Shorter Anterior Cranial Base Research Articles

Lateral cephalometric characteristics in individuals with Down Syndrome compared to non-syndromic controls: A meta-analysis

ObjectivesThe aim of the present meta-analysis was to provide a complete synthesis of all studies involving lateral cephalometric measurements in populations with Down Syndrome (DS). MethodsA literature search was carried out using six electronic databases to identify studies comparing cephalometric characteristics between populations with DS and control (healthy) populations. Studies were selected according to the research objectives, and predefined inclusion and exclusion criteria. Only the cephalometric measurements included in three or more studies selected were analyzed. The random-effects meta-analysis model was used for data analysis, and all analyses were carried out using RevMan5 software. ResultsFrom an initial 871 articles identified through the literature search, ten cross-sectional studies were finally selected based on the inclusion and exclusion criteria. Ten cephalometric measurements underwent meta-analysis, five linear and five angular measurements. Concerning the five linear measurements, namely S-N, ANS-PNS, Go-Gn, Ar-Go, and N-ANS, all were significantly smaller in the DS group with the exception of Go-Gn. Of the five angular measurements, only three were statistically different between the DS and control groups. SNB and ANB angles were smaller in individuals with DS, whereas the basilar angle was larger. Subgroup analysis was also carried out based on age, and it was found that the gonial angle was significantly smaller before puberty, in individuals with DS. No differences between groups were found for the SNA angle. ConclusionThere are significant cephalometric differences between individuals with and without DS. Individuals with DS have a shorter anterior cranial base, maxillary length, upper anterior facial height and mandibular height. The ANB and SNB angles were also smaller in those with DS, but the SNA angle showed no differences. These findings may indicate that the Class III malocclusion commonly found in individuals with DS does not seem to be due to mandibular prognathism. Clinical relevanceLateral cephalometric measurements in individuals with DS show significant differences from individuals without DS. Practitioners need to be aware of this and monitor growth from an early age in these children.

Anteroposterior length of the maxillary complex and its relationship with the anterior cranial base.

To use both absolute anteroposterior maxillary complex length (APMCL) and relative APMCL to investigate the relationship between the maxillary complex, its individual bony segments, and their association to the anterior cranial base. In addition, the relationship between length and position of the maxillary complex was analyzed. Sixty human skulls were analyzed using cone beam computed tomography. The maxillary complex length was measured between anterior and posterior nasal spine (ans-pns), and the average was used as the cut-off to identify a high- and a low-length group based on absolute APMCL. The length ratio between the maxillary complex and the anterior cranial base (ans-pns/SN) was used to identify the two groups based on relative APMCL. The anterior cranial base length and the lengths of the maxillary complex bones were compared between the high- and low-length groups. Based on absolute APMCL, individuals with shorter maxillary complex had shorter anterior cranial base (P = .003), representing normal proportions. Based on relative APMCL, individuals with shorter maxillary complex had longer anterior cranial base and vice versa (P = .014), indicating disproportions. Individuals with shorter maxillary complex exhibited shorter maxilla (Δ = -1.5 mm, P = .014). When skeletal deformity of the midface is suspected, individual disproportions in the anteroposterior length of the maxillary complex in relation to the anterior cranial base (relative measurements) should be assessed through radiological imaging. A shorter maxillary complex may be associated with a shorter maxilla, and not with a shorter premaxilla or palatine bone.

Craniofacial and Oral Features of Williams Syndrome- A Rare Case Report

Williams syndrome is a rare genetic disorder that occurs due to deletion on chromosome 7q11.23. The prevalence is said to be 1:7500-1:20,000. The typical presentation of the syndrome includes dysmorphic facial features, cardiovascular malformations and intellectual disability. Craniofacial features of these children include short anterior cranial base, protrusive maxilla, increased Mandibular Plane- Occlusal angle, steep mandibular plane and reduced ratio of posterior to anterior facial height. The unique characteristics of these children are over friendliness, out-going personality, hyper-acusis and tendency to get easily distracted. This is a unique case of Williams syndrome in an eight-year-old female patient.

