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Ramus Frame Implant Technique
___ JAD)A T EC HN IQU ES
Ramus frame implant technique
H. Ford Turner, PhD, DMD
h e ra m u s fra m e is a o n e - p ie c e m andibular im plant, with right and left posterior extensions which are seated in the corresponding right and left a s c e n d in g ra m i, a n d a n a n t e r io r f o o t which is seated in the bone o f the symphy sis. This one piece rail has a u-shaped con figuration that usually flares laterally as the p o sterio r extensions e n te r the rami. T he tripodial design offers exceptional stability an d su pp o rt for the m andibular denture. T h e success rate o f th e first g e n e ra tio n fram e, the M2, has been good, b u t settling o f the fram e inferiorly has been a com pli cation in a n um ber of cases. New designs with im proved insertion techniques allow alm ost no settling and also reduce the inci dence o f paresthesia. T h e f ir s t ra m u s f ra m e (M 2) w as d esig n ed an d d ev elo p ed by H aro ld a n d R alph R oberts in th e 1970s. T he design an d insertion technique o f this fram e has chan g ed little since its inception. Several design m odifications have resisted settling because an terio r labial tabs ,1 an terio r lin gual tabs ,2 an d tissue su p p o rt have been used.s T h e ram us fram e p ro sth esis has b ee n a tta c h e d to th e fra m e by lo c k in g w ith acrylic resin ,4 frictional resistance ,5 m odi fied Nelson locks ,6 Lew attachm ents ,3 and cem en tation .7
T
418 ■ JADA, Vol. 121, September 1990 I
Insertion technique
M2 (Fig 1). A 15 m m vertical incision is m ade through all layers o f soft tissue ju st mesial to the an terio r b o rd er o f the right ram us. This incision will be in the lower h a lf o f th e v ertical ra m u s b etw e en th e oblique ridges an d between the tendons of insertion o f the tem poralis muscle. T he tis sues are then retracted with the b lu n t ends o f two no. 31 spatulas (one for the assis ta n t an d o n e fo r th e s u rg e o n ). A 6 mm vertical channel is m ade th ro u g h the corti cal plate o f this exposed b one with a 560 bu r which is constantly irrigated with ster ile w ater o r sa lin e s o lu tio n . An acrylic trim m ing b u r is used in a slow handpiece to com plete the p reparation of the ram us ch an n el (Fig 2). T h e ch a n n el should be parallel with, b u t buccal an d superior to, the m andib u lar canal an d should have a depth and height to accom m odate a 5 mm trial insert th at is 12 to 15 m m long. T he try-in arm is m anipulated moving posteri orly a n d s u p e rio rly to th e fin al d e p th . G auze is packed in th e rig h t ram us and the incision, retraction, ch an n el p rep ara tion, and try-in are p erfo rm ed on the left ramus. T h e p r o p e r size fra m e (av a ilab le in three basic sizes) is selected by placing the posterior ends in the p repared channels of
th e ram i a n d th e a n te rio r fo o t over th e sy m p h y sis. T h e p o s te r i o r e n d s o f th e fra m e a re b e n t to fit passively in to th e rami and the an terio r foot is b en t to con form to the curvature of the symphysis. A 40-mm incision is m ade along the crest of th e an terio r ridge. If the m ental foram ina c a n n o t be located by palpation, they are surgically exposed to avoid encro ach m en t w ith a b u r o r p e r io s te a l elev a to r. T h e p e r io s te u m a n d o th e r so ft tissu es a re reflected an d an an terio r channel is m ade 5 to 7 m m deep an d 2 m m wide with a 560 su rg ical b u r. S om e e n g a g e m e n t o f th e c o rtic a l p la te a d d s stability.» A shallow layer o f hydroxylapatite placed in the floor
Fig 1 ■ Acrylic trim m ing b u r in ram us.
