when referencing the figures , standard anatomical terms of location are used . for example , a sagittal plane is a plane parallel to the sagittal suture 5 and divides the body into sinister and dexter portions . a coronal plane divides the body into posterior and anterior portions . a transverse plane divides the body into superior and inferior portions . fig1 through fig4 show a headrest 10 that is the preferred embodiment of the present invention . the headrest 10 comprises a bottom surface 12 for contacting a resting surface 14 , and a top surface 16 for contacting an infant &# 39 ; s cranium . the top surface 16 comprises a generally hemi - ellipsoidal depression 18 , a contact surface 19 that corresponds to the shape of a normal infantile cranium , and a rim 22 defining a substantial portion of the depression 18 . at one end of the depression 18 , a ridge 20 is positioned to support the neck of the infant . the top surface 16 is preferably made of a closed cell foam material , but may alternatively be made of open cell foam material covered with a vinyl or other surface coating , closed cell foam layered over higher density foam , open cell foam layered over higher density foam , or closed cell foam layered over a more rigid solid or hollow plastic . a front surface 24 , preferably curved , is positioned to cradle the infant &# 39 ; s shoulders and support the neck of the infant while the infant &# 39 ; s cranium is in contact with the top surface 16 . a preferably - curved side surface 26 extends between the rim 22 and the bottom surface 12 . in this preferred embodiment , the headrest 10 is a continuous , uniform , solid body . however , it is anticipated that variations of the uniformity or continuity of the body could occur and be utilized . in normal operation for correction of an abnormally shaped infant cranium , the headrest 10 is placed on the resting surface 14 so that the bottom surface 12 is in contact therewith . the infant &# 39 ; s head is then placed in the depression 18 with the infant &# 39 ; s cranium resting on the contact surface 19 . initially , the posterior and part of the side aspects of the infant &# 39 ; s head contact the contact surface 19 , although during the sleep period the infant &# 39 ; s head may roll to one side or the other . throughout the sleep period , the infant &# 39 ; s neck is supported by the ridge 20 . the infant &# 39 ; s shoulders are aligned in and cradled by the curved front surface 24 . as the infant &# 39 ; s head makes contact with the top surface 16 , the contact surface 19 provides external forces acting on any abnormal bulges of the infant &# 39 ; s cranium and reduces or eliminates external forces that act on abnormal depressions ( flattened areas ) of the infant &# 39 ; s cranium . this contact reduces the net outward forces from brain and skull growth at these prominences , and redirects the growth to areas of the cranium where the infant &# 39 ; s head is not in contact with the top surface 16 . it should be noted that that amount of contact of the infant &# 39 ; s cranium with the contact surface 19 varies according to the size of the infant &# 39 ; s cranium . for example , a newborn infant &# 39 ; s cranium will contact relatively little of the contact surface 19 and , in a non - rotated position , the contact will occur primarily at the occipital bone and adjacent areas of the left and right parietal bones . as the infant grows over time , the size of the cranium approaches the size of the depression 18 , with an increasingly greater area of contact . the headrest 10 works similarly to prevent cranial deformities . the infant &# 39 ; s head is placed in the depression 18 , the contact surface 19 of which matches the round , normally - shaped contour of the posterior and side aspects of the head , resulting in the head “ growing into ” the properly - shaped contact surface 19 over time . as the cranium grows , any existing deformities will conform to the normal shape of the contact surface 19 of the depression 18 . because of its semi - rigid character , the contact surface 19 allows the infant &# 39 ; s cranium to grow evenly and maintain its normal shape . typically , this occurs as the headrest is used from two to seven months of age , although , due to statistical variations in head circumference of infants , this is more appropriately a function of the cranial circumference ( i . e ., until the head grows to the same size as the depression 18 ). fig7 a and fig7 b are a rear elevational view and a top elevational view , respectively , of a normally - shaped infant cranium 400 having a circumference of less than 46 . 