Dental Anomalies Associated with Craniometaphyseal Dysplasia

Craniometaphyseal dysplasia (CMD) is a rare genetic disorder encompassing hyperostosis of craniofacial bones and metaphyseal widening of tubular bones. Dental abnormalities are features of CMD that have been little discussed in the literature. We performed dentofacial examination of patients with CMD and evaluated consequences of orthodontic movement in a mouse model carrying a CMD knock-in (KI) mutation (Phe377del) in the Ank gene. All patients have a history of delayed eruption of permanent teeth. Analysis of data obtained by cone-beam computed tomography showed significant bucco-lingual expansion of jawbones, more pronounced in mandibles than in maxillae. There was no measurable increase in bone density compared with that in unaffected individuals. Orthodontic cephalometric analysis showed that patients with CMD tend to have a short anterior cranial base, short upper facial height, and short maxillary length. Microcomputed tomography (micro-CT) analysis in homozygous AnkKI/KI mice, a model for CMD, showed that molars can be moved by orthodontic force without ankylosis, however, at a slower rate compared with those in wild-type Ank+/+ mice (p < .05). Histological analysis of molars in AnkKI/KI mice revealed decreased numbers of TRAP+ osteoclasts on the bone surface of pressure sides. Based on these findings, recommendations for the dental treatment of patients with CMD are provided.

The primary site of the acrocephalic feature in Apert syndrome is a dwarf cranial base with accelerated chondrocytic differentiation due to aberrant activation of the FGFR2 signaling

Activation of osteoblastic bone anabolism in the calvarial sutures is considered to be the essential pathologic condition underlying mutant FGFR2-related craniofacial dysostosis. However, early clinical investigations indicated that abnormal cartilage development in the cranial base was rather a primary site of abnormal feature in Apert Syndrome (AS). To examine the significance of cartilaginous growth of the cranial base in AS, we generated a transgenic mouse bearing AS-type mutant Fgfr2IIIc under the control of the Col2a1 promoter–enhancer (Fgfr2IIIcP253R mouse). Despite the lacking expression of Fgfr2IIIcP253R in osteoblasts, exclusive disruption of chondrocytic differentiation and growth reproduced AS-like acrocephaly accompanied by short anterior cranial base with fusion of the cranial base synchondroses, maxillary hypoplasia and synostosis of the calvarial sutures with no significant abnormalities in the trunk and extremities. Gene expression analyses demonstrated upregulation of p21, Ihh and Mmp-13 accompanied by modest increase in expression of Sox9 and Runx2, indicating acceleration of chondrocytic maturation and hypertrophy in the cranial base of the Fgfr2IIIcP253R mice. Furthermore, an acquired affinity and specificity of mutant FGFR2IIIcP253R receptor with FGF2 and FGF10 is suggested as a mechanism of activation of FGFR2 signaling selectively in the cranial base. In this report, we strongly suggest that the acrocephalic feature of AS is not alone a result of the coronal suture synostosis, but is a result of the primary disturbance in growth of the cranial base with precocious endochondral ossification.

Inheritance of craniofacial features in Colombian families with class III malocclusion

The inheritance of class III malocclusion has been well documented, but the inheritance of craniofacial structures in Colombian families with this malocclusion has been not yet reported. The study sample of 25 families comprised 186 untreated orthodontic individuals from 8 to 60 years old. Pedigrees were drawn using Cyrillic software. Complete family histories for each proband were ascertained and the affection status of relatives was confirmed by lateral cephalograms and facial and dental photographs. Analysis of variance and odds ratio test for each parameter was performed to estimate inheritance from parents to offspring and to determine similar phenotypic features in relatives. The analysis of the pedigrees suggests autosomal dominant inheritance. The craniofacial characteristics that showed more resemblance between parents and offspring were middle facial height, shorter anterior cranial base and mandibular prognathism. In contrast the protrusion of upper lip and maxillary retrusion were the phenotypic features that contributed to class III in the majority of families. Knowledge of the inheritance of craniofacial phenotypes in class III malocclusion will enable the design of new therapies to treat this malocclusion.