T E C H N I Q U E S
Fig 2 ■ M2 frame in mandible with denture.
o f this an terior channel may help prevent se ttlin g . T h e c o m p le te d fra m e is again placed in the rami and the foot is lowered an d m an ip ulated into the an terio r ch an nel an d m alleted into place while support in g th e chin. T he incision is closed with continuous and mattress sutures with addi tional in te rru p te d sutures aro u n d the tis sue exits o f the frame. D u rin g surgery, th e p a tie n t’s existing d e n tu re is p rep a re d in th e lab o rato ry to allow m odification an d fit o f th e tem po rary prosthesis to the frame. This is do n e by hollow grin d in g the m a n d ib u la r d e n ture and shortening its borders. It is filled with chemical-cure acrylic resin, d ipped in h o t water, an d held in occlusion against th e m a x illa ry te e th . W hen th e re sin is “d o u g h y ,” th e p a tie n t closes his o r h e r m o u th to a p rem easured vertical dim en sio n . W h e n s e m ic u re d , th e d e n tu r e is rem oved from the m outh and the cure is co m p leted in a h o t w ater pressure tank. T h e excess resin is rem oved and the d en tu re is polished and placed on the frame. If fric tio n a l resistance does n o t provide a d e q u a te r e t e n t i o n , th e d e n t u r e is c e m e n te d to th e fra m e. T h e p a tie n t is g iven an ice pack, m e d ic a tio n , w ritte n p o sto p erative instructions, an d asked to retu rn in 2 weeks for suture removal and occlusal adjustm ents. After healing is com plete, usually after 3 m onths (Fig 3), new d en tu re s th a t have attachm ents to facili tate passive removal may be provided .3-68 RA2. T h e anterior foot o f the RA2 is 32 m m long and has 5 mm labial tabs at each end th at are b en t to be recessed 19 into the labial cortical plate (Fig 4). T he m idline of th e ridge in the symphysis is m arked and th e a n te r io r in c isio n is m a d e a p p r o x i m ately 40 mm in length. E xcept fo r the recesses, the an terio r channel is prepared in the same m anner as the M2. T he posterior extensions o f the RA2 are 40 m m in len g th with small buccal tabs n ear their mesial ends that are designed to fit over th e e x tern al obliq u e ridge. T h e
rig h t p o sterio r incision th ro u g h th e soft tissues ex ten d s from th e retro m o la r pad f o rw a r d to a p o in t o v e r th e e x t e r n a l oblique ridge th at is approxim ately 20 mm from th e rig h t distal en d o f the an terio r channel. T he tissue is retracted an d a 30m m v e rtic a l c h a n n e l is p r e p a r e d in a stra ig h t line alo n g th e e x te rn a l o b liq u e ridge from a po in t n ear the mesial en d of th e soft tissue incision. T h e distal e n d o f this channel is extended into the ram us in u n d erc u t bone with a 701 b u r 8 in a bayo n e t h a n d p ie c e . T h e ex p o sed c h a n n e l is w idened slightly with a 562 b u r in a slowspeed contra-angle. T h e accuracy o f th e channel preparation is tested with a try-in, a n d if satisfactory, th e sam e p ro c e d u re s are rep eated on th e left side. T h e poste rio r ch a n n e ls a re p arallel to th e buccal borders of the m andible. T he ends o f the ram us fram e are squeezed (not bent) with one han d and pointed downward into the m iddle o f the ch annels an d th en moved backw ard. As th e en d s are released , the a n te rio r fo o t is low ered to its p re p a re d socket. T h e a n te rio r fo o t is b e n t in the m outh to conform to the curvature o f the a n te r io r c h a n n e l a n d th e n ta p p e d in to position. If the foot does n o t com pletely seat, th e p o ste rio r c h a n n e ls have to be d ee p en e d o r the rails b en t vertically down ward until the total fram e seats firmly but passively in all three sockets. Incision clos ing, d e n tu re adaptations, an d p o sto p era tive instructions are the same as with the M2. T he RA2 has been successfully used to restore severely resorbed mandibles. M25 (Fig 5). As with the M2, each poste rior incision is m ade vertically ju st mesial to the an terio r b o rd e r o f th e ram us and extends 15 mm upward from the retro m o lar pad. Tatum , at Symposium II o f AAID R e s e a rc h F o u n d a tio n in A p ril 1986, described the posterior socket (ch an n