5 cm and a left parietal bone 402 connected to a right parietal bone 404 with the sagittal suture 406 . the left and right parietal bones 402 , 404 are connected to the frontal bone 412 via the coronal suture 414 and to the occipital bone 416 with the lamboidal suture 418 . the sagittal suture 406 joins the coronal suture 414 at the anterior fontanelle 420 . the lamboidal suture 418 joins the sagittal suture 406 at the posterior fontanelle 422 . when positioned in the preferred embodiment of the headrest 10 , a cranial surface area 424 that includes a portion of the occipital bone 416 , and the posterior portions of the left and right parietal bones 402 , 404 makes contact with the contact surface 19 of the depression 18 , as described supra . fig8 a shows head circumference - for - age of males from birth to thirty - six months . fig8 b shows head circumference - for age for females from birth to thirty six months . as can be seen from these figures , less than five - percent of all infants have a head circumference of less than 36 . 5 cm at two months of age . at seven months , at least ninety - five percent of all infants have a head circumference less than 46 . 5 cm . thus , a preferred embodiment of an orthosis having the features of the present invention is configured to address , at a minimum , head circumferences within a range of 36 . 5 cm to 46 . 5 cm in circumference . however , it is anticipated that this will accommodate head circumferences within a range from thirty - two ( 32 ) to forty - eight ( 48 ) centimeters and still provide the benefits described herein . fig9 a and 9b depict side elevation views of two infants having normally - shaped craniums of differing circumferences positioned in the same preferred embodiment of the cranial orthosis 10 , and show the position of predetermined coronal planes relative to the orthosis 10 . head circumference for an infant is the largest distance around the head , and generally is found in a plane 47 that intersects the forehead of the infant and the most posterior point 54 of the cranium . more specifically , fig9 a depicts a first infant &# 39 ; s cranium 49 that has a circumference of 46 . 5 cm , and has an anterior - posterior distance apd 1 , which is the distance between the most posterior point 54 on the infant &# 39 ; s head and the most anterior point 57 on the infant &# 39 ; s forehead . a first coronal plane 51 is defined as a coronal ( i . e ., horizontal ) plane positioned approximately at forty percent ( 40 %) of the anterior - posterior distance apd 1 , a position which approximates the height of the earhole 52 for an infant having this head size . with respect to the orthosis 10 , the first coronal plane 51 is positioned approximately 4 . 8 to 5 . 3 cm above the nadir 23 ( i . e ., lowest point ) of the depression 18 . a third coronal plane 21 is defined as a coronal plane positioned at the most anterior contact point 27 between the infant &# 39 ; s cranium 49 and the headrest 10 . with respect to the headrest 10 , the third coronal plane 21 is positioned approximately 8 . 0 to 8 . 6 cm from the bottom surface . similarly , fig9 b depicts a second infant cranium 55 of 36 . 5 cm in circumference . a second coronal plane 56 is defined as a coronal plane positioned at approximately seventy percent ( 70 %) of apd 2 for an infant having this head size . with respect to the orthosis 10 , the second coronal plane is positioned approximately 8 . 0 to 9 . 0 cm above the nadir 23 of the depression . as shown in fig3 , in the preferred embodiment , the contact surface 19 is defined as the surface area of the depression 18 that is ( 1 ) superior to an inclined first plane 47 angled between 10 and 20 degrees from vertical in the superior direction and intersecting the nadir 23 , and ( 2 ) posterior of the third coronal plane 21 . at a minimum , however , the contact surface 19 is at least the surface area of the depression 18 that is ( 1 ) superior to a diagonal plane angled 45 - degrees from vertical in the superior direction and intersecting the nadir 23 , and ( 2 ) posterior of the third coronal plane 21 . fig5 and fig6 depict preferred dimensions of a specific embodiment of the orthosis 10 . as shown , the length of the orthosis 10 from its most inferior to its most superior point is 23 . 3 cm . the height of the ridge 20 above the bottom surface 12 where it intersects the longitudinal axis is 2 . 9 cm . at its highest point , the rim 22 is 9 . 4 cm from the bottom surface 12 . the ridge 20 is 6 . 5 cm from the mid - cranial transverse plane 70 , which is the transverse plane intersecting the nadir 23 of the depression 18 . the mid - cranial transverse plane is 7 . 5 cm from the most superior contact point 27 . in the preferred embodiment , that superior point 27 is 8 . 3 cm from the bottom surface 12 . in the preferred embodiment , as shown in fig6 , in which the shading has been removed for clarity , the width of the curved front surface 24 is 23 . 3 cm and the width of the ridge 20 is 13 . 3 cm . the depression has a front portion 37 extending 2 . 