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Principles and technique in sublingual flange extension of complete mandibular dentures
Principles extenhn Roberto
a~& tehnique in subli of cwmpkte mandibular
von Krammer
al flange dentures
K., Cirujano-Dentista
Santiago. Chile
M
andibular complete dentures frequently lack retention and stability and offer lessdenture-supporting area than maxillary dentures.’ A sublingual flange extension improves the retention and stability of complete lower dentures. It increasesthe tissue surface of the denture, augmenting simple adhesion and, therefore, retention.2 Stabifity is also enhanced by active incorporation of tongue activity into the task of maintaining the lower denture in place.
ANATOMIC
STRUCTURES
INVOLVED
The sublingual flange is placed in the sublingual region, which is bound posteriorly by the glossopalatine muscle(palatoglossalfold) and the lingual slip of the superior constrictor muscle of the pharynx. Its upper limit is the inferior surfaceof the tongue, and its lower limit the floor of the mouth. Here, its posterior third is prescribed by the mylohyoid muscle, which in this region is quite superficial and often inserts in a sharp and prominent bony ridge. In the first molar region: the muscle angles downward and inward toward the middle third of the sublingual region, where the mylohyoid muscle exerts its influence through the sublingual gland, which lies on top of it. This region allows for a certain degreeof downward displacement. In the anterior third, the inferior limit of the lingual flange is determined by the genioglossusmuscle.
PRINCIPLES
IN SUBLINGUAL
Fig. 1. Tongue in normal position in edentulous mouth.
Fig. 2. Acrylic resin custom tray with occlusion rim.
FLANGE
EXTENSION Regardlessof the technique usedfor the construction of a complete lower denture, a normal tongue position is important for success(Fig. l).” Singers and public speakers appear to acquire a good tongue position becauseit favors better resonanceand placesthe tongue at the best starting point for reaching the different articulating zones. If the patient has acquired a retracted tongue position, this bad habit must be corrected before the denture is made. Abnormal swallowing habits may also undermine the successof a complete lower denture and must be corrected before prosthodontic treatment begins.4-8
I,,Q-‘-3911
82 ‘050479
+ 04$00.40’0
’ 1982 The C. V Mosby
C:o
Fig. 3. Border molding with modeling compound.
THE
JOURNAL
OF PROSTHETIC
DENTISTRY
479
Fig. 8. Denture in mouth and tongue in correct Fig. 5. Stone cast. Sublingual flange extension has been outlined by broken line.
position.
phonation. This extension is accomplishedby having the patient swallow during the impression-making procedureswith the tongue in its normal position.
TECHNIQUE
Fig. 6. Finished denture. The function of the anatomic structures that surround the sublingual region makes its size and shape vary. Two dynamic elementscontrol the size and shape of the sublingual region: the tongue and the floor of the mouth. Our goal must be to obtain the maximum possibleextension of the sublingual flange that will not interfere with functions of mastication, deglutition, and
480
Sublingual flange extensions can be incorporated into the impression technique,‘-I1 developed once the denture has been waxed,‘2-‘4or formed on the finished denture with autopolymerizing acrylic resin.15Figs. 2 to 8 demonstrate the sublingual flange extension technique. A diagnostic cast is neededto design the tentative foundation area and to form the custom tray that will conform to this outline. The diagnostic cast can be obtained from an overextended preliminary impression (made from such materials as irreversible hydrocolloid or modeling compound), an adequately rebasedexisting denture (Fig. 9), or an interim denture that has beenincrementally rebased.The denture foundation is determined by the following procedure. The labial flange from one buccal frenum to the other is determined by observing the bottom of the vestibule with the
MAY
1982
VOLUME
47
NUMBER
5
SUBLINGUAL
FLANGE
EXTENSION
Fig. 11. Lower partial denture with distal extension on left side. Only three natural teeth are left in mandible: Two canines and second right molar. Sublingual flange extension provided enough retention so that claspswere unnecessaryon anterior abutments. Fig. 9. Left, Patient’s old denture was built up with self-curing acrylic resin and tissue conditioner. Procedure was carried out incrementally in successivesittings until comfortable denture was produced. Then diagnostic cast was obtained from it. Right, New denture. Note similarity in outline with rebased denture.
