2. Objectives:
Identify the different sutures in the human skull
and highlight which sutures are most commonly
affected.
Make a table of the times of suture closure for
the human skull, including the mid palatal suture
3. Sutures of the Skull
Cranial sutures are a type of joint or syndesmosis
between cranial bones composed of fibrous tissues.
The skull vault consists of five principal bones
The paired frontals and parietals
Occipital bone
Six primary sutures of the cranial vault exist, including
The paired coronal sutures (between the frontal and parietal bones)
The paired lambdoid sutures (between the parietal and interparietal bones)
The single sagittal suture (between the parietal bones)
The single metopic suture (between the paired frontal bones).
Levi, B., Wan, D. C., Wong, V. W., Nelson, E., Hyun, J., Longaker, M. T., 2012. Cranial suture biology: from pathways to patient care. J Craniofac Surg. 23, 13-9.
4. Sutures of the Skull
Levi, B., Wan, D. C., Wong, V. W., Nelson, E., Hyun, J., Longaker, M. T., 2012. Cranial suture biology: from pathways to patient care. J Craniofac Surg. 23, 13-9.
5. Origins of the calvaria – partly
neural crest cells and partly
mesoderm
The cranium develops from mesenchyme around the
developing brain and consists of:
The Neurocranium – protective case around the brain
The Viscerocranium – the face
6. Origins of the calvaria – partly
neural crest cells and partly
mesoderm
Morriss-Kay GM, Wilkie AO. Growth of the normal skull vault and its alteration in craniosynostosis: insights from human genetics and experimental studies. J Anat
2005; 207:637–653.
7. Affected Sutures
Craniosynostosis can involve any of these sutures either
alone or in multiple combinations.
Several other minor sutures, including the
temporosquamosal, frontonasal, and frontosphenoidal,
may also be involved in premature fusion but less is
comparatively known regarding these.
Levi, B., Wan, D. C., Wong, V. W., Nelson, E., Hyun, J., Longaker, M. T., 2012. Cranial suture biology: from pathways to patient care. J Craniofac Surg. 23, 13-9.
8. Affected Sutures
Can you identify the sutures affected ?
http://www.craniofacialmd.com/diagnoses/non-syndromic-craniosynostosis/
9. Suture closure
Suture Timing
Coronal 22-39 Years
Sagittal 22-39 Years
Lambdoid 22-39 Years
Metopic 3-9 months
Mid Palatal After 11 years
• Cunningham ML, Heike CL. Evaluation of the infant with an abnormal skull shape. Curr Opin Pediatr 2007;19:645–51
• Angelieri F, Cevidanes LH, Franchi L, Gonçalves JR, Benavides E, McNamara JA Jr. Midpalatal suture maturation: classification method for individual
assessment before rapid maxillary expansion. Am J Orthod Dentofacial Orthop. 2013;144:759-69..
10. Midpalatal suture maturation: Classification
method for individual assessment before rapid
maxillary expansion
The aim of this study:
was to present a novel classification method for the individual
assessment of midpalatal suture morphology using CBCT images
because RME is an unpredictable treatment for late adolescent and
young adult patients
Methods:
CBCT scans from 140 subjects (86 female, 54 male), with ages from 5.6 to
58.4 years and no history of previous orthodontic treatment, were
examined to determine the radiographic stages of midpalatal suture
maturation
• Angelieri F, Cevidanes LH, Franchi L, Gonçalves JR, Benavides E, McNamara JA Jr. Midpalatal suture maturation: classification method for individual
assessment before rapid maxillary expansion. Am J Orthod Dentofacial Orthop. 2013;144:759-69..
11. The definition of each CBCT radiographic appearance of the sutural
maturation stage followed the findings of unique morphology in the
maturation of the midpalatal suture described in previous histologic
studies.
Midpalatal suture maturation: Classification
method for individual assessment before rapid
maxillary expansion
• Angelieri F, Cevidanes LH, Franchi L, Gonçalves JR, Benavides E, McNamara JA Jr. Midpalatal suture maturation: classification method for individual
assessment before rapid maxillary expansion. Am J Orthod Dentofacial Orthop. 2013;144:759-69..
12. Stages of Maturation
A B C
ED
• Angelieri F, Cevidanes LH, Franchi L, Gonçalves JR, Benavides E, McNamara JA Jr. Midpalatal suture maturation: classification method for individual
assessment before rapid maxillary expansion. Am J Orthod Dentofacial Orthop. 2013;144:759-69..