3 cm from the ridge 20 along the horizontal , longitudinal axis 31 , and is bounded on either side with symmetrical protrusions 33 . a middle portion 25 is immediately adjacent the front portion 37 wherein the interior boundary 29 of the rim 22 adjacent the middle portion 25 is substantially straight . an arced rear portion 35 is adjacent the middle portion 25 , wherein the interior boundary 29 of the rim is symmetrically curved to connect one sides of the middle portion 25 to the other . the maximum depth of the arced rear portion 35 from the middle portion 25 to the interior boundary 29 of the rim 22 along the horizontal longitudinal axis 31 is 3 . 9 cm . the greatest width of the middle portion 25 is at the boundary with the front portion 37 ( line b ) at 16 . 3 cm . the middle portion 25 is narrowest immediately adjacent the arced rear portion 35 ( line a ) at 12 . 7 cm . the depth of the middle portion 25 — i . e ., the distance between the front portion 37 and arced rear portion 35 — is approximately 8 . 0 cm . the superior - to inferior widening of the middle portion 25 provides space for the ears of an infant who is resting in the headrest 10 in a supine position , which is important to avoid misshaping of the ear . the depth of the depression 18 from the crest of the ridge 20 to the interior boundary of the rim 22 along the horizontal longitudinal axis is 14 . 2 cm . the thickness c of the rim 22 around the arced portion 35 is approximately 2 cm . although the dimensions of the preferred embodiment are given with specific measurements , it is understood that the measurements could vary slightly without altering the effectiveness of the device . in that regard , the dimensions provided are understood to be substantial approximations of the preferred embodiment of the device . returning now to a description of the present invention , fig1 and 11 depict the preferred embodiment of the present invention in which an infant 60 having a normally - shaped cranium 62 of approximately forty ( 40 ) centimeters in circumference is supinely positioned on the headrest 10 . the first coronal plane 51 — as defined above with respect to the predetermined circumference of 46 . 5 cm — extends longitudinally , and is parallel to the second coronal plane 56 . the mid - cranial transverse plane 70 is orientated perpendicular to the first coronal plane 51 and extends through the nadir 23 , in which the most posterior point 54 of the cranium 62 rests . an inclined first plane 74 , which is representative of a typical plane in which the head circumference is measured , is positioned superior and inclined relative to the mid - cranial transverse plane 70 , and intersects the nadir 23 , and the most anterior point on the forehead . as noted with respect to fig1 through fig4 , the headrest 10 ( or orthosis ) comprises the bottom surface 12 that contacts the resting surface 14 during use and a contact surface 92 that contacts the infant &# 39 ; s cranium 62 . the generally hemi - ellipsoidal depression 18 is formed in the top surface 16 with at least a contact surface 19 ( see fig3 ) having a shape of a portion of a normal infant cranium 62 . in the preferred embodiment , and as noted with respect to fig3 supra , the contact surface 19 has a surface area generally corresponding to the posterior aspects of the left and right parietal bones in addition to a substantial portion of the occipital area , as discussed with reference to fig5 . the top surface 16 is semi - rigid and relatively non - flexible , maintains its overall shape under stress , and demonstrates minimal superficial focal elasticity at the site of cutaneous contact . the ridge 20 at an end of the depression 18 supports , and is contoured to the shape of , the infant &# 39 ; s neck 86 . the contact surface 19 of the preferred embodiment has a hardness of between sixty - five and seventy - five when measured with a oo - scale durometer , which is the preferred hardness required for the both prevention and correction of positional deformities as described herein . in an alternative embodiment , the hardness may get as low as fifty on a oo - scale durometer for infants born premature or with low birth weights and which have a smaller , lighter head . because the headrest 10 is preferably of uniform consistency , it is anticipated that the entire outer surface of the headrest 10 will have the same hardness . it should also be noted that , for infants with normal sized craniums , prevention only , as opposed to both prevention and correction , can be accomplished with a hardness of between twenty - five and thirty - five on the same scale . still referring to fig1 and fig1 , the contact surface 19 further comprises at least a portion of first and second lateral support surfaces 88 , 92 . a portion 90 of the first and second lateral support surfaces 88 , 92 is positioned anterior of the first coronal plane 51 and superior