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Functional mouth protectors for contact sports
W ATTS— W O O L A R D — S IN G E R . . . V O L U M E 49, JU L Y 1954 • 7
for this technic of reconstruction. In two of the seven cases, the patients died with the recurrence of the disease; in two cases exposures of the prosthesis resulted, in one case intraorally, in the other extraorally. In the latter case, the opening was closed successfully; the intraoral ex posure still persists. In the three remain ing cases, the patients had uneventful recoveries after primary reconstruction. In the successful cases, eight months is the longest interval that has elapsed since the insertion of the prosthesis. The cases are being followed carefully to observe any clinical manifestations of unfavorable tissue reaction. Concurrent with this clinical study, a laboratory research project is being conducted with the use of live animals. The results of this study will be reported on its conclusion.
SUM M ARY
Methyl methacrylate was used in an effort to find a suitable material for im mediate and permanent replacement of the resected mandible. Satisfactory pros thetic mandibles can be produced from detailed measurements and roentgeno grams. The only cause of early failure has been excessive tension of the tissues overlying the implanted prosthesis. The long-range effect of this material on tissue will be reported at the conclusion of clinical and laboratory studies now in progress. It is hoped that this report will stimulate further investigation of this and other materials that may be adaptable for use in this important phase of surgical prosthetic reconstruction.
Functional mouth protectors for contact sports George Watts, D .D .S .; Archie Woolard, D .D .S ., and Carl E. Singer, D .D .S ., Chicago
Th e two main purposes of this article are (1) to stress the necessity for mouth pro tectors in contact sports and (2) to pre sent a simplified technic by which the basic requirements can be incorporated into a functional mouth protector. A mouth protector, any device afford ing protection to the lips, teeth, bony supporting structure and temporoman dibular joint, may be merely a piece of sponge rubber held between the teeth, or it may be an expensive, elaborately constructed device fitted to the teeth. The idea of a mouth protector is not new in
athletics and certainly not in dentistry. T h e need for such a device was realized as far back as 1927.1 Boxers began to de sire something to protect them from the violent blows they received— blows that lacerated lips and fractured teeth and bony supporting structures, blows that sometimes resulted in death. The dentist became interested in help ing athletes gain this protection. Mouth
C o ll e g e
of
D e ntistry,
I. A b ram s, M a r c h 1930.
A.
M.
U n iv e rsity o f P ra c tic a l
Illin o is.
hints.
D.
D ig e s t 36:200
8 • T H E J O U R N A L O F THE A M E R IC A N DEN T A L A S S O C IA T IO N
protectors were fabricated; as time went by, descriptions of various technics for their construction were published. A satis factory mouth protector must be so con structed that it ( 1 ) affords maximum protection, (2 ) will not be rejected by the athlete because it encroaches on his airway when he is forced to breathe through his mouth, (3) will not make speech difficult or impossible, (4) will not be uncomfortable and (5) will re main in place. In view of the fact that functional mouth protectors have been developed for some time, it is surprising that they are not more popular among amateur athletes. One of the reasons is the failure of the dental profession to educate the laity concerning the absolute necessity of the use of mouth protectors in contact sports. Another reason is that the tech nics used in their fabrication have made the cost prohibitive in the majority of cases. A recent survey of 62 colleges, made by the University of Missouri, showed that 733 dental injuries were incurred in one football season.2 Cathcart3 states that a survey recently conducted in three states showed that over 50 per cent of injuries to high school players occur in and about the oral cavity. W ith the great increase in number of participants in high school, college and even grammar
regions in which 48 per cent of the in juries occur. Only a limited number of schools make any attempt to provide any sort of protection for the region where 52 per cent of the injuries occur. If the public is convinced of and educated to the necessity of mouth protectors in con tact sports, it will insist that they be made available to the young people par ticipating in any and all contact sports. The magazine Life4 with the controversial pictures of misnamed players who had lost their anterior teeth while playing football probably did more in the way of public education in the need of some form of mouth protection than the dental profession had done in years. As the situa tion stands today, something must be done to make mouth protection available to all school athletes; otherwise the stigma associated with contact sport injuries will increase to the point where such sports will be discouraged and frowned on. Every practicing dentist should recog nize the importance of this problem of protective dentistry and should do his part in its solution. For the most part, it is a problem of making functional mouth protectors available to all amateur athletes participating in contact sports. T h e first necessity is a technic which in corporates the following features: 1.