el) prep aratio n for the M25: “a No. 2 ro u n d b u r in a s tra ig h t h a n d p ie c e is u se d to make a vertical cut through cortical bone o n th e m e d ia l a s p e c t o f th e e x te r n a l oblique ridge. T he groove is w idened with a no. 6 ro u n d bur. A try-in with a long han dle is p laced in this groove an d p u sh ed w ith an u p a n d d o w n m o tio n in th e m edullary bo n e betw een th e buccal an d lingual cortical plates form ing a posterior receptor site.” T he an terio r channel is pre pared in the symphysis in the same m an n e r as for the RA2. T he selected im plant (four sizes are available) is positioned and sq u e e z e d w ith h a n d p re ssu re u n til th e ends are started inside the posterior sock ets. A seating in stru m en t is placed on the an terio r post n ear the rail and the fram e is tapped into final position n ear or through
the posterior borders o f the rami. T h e foot of the fram e is rotated downward an d mal leted in to position. T h e incision is closed and the d e n tu re is m odified in th e same m an n er as with the o th e r frames. Much of the success of this fram e may be attributed to the increase in im plant interface in the ram i which may prevent m uch o f the ante rior settling o f the older type frames. M20 (Fig 5). This fram e can be used in any m andible that has adequate b one over the nerve canal in the m olar region. T he posterior ends resem ble ram us blades and a re in s e rte d in to th e d istal rid g e s a n d angled to the rami. T h e M20 is available in four sizes. T he selected fram e is placed in an d o u t o f the m o u th as necessary. B ends are m ad e in th e a n te rio r an d p o ste rio r ex ten sio n s to m atch th e p ro jec ted re c e p to r sites. T h e a n te r io r in c isio n site is m a rk e d w ith a m ic ro w a v e-ste rilize d T h o m p s o n ’s b lu e m arking stick while using the an terio r foot as a g u id e . T h e fra m e is re m o v e d , th e an te rio r incision m ade, an d th e ch an n el p repared. T he fram e is placed again in the m o u th a n d th e a n te rio r fo o t is partw ay seated into its channel and held while the
Fig 3 ■ Healed anterior foot.
Fig 4 ■ RA2 (upper), M25 (m iddle), M20 (lower).
JADA, Vol. 121, September 1990 ■ 419 I
T E C H N I Q U E S
lo c a tio n o f th e p o s te rio r in c isio n s are m ark ed w ith a b lu e stick. T h e fram e is removed and incisions are m ade and chan nels p re p a re d alo n g th e p o ste rio r b lu e m ark s. T h e p o sitio n o f th e m y lohyoid ridge and th e m a n d ib u lar canal m ust be k n o w n . T h e b o n y c h a n n e l p r e p s a re started by carefully m aking punctures with a 700 XL bur along the desired path o f the ch annel, th en co nnecting the punctures. The d epth is established with a 560 high speed b u r and the width with a 562 slowspeed bur. T he distal p o rtion o f each prep is m ade in u n d e rc u t b o n e w ith a fissure bur in a bayonet handpiece. T he im plant is seated by squeezing the fram e and plac ing the posterior ends in their channels at m id p o in t an d forcing them backw ard by tapping until the an terio r foot is over the ch a n n el. T h e a n te rio r fo o t is th e n malle te d in to p o s itio n . T h e in c is io n s a re closed and the d en tu re fitted as with other type frames. A relatively high rate ( 8 %) o f paresthe sia o r anesthesia o f the lip and chin is asso ciated with the ram us fram e im plant. This in c id e n c e may be re d u c e d w ith b e tte r bleeding control, careful surgery, and bet ter knowledge o f anatom ical limitations. Settling is the m ain cause o f failure o f the M2 ram us fram e. T h e deg ree o f set tling is re d u c e d by u sin g sm aller te e th , m ain ta in in g n o rm al curves o f Spee an d M onson, by not increasing vertical dim en sion, an d by increasing the m etal-to-bone interface with the m odified designs. M inor s e ttlin g m ay b e c o n f u s e d w ith b o n e
420 ■ JADA, Vol. 121, September 1990
*
understanding on the p art o f the surgeon. Most p atien ts are best tre a te d with co n scious sedation. Properly done, the ram us fra m e a ffo rd s c o m fo r t, g o o d e s th e tic appearance, psychological well-being, and function to those patients unable to wear conventional dentures.