to the mid - cranial transverse plane 70 . in order to prevent obstructive amblyopia , the first and second lateral support surfaces 88 , 92 do not extend anteriorly of the second coronal plane 56 , as providing a completely unobstructed visual field is imperative to eliminate the risk of iatrogenic - induced neuro - opthalmological injury ( i . e ., obstructive amblyopia ). fig1 is a partial sectional view of the normal infant cranium 62 in the inclined first plane 74 of fig1 . in the preferred embodiment , the first and second lateral support surfaces 88 , 92 are substantially vertical at their upper end with slight curvature anterior of the first coronal plane 51 . when the infant &# 39 ; s cranium 62 is in the supine position , contacting forces 96 are applied proximal to the occipital bone 98 at the posterior aspect of the cranium 62 with only minimal application at the most posterior end of the parietal bones 100 , 102 . as growth occurs , the left and right parietal bones 100 , 102 expand laterally and eventually contact substantially the entire contact surface 19 when the infant &# 39 ; s cranium 62 grows to a circumferences of 46 . 5 cm as shown in fig9 a . in this manner the shape of the parietal and occipital regions on the infant &# 39 ; s cranium 62 conforms over time ( i . e ., months ) to the shape of the contact surface 19 . fig1 depicts the normal infant cranium 62 shown in fig1 rotated thirty degrees clockwise about the longitudinal axis 94 . such rotation causes a corresponding shift in the area of contact of the cranium 62 with the contact surface 19 , and thus where external forces 96 are applied to the cranium 62 . the contact forces 96 still contact the occipital bone 98 and a greater portion of the posterior right parietal bone 102 . in addition , the second lateral support surface 92 contacts the cranium 62 at the frontal bone 104 anterior of the coronal suture 106 . as overall growth of the cranium 62 occurs , less rotation of the cranium 62 is allowed , which results in further maintenance of the normal head shape . additional expansion and overall growth causes eventual de - rotation of the cranium 62 back to twenty degrees of rotation or less with the contact surface 19 and first and second lateral support surfaces 88 , 92 limiting lateral expansion of the parietal bones 100 , 102 . in other words , as the infant continues to grow and the circumference of the cranium 62 approaches the size of the depression 18 , the head is progressively limited to less rotation , resulting in the head “ growing into ” the properly - shaped contact surface 19 . for example , if the size of the cranium 62 is identical to the size of the depression 18 , rotation of the cranium 62 will be entirely prohibited . thus , as the cranium 62 grows , any existing deformities will conform to the normal shape of the contact surface 19 of the depression 18 . fig1 depicts a partial sectional view of the inclined first plane 74 in fig1 wherein a scaphocephalic cranium 134 of an infant is supinely positioned in the depression 18 in the top surface 16 of the orthosis 10 . in this supine position , the contact surface 19 of the depression 18 causes forces 146 to act on the scaphocephalic cranium 134 at the occipital bone 144 . if this non - rotated , supine position can be maintained , the absence of forces acting on the parietal bones 147 , 149 will allow the parietal bones 147 , 149 to grow laterally into a normally - shaped cranium . fig1 depicts the scaphocephalic cranium 134 shown in fig1 rotated thirty degrees clockwise about its longitudinal axis 148 . in this rotated position , the second lateral support surface 92 contacts the frontal bone 150 and thereby prevents contact between the mid - or upper - right parietal bone 149 with the contact surface 19 of the depression 18 , and allowing for only minimal contact with the right parietal bone 149 at its most posterior point . once again , the contact surface 19 of the depression 18 contacts and provides forces acting on the occipital bone 144 . the absence of contact and forces 146 acting on the left parietal bone 147 and almost all of the right parietal bone 149 allows for parietal expansion and progression toward a normal head shape . rotation in the counter - clockwise direction results in similar contact of the cranium 134 with the orthosis 10 on the opposite side of the cranium 134 . fig1 is a partial sectional view of the preferred embodiment through the first plane 74 of fig8 with an infant having a plagiocephalic cranium 170 with abnormal prominent growth at the left parietal bone 196 and the right side of the frontal bone 198 , in addition to a flattened configuration at the right parietal bone 202 and the occipital bone 200 . in the supine position shown , initial forces 194 are concentrated on the lower end of the left parietal bone 196 and left occipital