The apparatus is simple in design
school contact sports, the number of den tal injuries, if accurately compiled to in clude injuries of all participants, would
and construction; it provides ample func
prove astounding. A functional mouth protector not only
apparatus require a limited amount of time in the dental chair. 3. A limited amount of laboratory
lends protection to the oral cavity and associated structures but also minimizes the force of blows transmitted to the brains— blows which might lead to un consciousness, concussion with permanent or cumulative injury to the brain and, in extreme cases, even to death. Schools spend on an average $90 to
tional protection. 2. T h e making and adaptation of the
time is required. 4. T h e expense of materials used in the preliminary work is kept at a mini m um ; the materials best adapted to the
$120 annually to outfit each football player with protective clothing, which
2. Vanet, R andy . ’ G r id ir o n c h a lle n g e . D. Survey 27:1258 S e p t. 1951. 3. C a t h c a r t, J. F. M o u t h p r o te c to r s fo r c o n ta c t sp o rts. D. D ig e s t 57:346 A u g . 1951.
affords him
4. The fig h t in g Se p t. 29, 1952.
protection only for
those
Irish
lo o k
to u g h
a g a in .
Life
33:60
W ATTS— W O O L A R D — S IN G E R . . . V O L U M E 49, JU L Y 1954 • 9
purpose are used in the finished appa ratus. TECH N IC FOR CONSTRUCTION
The first step in the construction of a mouth protector consists of recording the patient’s normal bite in wax. One and a half sheets of soft baseplate wax is heated and folded together to form a horseshoe
bite-block (illustration, above left). The block is warmed and inserted in the mouth, and the patient is instructed to bite. A small wax spatula is inserted in the block close to the lower occlusal plane between the anterior teeth to prevent complete closure. Wax 2 mm. in thickness is desirable between the incisal edges of the anterior teeth. The patient is in structed to bite and to thrust the tongue
A b o v e le ft : H o rsesh o e-sh a p ed b ite-b lo ck w ith in stru m en t in serted . A b o v e rig h t: A d a p te d b iteblock in m ou th . C e n te r l e f t : C ross s ec tio n o f b ite -b lo c k sh ow in g rela tiv e th ickn ess o f wax. C e n te r rig h t: C ross sectio n o f c o m p le te d in vestm en t b e fo r e and a fter w a x elim in a tion . B elow le ft : F in ish ed m o u th p ie c e in p la ce. B elo w rig h t: In d ivid u ally m ade ( l e f t ) and sto ck (r ig h t) m ou th p ieces. C o m p a re size and bulkiness
10 • T H E J O U R N A L O F T H E A M E R IC A N DEN T A L A S S O C IA T IO N
forward as far as possible to adapt the wax to the lingual surfaces of the upper teeth. T h e operator adapts the labial and buccal surfaces with his fingers and thumbs (illustration, above rig h t); the upper lip is pressed down over the wax as in muscle trimming of a snap impres sion. Overextension and muscle inter ference are to be avoided here also. T h e wax impression is removed from the mouth, chilled and trimmed with a knife. A ll wax below the occlusal surface of the lower teeth is removed. Care must be taken to ensure that the upper and lower jaws are not locked together in occlusion in the finished product. Suffi cient wax is removed from the lingual edge so that the patient can speak when the impression is reinserted. The labial and buccal flange is trimmed to approxi mately
2
mm .
