Flexible retentive bite block and fabrication process

A dentally retained intra-oral appliance worn at night for treatment of snoring and obstructive sleep apnea and its fabrication process. The appliance maintains the patient's mandible in an anterior, protruded position to prevent obstruction of the pharyngeal airway. The appliance allows a limited degree of lateral movement of the mandible relative to the upper jaw in the protruded position to prevent aggravation of the patient's temporomandibular joint and associated muscles and ligaments. The appliance includes a lower bite block conforming to the patient's mandibular dentition, an upper bite block conforming to the patient's maxillary dentition, and a hinge connecting the upper bite block to the lower bite block. The upper bite block and the lower bite block are thin walled polyamide eliminating the need for dental wires to maintain them to the mandibular detention and the maxillary dentition and the problems associated therewith.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a bite block. More particularly, the 
present invention relates to a flexible retentive bite block and 
fabrication process. 
2. Description of the Prior Art 
Snoring and Obstructive sleep apnea are typically caused by complete or 
partial obstruction of an individuals pharyngeal airway during sleep. 
Usually, airway obstruction results from the apposition of the rear 
portion of the tongue or soft palate with the posterior pharyngeal wall. 
Obstructive sleep apnea is a potentially lethal disorder in which breathing 
stops during sleep for 10 seconds or more, sometimes up to 300 times per 
night. Snoring occurs when the pharyngeal airway is partially obstructed, 
resulting in vibration of the oral tissues during respiration. These sleep 
disorders tend to become more severe as patients grow older, likely as a 
result of a progressive loss of muscle tone in the patient's throat and 
oral tissues. 
Habitual snoring and sleep apnea have been associated with other 
potentially serious medical conditions, such as hypertension, ischemic 
heart disease and strokes. Accordingly, early diagnosis and treatment is 
recommended. 
One surgical approach, known as uvulopalatopharyngoplasty, involves removal 
of a portion of the soft palate to prevent closure of the pharyngeal 
airway during sleep. This operation, however, is not always effective and 
may result in undesirable complications, such as nasal regurgitation. 
A wide variety of non-surgical approaches for treating sleep disorders have 
been proposed including the use of oral cavity appliances. It has been 
previously recognized that movement of the mandible (lower jaw) forward 
relative to the maxilla (upper jaw) can eliminate or reduce sleep apnea 
and snoring symptoms by causing the pharyngeal air passage to remain open. 
Several intra-oral dental appliances have been developed which the user 
wears at night to fix the mandible in an anterior, protruded (i.e. 
forward) position. Such dental appliances essentially consist of acrylic 
or elastomeric bite blocks, similar to orthodontic retainers or athletic 
mouth guards, which are custom-fitted to the user's upper and lower teeth 
and which may be adjusted to vary the degree of anterior protrusion. 
While prior art dental appliances have proven effective in maintaining the 
mandible in a protruded position to improve airway patency, they often 
result in undesirable side effects. One of the most common side effects is 
aggravation of the temporomandibular joint and related jaw muscles and 
ligaments, especially in individuals who have a tendency to grind their 
teeth during sleep. 
Aggravation of the temporomandibular joint has been associated with a wide 
variety of physical aliments, including migraine headaches. Accordingly, 
many individuals suffering from sleep apnea and snoring disorders are not 
able to tolerate existing anti-snoring dental appliances for long periods 
of time. 
The need has therefore arisen for a dental appliance for treatment of 
snoring and sleep apnea which will maintain the mandible in a preferred 
anterior position, allow a limited degree of lateral excursion of the 
mandible relative to the upper jaw to avoid discomfort to the 
temporomandibular joint and related muscles and ligaments, and be 
replaceably maintained on the user's teeth by virtue of its own 
flexibility and thereby eliminating the need for dental wires that can 
aggravate the teeth and gums and which requires the appliance to have 
thick walls for their support which can lead to further discomfort for the 
user, such as gum and cheek irritation and gagging. 
Numerous innovations for mouthpieces have been provided in the prior art 
that will be described. Even though these innovations may be suitable for 
the specific individual purposes to which they address, however, they 
differ from the present invention. 