bone 200 . however , it should be noted that this is an unstable configuration that will inevitably lead to rotation — in this case , clockwise rotation — about the longitudinal axis 192 . fig1 is a partial sectional view within the inclined first plane 74 of fig1 depicting the infant having a plagiocephalic cranium 170 rotated thirty degrees clockwise about its longitudinal axis 192 . in this rotated position , the contact surface 19 contacts and provides forces 194 acting on the prominent left parietal bone 196 , thereby restricting further lateral growth of that prominent bone . additionally , the second lateral support surface 92 contacts and provides forces 199 acting on the right side of the frontal bone 198 and also restricting growth in that prominent area . the contact with the second lateral support surface 92 further eliminates all external forces from the flattened occipital bone 200 and right parietal bone 202 , thus redirecting growth to these bones by allowing the bones to expand . in this manner , the infant &# 39 ; s plagiocephalic cranium 170 is allowed to grow into a normal shape . fig1 depicts the preferred embodiment in use with a brachycephalic cranium 204 having a flattened occipital bone 216 and bulging , prominent left and right parietal bones 208 , 210 resting in a supine position . the contact surface 19 contacts and provides forces 206 acting on both parietal bones 208 , 210 restricting lateral growth of these parietal prominences . the normal cranial shape of the contact surface 19 eliminates any contact and forces acting on the occipital bone 216 . this redirects growth and expansion in a more frontal direction as well as allows the flattened occipital bone 216 to grow outward , thereby allowing for correction of the deformity over time with growth . fig1 shows the same brachycephalic cranium 204 depicted in fig1 resting in the preferred embodiment of the orthosis 10 and rotated forty degrees about the longitudinal axis of the headrest 10 . the contact surface 19 of the depression 18 contacts and provides forces acting on the prominent right parietal bone 210 and thereby restricts growth of that bone . at the same time , the first lateral support surface 88 contacts and provides forces 206 acting on the prominent left parietal bone 208 and , once again , restricts growth of that bone 208 . the normal cranial shape of the contact surface 19 provides a gap between the contact surface 19 of the depression 18 and the flattened occipital bone 216 , thereby eliminating forces acting on the occipital bone 216 and , once again , allows for outward growth in that area . the lack of contact forces acting on the frontal bone 211 also allows for forward growth to the cranium 204 . in this manner , the orthosis 10 provides for correction of a brachycephalic cranium 204 resting in a rotated position . although the invention has thus far been described with reference to only full term infants , the principles and concepts are also applicable to a premature infant &# 39 ; s cranium , albeit on a smaller scale . in fact , the cranial vault of a premature infant is more susceptible to development of positional deformities than a full term infant because the cranial bones are much weaker and more malleable , and the skin more fragile . according to industry data , the mean head circumference of a premature infant at 26 weeks gestation is about 23 . 5 centimeters , the mean head circumference of an infant at 36 weeks is roughly 33 cm , and two standard deviations on either side of this 26 - to 36 - week growth curves is slightly larger than ± 2 cm . thus , by simply “ shrinking ” the preferred embodiment described herein to accommodate this curve , the same principles are operative to correct and prevent positional deformities in premature infants in the same manner . because of the weaker and more malleable cranial bones of a premature infant , the top surface should be softer than the top surface as described with reference to the preferred embodiment herein . the inventor has found that the hardness of the surface when used for very premature infants can be between 20 - 30 on the oo scale durometer . typically , these type of infants will only require prevention of deformities . fig1 through fig2 show an alternative embodiment of the present invention that requires less material to manufacture . the headrest 300 comprises two beams 302 for contacting a resting surface 304 , and a top surface 306 for contacting an infant &# 39 ; s cranium . the elongated beams 302 are positioned along opposite sides of the headrest 300 . the front and back of the headrest 300 are open , forming an opening 308 defined on either side by the beams 302 . the top surface 306 of the headrest 300 comprises a generally hemi - ellipsoidal depression 310 having the top surface 306 that corresponds to the shape of a normal infantile cranium