Speech intelligibility
with the buccal flange obturator
Koray Oral, D.D.S., M.S.D., Ph.D.,* M. A. Aramany, McWilliams, Ph.D.* ** Eye and Ear Hospital of Pittsburgh
M.S.,** and Betty Jane
and the Cleft Palate Center, University
habilitation of patients who have undergone extensive surgery for eradication of neoplasm of the maxillae requires restoration of the functions of speech, mastication, and deglutition. The options for rehabilitation of these patients are surgical reconstruction or prosthetic restoration. According to Sharry,’ even when surgical techniques are available, prosthetic reconstruction is chosen most frequently. Prostheses for acquired defects of the hard palate consist of either complete or removable partial dentures with nasal extensions designed to obturate the defect. The objectives of such prostheses as outlined by Aramany and Drane’ are (1) oronasal separation, (2) retention and stabilization of the prosthesis, and (3) rehabilitation of speech.
LITERATURE
D.M.D.,
REVIEW
According to Baden,’ until about 1820, obturators were used primarily for the treatment of acquired palatal defects. Miglani and Drane’ explained the use of a prosthesis for maxillary closure following surgical resection. Pettit and associates,” Sala and Spear,” Robinson,’ and Gutman and associate? discussed the use of presurgical and postsurgical maxillary prostheses. Since patients who are not treated immediately after maxillary resection often become despondent hecause of difficulties with speech and mastication,!’ presurgical prostheses have been advocated. Most obturators have some kind of extension into the nasal cavity.“‘-“’ Early obturator prostheses were This study was supported in part by U.S. Public Health Service Grant DE-01697. National Institute of Dental Research. *Assistant Professor of Prosthodontics. University of Pittsburgh, School of Dental Medicine. **Professor of Prosthodontics. University of Pittsburgh, School of Drntal Medicine; Director, Regional Center for Maxillofacial Prosthetic Rehabilitation. ***Professor of Speech. University of Pittsburgh Cleft Palate
of Pittsburgh.
Pittsburph.
P;r
constructed with solid nasal extensions that made the prosthesis too heavy. The weight of the maxillary obturator often caused the prosthesis to act as a cantilever.“” The development of the hollow obturator prosthesis helped to overcome this problem. There are various methods of fabricat.ing the twopiece hollow obturator and joining the sections using autopolymerizing methyl methacrylate resin. However, the autopolymerizing methyl methacrylate resin will cause a discolored demarcation line, and leakage may result into the hollow extension.” Chalian and Barnet”’ proposed a new technique for making the hollow obturator in one piece to climinate the leakage and the demarcation line. Hollow obturator prostheses were not the only proposed solution for reducing the weight of the more bulky prostheses. Boucher’;’ introduced Silastic 5370 foam for the construction of the nasal extension. He maintained that the Silastic would make the insertion of the prosthesis easier and that it would absorb much of the pressure cr,eated during mastication. Nadeau” and Zarb’- used a siliconecovered nasal extension section to lighten the obturator prosthesis. Payne and Welton” introduced a latex rubber balloon with an ncorpor;tted air valve which was attached to the denture and could be inflated with air to fill the surgical defect. All of these prostheses have on:’ feature in common: they are designed to fill the entirr defect. However. according to Sharry.’ extensive, bulky prostheses may not be necessary becartsc- it is essential to cover only the area of the defect rather than obturate the entire nasal and sinus c;tvities. Zarb” maintained that the final prosthesrs should be constructed so that it extends as far superiorlv as possible into the anterior and lateral aspects of the defect, thus supporting the side of the face. He
Drpart~nerlt.