FOR EXAMPLE, U.S. Pat. No. 5,203,324 to Kinkade teaches a mouthpiece for 
use in diving or medical equipment, among others made of moldable 
resilient material having an offset between upper and lower jaw, a bite 
plane which is tapered with the bite plane formed by wings which have 
varying thickness to create the taper in which the wing members have 
substantially vertical surfaces on either side thereof for contacting the 
lateral surfaces of the user's cuspids and bicuspids and in which the main 
body portion has upper and lower apron and eminence skirts for avoiding 
contact with the user's frenum and cuspid eminences and in which the 
internal wing members have a range in size, at the cuspid, from about 6 to 
about 12 mm in width, from about 14 to about 40 mm in length and from 
about 2 mm to about 8 mm in thickness. The greater the offset, the shorter 
the length of the internal wind members. 
ANOTHER EXAMPLE, U.S. Pat. No. 5,365,945 to Halstrom teaches a dentally 
retained intra-oral appliance worn at night for treatment of snoring and 
obstructive sleep apnea. The appliance maintains the patient's mandible in 
an anterior, protruded position to prevent obstruction of the pharyngeal 
airway. The appliance allows a limited degree of lateral movement of the 
mandible relative to the upper jaw in the protruded position to prevent 
aggravation of the patient's temporomandibular joint and associated 
muscles and ligaments. 
As shown in FIG. 1, the appliance 10 preferably consists of a lower bite 
block 12 conforming to the patient's mandibular dentition 14, an upper 
bite block (not shown, but constructed similar to the lower bite block 12) 
conforming to the patient's maxillary dentition (not shown), and a 
connecting assembly (not shown) secured to an anterior region (not shown) 
of the upper (not shown) and lower bite blocks 12. 
Unfortunately, the apparatus 10 requires dental wires 16 to maintain it to 
the mandibular detention 14 and the maxillary dentition (not shown). The 
dental wires 16 are embedded in the appliance 10 and bias against the 
mandibular detention 14 and the maxillary dentition (not shown), causing 
discomfort to the wearer, especially those with sensitive teeth. To 
support the dental wires 16, the walls 20 of the appliance 10 are thick, 
which lead to further discomfort for the user, such as inter alia gum, 
tongue, palate, and cheek irritation. 
With the dental wires 16 being biased when worn, they are under stress and 
exert a stress on the walls 20 of the appliance 10 housing them. The 
stress can cause the walls 12 of the appliance 10 to fracture, splinter, 
or cause the dental wires 16 to separate from the appliance. 
Furthermore, the appliance 10 includes a pair of opposing bite pads 22 that 
are separate and affixed on the biting surfaces 24 of the posterior 
portions 26 of the appliance 10; they are thereby subject to dislodgement 
from the appliance 10. 
In contradistinction, however, as shown in FIG. 2, the flexible retention 
bite block 30 of the present invention requires no dental wires to 
maintain it to the mandibular detention 14 and the maxillary dentition 
(not shown), eliminating discomfort to the wearer, especially those with 
sensitive teeth. Absent the dental wires, the walls 32 of the appliance 10 
are thin, eliminating further discomfort to the user, such as inter alia 
gum, tongue, and cheek irritation. 
Absent the dental wires and the biasing associated therewith, no stress is 
exerted on the walls 32 of the flexible retention bite block 30, 
eliminating fracture, splinter, of the walls 32. 
Furthermore, the flexible retention bite block 30 includes a pair of 
opposing bite pads 34 that are integrally formed on the biting surfaces 24 
of the posterior portions 26 of the flexible retentive bite block 30; they 
are therefore not subject to dislodgement from the flexible retention bite 
block 30. 
The flexible retentive bite block 30 is maintained on the mandibular 
detention 14 and the maxillary dentition (not shown), by virtue of its 
side walls 32 extending 1 mm past and capturing the supra bulge 36 of the 
mandibular detention 14 and the maxillary dentition (not shown), and the 
inherent flexibility of the polyamide material it is made of. 