-------------------- J!£OA -------------------Fig 5 ■ O m n ii im p la n t 6 y e a rs in s e r v ic e (Courtesy H. Tatum).
growth, which often h appens in the m olar area after a few years. A fo llo w -u p s tu d y was m a d e o f th e a u th o r’s records o f ram us fram es inserted between 1973 an d 1985. O f the 417 fram es that were inserted, 27 were rem oved d u r ing this 12-year period. O f the 27 patients who had their fram es removed, all b ut ten had them reinserted. T he ram us fram e im p lan t sim plicity of design provides im m ediate function, good appearance, and uncom plicated econom i cal p r o s th e tic s f o r th e e d e n tu lo u s m andible. No o th e r m an d ib u la r im p lan t can offer such featu res in a co m p arab le treatm ent time. The fram e provides in one a p p o in tm e n t a reten tiv e, stable su p p o rt system for a m andibular d enture. Conclusion T h is im p la n t r e q u ir e s a h ig h le v el o f im p la n t s u rg ic a l sk ill a n d r e s to r a tiv e
Dr. T u rn e r is in private practice, 545 H uffm an Rd, B irm ingham , AL 35215. A ddress requests for reprints to the author.
1. R oberts R. R am us fram e m an d ib u la r im plant; a 16 year prelim inary statistical evaluation. C lark’s Clin D ent 1987;5:1-11. 2. C ollin g s G. A new m o d ific a tio n in th e ra m u s fram e. J O ral Im plantol 1977;6:546-57. 3. Praiss A. A m ethod to prevent the settling o f the ram us fram e im plant. J O ral Im plantol 1982;10:289-91. 4. R oberts H. Surgical a n d la b o ra to ry p ro c e d u re s f o r th e p la c e m e n t o f th e ra m u s, s in g le to o th a n d r a m u s f r a m e im p la n ts . C o lle g e P la c e : C o lle g e Press; 1971:19-27. 5. C ram D, Roberts H , Baum L. R am us endosseous fra m e im p la n t fo r u se w ith th e p a tie n t’s d e n tu re : re p o rt o f case. JADA 1972;84:156-62. 6. N elson R. T h e ram us fram e im p la n t for stabiliz ing impossible m andibular dentures. J O ral Im plantol 1974;6:475-503. 7. T u rn e r F. T he ram us fram e im plant. J Im plant In D ent 1981;1:14-6. 8. Taylor A. E ndosseous d e n ta l im plants. L ondon: B utterw orth; 1970:28,113. 9. K ru g e r G. T e x tb o o k o f o ra l a n d m axillofacial surgery. 6th ed. St. Louis: Mosby; 1984:155-66.
Ramus frame implant technique
H. Ford Turner, PhD, DMD
h e ra m u s fra m e is a o n e - p ie c e m andibular im plant, with right and left posterior extensions which are seated in the corresponding right and left a s c e n d in g ra m i, a n d a n a n t e r io r f o o t which is seated in the bone o f the symphy sis. This one piece rail has a u-shaped con figuration that usually flares laterally as the p o sterio r extensions e n te r the rami. T he tripodial design offers exceptional stability an d su pp o rt for the m andibular denture. T h e success rate o f th e first g e n e ra tio n fram e, the M2, has been good, b u t settling o f the fram e inferiorly has been a com pli cation in a n um ber of cases. New designs with im proved insertion techniques allow alm ost no settling and also reduce the inci dence o f paresthesia. T h e f ir s t ra m u s f ra m e (M 2) w as d esig n ed an d d ev elo p ed by H aro ld a n d R alph R oberts in th e 1970s. T he design an d insertion technique o f this fram e has chan g ed little since its inception. Several design m odifications have resisted settling because an terio r labial tabs ,1 an terio r lin gual tabs ,2 an d tissue su p p o rt have been used.s T h e ram us fram e p ro sth esis has b ee n a tta c h e d to th e fra m e by lo c k in g w ith acrylic resin ,4 frictional resistance ,5 m odi fied Nelson locks ,6 Lew attachm ents ,3 and cem en tation .7
T
418 ■ JADA, Vol. 121, September 1990 I
Insertion technique