THE JOURNAL
OF PROSTHETK
IX:NTISTRI
323
ORAL, ARAMANY,
agreed with Sharry that the medial wall of the prosthesis along the midline of the palate should extend only as high as the remaining hard palate. Sharry’ and King”’ also stated that the medial wall of the defect, covered by a very thin layer of mucosa, would be easily irritated by a large prosthesis. Aramany and Drane’ studied the effects on the voice quality of variously designed nasal extension sections that closed the acquired palatal defects and concluded that voice quality was generally better with smaller nasal extensions than with larger nasal extensions. A survey of the literature shows that there is agreement that the remaining part of the maxillae and the borders of the defect can be used for gaining satisfactory retention of the obturator prosthesis. According to Brown,“’ use of those sites is necessary for satisfactory stability but is not sufficient by itself. He feels that additional support of the prosthesis can be gained by extending the buccal flange of the obturator superiorly as far as possible, and he verifies mathematically that the amount of mechanical retention derived from the borders of the prosthesis is directly proportional to the vertical height of the buccal flange. Chalian and Barnett”’ discussed the unsealed nasal extension prosthesis as another method of prosthetic treatment of patients with acquired palatal defects. In this study the prosthesis is called the huccal jange obturator. PROCEDURE The buccal flange obturator is constructed without a closed nasal extension. Instead of complete extension of the prosthesis into the defect, only the anterior, posterior, and lateral flanges of the obturator are so extended. Cleanliness, simplicity of construction, and light weight are important considerations in the construction of any intraoral prosthesis. The buccal flange obturator has these qualities. The prosthesis meets the following criteria: (1) satisfactory stability, (2) satisfactory support for the external anterior and lateral soft tissues of the face, and (3) good hygiene. This study was designed to evaluate the speech results of the buccal flange obturator prosthesis. The experimental objectives were to determine if the buccal flange obturator (1) is more effective than no obturator at all and/or the hollow obturator in the production of speech, as judged by speech, nasality, articulation, hoarseness, intelligibility, and overall
324
AND
McWILLIAMb
production; (2) is superior to the hollow obturator, and (3) fulfills the necessary hygienic requirements. METHOD Subjects. Ten adults (four women and six men) were selected for the study. These patients had all previously undergone partial surgical resection of the maxillae for the removal of squamous cell carcinomas. Their surgical defects were similar. Six of the patients had experienced right partial maxillcctomies. Generally, the anatomic defects were bordered medially by the nasal septum, posteriorly by the anterior border of the soft palate, laterally and anteriorly by the side of the cheek covered by a skin graft, superiorly by the floor of the orbit and the cribriform plate, and inferiorly by a horizontal plane extending from the residual hard and soft palates to the lateral fibrous contraction band. Only two patients had additional problems created by removal of the nasal septum. All patients had intact soft palates which functioned within normal limits. Eight of the 10 patients were completely edentuedentulous. ‘l’he lous, while two were partially patients ranged from 43 to 79 years of age, with a mean age of 63.3 years. None of the patients had any speech or hearing problems before surgery. Five of the patients had been wearing surgical or temporary obturators, while five had definitive hollow obturators before the flange-type obturators used in this study were made. Only two patients, both completely edentulous, had presurgical radiation therapy. Speech recordings. Each patient used the buccal flange obturator for at least 2 months before speech evaluations were performed. Each subject recorded the following speech samples*: (1) Counting from 1 to 10. (2) “Sissi sees the sun in the sky.” (3 j “-My name may mean money.” [a) “Put the baby in the buggy.” (5) “Kindly give Grace the chocolate cake.” These recordings were made under three experimental conditions: (1) with the hollow obturator in place, (2) with the buccal flange obturator in place, and (3) without any obturator. A Sony tape recorder Model TC 800 and a Sony F-226 S cardiod dynamic microphone? were used. Subjects were seated in a soundproof room jmanufacturer Model No. 1202A), facing the microphone, which was placed approximately 10 inches from the *Personal Communication: 'iSuper Scope, Los Angeles,
B. J. McWiiliams, Calif.
MARCH
1979
VOLUME
1974.