Fig. 10. In this lower denture, effect of left side
dominance of tongue is prominent.
mouth slightly open. The buccal flange from the buccal frenum to the retromolar pad reachesup to the external oblique line, the posterior border coversthe retromolar pad completely, and the distolingual border should extend downward and backward from the retromolar pad at an angle of approximately 45 degrees.3The lingual border follows the mylohyoid ridge up to the first molar region. The lingual flange between the first molars is also determined by observing the level of the floor of the mouth with the tongue slightly elevated. An occlusion rim that simulatesthe correct occlusal plane
THE
JOURNAL
OF PROSTHETIC
DENTISTRY
Fig. 12. Sublingual flange extension helps keep in place this clasplessbilateral distal-extension lower partial denture.
and the proper arch arrangement is used to help maintain a normal tongue position (Fig. 2).’ The impressionmaterial of choice is used, and buccal and labial border molding are accomplishedbv the familiar whistle-grin movements. The material of choice for the sublingual flange extension is modeling compound. As this step of the procedure is carried out, the dentist will note that, in lateral pressuremagnitudes,there is dominanceof one side of the tongue, usually the left side (Fig. IO).‘” Of
481
VON KRAMMER
course, keep (Figs.
a sublingual in
place 11 and
flange
can
distal-extension
also lower
be
used
partial
to help dentures
10.
REFERENCES 1.
2. 3.
4. 5.
6. 7.
8.
9.
12).
Woelfel, J. B., Winter, C. M., and Igarashi, T.: Five-year cephalometric study of mandibular ridge resorption with different posterior occlusal forms. Part I: Denture construction and initial comparison. J PROSTHET DENT 36:602, 1976. Saizar, P.: Protesis a Placa, ed 4. Buenos Aires, 1950, Progrental, p 73. Wright, C.: Evaluation of the factors necessary to develop stability in mandibular dentures. J PROSTHET DENT l&414, 1966. Ramfjord, S. P., and Ash, M. M.: Occlusion, ed 2. Philadelphia, 1971, W. B. Saunders Co. p 90. Mohl, N. D., and Drinnan, A. J.: Anatomy and physiology of the edentulous mouth. In Winkler, S., editor: Symposium on complete dentures. Dent Clin North Am 21:199, 1977. Garliner, D.: Myofunctional Therapy in Dental Practice. Brooklyn, 1971, Bartel Dental Book Co., pp 4-5. Massengill, R., Robinson, M., and Quinn, G.: Cinefluorographic analysis of tongue-thrusting. Am J Orthod 61:402, 1972. Massengill, R., Quinn, G., Hall, A. S., and Boyd, D.:
IADR PROSTHODONTIC The influence
of overdenture
11.
12.
Tongue-thrusting patterns and the lower incisors. Am J Orthod 66:287, 1974. Hromatka, A.: Die Methode des Schluckabdruckes zur funktionellen Unterkieferabformung. Schweiz Mschr Zahnheilk 65:160, 1955. Fish, W.: Principles of Full Denture Prosthesis, ed 6. London, 1964, Staples Press. Tryde, G., Olsson, K., Jensen, S. Aa., Cantor, R., Tarsetano, J. J., and Brill, N.: Dynamic impression methods. J PROSTHET DENT 15:1023, 1965. Barone, J. V.: Physiologic complete denture impressions. J PROSTHET
13. 14. 15. 16.
K.
DENT
13:800,
1963.
Cavadini, P. E.: Increased mandibular denture retention by the use of the flange technique. Dent Digest 72:259, 1966. Kabcenell, J. L.: More retentive complete dentures. J Am Dent Assoc 8&l 16, 1970. Saxon, H.: Sublingual extension: Technique for loose lower dentures. Dent Digest 69:10, 1963. Proffit, W. R.: Lingual pressure patterns in the transition from tongue thrust to adult swallowing, Arch Oral Biol 17:555, 1972.