M2 (Fig 1). A 15 m m vertical incision is m ade through all layers o f soft tissue ju st mesial to the an terio r b o rd er o f the right ram us. This incision will be in the lower h a lf o f th e v ertical ra m u s b etw e en th e oblique ridges an d between the tendons of insertion o f the tem poralis muscle. T he tis sues are then retracted with the b lu n t ends o f two no. 31 spatulas (one for the assis ta n t an d o n e fo r th e s u rg e o n ). A 6 mm vertical channel is m ade th ro u g h the corti cal plate o f this exposed b one with a 560 bu r which is constantly irrigated with ster ile w ater o r sa lin e s o lu tio n . An acrylic trim m ing b u r is used in a slow handpiece to com plete the p reparation of the ram us ch an n el (Fig 2). T h e ch a n n el should be parallel with, b u t buccal an d superior to, the m andib u lar canal an d should have a depth and height to accom m odate a 5 mm trial insert th at is 12 to 15 m m long. T he try-in arm is m anipulated moving posteri orly a n d s u p e rio rly to th e fin al d e p th . G auze is packed in th e rig h t ram us and the incision, retraction, ch an n el p rep ara tion, and try-in are p erfo rm ed on the left ramus. T h e p r o p e r size fra m e (av a ilab le in three basic sizes) is selected by placing the posterior ends in the p repared channels of
th e ram i a n d th e a n te rio r fo o t over th e sy m p h y sis. T h e p o s te r i o r e n d s o f th e fra m e a re b e n t to fit passively in to th e rami and the an terio r foot is b en t to con form to the curvature of the symphysis. A 40-mm incision is m ade along the crest of th e an terio r ridge. If the m ental foram ina c a n n o t be located by palpation, they are surgically exposed to avoid encro ach m en t w ith a b u r o r p e r io s te a l elev a to r. T h e p e r io s te u m a n d o th e r so ft tissu es a re reflected an d an an terio r channel is m ade 5 to 7 m m deep an d 2 m m wide with a 560 su rg ical b u r. S om e e n g a g e m e n t o f th e c o rtic a l p la te a d d s stability.» A shallow layer o f hydroxylapatite placed in the floor
Fig 1 ■ Acrylic trim m ing b u r in ram us.
T E C H N I Q U E S
Fig 2 ■ M2 frame in mandible with denture.
o f this an terior channel may help prevent se ttlin g . T h e c o m p le te d fra m e is again placed in the rami and the foot is lowered an d m an ip ulated into the an terio r ch an nel an d m alleted into place while support in g th e chin. T he incision is closed with continuous and mattress sutures with addi tional in te rru p te d sutures aro u n d the tis sue exits o f the frame. D u rin g surgery, th e p a tie n t’s existing d e n tu re is p rep a re d in th e lab o rato ry to allow m odification an d fit o f th e tem po rary prosthesis to the frame. This is do n e by hollow grin d in g the m a n d ib u la r d e n ture and shortening its borders. It is filled with chemical-cure acrylic resin, d ipped in h o t water, an d held in occlusion against th e m a x illa ry te e th . W hen th e re sin is “d o u g h y ,” th e p a tie n t closes his o r h e r m o u th to a p rem easured vertical dim en sio n . W h e n s e m ic u re d , th e d e n tu r e is rem oved from the m outh and the cure is co m p leted in a h o t w ater pressure tank. T h e excess resin is rem oved and the d en tu re is polished and placed on the frame. If fric tio n a l resistance does n o t provide a d e q u a te r e t e n t i o n , th e d e n t u r e is c e m e n te d to th e fra m e. T h e p a tie n t is g iven an ice pack, m e d ic a tio n , w ritte n p o sto p erative instructions, an d asked to retu rn in 2 weeks for suture removal and occlusal adjustm ents. After healing is com plete, usually after 3 m onths (Fig 3), new d en tu re s th a t have attachm ents to facili tate passive removal may be provided .3-68 RA2. T h e anterior foot o f the RA2 is 32 m m long and has 5 mm labial tabs at each end th at are b en t to be recessed 19 into the labial cortical plate (Fig 4). T he m idline of th e ridge in the symphysis is m arked and th e a n te r io r in c isio n is m a d e a p p r o x i m ately 40 mm in length. E xcept fo r the recesses, the an terio r channel is prepared in the same m anner as the M2. T he posterior extensions o f the RA2 are 40 m m in len g th with small buccal tabs n ear their mesial ends that are designed to fit over th e e x tern al obliq u e ridge. T h e