STILL ANOTHER EXAMPLE, U.S. Pat. No. 5,409,017 to Lowe teaches a mandible 
repositioning appliance formed by an upper bite block and a lower bite 
block interconnected by an adjustable mechanism including a posterior 
section connected to the rear portion of the upper bite block and an 
anterior section connected to the front portion of the lower bite block 
and an adjustable interconnection between the anterior and posterior 
sections. Preferably, the adjustable interconnection includes a double 
thread element rotation of which changes the relative positions of the 
posterior and interior sections axially of the appliance and abutments to 
define each incremental rotation of the element. The comfort of the wearer 
is further improved by using a heat sensitive material in the tooth 
retention sections and by permitting limited relative lateral movement 
between the bite blocks. 
YET ANOTHER EXAMPLE, U.S. Pat. No. 5,499,633 to Fenton teaches an 
adjustable oral device for placement within the mouth of a user to reduce 
or eliminate snoring. The device comprises an upper member having a 
substantially curved shape and defining an upwardly oriented channel for 
receiving at least some of the upper teeth of a user. A lower member has a 
substantially curved shape and defines a downwardly oriented channel for 
receiving at least some of the lower teeth of a user. The upper member is 
adjustably coupled by the user to the lower member in a spaced 
relationship such that the lower member is positioned relative to the 
upper member so that when the user's teeth are retained within the device, 
the user's lower jaw is biased substantially forward of its normal biting 
or resting position to reduce snoring. The device can include an anterior 
tongue space between the upper and lower members, and can further include 
moldable material positioned within at least one of the channels for 
substantially conforming to a shape of the teeth, thus allowing the device 
to be customized for individual users. 
FINALLY, YET STILL ANOTHER EXAMPLE, U.S. Pat. No. 5,562,106 to Heeke et al. 
teaches a non-surgical oral appliance for improving breathing, and abating 
or completely alleviating snoring sounds and symptoms while sleeping. The 
patient is pre-tested and pre-fitted for the appliance so that the 
appliance positions the mandible in an open position and protrusive 
position to hold the mouth partially open. The appliance has a right and 
left extension wherein each extension has upper and lower surfaces 
pre-molded to the contour of the patient's back teeth. A bridge connects 
the right and left extensions having been pre-molded to conform to the 
upper palate of the patient's mouth. The upper and lower surfaces of each 
extension are spaced to provide optimum mouth height that was pre-tested 
to alleviate the snoring sound. Upon insertion, the appliance facilitates 
an air passage for breathing and also allows the patient to talk while 
remaining virtually invisible to an observer. 
It is apparent that numerous innovations for mouthpieces have been provided 
in the prior art that are adapted to be used. Furthermore, even though 
these innovations may be suitable for the specific individual purposes to 
which they address, however, they would not be suitable for the purposes 
of the present invention as heretofore described. 
SUMMARY OF THE INVENTION 
ACCORDINGLY, AN OBJECT of the present invention is to provide a flexible 
retentive bite block and fabrication process that avoids the disadvantages 
of the prior art. 
ANOTHER OBJECT of the present invention is to provide a flexible retentive 
bite block and fabrication process that is simple and inexpensive to 
manufacture. 
STILL ANOTHER OBJECT of the present invention is to provide a flexible 
retentive bite block and fabrication process that is simple to use. 
BRIEFLY STATED, YET ANOTHER OBJECT of the present invention is to provide a 
dentally retained intra-oral appliance worn at night for treatment of 
snoring and obstructive sleep apnea and its fabrication process. The 
appliance maintains the patient's mandible in an anterior, protruded 
position to prevent obstruction of the pharyngeal airway. The appliance 
allows a limited degree of lateral movement of the mandible relative to 
the upper jaw in the protruded position to prevent aggravation of the 
patient's temporomandibular joint and associated muscles and ligaments. 
The appliance includes a lower bite block conforming to the patient's 
mandibular dentition, an upper bite block conforming to the patient's 
maxillary dentition, and a hinge connecting the upper bite block to the 
lower bite block. The upper bite block and the lower bite block are thin 
walled polyamide eliminating the need for dental wires to maintain them to 
the mandibular detention and the maxillary dentition and the problems 
associated therewith. 