13. Midpalatal suture maturation: Classification
method for individual assessment before rapid
maxillary expansion
• Angelieri F, Cevidanes LH, Franchi L, Gonçalves JR, Benavides E, McNamara JA Jr. Midpalatal suture maturation: classification method for individual
assessment before rapid maxillary expansion. Am J Orthod Dentofacial Orthop. 2013;144:759-69..
14. Histologic analysis is limited to assessments of small sections of the
total anteroposterior suture length only, even if several serial sections
from 1 area are available.
In histologic studies only frontal sections have been evaluated; this
restricts their clinical application, especially since midpalatal suture
maturation occurs from the posterior to the anterior region.
Histologic data do not explain why it is difficult to open the
midpalatal suture clinically with conventional RME in patients older
than 25 years of age.
Histologic Assessment
• Angelieri F, Cevidanes LH, Franchi L, Gonçalves JR, Benavides E, McNamara JA Jr. Midpalatal suture maturation: classification method for individual
assessment before rapid maxillary expansion. Am J Orthod Dentofacial Orthop. 2013;144:759-69..
15. Midpalatal Suture Fusion
RME is obtained easily up to 10 years of age, with more skeletal
effects than in later circumpubertal ages (11-18 years).
A clinical attempt of RME in most adult patients would probably fail
in the posterior region despite the interincisal opening and in the
maxillary bone portion of the suture, leading to failure of the RME
procedure.
• Angelieri F, Cevidanes LH, Franchi L, Gonçalves JR, Benavides E, McNamara JA Jr. Midpalatal suture maturation: classification method for individual
assessment before rapid maxillary expansion. Am J Orthod Dentofacial Orthop. 2013;144:759-69..
16. References
Levi, B., Wan, D. C., Wong, V. W., Nelson, E., Hyun, J., Longaker, M. T.,
2012. Cranial suture biology: from pathways to patient care. J
Craniofac Surg. 23, 13-9.
Cunningham ML, Heike CL. Evaluation of the infant with an abnormal
skull shape. Curr Opin Pediatr 2007;19:645–51
Angelieri F, Cevidanes LH, Franchi L, Gonçalves JR, Benavides E,
McNamara JA Jr. Midpalatal suture maturation: classification
method for individual assessment before rapid maxillary expansion.
Am J Orthod Dentofacial Orthop. 2013;144:759-69..
Notes de l'éditeur
A syndesmosis is a slightly movable fibrous joint in which bones are joined together by connective tissue. (sharpey’s fibers)
Major bones and sutures of the adult human cranium. Lateral (left) and top (right) view demonstrating the bones (red line) and sutures (blue) of the calvarium. The metopic suture separating the right and left halves of the frontal bone generally closes by the second year of life
Skull vault consists of 5 flat bones – all formed from intramembranous ossification within a layer of mesenchyme
paired frontal and parietals
unpaired interparietal
The major sutures of the skull vault include the: sagittal(seperates the two parietal), coronal(frontal and parietal meet), metopic (seprates the 2 frontal bones) and lambdoidb (where the occipial and parietal bones meet) (sutures are composed of fibrous tissue)
sagittal suture – remains patent into adulthood
metopic suture- fuses within the first 2 years of life
3 of the calvarial sutures: the sagittal, metopic and lambdoid are formed by the narrowing of membraneous gaps between bones that are initially widely seperate.
coronal suture does not form in this way parietal bone overlaps the frontal bone from the start.
Growth of the sutures occurs perpendicular to the orientation of the suture and normally maintained throughout the period of growth of the brain
Most mesenchyme in the head region is derived from the neural crest. Neural crest cells migrate into the pharyngeal arches and form the bones and connective tissue of craniofacial structures. Homeobox (Hox Negative) genes regulate the migration and subsequent differentiation of the neural crest cells, which are crucial for the complex patterning of the head and face. These parts of the fetal cranium are derived from the cartilaginous skeleton of the first two pairs of pharyngeal arches
Mesodermal cells give rise to mesenchyme—a meshwork of loosely organized embryonic connective tissue. Bones first appear as condensations of mesenchymal cells that form bone models. Condensation marks the beginning of selective gene activity, which precedes cell differentiation (Figs. 14-2 and Fig. 14-3). Most flat bones develop in mesenchyme within preexisting membranous sheaths; this type of osteogenesis is called intramembranous bone formation. Mesenchymal models of most limb bones are transformed into cartilage bone models, which later become ossified by endochondral bone formation.
Neural crest and mesodermal contributions to the mouse head at E17.5.