rig h t p o sterio r incision th ro u g h th e soft tissues ex ten d s from th e retro m o la r pad f o rw a r d to a p o in t o v e r th e e x t e r n a l oblique ridge th at is approxim ately 20 mm from th e rig h t distal en d o f the an terio r channel. T he tissue is retracted an d a 30m m v e rtic a l c h a n n e l is p r e p a r e d in a stra ig h t line alo n g th e e x te rn a l o b liq u e ridge from a po in t n ear the mesial en d of th e soft tissue incision. T h e distal e n d o f this channel is extended into the ram us in u n d erc u t bone with a 701 b u r 8 in a bayo n e t h a n d p ie c e . T h e ex p o sed c h a n n e l is w idened slightly with a 562 b u r in a slowspeed contra-angle. T h e accuracy o f th e channel preparation is tested with a try-in, a n d if satisfactory, th e sam e p ro c e d u re s are rep eated on th e left side. T h e poste rio r ch a n n e ls a re p arallel to th e buccal borders of the m andible. T he ends o f the ram us fram e are squeezed (not bent) with one han d and pointed downward into the m iddle o f the ch annels an d th en moved backw ard. As th e en d s are released , the a n te rio r fo o t is low ered to its p re p a re d socket. T h e a n te rio r fo o t is b e n t in the m outh to conform to the curvature o f the a n te r io r c h a n n e l a n d th e n ta p p e d in to position. If the foot does n o t com pletely seat, th e p o ste rio r c h a n n e ls have to be d ee p en e d o r the rails b en t vertically down ward until the total fram e seats firmly but passively in all three sockets. Incision clos ing, d e n tu re adaptations, an d p o sto p era tive instructions are the same as with the M2. T he RA2 has been successfully used to restore severely resorbed mandibles. M25 (Fig 5). As with the M2, each poste rior incision is m ade vertically ju st mesial to the an terio r b o rd e r o f th e ram us and extends 15 mm upward from the retro m o lar pad. Tatum , at Symposium II o f AAID R e s e a rc h F o u n d a tio n in A p ril 1986, described the posterior socket (ch an n el) prep aratio n for the M25: “a No. 2 ro u n d b u r in a s tra ig h t h a n d p ie c e is u se d to make a vertical cut through cortical bone o n th e m e d ia l a s p e c t o f th e e x te r n a l oblique ridge. T he groove is w idened with a no. 6 ro u n d bur. A try-in with a long han dle is p laced in this groove an d p u sh ed w ith an u p a n d d o w n m o tio n in th e m edullary bo n e betw een th e buccal an d lingual cortical plates form ing a posterior receptor site.” T he an terio r channel is pre pared in the symphysis in the same m an n e r as for the RA2. T he selected im plant (four sizes are available) is positioned and sq u e e z e d w ith h a n d p re ssu re u n til th e ends are started inside the posterior sock ets. A seating in stru m en t is placed on the an terio r post n ear the rail and the fram e is tapped into final position n ear or through
the posterior borders o f the rami. T h e foot of the fram e is rotated downward an d mal leted in to position. T h e incision is closed and the d e n tu re is m odified in th e same m an n er as with the o th e r frames. Much of the success of this fram e may be attributed to the increase in im plant interface in the ram i which may prevent m uch o f the ante rior settling o f the older type frames. M20 (Fig 5). This fram e can be used in any m andible that has adequate b one over the nerve canal in the m olar region. T he posterior ends resem ble ram us blades and a re in s e rte d in to th e d istal rid g e s a n d angled to the rami. T h e M20 is available in four sizes. T he selected fram e is placed in an d o u t o f the m o u th as necessary. B ends are m ad e in th e a n te rio r an d p o ste rio r ex ten sio n s to m atch th e p ro jec ted re c e p to r sites. T h e a n te r io r in c isio n site is m a rk e d w ith a m ic ro w a v e-ste rilize d T h o m p s o n ’s b lu e m arking stick while using the an terio r foot as a g u id e . T h e fra m e is re m o v e d , th e an te rio r incision m ade, an d th e ch an n el p repared. T he fram e is placed again in the m o u th a n d th e a n te rio r fo o t is partw ay seated into its channel and held while the
Fig 3 ■ Healed anterior foot.
Fig 4 ■ RA2 (upper), M25 (m iddle), M20 (lower).