The novel features which are considered characteristic of the present 
invention are set forth in the appended claims. The invention itself, 
however, both as to its construction and its method of operation, together 
with additional objects and advantages thereof, will be best understood 
from the following description of the specific embodiments when read and 
understood in connection with the accompanying drawing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The fabrication process of the flexible retentive bite block 30 can best be 
seen in FIGS. 3 through 9MM inclusive, and as such will be discussed with 
reference thereto. 
STEP 1: Make a optional duplicate of an original lower casting forming a 
lower duplicate casting 38 having a gum 40, teeth 42 with the supra bulges 
36 and posterior portions with bite surfaces. 
STEP 2: Mount the lower duplicate casting 38 on an articulator 44. 
STEP 3: As shown in FIG. 3, survey the lower duplicate casting 38 forming a 
surveying line 46 thereon. 
STEP 4: As shown in FIG. 3, extend the surveying line 46 approximately 1 mm 
past the supra bulges 36 of the teeth 42 of the lower duplicate casting 
38, toward the gum 40 of the lower duplicate casting 38, forming an 
extended surveying line 48. 
STEP 5: Remove the lower duplicate casting 38 from the articulator 44. 
STEP 6: As shown in FIG. 4, put the lower duplicate casting 38 in a heat 
pressure former 50. A typical heat pressure former 50 is sold by either 
ERKOPRESS or BIOSTAR. 
STEP 7: As shown in FIG. 4, position at least one plastic spacer sheet 52 
on the teeth 42 of the lower duplicate casting 38. 
Step 8: As shown in FIG. 4, activate the heat pressure former 50 causing 
the at least one plastic spacer sheet 52 to melt and conform to the teeth 
42 of the lower duplicate casting 38 forming a conformed plastic spacer 
layer 54 thereon. 
STEP 9: Remove the lower duplicate casting 38 with the conformed plastic 
spacer layer 54 thereon from the heat pressure former 50. 
STEP 10: As shown in FIG. 5, affix a pair of opposing metal bite pads 56 on 
the conformed plastic spacer layer 54, at the bite surfaces of the 
posterior portions of the teeth 42 of the lower duplicate casting 38, 
utilizing a wax luting agent, and forming therewith a lower pattern 57 
(see FIG. 6). 
STEP 11: Replace the lower duplicate casting 38 with the lower pattern 57 
thereon on the articulator 44. 
STEP 12: As shown in FIG. 6, position a lower processing stylus 58 in a 
guide box 60 of a hinge, wherein the lower processing stylus 58 has a 
narrow stub portion 62. 
STEP 13: As shown in FIG. 6, secure the guide box 60 of the hinge to a base 
plate 64 of the hinge, by processing screws 66. 
STEP 14: As shown in FIG. 6, secure the base plate 64 of the hinge to the 
lower duplicate casting 38, utilizing the wax luting agent, forming a 
lower assemblage 67. 
STEP 15: Make a optional duplicate of an original upper casting forming an 
upper duplicate casting 68 having a gum 70, teeth 72 with supra bulges 74 
and posterior portions with bite surfaces. 
STEP 16: As shown in FIG. 3, mount the upper duplicate casting 68 on the 
articulator 44. 
STEP 17: As shown in FIG. 3, survey the upper duplicate casting 68, forming 
a surveying line 76 thereon. 
STEP 18: As shown in FIG. 3, extend the surveying line 76 approximately 1 
mm past the supra bulges 74 of the teeth 72 of the upper duplicate casting 
68, toward the gum 70 of the upper duplicate casting 68, forming an 
extended surveying line 78. 
STEP 19: Remove the upper duplicate casting 68 from the articulator 44. 
STEP 20: As similarly shown in FIG. 4, put the upper duplicate casting 68 
in the heat pressure former 50. 
STEP 21: As similarly shown in FIG. 4, position at least one plastic spacer 
sheet 80 on the teeth 72 of the upper duplicate casting 68. 