and a rim 312 that defines a substantial portion of the depression 310 . at one end of the depression 310 , a ridge 314 is positioned to support the neck of the infant . the top surface 306 is preferably made of a closed cell foam material , although other materials may be used as described hereinabove . a pair of side surfaces 316 , only one of which is shown by fig5 , adjoin the rim 312 to the beams 302 . as shown more clearly by fig2 , the beams 302 are positioned at opposing sides of the headrest 300 and along the perimeter thereof , thereby forming the opening 308 between the beams 302 . in another embodiment , however , the opposed beams 302 can be positioned at the front and rear of the headrest 300 . after placement of the headrest 300 on the resting surface 304 so that the beams 302 are in contact therewith , the infant &# 39 ; s head is placed in the depression 310 with the infant &# 39 ; s head resting in the depression 310 . correction and / or prevention of the infant &# 39 ; s abnormally shaped cranium is then accomplished in the same manner as in the preferred embodiment . fig2 and fig2 , which is a sectional view along line 23 - 23 of fig2 , show another embodiment of the present invention . the apparatus of this embodiment comprises a mattress or padded surface 340 and a generally hemi - ellipsoidal depression 342 in a portion of the mattress surface 340 . a top surface 344 in the depression 342 corresponds to the shape of a normal infantile cranium . in this embodiment , the top surface 344 of the depression 342 is semi - rigid , resilient , and made of a closed cell foam material , providing external forces acting on abnormal cranial bulges and minimizing or eliminating external forces acting on abnormal cranial depressions of the infant . however , it is anticipated that other materials could be utilized , such as open cell foam with a vinyl coating . in this embodiment , a ridge 346 at one end of the top surface 344 is shaped and positioned to support the neck of the infant while the infant &# 39 ; s head rests on the top surface 344 of the apparatus . in another version of this embodiment , it is anticipated that the ridge 346 will be eliminated . the embodiment shown by fig2 and fig2 is disclosed with a substantially flat mattress or padded surface 340 . however , it is anticipated that the mattress or padded surface 32 could be contoured to prevent an infant from rolling . it is further anticipated that the area of the mattress or padded surface 340 surround the depression 342 could be raised to provide support for the infant &# 39 ; s head in a slightly raised position . as with the already - described embodiments , the infant &# 39 ; s head is placed in the depression 342 formed in the mattress 340 such that the infant &# 39 ; s head is in contact with the top surface 344 . the infant &# 39 ; s neck is supported by the ridge 346 , while the infant &# 39 ; s body is supported in a comfortable resting position by the mattress 340 in a generally supine position . correction and / or prevention of the infant &# 39 ; s abnormally shaped cranium is then accomplished in the same manner as in the preferred embodiment . fig2 and fig2 , which is a sectional view along line 25 - 25 of fig2 , show another embodiment of the present invention , an apparatus comprised of a semi - rigid body 360 with a hemi - ellipsoidal depression 362 having a contact surface 364 that is in the shape of a normal infantile cranium . a plurality of legs 366 support the semi - rigid body 360 in a position to allow an infant &# 39 ; s head to rest on the contact surface 364 . in this embodiment , there are four legs 366 , as shown in fig2 and fig2 . however , it is anticipated that more or fewer legs could be used to support the body 360 . the contact surface 364 is resilient and made of closed cell foam , although in alternative embodiments of the present invention the contact surface 364 may be made of other material , including open cell foam covered with a vinyl coating and other materials as described hereinabove . furthermore , a ridge 368 at one end of the contact surface 364 is shaped and positioned to support the neck of the infant while the infant &# 39 ; s head rests on the contact surface 364 of the apparatus . after placement of the apparatus on a resting surface so that legs 366 are in contact therewith , the infant &# 39 ; s head is placed in the depression 362 with the infant &# 39 ; s head resting on the contact surface 364 and the infant &# 39 ; s neck being supported by the ridge 368 . correction and / or prevention of the infant &# 39 ; s abnormally shaped cranium is then accomplished in the same manner as in the preferred embodiment . it should be noted that the smaller the infant cranium , the more angular rotation of the cranium about the longitudinal axis is required to contact one of the lateral support