C) Diagram showing the neural crest-derived (blue) and mesodermal (red) contributions to the skull vault at E17.5. Modified from images in Jiang et al. (2002). bo, basioccipital; e, eye; m, meninges; pn, pinna of ear; s, skin. Other labels as
Only neural crest cells of the trigeminal crest which migrate to th frontonasal and first branchial arch regions contribute to the skull
-neural crest migration begins at the 4-5 somite stage
-trigeminal cest cells also maintain separation fron the adjacement mesodermal crnail mesenchyme cells whih have migrated to the cranial region of the embryo from the primitive streak.
-migration of the cells occur
-by the 23 somite stage migration is complete and a clear boundary forms between the neural crest deriveed and mesoderm derived tissue.
https://zfin.org/zf_info/zfbook/stages/seg_stgs.html
Interparietal bone which is present in mice nut not in human
all the three main sutures of the skull starts closing earlier in females compared to males
The following descriptive stages of midpalatal suture maturation are proposed:
Stage A
The midpalatal suture is almost a straight high-density sutural line with no or little interdigitation.
Stage B
The midpalatal suture assumes an irregular shape and appears as a scalloped high-density line. Patients at stage B can also have some small areas where 2 parallel, scalloped, high-density lines close to each other and separated by small low-density spaces are seen.
Stage C
The midpalatal suture appears as 2 parallel, scalloped, high-density lines that are close to each other, separated by small low-density spaces in the maxillary and palatine bones (between the incisive foramen and the palatino-maxillary suture and posterior to the palatino-maxillary suture). The suture can be arranged in either a straight or an irregular pattern.
Stage D,
The fusion of the midpalatal suture has occurred in the palatine bone, with maturation progressing from posterior to anterior. In the palatine bone, the midpalatal suture cannot be visualized at this stage, and the parasutural bone density is increased (high-density bone) compared with the density of the maxillary parasutural bone. In the maxillary portion of the suture, fusion has not yet occurred, and the suture still can be seen as 2 high- density lines separated by small low-density spaces.
Stage E
Fusion of the midpalatal suture has occurred in the maxilla. The actual suture is not visible in at least a portion of the maxilla.The bone density is the same as in other regions of the palate.
Great variability was verified in the distribution of the mat- urational stages of the midpalatal suture regarding chro- nologic age. Stage A was noted in the early childhood period from 5 to almost 11 years of age, except for one 13-year-old boy. Stage B was present mainly up to 13 years of age, with 6 of 32 subjects (23% of boys, 15.7% of girls) from 14 to 18 years of age. Stage C was observed mainly from 11 to 18 years of age. Howev- er, two 10-year-old girls (8.3% of girls) and 4 of 32 adults (15.7% of girls, 7.7% of boys) were in stage C. No subject from 5 to almost 11 years of age had fusion of the midpalatal suture.
From 11 to almost 14 years of age, 6 of 24 girls (25%) had fusion of the midpalatal suture in palatine (stage D) or maxillary (stage E) bone. For subjects between 14 and 18 years of age, 11 of 19 girls (57.9%) had fusion of the midpalatal suture in palatine (stage D) or maxillary (stage E) bone; only 3 boys (23%) were in stage D. This variability also was observed in adults, who most frequently had fusion of the midpalatal suture (stages D and E), 4 subjects (12.5%) had no fused suture in stage C, and 1 subject (3.1%) was in stage B.
stages A and B a conventional RME approach would have less resistant forces and probably more skeletal effects than at stage C when there are many initial ossification areas along the midpalatal suture.
Patients in stages D and E might be better treated by surgically assisted RME because fusion of the midpalatal suture already has occurred partially or totally, hampering the RME forces from opening the suture.
Many studies have advocated that most of the resis- tance to midpalatal suture separation in adults is due to fusion of the circummaxillary sutures.
The overall prevalence of craniosynostosis has been estimated at between 1 in 2100 and 1 in 2500 births
Metopic Suture usually disappears by the age of eight months, with the two halves of the frontal bone being fused together. It is also called the metopic suture, although this term may also refer specifically to a persistent frontal.
If the suture is not present at birth because both frontal bones have fused (craniosynostosis), it will cause a keel-shaped deformity of the skull called "trigonocephaly.”
Sagittal synostosis (scaphocephaly) is the most common type. It affects the main suture on the very top of the head. The early closing forces the head to grow long and narrow, instead of wide. Babies with this type tend to have a broad forehead. It is more common in boys than girls.
Frontal plagiocephaly is the next most common type. It affects the suture that runs from ear to ear on the top of the head. It is more common in girls.
Metopic synostosis is a rare form that affects the suture close to the forehead. The child's head shape may be described as trigonocephaly. It may range from mild to severe.
The two most common causes for premature closure of a suture are either a change in one of the child’s genes, or from pressure on the skull.