41
NUMBER
3
SPEECH INTELLlGlBILlTY
WITH
BUCCAL
FLANGE
OBTURATOR
lips. The speech was recorded without instrumental monitoring. However, each subject was instructed to maintain a constant vocal level and to pronounce each word as carefully as possible. Speakers were directed to maintain 4-second intervals between each sentence and 15-second intervals between each of the three conditions. Live speech evaluation. The live speech evaluation was carried out by two speech pathologists who conversed freely with each patient and listened to the test protocol noted earlier. Both speech pathologists have had experience with the treatment of patients with congenital and acquired defects. Speech was evaluated (1) with the hollow obturator in place, (2 j with the buccal flange obturator in place, and (3) without any obturator. A blind procedure was used for the live speech evaluations. Neither of the speech pathologists knew which type of obturator was being worn by the patient. The speech pathologists made independent evaluations simultaneously during the same session. ‘4 seven-point scale was used for the evaluation of nasality. intelligibility, and overall quality of speech. .Judges were told to consider the value I as being the highest, and 7 as being the lowest rating. After the evaluation of each criterion of speech the judges also indicated their preference for one obturator over the other based on their general subjective impressions of speech quality. Judgments of tape recordings. One group of judges, consisting of five trained speech pathologists, rated the tape recordings. The sequence of the experimental conditions was changed for each patient so that the judges did not have any prior knowledge as to which experimental condition they were evaluating at any particular time. The recordings were rated on seven-point scales for each of the following characteristics: (1) overall speech quality, (2) nasality, (3) articulation, (4) hoarseness, and (5) intelligibility. The most satisfactory were represented by I, and seven represented the least satisfactory resuits. A second group of judges consisted of 10 untrained listeners who rated their overall impressions of speech qualities after listening to the tapes. Each judge independently filled out a form and indicated the speech sample he preferred for each patient. The judges were unaware of the experimental conditions represented on the tapes. Methods of analysis. Nonparametric statistical procedures” were used to determine overall prefer-
THE JOURNAL
OF PROSTHETIC
DENTISTRY
Table
I. Live speech evaluatior Condition selected as best Buccal flange obturator
Frequency
Table
obturator
15
II. Tape-recorded Condition Buccal flange obturator
Frequency
Hnliow-bulb
32
Total 23
speech evdludilvn selected as best Hollow-bulb
obturator !F
Total 50
ences among the judges. Analysis of c;iriance I’or repeated measures was used to coml~re the three conditions (with the buccal flange obturator, with the hollow obturator, and with no obtllr:ltor) according to these five criteria: (,l) o\:rrall sp~ch quality, (2) nasality, (3) articulation, (4) hoarse ~‘45, and !5 1 intelligibility of speech. Individual differences among the three r,onditions were tested using Scheffe’s rn~rltip~e c~cmt)arison method.” RESULTS Live speech evaluation. Since nobcody selcctet! “without anv obturator” as producing the best overall speech quality, a binominal IW was used (Table I) to evaluate the effectiveness gjf’ the hr)llo~ obturator versus the buccal flar-rgt: vhturator f;)r production of good speech. The buccal flange obturator rated significanti) higher & = .02) than the hollow obtlirator as thr “preferred condition” for speech prodltccion. Tape-recorded evaluation by five trained speech pathologists. Five speech pathologists rated the recorded samples of the speech of the 10 patients on overall speech quality, nasality, articul;ftion, hoarseness, and intelligibility of speech wi thollt cjbtcirators, with buccal flange obturators. and M ~rh hollow obturators, again using tha seven-poI1’ I rating scalp previously described. Since no one selected the “without ally obturator” condition as producing the best speech, a hinominal test was used (Table II) to test the starisrical signifcance of the difference between the hollow obturator and the buccal flange obturaror in Y~UX~~ production. The buccal flange obturator ratczt,xT 28:620. 1972. 27. Majid. A. A.. Weinberg, B., and Chalian. \‘.: Speech intelligibility following prosthetic obturation of surgically acquired maxillary defects. J PR~STHPTDtsu 32:8i. 1974.
19.55.
pp
Mc WILLIAMS
22.
11. Sidiffer. ‘1‘. J,, and Shipmoo, ‘r. J.: The hollow bulb ohturator for acquired palatal openings. J I’KOSTHF:~Drs~ 7: 12.5, 19.5;. 12. Harkins, (:. S.: principles of Cleft Palate Prosthesis. New York. 1960, Columbia University Press, pp 148-175. 13. Adisman, I. K.: Removable partial dentures for jaw defects of thr maxilla and mandible. Dent Clin North Am. No\-. 19F2.
AND
848-870.
14. Payne, A. G., and Welton, W. G.: An inflatable obturator for use following maxillectomy. .J P~os~rwT 111,s~ 15:759, 1965.