Re,brmt requests to: Dr. ROBERTO VON KRAMMER CASILLA 3501, CORREO SANTIAGO, CHILE
K.
CENTRAL
ABSTRACT abutment
tooth contour
upon the periodontium
G. N. Graser and J. Caton Eastman Dental
Center, Rochester, N.Y.
The purpose of this investigation was to determine the effect of the height and contour of overdenture abutments upon plaque retention and periodontal health. Four subjects were selected with mandibular cuspids having approximately the same amount of bone and connective tissue support. One of the two abutments was reduced to a dome shape allowing no natural root contour. The contralateral abutment was reduced to allow 2 mm of the natural peripheral root contour to remain coronal to the free gingival margin. Clinical parameters were measured at denture insertion and thereafter at l-month, 6-month, and l-year intervals. Parameters included: plaque index (PI),
Reprinted from the Journal of Dental Research [60 (Special 1981 (Abst No. 1365)] with permission of the author editor.
482
issue A), and the
gingival index (GI), pocket depth, gingival margin location, loss of attachment, and gingival width. Standardized radiographs were made at insertion and at 1 year. Analysis of the results for all subjects indicated that no significant differences in the clinical parameters were present when comparing dome-shaped with natural contour abutments. Two subjects had high plaque values (PI = 1.75) and two low (PI = 0). Increase in pocket depth (X = 1 mm) and attachment loss (X = 1.75 mm) occurred on the dome-shaped abutment in a patient with high plaque levels. Analysis of radiographs using the Bjom method revealed no significant changes after 1 year in proximal bone height for any of the abutments (a = 0.25 Bjorn. units (BU) dome, and ;i = 0 BU natural). Those abutments kept plaque free were associated with a stable and healthy periodontium, irrespective of their height and contour.
MAY
1982
VOLUME
47
NUMBER
5
a~& tehnique in subli of cwmpkte mandibular
von Krammer
al flange dentures
K., Cirujano-Dentista
Santiago. Chile
M
andibular complete dentures frequently lack retention and stability and offer lessdenture-supporting area than maxillary dentures.’ A sublingual flange extension improves the retention and stability of complete lower dentures. It increasesthe tissue surface of the denture, augmenting simple adhesion and, therefore, retention.2 Stabifity is also enhanced by active incorporation of tongue activity into the task of maintaining the lower denture in place.
ANATOMIC
STRUCTURES
INVOLVED
The sublingual flange is placed in the sublingual region, which is bound posteriorly by the glossopalatine muscle(palatoglossalfold) and the lingual slip of the superior constrictor muscle of the pharynx. Its upper limit is the inferior surfaceof the tongue, and its lower limit the floor of the mouth. Here, its posterior third is prescribed by the mylohyoid muscle, which in this region is quite superficial and often inserts in a sharp and prominent bony ridge. In the first molar region: the muscle angles downward and inward toward the middle third of the sublingual region, where the mylohyoid muscle exerts its influence through the sublingual gland, which lies on top of it. This region allows for a certain degreeof downward displacement. In the anterior third, the inferior limit of the lingual flange is determined by the genioglossusmuscle.
PRINCIPLES
IN SUBLINGUAL
Fig. 1. Tongue in normal position in edentulous mouth.
Fig. 2. Acrylic resin custom tray with occlusion rim.
FLANGE
EXTENSION Regardlessof the technique usedfor the construction of a complete lower denture, a normal tongue position is important for success(Fig. l).” Singers and public speakers appear to acquire a good tongue position becauseit favors better resonanceand placesthe tongue at the best starting point for reaching the different articulating zones. If the patient has acquired a retracted tongue position, this bad habit must be corrected before the denture is made. Abnormal swallowing habits may also undermine the successof a complete lower denture and must be corrected before prosthodontic treatment begins.4-8
I,,Q-‘-3911
82 ‘050479
+ 04$00.40’0
’ 1982 The C. V Mosby
C:o
Fig. 3. Border molding with modeling compound.