STEP 22: As similarly shown in FIG. 4, activate the heat pressure former 50 
causing the at least one plastic spacer sheet 80 to melt and conform to 
the teeth 72 of the upper duplicate casting 68, forming a conformed 
plastic spacer layer 82 thereon. 
STEP 23: Remove the upper duplicate casting 68 with the conformed plastic 
spacer layer 82 thereon from the heat pressure former 50. 
STEP 24: As similarly shown in FIG. 5, affix a pair of opposing metal bite 
pads 84 on the conformed plastic spacer layer 82, at the bite surfaces of 
the posterior portions of the teeth 72 of the upper duplicate casting 68, 
utilizing the wax luting agent, and forming therewith an upper pattern 85 
(see FIG. 6). 
STEP 25: Replace the upper duplicate casting 68 with the upper pattern 85 
thereon on the articulator 44. 
STEP 26: As shown in FIG. 6, set a retention plate 86 on the lower 
processing stylus 58, with the narrow stub portion 62 of the lower 
processing stylus 58 removably entering into an aperture 88 in the 
retention plate 86 assuring proper alignment of the retention plate 86 
when securing the retention plate 86 to the upper pattern 85. 
STEP 27: As shown in FIG. 6, secure the retention plate 86 of the hinge to 
the upper pattern 85, utilizing the wax luting agent. 
STEP 28: As shown in FIG. 6, position a part 90 of an upper processing jig 
92 into the retention plate 86 of the hinge. 
STEP 29: As shown in FIG. 6, secure the upper processing jig 92 to the 
retention plate 86, by passing a non-threaded portion 94 of a final stylus 
96 through the upper processing jig 92, with a threaded portion 98 of the 
final stylus 96 threadably engaging the aperture 88 in the retention plate 
86, forming an upper assemblage 100. 
STEP 30: Remove the upper assemblage 100 from the articulator 44. 
STEP 31: Apply the separating medium to exposed portions of the upper 
assemblage 100. 
STEP 32: As shown in FIG. 7, position stone 102 in a lower portion 104 of a 
flask 106 that has an upper portion 108. 
STEP 33: As similarly shown in FIG. 7, place the upper assemblage 100 in 
the lower portion 104 of the flask 106. 
STEP 34: As similarly shown in FIG. 7, place a wax sprue 110 on the upper 
assemblage 100. 
STEP 35: As shown in FIG. 7, position additional stone 102 in the lower 
portion 104 of the flask 106 to the extended surveying line 78. 
STEP 36: Apply the separating medium to exposed stone and the upper pattern 
85. 
STEP 37: Secure the upper portion 108 of the flask 106 to the lower portion 
104 of the flask 106. 
STEP 38: Fill the upper portion 108 of the flask 106 with additional stone 
102. 
STEP 39: Harden contents of the flask 106, forming an upper bite block 
mold. 
STEP 40: Remove the wax luting agent and the wax sprue 110 from the upper 
bite block mold, utilizing boiling water, with the retention plate 86 of 
the hinge retained in the upper bite block mold. 
STEP 41: Separate the upper portion 108 of the flask 106 from the lower 
portion 104 of the flask 106. 
STEP 42: Pick out the conformed plastic spacer layer 80 and the pair of 
opposing metal bite pads 84 from the upper bite block mold. 
STEP 43: Apply the separating medium to the upper bite block mold. 
STEP 44: Preheat the upper portion 108 of the flask 106 and the lower 
portion 104 of the flask 106 under heat lamps. 
STEP 45: Heat polyamide material forming preheated polyamide material. A 
typical polyamide material is sold by RAPID INJECTION SYSTEMS CORP. 
STEP 46: Secure the upper portion 108 of the flask 106 to the lower portion 
104 of the flask 106. 
STEP 47: Inject the preheated polyamide material into the flask 106, 
forming an upper bite block 103 (see FIG. 8) having the retention plate 86 
of the hinge embedded therein. 
STEP 48: Cool the flask 106. 
STEP 49: Separate the upper portion 108 of the flask 106 from the lower 
portion 104 of the flask 106. 