Further evidence of association between mutations in FGFR2 and syndromic craniosynostosis with sacrococcygeal eversion

Pfeiffer syndrome (PS; OMIM #101600) is an autosomal dominant disorder characterized by craniosynostosis, midface hypoplasia, broad thumbs, brachydactyly, broad great toes, and variable syndactyly. We report a case of PS (type 3) with tracheal and visceral involvement and sacrococcygeal eversion. The patient shows facial dysmorphism with macrocephaly, dolichocephaly, and trigonocephaly, and an asymmetric skull, bilateral and severe exophthalmia with shallow orbits and ocular hypertelorism, downslanting palpebral fissures, constant strabismus, short anterior cranial base, and midface hypoplasia. Molecular analysis of the FGFR2 gene in this patient revealed a point mutation (c.890G>C NM_000141). This mutation leads to the substitution of the residue tryptophan at position 290 to cysteine in the protein (p.Try290Cys). These data reinforce the hypothesis that the p.Trp290Cys mutation is more often associated with a severe and poor prognosis of PS. Furthermore they suggest that the presence of sacrococcygeal defects is not associated with any specific FGFR2 mutation.

Changes in dentofacial morphology after adeno-/tonsillectomy in young children with obstructive sleep apnoea--a 5-year follow-up study

The aim of this study was to compare a number of dentofacial variables and airway space in children suffering from obstructive sleep apnoea (OSA) syndrome with the corresponding variables in control children exhibiting a normal breathing pattern, to study the development of these variables prospectively over a 5-year-period following treatment for OSA, and to compare the recorded changes with the corresponding changes occurring in the controls. The subjects were 17 children (10 boys and 7 girls, mean age 5.6 years) diagnosed with OSA syndrome. The treatment for the OSA was adeno-/tonsillectomy. The control group comprised 17 age- and gender-matched children (mean age 5.8 years) without breathing problems. Lateral cephalograms were taken of the OSA children at baseline and then at 1, 3, and 5 years post-treatment. The control records comprised registrations at baseline and then after 1 and 5 years. In comparison with the controls, the OSA children exhibited a more posteriorly inclined mandible (P < 0.05), a more anteriorly inclined maxilla (P < 0.001), a greater lower anterior face height (P < 0.01), a shorter anterior cranial base (P < 0.01), retroclined upper and lower incisors (P < 0.05 and P < 0.01, respectively), reduced airway space (P < 0.05 and P < 0.01), and a less pronounced nose (P < 0.05). At 5 years post-treatment, there were no statistically significant differences between the groups except for the lengths of the anterior cranial base and the nose which were still shorter (P < 0.05) in the patient group. OSA in young children has an unfavourable effect on the development of several dental and facial components. However, if OSA is diagnosed and treated at an early age, an almost complete normalization of dentofacial morphology may be achieved.

The growth of the nasal septum in the 6–9 week period of foetal development—Warfarin embryopathy offers a new insight into prenatal facial development

The aim of this study was to de the role of the nasal septum in embryonic facial development. Nasal septal growth and facial development were examined in sagittally-sectioned 6-9 week human foetuses and compared to previously published data for later prenatal periods. To complement this data a cephalometric study of a child with untreated warfarin embryopathy was undertaken since a previous study in rats had shown warfarin exposure interferes with septal growth. The results showed that prenatal septal growth was maximal during the 6-9 week period and resulted in the establishment of a facial profile that was maintained until birth. This critical of growth corresponds to the period of warfarin exposure of the human foetus that results warfarin embryopathy. The cephalometric examination of a child with untreated warfarin embryopathy showed a combination of short anterior cranial base and a short maxilla had contributed to a significant retrusion of the maxilla suggestive of failure of the midface to devel the 6-9 week period. These findings would support the hypothesis that the nasal septum plays an active role in embryonic midfacial development.

Morphological differences in the craniofacial structure between Japanese and Caucasian girls with Class II Division 1 malocclusions.