15. Boucher. I,. .J.: Prosthetic restoration of the maxilla and associated structures. .J PKOSI’RI..~,,kNT 16:154, 1966. 16. Hammond, J.: Dental care of edentulous patients after resection of maxilla. Hr Dent J 12:591, 1966. 17. Zarb. G. A.: The maxillary resection and its prosthetic replacement. J PKOSTHPT DFNT 18:285, 1967. 18. Drane. .J. fj.. and Guerra, I,. I.: f’rosthetics and reconstruction. ,JAMA 219:351, 1972. 19. (:halian. V.. and Barnct, bl. 0.: A new technique for constructing a one-piece hollow bulb obturator after partial maxillectomy. J PROSTIIF~ Dl;w 28:448, 1972.
ARTICLES TO APPEAR IN FUTURE ISSUES Iatrogenic Nathan
TMJ difficulty:
Allen
Shore, D.D.S.,
Effects of subgingival R. J. Smales, M.D.%, 1:.R.A.C.D.S.
Cervical traction may be the etiology Merlin
G. Schaefer.
D.D.S.,
and Stanley
Hoppenfeld,
M.D.
restorations in beagle dogs. Part I: Plaque formation
F.D.S..
R.C.S.,
K. C. Sixon.
M.D.S.,
and K. P. Joyce,
LM.D.Sc.,
Use of silicone in treatment phase of radiotherapy Francis
S. ‘I’autin,
D.D.S.,
Robert
W. Edland,
M.D..
and R. Jerome
Rage, M.S.
Geometric analysis of tooth arrangement Ding
H. Tsao, D.D.S.
Role of condylar position
in TMJ dysfunction-pain
I,awrence
M.S.
A. Weinberg,
D.D.S.,
syndrome
The anterior point of reference Soel
1). Wilkic.
D.D.S.
Porous titanium I;. A. Young, 328
tooth roots: Clinical
D.Sc., C. H. Kresch,
D.D.S.,
evaluation
M.S., and M. Spector,
Ph.D. MARCH
1979
VOLUME
41
NUMBER
3
with the buccal flange obturator
Koray Oral, D.D.S., M.S.D., Ph.D.,* M. A. Aramany, McWilliams, Ph.D.* ** Eye and Ear Hospital of Pittsburgh
M.S.,** and Betty Jane
and the Cleft Palate Center, University
habilitation of patients who have undergone extensive surgery for eradication of neoplasm of the maxillae requires restoration of the functions of speech, mastication, and deglutition. The options for rehabilitation of these patients are surgical reconstruction or prosthetic restoration. According to Sharry,’ even when surgical techniques are available, prosthetic reconstruction is chosen most frequently. Prostheses for acquired defects of the hard palate consist of either complete or removable partial dentures with nasal extensions designed to obturate the defect. The objectives of such prostheses as outlined by Aramany and Drane’ are (1) oronasal separation, (2) retention and stabilization of the prosthesis, and (3) rehabilitation of speech.
LITERATURE
D.M.D.,
REVIEW
According to Baden,’ until about 1820, obturators were used primarily for the treatment of acquired palatal defects. Miglani and Drane’ explained the use of a prosthesis for maxillary closure following surgical resection. Pettit and associates,” Sala and Spear,” Robinson,’ and Gutman and associate? discussed the use of presurgical and postsurgical maxillary prostheses. Since patients who are not treated immediately after maxillary resection often become despondent hecause of difficulties with speech and mastication,!’ presurgical prostheses have been advocated. Most obturators have some kind of extension into the nasal cavity.“‘-“’ Early obturator prostheses were This study was supported in part by U.S. Public Health Service Grant DE-01697. National Institute of Dental Research. *Assistant Professor of Prosthodontics. University of Pittsburgh, School of Dental Medicine. **Professor of Prosthodontics. University of Pittsburgh, School of Drntal Medicine; Director, Regional Center for Maxillofacial Prosthetic Rehabilitation. ***Professor of Speech. University of Pittsburgh Cleft Palate
of Pittsburgh.
Pittsburph.