STEP 50: Remove the upper bite block 103 from the upper bite block mold. 
STEP 51: Remove the final stylus 96. 
STEP 52: Remove the processing jig 92. 
STEP 53: Remove all rough edges from the upper bite block 103. 
STEP 54: Smooth the upper bite block 103. 
STEP 55: Check and adjust the upper bite block 103, as required. 
STEP 56: Polish the upper bite block 103, forming a finished upper bite 
block. 
STEP 57: Transfer the finished upper bite block to the original upper 
casting, forming a final upper assemblage. 
STEP 58: Put the final upper assemblage On the articulator 44. 
STEP 59: Remove the lower assemblage 67 from the articulator 44. 
STEP 60: Apply the separating medium to exposed portions of the lower 
assemblage 67. 
STEP 61: As shown in FIG. 7, position stone 102 in the lower portion 104 of 
the flask 106. 
STEP 62: As shown in FIG. 7, place the lower assemblage 67 in the lower 
portion 104 of the flask 106. 
STEP 63: As shown in FIG. 7, place a wax sprue 112 on the lower assemblage 
67. 
STEP 64: Position additional stone 102 in the lower portion 104 of the 
flask 106 to the extended surveying line 48. 
STEP 65: Apply the separating medium to exposed stone and the lower pattern 
66. 
STEP 66: Secure the upper portion 108 of the flask 106 to the lower portion 
104 of the flask 106. 
STEP 67: Fill the upper portion 108 of the flask 106 with additional stone 
102. 
STEP 68: Harden contents of the flask 106, forming a lower bite block mold. 
STEP 69: Remove the wax luting agent and the wax sprue 112 from the lower 
bite block mold, utilizing boiling water, with the base plate 64 of the 
hinge retained in the lower bite block mold. 
STEP 70: Separate the upper portion 108 of the flask 106 from the lower 
portion 104 of the flask 106. 
STEP 71: Pick out the conformed plastic spacer layer 54 and the pair of 
opposing metal bite pads 56 from the lower bite block mold. 
STEP 72: Apply the separating medium to the lower bite block mold. 
STEP 73: Preheat the upper portion 108 of the flask 106 and the lower 
portion 104 of the flask 106 under the heat lamps. 
STEP 74: Heat polyamide material forming preheated polyamide material. 
STEP 75: Secure the upper portion 108 of the flask 106 to the lower portion 
104 of the flask 106. 
STEP 76: Inject the preheated polyamide material into the flask 106 forming 
a lower bite block 105 (see FIG. 8) having the base plate 64 of the hinge 
embedded therein. 
STEP 77: Cool the flask 106. 
STEP 78: Separate the upper portion 108 of the flask 106 from the lower 
portion 104 of the flask 106. 
STEP 79: Remove the lower bite block 105 from the lower bite block mold. 
STEP 80: Remove the processing screws 66, freeing the guide box 60 and the 
lower processing stylus 58. 
STEP 81: As shown in FIG. 8, replace the lower processing stylus 58 with 
the final stylus 96. 
STEP 82: As shown in FIG. 8, resecure the guide box 60 of the hinge to the 
base plate 64 of the hinge with permanent screws 106. 
STEP 83: Remove all rough edges from the lower bite block 105. 
STEP 84: Smooth the lower bite block 105. 
STEP 85: Check and adjust the lower bite block 105, as required. 
STEP 86: Polish the lower bite block 105, forming a finished lower bite 
block. 
STEP 87: Transfer the finished lower bite block to the original lower 
casting, forming a final lower assemblage. 
STEP 88: Put the final lower assemblage in the articulator 44. 
STEP 89: Verify accuracy of bite registration of finished upper bite block 
and finished lower bite block, i.e. is bite registration accurate?. 
STEP 90 Adjust accordingly, if answer to step 89 is no. 
STEP 91 Secure the finished upper bite block to the finished lower bite 
block by threadably engaging the final stylus 96 into the retention plate 
86, if answer to step 89 is yes, forming the flexible retentive bite block 
30. 