surfaces . in other words , generally speaking , a smaller infant cranium placed in a given headrest and depression will require more rotation about the longitudinal axis than a larger , similarly - shaped cranium positioned in the same headrest and depression . however , it is desirable that rotation of an infant &# 39 ; s cranium located within a depression be limited to approximately the range of angular rotation described with reference to the foregoing figures . although this concern could be addressed by manufacturing the headrest in various sizes to correspond to the range of expected cranial sizes as set forth supra , for commercialization , it is desirable for cost reduction purposes that fewer variations of the present invention be produced to take advantage of manufacturing economies of scale . this conflict between manufacturing preference and patient treatment preference can be addressed , however , by providing for adjustability of the positions of the lateral support surfaces , thus allowing rotation of the cranium to be limited as desired based on the size of the cranium . for example , fig2 through fig2 show another embodiment of a headrest 510 having the features of the present invention wherein the position of the lateral support surfaces is adjustable to accommodate various cranium sizes ( i . e ., limit the range of possible rotation of the cranium within the depression ). fig2 is a front perspective view of the embodiment . fig2 and fig2 are sectional views through line 27 - 27 and line 28 - 28 , respectively , of fig2 . as referenced with respect to the previously - described embodiments , the headrest 510 of this alternative embodiment comprises a bottom surface 512 , and a top surface 516 for contacting an infant &# 39 ; s cranium . the top surface 516 comprises a generally hemi - ellipsoidal depression 518 , a contact surface 519 that corresponds to the shape of a normal infantile cranium , and a rim 522 defining a substantial portion of the depression 518 . a ridge 520 is positioned at one end of the depression 518 to support the neck of the infant . the top surface 516 is preferably made of a closed cell foam material , but may alternatively be made of open cell foam material covered with a vinyl or other surface coating , closed cell foam layered over higher density foam , open cell foam layered over higher density foam , or closed cell foam layered over a more rigid solid or hollow plastic . a curved front surface 524 is positioned to cradle the infant &# 39 ; s shoulders and support the neck of the infant while the infant &# 39 ; s cranium is in contact with the top surface 516 . a preferably - curved side surface 526 extends between the rim 522 and the bottom surface 512 . two attachable spacing members 550 are positioned over the rim 522 and preferably centered at preferably approximately sixty degrees from the longitudinal axis 531 . preferably , the spacing members 550 are substantially u - shaped and sized to fit snugly over the rim 522 , and each has a first leg 551 which extends into the depression 518 and contacts the lateral support surfaces 588 , 592 , and a second leg 552 extending downward adjacent to and contacting the sidewall 526 of the headrest 510 . the spacing members 550 are made of a closed cell foam material , but may alternatively be made of open cell foam material covered with a vinyl or other surface coating , closed cell foam layered over higher density foam , open cell foam layered over higher density foam , or closed cell foam layered over a more rigid solid or hollow plastic . as shown in fig2 , in this specifically - described embodiment , the outer portion 552 of the spacing member 550 is removeably attached to the body of the headrest 510 with a hook - and - loop fastener 554 . alternative embodiments contemplate other fastening hardware and adhesives . placement of the spacing members 550 on the rim 522 provides the ability to alter the rotation range of the infant &# 39 ; s head when placed in the headrest 510 . normal operation for correction of an abnormally shaped infant cranium is as referenced with respect to the previously - described embodiments . the headrest 510 is placed on a resting surface ( not shown ) so that the bottom surface 512 is in contact therewith . the infant &# 39 ; s head is then placed in the depression 518 with the infant &# 39 ; s cranium resting on the contact surface 519 . the effective distance between the lateral support surfaces 588 , 592 can be altered by attaching one or more of the spacing members 550 for proper fitting of the infant &# 39 ; s cranium within the headrest 510 . in this specific embodiment , it is preferred that the maximum thickness ti of the leg 551 of the spacing members 550 extending into the depression 518 and along a sagittal axis is approximately eight millimeters . initially , the posterior and