thickness
(illustration,
center le ft). The impression is trimmed to terminate distally at the six year molar. W hen reinserted, the impression is re adapted to correct any distortion that may have occurred in the trimming. W hile the wax impression is still in place, the patient is instructed to move the mandible to the right and left; it is necessary that sufficient wax be retained on either side of the cusp imprints to permit the lower teeth to contact it in all excursions of the mandible. After the wax impression is taken and trimmed to form properly, the remaining steps are per formed in the laboratory. T h e impression is washed and dried. T o gain added retention, a slight excess ring of wax may be added to the cervical region of each tooth. This wax will make the finished product fit snugly around each tooth; care must be taken, however, as an excess of wax may impinge on and traumatize the gingiva. T h e wax impres sion is then immersed in green soap or in any commercially prepared product which will reduce surface tension. For the investment procedure, the upper half of a denture flask should be used, since its greater depth is necessary
to accommodate the high flange on the wax impression. This half o f the flask is filled with a good mix of stone, and some of the same mix is vibrated into the wax impression of the upper teeth. Special care must be exercised at this time so that no air is trapped in the impression. The impression is then placed in the flask deep enough that the flat surface of the impression is even with the edges of the surface formed by the edges of the flask. The upper half of the flask containing the invested impression is allowed to set. T h e surface is covered with petroleum jelly when the stone is set, but care must be exercised not to get any of the petroleum jelly into the incisal indenta tions of the exposed underside of the impression. The stone is then poured into the lower half of the flask and vibrated into the lower incisal grooves of the invested wax impression. Next, the invested impression is picked up and turned over and placed on the lower half of the flask; the excess of stone is allowed to escape from the sides. After the stone has set, the flask is boiled for five minutes, opened and flushed with boiling water (illustration, center right). Each half of the flask is painted with water glass, or any commer cial case paint, while it is still warm. After these steps are completed, vellum acrylic resin is packed in the same man ner as the standard dental acrylic resins and cured in boiling water for half an hour. The flask must be cooled com pletely before an attempt is made to re move the mouth protector. Immersion in cold water will speed up this process. No precautions are necessary for this part of the procedure. Finishing is ac complished in the same manner as with denture acrylic resins, but high polishing is eliminated (illustration, below left). For packing with vellum rubber, one and a half sheets is sufficient for even the largest mouth protector. The half sheet is cut into small pieces (quarter inch squares), while the large piece is
W ATTS— W O O L A R D — S IN G E R . . . V O L U M E 49, JU L Y 1954 • II
cut into strips about half an inch wide. These pieces of rubber are placed on a metal plate (pie tin or cookie sheet), covered with a towel and steamed over the boil-out pan until they are warm and pliable. T h e small pieces are packed into the deepest part of the stone mold. Cello phane is placed between each half of the flask, and a test pack is made. The cello phane is removed before the packed case is placed in the vulcanizer, where it is allowed to remain for one hour. For the completion of the finishing, a sand paper arbor is used. The apparatus is now ready (illustration, below right). R E P O R T OF U SE OF APPARATU S
By this technic, 26 mouth protectors were fabricated for members of St. Rita’s H igh School football team. The boys in the line were equipped with vellum rubber mouth
dentists, it is fortunate that vellum acrylic is a satisfactory material. Although the football season had only begun, the team had already incurred four dental injuries before the mouth protectors became available. T h e injuries included one fractured central tooth in volving the pulp, two fractured central teeth not involving the pulp and a frac tured mandible. A t the end of the season, dental injuries had been reduced 100 per cent. T h e opposing teams in the same games had suffered an average of two injuries in and about the oral cavity. This record seems to indicate that the device will serve the purpose for which it is in tended. During the development of the project, routine records were made o f the boys’ teeth. Only 5 of the 26 boys had a family dentist; 21 had none; 13 requested dental care when they learned of the condition
protectors, while the backfield team m em bers were equipped with vellum acrylic protectors. O f the materials tested, vellum rubber proved to be most desirable; but
of their teeth. Thus, the effort to make a contribution to preventive dental pro
since vulcanizers are not available to all
office.
cedure led incidentally to a new means of introducing the teen-ager to the dental
A D ilem m a of Science • M odern scientific education is presented with a well-known dilemma. T h e am ount o f facts in m odern science, and in any o f its smallest branches, is enormous. Life in general, and the academ ic curriculum in particular, is short. T h e abundance o f factual data, as w ell as the intricacy o f m odern scientific techniques, experimental and theoretical, necessi tates utmost specialization. This specialization, unavoidable though it is, involves serious danger fo r both the education o f the scientist and the social function o f science. Ludw ig von Bertalanffy, “ Philosophy of Science in Scientific E d u ca tio n " T h e Scientific M on thly, 7 7 :2 3 3 N ovem ber 1953.