THE
JOURNAL
OF PROSTHETIC
DENTISTRY
479
Fig. 8. Denture in mouth and tongue in correct Fig. 5. Stone cast. Sublingual flange extension has been outlined by broken line.
position.
phonation. This extension is accomplishedby having the patient swallow during the impression-making procedureswith the tongue in its normal position.
TECHNIQUE
Fig. 6. Finished denture. The function of the anatomic structures that surround the sublingual region makes its size and shape vary. Two dynamic elementscontrol the size and shape of the sublingual region: the tongue and the floor of the mouth. Our goal must be to obtain the maximum possibleextension of the sublingual flange that will not interfere with functions of mastication, deglutition, and
480
Sublingual flange extensions can be incorporated into the impression technique,‘-I1 developed once the denture has been waxed,‘2-‘4or formed on the finished denture with autopolymerizing acrylic resin.15Figs. 2 to 8 demonstrate the sublingual flange extension technique. A diagnostic cast is neededto design the tentative foundation area and to form the custom tray that will conform to this outline. The diagnostic cast can be obtained from an overextended preliminary impression (made from such materials as irreversible hydrocolloid or modeling compound), an adequately rebasedexisting denture (Fig. 9), or an interim denture that has beenincrementally rebased.The denture foundation is determined by the following procedure. The labial flange from one buccal frenum to the other is determined by observing the bottom of the vestibule with the
MAY
1982
VOLUME
47
NUMBER
5
SUBLINGUAL
FLANGE
EXTENSION
Fig. 11. Lower partial denture with distal extension on left side. Only three natural teeth are left in mandible: Two canines and second right molar. Sublingual flange extension provided enough retention so that claspswere unnecessaryon anterior abutments. Fig. 9. Left, Patient’s old denture was built up with self-curing acrylic resin and tissue conditioner. Procedure was carried out incrementally in successivesittings until comfortable denture was produced. Then diagnostic cast was obtained from it. Right, New denture. Note similarity in outline with rebased denture.
Fig. 10. In this lower denture, effect of left side
dominance of tongue is prominent.
mouth slightly open. The buccal flange from the buccal frenum to the retromolar pad reachesup to the external oblique line, the posterior border coversthe retromolar pad completely, and the distolingual border should extend downward and backward from the retromolar pad at an angle of approximately 45 degrees.3The lingual border follows the mylohyoid ridge up to the first molar region. The lingual flange between the first molars is also determined by observing the level of the floor of the mouth with the tongue slightly elevated. An occlusion rim that simulatesthe correct occlusal plane
THE
JOURNAL
OF PROSTHETIC
DENTISTRY
Fig. 12. Sublingual flange extension helps keep in place this clasplessbilateral distal-extension lower partial denture.
and the proper arch arrangement is used to help maintain a normal tongue position (Fig. 2).’ The impressionmaterial of choice is used, and buccal and labial border molding are accomplishedbv the familiar whistle-grin movements. The material of choice for the sublingual flange extension is modeling compound. As this step of the procedure is carried out, the dentist will note that, in lateral pressuremagnitudes,there is dominanceof one side of the tongue, usually the left side (Fig. IO).‘” Of
481
VON KRAMMER
course, keep (Figs.
a sublingual in
place 11 and
flange
can
distal-extension
also lower
be
used
partial
to help dentures
10.
REFERENCES 1.
2. 3.
4. 5.
6. 7.
8.
9.
12).
