confined to the visual syst.ern. Thumb-Sucking
in
an
Adult
By Eugene B. Brody. J. A. M. A.
189: 971 (Sept. al), 1964.
A physician describes the case of a 19-year-old girl who sucks her t.humb at bedtirne and during the night, despite attcrnpts to break the habit by wearing gloves, painting the thumb with a. bitter-tasting solution, and tying her hand to the bed. In reply to his request for recommendations, it is pointed out that in such a case the thumb-sucking may bc regarded as having some need-gratifying, anxiety-reducing, or conflict-solving function. Therefore, the source of the patient’s anxiety or the nature of the conflict must be deterrnined and dealt with. It is also possible that this is only the presenting aspect of a more extensive disorder, such as an obsessive-compulsive neurosis, a depression, or an early schizophrenia. In any event, a careful history should be taken, with special reference to the patient’s fears and fantasies about sleeping and going to bed. The social situation, particularly the patient’s relations with her family and boy friend (if any), should be explored. Occasionally, although it is rare in a person of this age, some change in a stressful psychosocial situation will be followed by the disappearance or modification of behavior of this kind. Psychiatric consultation, if available, is recommended. Diagnostic0 (Mandibular
Cefalometrico
del
Prognatismo
Inferior
(Cephalometric
Diagnosis
of
Prognathism)
By Guillermo Mayora.1 Her,rero. Rev. Pac. odontol. d.e la Universidad National (Bogot6, Colombia). Xeptember-December, 1963. Routine use of cephalometry by the oral surgeon is indispensable in th? diagnosis of dentofacial anomalies that require surgical treatment. One should establish the differential diagnosis of each case studied, classifying the anomalies in the soft tissues, teeth, jaws, temporomandibular articulation, and occlusion. In each of these groups must be noted the nature of the alterations according to