P;r
constructed with solid nasal extensions that made the prosthesis too heavy. The weight of the maxillary obturator often caused the prosthesis to act as a cantilever.“” The development of the hollow obturator prosthesis helped to overcome this problem. There are various methods of fabricat.ing the twopiece hollow obturator and joining the sections using autopolymerizing methyl methacrylate resin. However, the autopolymerizing methyl methacrylate resin will cause a discolored demarcation line, and leakage may result into the hollow extension.” Chalian and Barnet”’ proposed a new technique for making the hollow obturator in one piece to climinate the leakage and the demarcation line. Hollow obturator prostheses were not the only proposed solution for reducing the weight of the more bulky prostheses. Boucher’;’ introduced Silastic 5370 foam for the construction of the nasal extension. He maintained that the Silastic would make the insertion of the prosthesis easier and that it would absorb much of the pressure cr,eated during mastication. Nadeau” and Zarb’- used a siliconecovered nasal extension section to lighten the obturator prosthesis. Payne and Welton” introduced a latex rubber balloon with an ncorpor;tted air valve which was attached to the denture and could be inflated with air to fill the surgical defect. All of these prostheses have on:’ feature in common: they are designed to fill the entirr defect. However. according to Sharry.’ extensive, bulky prostheses may not be necessary becartsc- it is essential to cover only the area of the defect rather than obturate the entire nasal and sinus c;tvities. Zarb” maintained that the final prosthesrs should be constructed so that it extends as far superiorlv as possible into the anterior and lateral aspects of the defect, thus supporting the side of the face. He
Drpart~nerlt.
THE JOURNAL
OF PROSTHETK
IX:NTISTRI
323
ORAL, ARAMANY,
agreed with Sharry that the medial wall of the prosthesis along the midline of the palate should extend only as high as the remaining hard palate. Sharry’ and King”’ also stated that the medial wall of the defect, covered by a very thin layer of mucosa, would be easily irritated by a large prosthesis. Aramany and Drane’ studied the effects on the voice quality of variously designed nasal extension sections that closed the acquired palatal defects and concluded that voice quality was generally better with smaller nasal extensions than with larger nasal extensions. A survey of the literature shows that there is agreement that the remaining part of the maxillae and the borders of the defect can be used for gaining satisfactory retention of the obturator prosthesis. According to Brown,“’ use of those sites is necessary for satisfactory stability but is not sufficient by itself. He feels that additional support of the prosthesis can be gained by extending the buccal flange of the obturator superiorly as far as possible, and he verifies mathematically that the amount of mechanical retention derived from the borders of the prosthesis is directly proportional to the vertical height of the buccal flange. Chalian and Barnett”’ discussed the unsealed nasal extension prosthesis as another method of prosthetic treatment of patients with acquired palatal defects. In this study the prosthesis is called the huccal jange obturator. PROCEDURE The buccal flange obturator is constructed without a closed nasal extension. Instead of complete extension of the prosthesis into the defect, only the anterior, posterior, and lateral flanges of the obturator are so extended. Cleanliness, simplicity of construction, and light weight are important considerations in the construction of any intraoral prosthesis. The buccal flange obturator has these qualities. The prosthesis meets the following criteria: (1) satisfactory stability, (2) satisfactory support for the external anterior and lateral soft tissues of the face, and (3) good hygiene. This study was designed to evaluate the speech results of the buccal flange obturator prosthesis. The experimental objectives were to determine if the buccal flange obturator (1) is more effective than no obturator at all and/or the hollow obturator in the production of speech, as judged by speech, nasality, articulation, hoarseness, intelligibility, and overall
324
AND
McWILLIAMb