for this technic of reconstruction. In two of the seven cases, the patients died with the recurrence of the disease; in two cases exposures of the prosthesis resulted, in one case intraorally, in the other extraorally. In the latter case, the opening was closed successfully; the intraoral ex posure still persists. In the three remain ing cases, the patients had uneventful recoveries after primary reconstruction. In the successful cases, eight months is the longest interval that has elapsed since the insertion of the prosthesis. The cases are being followed carefully to observe any clinical manifestations of unfavorable tissue reaction. Concurrent with this clinical study, a laboratory research project is being conducted with the use of live animals. The results of this study will be reported on its conclusion.
SUM M ARY
Methyl methacrylate was used in an effort to find a suitable material for im mediate and permanent replacement of the resected mandible. Satisfactory pros thetic mandibles can be produced from detailed measurements and roentgeno grams. The only cause of early failure has been excessive tension of the tissues overlying the implanted prosthesis. The long-range effect of this material on tissue will be reported at the conclusion of clinical and laboratory studies now in progress. It is hoped that this report will stimulate further investigation of this and other materials that may be adaptable for use in this important phase of surgical prosthetic reconstruction.
Functional mouth protectors for contact sports George Watts, D .D .S .; Archie Woolard, D .D .S ., and Carl E. Singer, D .D .S ., Chicago
Th e two main purposes of this article are (1) to stress the necessity for mouth pro tectors in contact sports and (2) to pre sent a simplified technic by which the basic requirements can be incorporated into a functional mouth protector. A mouth protector, any device afford ing protection to the lips, teeth, bony supporting structure and temporoman dibular joint, may be merely a piece of sponge rubber held between the teeth, or it may be an expensive, elaborately constructed device fitted to the teeth. The idea of a mouth protector is not new in
athletics and certainly not in dentistry. T h e need for such a device was realized as far back as 1927.1 Boxers began to de sire something to protect them from the violent blows they received— blows that lacerated lips and fractured teeth and bony supporting structures, blows that sometimes resulted in death. The dentist became interested in help ing athletes gain this protection. Mouth
C o ll e g e
of
D e ntistry,
I. A b ram s, M a r c h 1930.
A.
M.
U n iv e rsity o f P ra c tic a l
Illin o is.
hints.
D.
D ig e s t 36:200
8 • T H E J O U R N A L O F THE A M E R IC A N DEN T A L A S S O C IA T IO N
protectors were fabricated; as time went by, descriptions of various technics for their construction were published. A satis factory mouth protector must be so con structed that it ( 1 ) affords maximum protection, (2 ) will not be rejected by the athlete because it encroaches on his airway when he is forced to breathe through his mouth, (3) will not make speech difficult or impossible, (4) will not be uncomfortable and (5) will re main in place. In view of the fact that functional mouth protectors have been developed for some time, it is surprising that they are not more popular among amateur athletes. One of the reasons is the failure of the dental profession to educate the laity concerning the absolute necessity of the use of mouth protectors in contact sports. Another reason is that the tech nics used in their fabrication have made the cost prohibitive in the majority of cases. A recent survey of 62 colleges, made by the University of Missouri, showed that 733 dental injuries were incurred in one football season.2 Cathcart3 states that a survey recently conducted in three states showed that over 50 per cent of injuries to high school players occur in and about the oral cavity. W ith the great increase in number of participants in high school, college and even grammar
regions in which 48 per cent of the in juries occur. Only a limited number of schools make any attempt to provide any sort of protection for the region where 52 per cent of the injuries occur. If the public is convinced of and educated to the necessity of mouth protectors in con tact sports, it will insist that they be made available to the young people par ticipating in any and all contact sports. The magazine Life4 with the controversial pictures of misnamed players who had lost their anterior teeth while playing football probably did more in the way of public education in the need of some form of mouth protection than the dental profession had done in years. As the situa tion stands today, something must be done to make mouth protection available to all school athletes; otherwise the stigma associated with contact sport injuries will increase to the point where such sports will be discouraged and frowned on. Every practicing dentist should recog nize the importance of this problem of protective dentistry and should do his part in its solution. For the most part, it is a problem of making functional mouth protectors available to all amateur athletes participating in contact sports. T h e first necessity is a technic which in corporates the following features: 1.