The configurations of the base plate 64, the guide box 60, and the 
retention plate 86 is of that taught by U.S. Pat. No. 5,365,945 to 
Halstrom. The configurations of the processing stylus 58, the processing 
screws 66, the processing jig 92, the final stylus 96, and the permanent 
screws 106, however, are different and will be discussed with reference to 
FIGS. 6 and 8. 
As shown in FIG. 6, the processing stylus 58 has a head 114 that fills a 
milled-out cavity 116 in the guide box 60, and a shaft 118 that is 
non-threaded and extends coaxially from and is narrower than the head 1114 
and enters a kidney-shaped aperture 120 in an upper surface 122 of the 
guide box 60, wherein the narrow stub portion 62 is non-threaded and 
extends coaxially from and is narrower than the shaft 118. 
As shown in FIG. 6, each of the processing screws 66 has a head 124, a 
shaft 126 that is non-threaded and extends coaxially from and is narrower 
than the head 124 and passes through a respective outermost non-threaded 
aperture 128 of a pair of outermost non-threaded apertures 128 of three 
non-threaded apertures 128 in the base plate 64, a stub portion 130 that 
is threaded and extends coaxially from and is narrower than the shaft 126 
and threadably engages a respective threaded aperture 132 of a pair of 
threaded apertures 132 in the guide box 60, and a shaft 134 that is 
non-threaded and extends coaxially from and is narrower than the stub 
portion 130 and extends past the upper surface 122 of the guide box 60 so 
as to prevent casting material from entering the pair of threaded 
apertures 132 in the guide box 60 during processing. 
As shown in FIG. 6, the processing jig 92 has a base 136 that is flat, 
thin, and has a center portion 138 that is circular-shaped with an 
aperture 140 and a pair of opposing wing portions 142 that are 
rectangular-shaped and extend coplanarly from the center portion 138 of 
the base 136, wherein the part 90 of the processing jig 92 is a plurality 
of stub portions 144 that are cylindrically-shaped, spaced-apart, and 
extend perpendicularly from the base 136 and fill the aperture 88 in the 
retention plate 86 so as to prevent casting material from entering the 
aperture 88 in the retention plate 86 during processing. 
As shown in FIG. 8, the final stylus 96 has a head 146 that is 
circular-shaped and moves laterally in the milled-out cavity 116 in the 
guide box 60, wherein the non-threaded portion 94 is a shaft 94 that 
extends coaxially from and is narrower than the head 146 and moves 
laterally in the kidney-shaped aperture 120 in the upper surface 122 of 
the guide box 60, and wherein the threaded portion 98 is a stub portion 98 
that extends coaxially from and is narrower than the shaft 94 and 
threadably engages the aperture 88 in the retention plate 86. 
As shown in FIG. 8, each of the permanent screws 113 has a head 148 that is 
circular-shaped and recessed in a respective outermost aperture of three 
non-threaded apertures in the lower bite block 105, a shaft 150 that is 
non-threaded and extends coaxially from and is narrower than the head 148 
and passes through the respective outermost non-threaded aperture 128 of 
the pair of outermost non-threaded apertures 128 of the three non-threaded 
apertures 128 in the base plate 164, and a stub portion 152 that is 
threaded and extends coaxially from and is narrower than the shaft 150 and 
threadably engages the respective threaded aperture 132 of the pair of 
threaded apertures 132 in the guide box 60. 
It will be understood that each of the elements described above, or two or 
more together, may also find a useful application in other types of 
constructions differing from the types described above. 
While the invention has been illustrated and described as embodied in a 
flexible retentive bite block and fabrication process, however, it is not 
limited to the details shown, since it will be understood that various 
omissions, modifications, change in the order of steps, change in the 
number of or necessarity of optional duplicate castings, substitutions and 
changes in the forms and details of the device illustrated and its 
operation can be made by those skilled in the art without departing in any 
way from the spirit of the present invention. 
Without further analysis, the foregoing will so fully reveal the gist of 
the present invention that others can, by applying current knowledge, 
readily adapt it for various applications without omitting features that, 
from the standpoint of prior art, fairly constitute characteristics of the 
generic or specific aspects of this invention.