Premature closure of the spheno‐occipital synchondrosis in the horned Hereford dwarf of the “short‐headed” variety

Julian, L. M.; Tyler, W. S.; Hage, Theodore J.; Gregory, P. W.

doi:10.1002/aja.1001000206

Cited by 28 publications

(11 citation statements)

References 4 publications

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“…Schmidt et al (2013) found that the probability of finding a closed spheno-occipital synchondrosis at a given age was significantly higher in the brachycephalic breeds when compared with the mesocephalic ones. Facial hypoplasia in combination with prematurely fused cranial base synchondroses has also been reported for other species, for example, cattle (Julian et al, 1957), mice (Chen et al, 1999), and humans (Cohen et al, 1985). However, the causality of the bulldog-type skull conformation and patterns of suture closure in domestic dogs is not clear.…”

Section: Discussionmentioning

confidence: 77%

Cranial Suture Closure in Domestic Dog Breeds and Its Relationships to Skull Morphology

Geiger

Haussman

2016

The Anatomical Record

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Bulldog-type brachycephalic domestic dog breeds are characterized by a relatively short and broad skull with a dorsally rotated rostrum (airorhynchy). Not much is known about the association between a bulldog-type skull conformation and peculiar patterns of suture and synchondrosis closure in domestic dogs. In this study, we aim to explore breed-specific patterns of cranial suture and synchondrosis closure in relation to the prebasial angle (proxy for airorhynchy and thus bulldog-type skull conformation) in domestic dogs. For this purpose, we coded closure of 18 sutures and synchondroses in 26 wolves, that is, the wild ancestor of all domestic dogs, and 134 domestic dogs comprising 11 breeds. Comparisons of the relative amount of closing and closed sutures and synchondroses (closure scores) in adult individuals showed that bulldog-type breeds have significantly higher closure scores than non-bulldog-type breeds and that domestic dogs have significantly higher closure scores than the wolf. We further found that the prebasial angle is significantly positively correlated with the amount of closure of the basispheno-presphenoid synchondrosis and sutures of the nose (premaxillo-nasal and maxillo-nasal) and the palate (premaxillo-maxillary and interpalatine). Our results show that there is a correlation between patterns of suture and synchondrosis closure and skull shape in domestic dogs, although the causal relationships remain elusive. Anat Rec,

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Section: Discussionmentioning

confidence: 77%

Cranial Suture Closure in Domestic Dog Breeds and Its Relationships to Skull Morphology

Geiger

Haussman

2016

The Anatomical Record

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“…The association of the brachycephalic skull morphology and developmental defects of the cranial base has been reported in other species . Specifically, the early fusion of the spheno‐occipital synchondrosis has been reported to be responsible for morphological variation in brachycephalic skull types because this synchondrosis primarily accounts for the longitudinal expansion of the skull base . In brachycephalic cattle, a premature closure of the spheno‐occipital synchondrosis was found to lead to the “short‐headed” variant of the Hereford and Aberdeen Angus cattle.…”

Section: Discussionmentioning

confidence: 96%

Comparison of Closure Times for Cranial Base Synchondroses in Mesaticephalic, Brachycephalic, and Cavalier King Charles Spaniel Dogs

Schmidt

Volk

Klingler

et al. 2013

Vet Radiology Ultrasound

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Premature closure of cranial base synchondroses has been proposed as the mechanism for brachycephaly in dogs and caudal occipital malformation syndrome (COMS) in Cavalier King Charles Spaniels. The purpose of this retrospective study was to compare times of closure for cranial base synchondroses in mesaticephalic, brachycephalic, and Cavalier King Charles Spaniel dogs. Cranial magnetic resonance imaging studies were retrieved for client-owned dogs less than 18 months of age. Breed, age, skull conformation, and the open or closed state of cranial base synchondroses were independently recorded by two observers. For dogs with a unanimous observer agreement, regression analysis was used to test effects of age and gender on the open or closed status of synchondroses and differences between groups. A total of 174 dogs were included in MRI interpretations and 165 dogs were included in the regression analysis. Statistically significant differences in closure time of the spheno-occipital synchondrosis were identified between brachycephalic and mesaticephalic dogs (P = 0.016), Cavalier King Charles Spaniels and mesaticephalic dogs (P < 0.0001), and Cavalier King Charles Spaniels and brachycephalic dogs (P = 0.014). Findings from the current study supported the theory that morphological changes leading to the skull phenotype of the Cavalier King Charles Spaniels could be due to an earlier closure of the spheno-occipital synchondrosis.

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“…Removal of this important growth center from a n infant r a t has been shown to cause early basicranial ossification (synostosis) by premature fusion of the basisphenoid and basioccipital bones (DuBrul and Laskin, 1961;Riesenfeld, 1974). A premature synostosis, in turn, can result in a shortened and flexed skull base (Julian et al, 1957). Once this flexion is accomplished, any resulting effects on larynx and hyoid positions can be assessed.…”

Section: Surgical Methodsmentioning

confidence: 99%

Effect of basicranial flexion on larynx and hyoid position in rats: An experimental study of skull and soft tissue interactions

Reidenberg

Laitman

1991

Anat. Rec.

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The mammalian upper respiratory tract is a functionally dynamic region involved in respiration, deglutition, and phonation. As the structures of this area (e.g., larynx, hyoid) are suspended from the basicranium, changes in basicranial shape may affect both their anatomy and function. Although skeletal/soft tissue relationships have been examined through descriptive, comparative anatomy, these relationships have remained largely unexplored via experimental study. In this study, mechanical relationships between basicranial shape and positions of the larynx and hyoid bone are investigated experimentally. Skull base flexion was induced by surgically ablating the spheno-occipital synchondrosis in 13-day-old rats. Lateral radiograms were taken at 40, 60, 80, 100, and 120 days, and angular measurements made of basicranial shape and positions of the larynx and hyoid bone. Statistical analysis shows significant differences between experimental and control groups for skull base, hyoid, and larynx angles, and negative (inverse) correlations for basicranial shape change vs. hyoid position, and basicranial shape change vs. larynx position. Results show induced basicranial flexion caused inferior displacement of the larynx and hyoid bone, thus indicating a direct, mechanical relationship between skeletal and soft tissues. These observations may aid in understanding the basic biological, pathological, and evolutionary interactions of hard and soft tissues of the upper respiratory region.

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Premature closure of the spheno‐occipital synchondrosis in the horned Hereford dwarf of the “short‐headed” variety

Cited by 28 publications

References 4 publications

Cranial Suture Closure in Domestic Dog Breeds and Its Relationships to Skull Morphology

Cranial Suture Closure in Domestic Dog Breeds and Its Relationships to Skull Morphology

Comparison of Closure Times for Cranial Base Synchondroses in Mesaticephalic, Brachycephalic, and Cavalier King Charles Spaniel Dogs

Effect of basicranial flexion on larynx and hyoid position in rats: An experimental study of skull and soft tissue interactions

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