The apparatus is simple in design
school contact sports, the number of den tal injuries, if accurately compiled to in clude injuries of all participants, would
and construction; it provides ample func
prove astounding. A functional mouth protector not only
apparatus require a limited amount of time in the dental chair. 3. A limited amount of laboratory
lends protection to the oral cavity and associated structures but also minimizes the force of blows transmitted to the brains— blows which might lead to un consciousness, concussion with permanent or cumulative injury to the brain and, in extreme cases, even to death. Schools spend on an average $90 to
tional protection. 2. T h e making and adaptation of the
time is required. 4. T h e expense of materials used in the preliminary work is kept at a mini m um ; the materials best adapted to the
$120 annually to outfit each football player with protective clothing, which
2. Vanet, R andy . ’ G r id ir o n c h a lle n g e . D. Survey 27:1258 S e p t. 1951. 3. C a t h c a r t, J. F. M o u t h p r o te c to r s fo r c o n ta c t sp o rts. D. D ig e s t 57:346 A u g . 1951.
affords him
4. The fig h t in g Se p t. 29, 1952.
protection only for
those
Irish
lo o k
to u g h
a g a in .
Life
33:60
W ATTS— W O O L A R D — S IN G E R . . . V O L U M E 49, JU L Y 1954 • 9
purpose are used in the finished appa ratus. TECH N IC FOR CONSTRUCTION
The first step in the construction of a mouth protector consists of recording the patient’s normal bite in wax. One and a half sheets of soft baseplate wax is heated and folded together to form a horseshoe
bite-block (illustration, above left). The block is warmed and inserted in the mouth, and the patient is instructed to bite. A small wax spatula is inserted in the block close to the lower occlusal plane between the anterior teeth to prevent complete closure. Wax 2 mm. in thickness is desirable between the incisal edges of the anterior teeth. The patient is in structed to bite and to thrust the tongue
A b o v e le ft : H o rsesh o e-sh a p ed b ite-b lo ck w ith in stru m en t in serted . A b o v e rig h t: A d a p te d b iteblock in m ou th . C e n te r l e f t : C ross s ec tio n o f b ite -b lo c k sh ow in g rela tiv e th ickn ess o f wax. C e n te r rig h t: C ross sectio n o f c o m p le te d in vestm en t b e fo r e and a fter w a x elim in a tion . B elow le ft : F in ish ed m o u th p ie c e in p la ce. B elo w rig h t: In d ivid u ally m ade ( l e f t ) and sto ck (r ig h t) m ou th p ieces. C o m p a re size and bulkiness
10 • T H E J O U R N A L O F T H E A M E R IC A N DEN T A L A S S O C IA T IO N
forward as far as possible to adapt the wax to the lingual surfaces of the upper teeth. T h e operator adapts the labial and buccal surfaces with his fingers and thumbs (illustration, above rig h t); the upper lip is pressed down over the wax as in muscle trimming of a snap impres sion. Overextension and muscle inter ference are to be avoided here also. T h e wax impression is removed from the mouth, chilled and trimmed with a knife. A ll wax below the occlusal surface of the lower teeth is removed. Care must be taken to ensure that the upper and lower jaws are not locked together in occlusion in the finished product. Suffi cient wax is removed from the lingual edge so that the patient can speak when the impression is reinserted. The labial and buccal flange is trimmed to approxi mately
2
mm .