production; (2) is superior to the hollow obturator, and (3) fulfills the necessary hygienic requirements. METHOD Subjects. Ten adults (four women and six men) were selected for the study. These patients had all previously undergone partial surgical resection of the maxillae for the removal of squamous cell carcinomas. Their surgical defects were similar. Six of the patients had experienced right partial maxillcctomies. Generally, the anatomic defects were bordered medially by the nasal septum, posteriorly by the anterior border of the soft palate, laterally and anteriorly by the side of the cheek covered by a skin graft, superiorly by the floor of the orbit and the cribriform plate, and inferiorly by a horizontal plane extending from the residual hard and soft palates to the lateral fibrous contraction band. Only two patients had additional problems created by removal of the nasal septum. All patients had intact soft palates which functioned within normal limits. Eight of the 10 patients were completely edentuedentulous. ‘l’he lous, while two were partially patients ranged from 43 to 79 years of age, with a mean age of 63.3 years. None of the patients had any speech or hearing problems before surgery. Five of the patients had been wearing surgical or temporary obturators, while five had definitive hollow obturators before the flange-type obturators used in this study were made. Only two patients, both completely edentulous, had presurgical radiation therapy. Speech recordings. Each patient used the buccal flange obturator for at least 2 months before speech evaluations were performed. Each subject recorded the following speech samples*: (1) Counting from 1 to 10. (2) “Sissi sees the sun in the sky.” (3 j “-My name may mean money.” [a) “Put the baby in the buggy.” (5) “Kindly give Grace the chocolate cake.” These recordings were made under three experimental conditions: (1) with the hollow obturator in place, (2) with the buccal flange obturator in place, and (3) without any obturator. A Sony tape recorder Model TC 800 and a Sony F-226 S cardiod dynamic microphone? were used. Subjects were seated in a soundproof room jmanufacturer Model No. 1202A), facing the microphone, which was placed approximately 10 inches from the *Personal Communication: 'iSuper Scope, Los Angeles,
B. J. McWiiliams, Calif.
MARCH
1979
VOLUME
1974.
41
NUMBER
3
SPEECH INTELLlGlBILlTY
WITH
BUCCAL
FLANGE
OBTURATOR
lips. The speech was recorded without instrumental monitoring. However, each subject was instructed to maintain a constant vocal level and to pronounce each word as carefully as possible. Speakers were directed to maintain 4-second intervals between each sentence and 15-second intervals between each of the three conditions. Live speech evaluation. The live speech evaluation was carried out by two speech pathologists who conversed freely with each patient and listened to the test protocol noted earlier. Both speech pathologists have had experience with the treatment of patients with congenital and acquired defects. Speech was evaluated (1) with the hollow obturator in place, (2 j with the buccal flange obturator in place, and (3) without any obturator. A blind procedure was used for the live speech evaluations. Neither of the speech pathologists knew which type of obturator was being worn by the patient. The speech pathologists made independent evaluations simultaneously during the same session. ‘4 seven-point scale was used for the evaluation of nasality. intelligibility, and overall quality of speech. .Judges were told to consider the value I as being the highest, and 7 as being the lowest rating. After the evaluation of each criterion of speech the judges also indicated their preference for one obturator over the other based on their general subjective impressions of speech quality. Judgments of tape recordings. One group of judges, consisting of five trained speech pathologists, rated the tape recordings. The sequence of the experimental conditions was changed for each patient so that the judges did not have any prior knowledge as to which experimental condition they were evaluating at any particular time. The recordings were rated on seven-point scales for each of the following characteristics: (1) overall speech quality, (2) nasality, (3) articulation, (4) hoarseness, and (5) intelligibility. The most satisfactory were represented by I, and seven represented the least satisfactory resuits. A second group of judges consisted of 10 untrained listeners who rated their overall impressions of speech qualities after listening to the tapes. Each judge independently filled out a form and indicated the speech sample he preferred for each patient. The judges were unaware of the experimental conditions represented on the tapes. Methods of analysis. Nonparametric statistical procedures” were used to determine overall prefer-