JADA, Vol. 121, September 1990 ■ 419 I
T E C H N I Q U E S
lo c a tio n o f th e p o s te rio r in c isio n s are m ark ed w ith a b lu e stick. T h e fram e is removed and incisions are m ade and chan nels p re p a re d alo n g th e p o ste rio r b lu e m ark s. T h e p o sitio n o f th e m y lohyoid ridge and th e m a n d ib u lar canal m ust be k n o w n . T h e b o n y c h a n n e l p r e p s a re started by carefully m aking punctures with a 700 XL bur along the desired path o f the ch annel, th en co nnecting the punctures. The d epth is established with a 560 high speed b u r and the width with a 562 slowspeed bur. T he distal p o rtion o f each prep is m ade in u n d e rc u t b o n e w ith a fissure bur in a bayonet handpiece. T he im plant is seated by squeezing the fram e and plac ing the posterior ends in their channels at m id p o in t an d forcing them backw ard by tapping until the an terio r foot is over the ch a n n el. T h e a n te rio r fo o t is th e n malle te d in to p o s itio n . T h e in c is io n s a re closed and the d en tu re fitted as with other type frames. A relatively high rate ( 8 %) o f paresthe sia o r anesthesia o f the lip and chin is asso ciated with the ram us fram e im plant. This in c id e n c e may be re d u c e d w ith b e tte r bleeding control, careful surgery, and bet ter knowledge o f anatom ical limitations. Settling is the m ain cause o f failure o f the M2 ram us fram e. T h e deg ree o f set tling is re d u c e d by u sin g sm aller te e th , m ain ta in in g n o rm al curves o f Spee an d M onson, by not increasing vertical dim en sion, an d by increasing the m etal-to-bone interface with the m odified designs. M inor s e ttlin g m ay b e c o n f u s e d w ith b o n e
420 ■ JADA, Vol. 121, September 1990
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understanding on the p art o f the surgeon. Most p atien ts are best tre a te d with co n scious sedation. Properly done, the ram us fra m e a ffo rd s c o m fo r t, g o o d e s th e tic appearance, psychological well-being, and function to those patients unable to wear conventional dentures.
-------------------- J!£OA -------------------Fig 5 ■ O m n ii im p la n t 6 y e a rs in s e r v ic e (Courtesy H. Tatum).
growth, which often h appens in the m olar area after a few years. A fo llo w -u p s tu d y was m a d e o f th e a u th o r’s records o f ram us fram es inserted between 1973 an d 1985. O f the 417 fram es that were inserted, 27 were rem oved d u r ing this 12-year period. O f the 27 patients who had their fram es removed, all b ut ten had them reinserted. T he ram us fram e im p lan t sim plicity of design provides im m ediate function, good appearance, and uncom plicated econom i cal p r o s th e tic s f o r th e e d e n tu lo u s m andible. No o th e r m an d ib u la r im p lan t can offer such featu res in a co m p arab le treatm ent time. The fram e provides in one a p p o in tm e n t a reten tiv e, stable su p p o rt system for a m andibular d enture. Conclusion T h is im p la n t r e q u ir e s a h ig h le v el o f im p la n t s u rg ic a l sk ill a n d r e s to r a tiv e
Dr. T u rn e r is in private practice, 545 H uffm an Rd, B irm ingham , AL 35215. A ddress requests for reprints to the author.
1. R oberts R. R am us fram e m an d ib u la r im plant; a 16 year prelim inary statistical evaluation. C lark’s Clin D ent 1987;5:1-11. 2. C ollin g s G. A new m o d ific a tio n in th e ra m u s fram e. J O ral Im plantol 1977;6:546-57. 3. Praiss A. A m ethod to prevent the settling o f the ram us fram e im plant. J O ral Im plantol 1982;10:289-91. 4. R oberts H. Surgical a n d la b o ra to ry p ro c e d u re s f o r th e p la c e m e n t o f th e ra m u s, s in g le to o th a n d r a m u s f r a m e im p la n ts . C o lle g e P la c e : C o lle g e Press; 1971:19-27. 5. C ram D, Roberts H , Baum L. R am us endosseous fra m e im p la n t fo r u se w ith th e p a tie n t’s d e n tu re : re p o rt o f case. JADA 1972;84:156-62. 6. N elson R. T h e ram us fram e im p la n t for stabiliz ing impossible m andibular dentures. J O ral Im plantol 1974;6:475-503. 7. T u rn e r F. T he ram us fram e im plant. J Im plant In D ent 1981;1:14-6. 8. Taylor A. E ndosseous d e n ta l im plants. L ondon: B utterw orth; 1970:28,113. 9. K ru g e r G. T e x tb o o k o f o ra l a n d m axillofacial surgery. 6th ed. St. Louis: Mosby; 1984:155-66.