thickness
(illustration,
center le ft). The impression is trimmed to terminate distally at the six year molar. W hen reinserted, the impression is re adapted to correct any distortion that may have occurred in the trimming. W hile the wax impression is still in place, the patient is instructed to move the mandible to the right and left; it is necessary that sufficient wax be retained on either side of the cusp imprints to permit the lower teeth to contact it in all excursions of the mandible. After the wax impression is taken and trimmed to form properly, the remaining steps are per formed in the laboratory. T h e impression is washed and dried. T o gain added retention, a slight excess ring of wax may be added to the cervical region of each tooth. This wax will make the finished product fit snugly around each tooth; care must be taken, however, as an excess of wax may impinge on and traumatize the gingiva. T h e wax impres sion is then immersed in green soap or in any commercially prepared product which will reduce surface tension. For the investment procedure, the upper half of a denture flask should be used, since its greater depth is necessary
to accommodate the high flange on the wax impression. This half o f the flask is filled with a good mix of stone, and some of the same mix is vibrated into the wax impression of the upper teeth. Special care must be exercised at this time so that no air is trapped in the impression. The impression is then placed in the flask deep enough that the flat surface of the impression is even with the edges of the surface formed by the edges of the flask. The upper half of the flask containing the invested impression is allowed to set. T h e surface is covered with petroleum jelly when the stone is set, but care must be exercised not to get any of the petroleum jelly into the incisal indenta tions of the exposed underside of the impression. The stone is then poured into the lower half of the flask and vibrated into the lower incisal grooves of the invested wax impression. Next, the invested impression is picked up and turned over and placed on the lower half of the flask; the excess of stone is allowed to escape from the sides. After the stone has set, the flask is boiled for five minutes, opened and flushed with boiling water (illustration, center right). Each half of the flask is painted with water glass, or any commer cial case paint, while it is still warm. After these steps are completed, vellum acrylic resin is packed in the same man ner as the standard dental acrylic resins and cured in boiling water for half an hour. The flask must be cooled com pletely before an attempt is made to re move the mouth protector. Immersion in cold water will speed up this process. No precautions are necessary for this part of the procedure. Finishing is ac complished in the same manner as with denture acrylic resins, but high polishing is eliminated (illustration, below left). For packing with vellum rubber, one and a half sheets is sufficient for even the largest mouth protector. The half sheet is cut into small pieces (quarter inch squares), while the large piece is
W ATTS— W O O L A R D — S IN G E R . . . V O L U M E 49, JU L Y 1954 • II
cut into strips about half an inch wide. These pieces of rubber are placed on a metal plate (pie tin or cookie sheet), covered with a towel and steamed over the boil-out pan until they are warm and pliable. T h e small pieces are packed into the deepest part of the stone mold. Cello phane is placed between each half of the flask, and a test pack is made. The cello phane is removed before the packed case is placed in the vulcanizer, where it is allowed to remain for one hour. For the completion of the finishing, a sand paper arbor is used. The apparatus is now ready (illustration, below right). R E P O R T OF U SE OF APPARATU S
By this technic, 26 mouth protectors were fabricated for members of St. Rita’s H igh School football team. The boys in the line were equipped with vellum rubber mouth
dentists, it is fortunate that vellum acrylic is a satisfactory material. Although the football season had only begun, the team had already incurred four dental injuries before the mouth protectors became available. T h e injuries included one fractured central tooth in volving the pulp, two fractured central teeth not involving the pulp and a frac tured mandible. A t the end of the season, dental injuries had been reduced 100 per cent. T h e opposing teams in the same games had suffered an average of two injuries in and about the oral cavity. This record seems to indicate that the device will serve the purpose for which it is in tended. During the development of the project, routine records were made o f the boys’ teeth. Only 5 of the 26 boys had a family dentist; 21 had none; 13 requested dental care when they learned of the condition
protectors, while the backfield team m em bers were equipped with vellum acrylic protectors. O f the materials tested, vellum rubber proved to be most desirable; but
of their teeth. Thus, the effort to make a contribution to preventive dental pro
since vulcanizers are not available to all
office.
cedure led incidentally to a new means of introducing the teen-ager to the dental
A D ilem m a of Science • M odern scientific education is presented with a well-known dilemma. T h e am ount o f facts in m odern science, and in any o f its smallest branches, is enormous. Life in general, and the academ ic curriculum in particular, is short. T h e abundance o f factual data, as w ell as the intricacy o f m odern scientific techniques, experimental and theoretical, necessi tates utmost specialization. This specialization, unavoidable though it is, involves serious danger fo r both the education o f the scientist and the social function o f science. Ludw ig von Bertalanffy, “ Philosophy of Science in Scientific E d u ca tio n " T h e Scientific M on thly, 7 7 :2 3 3 N ovem ber 1953.