THE JOURNAL
OF PROSTHETIC
DENTISTRY
Table
I. Live speech evaluatior Condition selected as best Buccal flange obturator
Frequency
Table
obturator
15
II. Tape-recorded Condition Buccal flange obturator
Frequency
Hnliow-bulb
32
Total 23
speech evdludilvn selected as best Hollow-bulb
obturator !F
Total 50
ences among the judges. Analysis of c;iriance I’or repeated measures was used to coml~re the three conditions (with the buccal flange obturator, with the hollow obturator, and with no obtllr:ltor) according to these five criteria: (,l) o\:rrall sp~ch quality, (2) nasality, (3) articulation, (4) hoarse ~‘45, and !5 1 intelligibility of speech. Individual differences among the three r,onditions were tested using Scheffe’s rn~rltip~e c~cmt)arison method.” RESULTS Live speech evaluation. Since nobcody selcctet! “without anv obturator” as producing the best overall speech quality, a binominal IW was used (Table I) to evaluate the effectiveness gjf’ the hr)llo~ obturator versus the buccal flar-rgt: vhturator f;)r production of good speech. The buccal flange obturator rated significanti) higher & = .02) than the hollow obtlirator as thr “preferred condition” for speech prodltccion. Tape-recorded evaluation by five trained speech pathologists. Five speech pathologists rated the recorded samples of the speech of the 10 patients on overall speech quality, nasality, articul;ftion, hoarseness, and intelligibility of speech wi thollt cjbtcirators, with buccal flange obturators. and M ~rh hollow obturators, again using tha seven-poI1’ I rating scalp previously described. Since no one selected the “without ally obturator” condition as producing the best speech, a hinominal test was used (Table II) to test the starisrical signifcance of the difference between the hollow obturator and the buccal flange obturaror in Y~UX~~ production. The buccal flange obturator ratczt,xT 28:620. 1972. 27. Majid. A. A.. Weinberg, B., and Chalian. \‘.: Speech intelligibility following prosthetic obturation of surgically acquired maxillary defects. J PR~STHPTDtsu 32:8i. 1974.
19.55.
pp
Mc WILLIAMS
22.
11. Sidiffer. ‘1‘. J,, and Shipmoo, ‘r. J.: The hollow bulb ohturator for acquired palatal openings. J I’KOSTHF:~Drs~ 7: 12.5, 19.5;. 12. Harkins, (:. S.: principles of Cleft Palate Prosthesis. New York. 1960, Columbia University Press, pp 148-175. 13. Adisman, I. K.: Removable partial dentures for jaw defects of thr maxilla and mandible. Dent Clin North Am. No\-. 19F2.
AND
848-870.
14. Payne, A. G., and Welton, W. G.: An inflatable obturator for use following maxillectomy. .J P~os~rwT 111,s~ 15:759, 1965.
15. Boucher. I,. .J.: Prosthetic restoration of the maxilla and associated structures. .J PKOSI’RI..~,,kNT 16:154, 1966. 16. Hammond, J.: Dental care of edentulous patients after resection of maxilla. Hr Dent J 12:591, 1966. 17. Zarb. G. A.: The maxillary resection and its prosthetic replacement. J PKOSTHPT DFNT 18:285, 1967. 18. Drane. .J. fj.. and Guerra, I,. I.: f’rosthetics and reconstruction. ,JAMA 219:351, 1972. 19. (:halian. V.. and Barnct, bl. 0.: A new technique for constructing a one-piece hollow bulb obturator after partial maxillectomy. J PROSTIIF~ Dl;w 28:448, 1972.
ARTICLES TO APPEAR IN FUTURE ISSUES Iatrogenic Nathan
TMJ difficulty:
Allen
Shore, D.D.S.,
Effects of subgingival R. J. Smales, M.D.%, 1:.R.A.C.D.S.
Cervical traction may be the etiology Merlin
G. Schaefer.
D.D.S.,
and Stanley
Hoppenfeld,
M.D.
restorations in beagle dogs. Part I: Plaque formation
F.D.S..
R.C.S.,
K. C. Sixon.
M.D.S.,
and K. P. Joyce,
LM.D.Sc.,
Use of silicone in treatment phase of radiotherapy Francis
S. ‘I’autin,
D.D.S.,
Robert
W. Edland,
M.D..
and R. Jerome
Rage, M.S.
Geometric analysis of tooth arrangement Ding
H. Tsao, D.D.S.
Role of condylar position
in TMJ dysfunction-pain
I,awrence
M.S.
A. Weinberg,
D.D.S.,
syndrome
The anterior point of reference Soel
1). Wilkic.
D.D.S.
Porous titanium I;. A. Young, 328
tooth roots: Clinical
D.Sc., C. H. Kresch,
D.D.S.,
evaluation
M.S., and M. Spector,
Ph.D. MARCH
1979
VOLUME
41
NUMBER
3