Woelfel, J. B., Winter, C. M., and Igarashi, T.: Five-year cephalometric study of mandibular ridge resorption with different posterior occlusal forms. Part I: Denture construction and initial comparison. J PROSTHET DENT 36:602, 1976. Saizar, P.: Protesis a Placa, ed 4. Buenos Aires, 1950, Progrental, p 73. Wright, C.: Evaluation of the factors necessary to develop stability in mandibular dentures. J PROSTHET DENT l&414, 1966. Ramfjord, S. P., and Ash, M. M.: Occlusion, ed 2. Philadelphia, 1971, W. B. Saunders Co. p 90. Mohl, N. D., and Drinnan, A. J.: Anatomy and physiology of the edentulous mouth. In Winkler, S., editor: Symposium on complete dentures. Dent Clin North Am 21:199, 1977. Garliner, D.: Myofunctional Therapy in Dental Practice. Brooklyn, 1971, Bartel Dental Book Co., pp 4-5. Massengill, R., Robinson, M., and Quinn, G.: Cinefluorographic analysis of tongue-thrusting. Am J Orthod 61:402, 1972. Massengill, R., Quinn, G., Hall, A. S., and Boyd, D.:
IADR PROSTHODONTIC The influence
of overdenture
11.
12.
Tongue-thrusting patterns and the lower incisors. Am J Orthod 66:287, 1974. Hromatka, A.: Die Methode des Schluckabdruckes zur funktionellen Unterkieferabformung. Schweiz Mschr Zahnheilk 65:160, 1955. Fish, W.: Principles of Full Denture Prosthesis, ed 6. London, 1964, Staples Press. Tryde, G., Olsson, K., Jensen, S. Aa., Cantor, R., Tarsetano, J. J., and Brill, N.: Dynamic impression methods. J PROSTHET DENT 15:1023, 1965. Barone, J. V.: Physiologic complete denture impressions. J PROSTHET
13. 14. 15. 16.
K.
DENT
13:800,
1963.
Cavadini, P. E.: Increased mandibular denture retention by the use of the flange technique. Dent Digest 72:259, 1966. Kabcenell, J. L.: More retentive complete dentures. J Am Dent Assoc 8&l 16, 1970. Saxon, H.: Sublingual extension: Technique for loose lower dentures. Dent Digest 69:10, 1963. Proffit, W. R.: Lingual pressure patterns in the transition from tongue thrust to adult swallowing, Arch Oral Biol 17:555, 1972.
Re,brmt requests to: Dr. ROBERTO VON KRAMMER CASILLA 3501, CORREO SANTIAGO, CHILE
K.
CENTRAL
ABSTRACT abutment
tooth contour
upon the periodontium
G. N. Graser and J. Caton Eastman Dental
Center, Rochester, N.Y.
The purpose of this investigation was to determine the effect of the height and contour of overdenture abutments upon plaque retention and periodontal health. Four subjects were selected with mandibular cuspids having approximately the same amount of bone and connective tissue support. One of the two abutments was reduced to a dome shape allowing no natural root contour. The contralateral abutment was reduced to allow 2 mm of the natural peripheral root contour to remain coronal to the free gingival margin. Clinical parameters were measured at denture insertion and thereafter at l-month, 6-month, and l-year intervals. Parameters included: plaque index (PI),
Reprinted from the Journal of Dental Research [60 (Special 1981 (Abst No. 1365)] with permission of the author editor.
482
issue A), and the
gingival index (GI), pocket depth, gingival margin location, loss of attachment, and gingival width. Standardized radiographs were made at insertion and at 1 year. Analysis of the results for all subjects indicated that no significant differences in the clinical parameters were present when comparing dome-shaped with natural contour abutments. Two subjects had high plaque values (PI = 1.75) and two low (PI = 0). Increase in pocket depth (X = 1 mm) and attachment loss (X = 1.75 mm) occurred on the dome-shaped abutment in a patient with high plaque levels. Analysis of radiographs using the Bjom method revealed no significant changes after 1 year in proximal bone height for any of the abutments (a = 0.25 Bjorn. units (BU) dome, and ;i = 0 BU natural). Those abutments kept plaque free were associated with a stable and healthy periodontium, irrespective of their height and contour.
MAY
1982
VOLUME
47
NUMBER
5