part of the side aspects of the infant &# 39 ; s head contact the contact surface 519 , although during the sleep period the infant &# 39 ; s head may roll to one side or the other . when this occurs , the side of the infant &# 39 ; s head will contact the interior surface 553 of the first leg 551 of one of the spacing members 550 . in this manner , the interior surface 553 acts as an adjusted lateral support surface . throughout the sleep period , the infant &# 39 ; s neck is supported by the ridge 520 . the infant &# 39 ; s shoulders are aligned in and cradled by the curved front surface 524 . as the infant &# 39 ; s head makes contact with the top surface 516 , the contact surface 519 provides external forces acting on any abnormal bulges of the infant &# 39 ; s cranium and reduces or eliminates external forces that act on abnormal depressions ( flattened areas ) of the infant &# 39 ; s cranium . as referenced with respect to the previously described embodiments , this contact reduces the net outward forces from brain and skull growth at these prominences , and redirects the growth to areas of the cranium where the infant &# 39 ; s head is not in contact with the top surface 516 . as the infant &# 39 ; s cranium grows , the spacing members 550 can be removed or replaced with spacing members having a thinner first leg 551 . although in this embodiment the spacing members 550 are described as being substantially u - shaped , it is anticipated that the spacing members 550 could have varying shapes and attachment locations on the headrest 510 . for example , the spacing members 550 could be a circular or rectangular pad having a flat interior surface to act as an adjusted lateral support surface and a flat exterior surface for adhesion to the lateral support surfaces of the headrest . fig2 and fig3 show an alternative embodiment of a “ low profile ” headrest 610 with first and second laterally adjustable siderails 626 . fig2 is a perspective view of the embodiment , while fig3 is a rear section view through plane 30 - 30 of fig2 . the “ low profile ” headrest 610 , as described supra , is provided that otherwise has some of the features of the present invention , such as the top surface 616 , depression 618 , and the like . however , as discussed supra , this “ low profile ” headrest 610 does not itself provide lateral support with lateral support surfaces . as shown in fig2 and fig3 , the laterally - adjustable siderails 626 are fixable to the top surface 616 of the “ low profile ” headrest 610 with hook - and - loop 630 or other fastening methodology and positioned to provide lateral support to an infant &# 39 ; s cranium resting in the headrest 610 with lateral support surfaces 688 , 692 on the interior sidewalls of the siderails 626 . the laterally adjustable siderails 626 are positioned such that the lateral support surfaces 688 , 692 are positioned anterior of the first coronal plane and superior to the mid - cranial transverse plane , as described with reference to the other embodiments . the first and second lateral support surfaces 688 , 692 do not extend anteriorly of the second coronal plane , as providing a completely unobstructed visual field is imperative to eliminate the risk of iatrogenic - induced neuro - opthalmological injury ( i . e ., obstructive amblyopia ). in addition , the laterally - adjustable siderails 626 allow for adjustment of the distance between the lateral support surfaces 688 , 692 by repositioning both laterally - adjustable siderails 626 toward the infantile cranium and reattaching them to the top surface 616 . the present invention is described above in terms of a preferred illustrative embodiment of a specifically described headrest , as well as alternative embodiments of the present invention . those skilled in the art will recognize that alternative constructions of such a headrest can be used in carrying out the present invention . other aspects , features , and advantages of the present invention may be obtained from a study of this disclosure and the drawings , along with the appended claims .
a device and method for preventing and correcting abnormal shaping of an infant &# 39 ; s cranium by applying external forces over time with the growth of an infant to achieve normal shaping of the infant &# 39 ; s head . the device is a cranial orthosis having a depression with a contact surface in the shape of at least a portion of a normal infantile cranium . the orthosis further provides lateral support surfaces creating points of contact to restrict rotation of the infant &# 39 ; s cranium and provide additional external forces for normal shaping of the infant &# 39 ; s cranium . because the present invention is non - conforming to the shape of an abnormal skull , the exerted forces cause accelerated expansion of the skull in less prominent areas coincident with brain and skull growth .