The craniofacial features of 49 Japanese and 75 British Caucasian girls with Class II division 1 malocclusions were evaluated from lateral cephalometric radiographs, and the morphological differences between both races were examined. The subjects' ages ranged from 11 years 1 month to 12 years 11 months. The mean values of 13 linear and 13 angular cephalometric parameters were compared. The Japanese Class II division 1 sample had a significantly shorter anterior cranial base length (S-N; P < 0.001) and a more obtuse articular angle (S-Ar-Go; P < 0.001). Analysis of the dentoalveolar components in Japanese subjects showed more proclined lower incisors (L1/Go-Me; P < 0.05) and a steeper occlusal plane (Occ.P/S-N; P < 0.01) relative to those of Caucasians. The short anterior cranial base length and excessive vertical development in the Japanese population might be common racial morphological features, but the main reason for the Class II division 1 skeletal disharmony in both races was different; it was caused by the anteriorly positioned maxilla in Caucasians and the backward rotated mandible in the Japanese.

Craniofacial morphology, dentition, and skeletal maturity in four siblings with Seckel syndrome.

To describe the craniofacial morphology, dentition, and hand maturity in four siblings with Seckel syndrome. Two boys and two girls, with Seckel syndrome. The children studied showed extreme growth retardation, severe microcephaly, bird-headed profile with receding chin, prominent nose, mental retardation, and extremely delayed skeletal maturation. The growth hormone axis and pituitary thyroid function was normal. Skeletal and dental development were investigated from radiographic material, and a cephalometric analysis was performed from profile radiographs. The craniums were remarkably small with an extremely short anterior cranial base (-4.3 to -5.5 standard units) and maxillary length (-3.8 to -4.7 SU). Differences in the morphology of the sella turcica were observed in girls and boys. Tooth maturity progressed normally. Tooth agenesis and tooth malformations were observed. Taurodontic root morphology was observed only in the girls. The approximate skeletal maturity showed retardation from 4 years 3 months to 4 years 11 months. Malformations of the hand-wrist skeleton occurred in the epiphyseal ossification centers of the middle phalangeal bone in the second, third, and fourth finger and in the distal phalangeal bone in the fifth finger. The epiphyseal ossification centers were lacking in the middle and distal phalangeal bones of the fifth finger. The underlying gene defect in the affected children seemingly affects bone development and growth but not dental maturation and eruption.

Face, palate, and craniofacial morphology in patients with a solitary median maxillary central incisor.

The occurrence of a solitary median maxillary central incisor (SMMCI) is a very rare condition and might be a sign of a mild degree of holoprosencephaly. In this investigation, material from 10 patients, nine girls and one boy with a SMMCI (8-17 years of age) registered in orthodontic clinics was examined. The purpose was to evaluate the clinical characteristics and craniofacial morphology in this group of patients. Oral photographs, study casts, profile radiographs, and orthopantomograms were analysed. The study showed that this group of SMMCI patients were characterized by an indistinct philtrum, an arch-shaped upper lip, absence of the fraenulum of the upper lip, a complete or incomplete mid-palatal ridge, a SMMCI, and nasal obstruction or septum deviation. The craniofacial morphology of the nine girls, compared with normal standards for girls showed a short anterior cranial base, a short, retrognathic and posteriorly inclined maxilla, and a retrognathic and posteriorly inclined mandible. Furthermore, the sella turcica had a deviant morphology in five of the 10 subjects. The results indicate that the presence of a SMMCI should not be considered as a simple dental anomaly, since it may be associated with other clinical characteristics and more complex craniofacial malformations. It is therefore suggested that the SMMCI condition in future studies is classified according to clinical symptoms and craniofacial morphology.

Short stature of prenatal origin: craniofacial growth and dental maturation.

Recently, children born small for gestational age (SGA) with a catch-up growth failure, have been selected for high dose growth hormone (GH) treatment. In order to gain greater insight concerning dentofacial growth and maturation of these patients, and to evaluate the possible effects of high does GH administration on facial structures, craniofacial growth and dental maturation were evaluated in short SGA persons. Seventy-seven cephalograms and orthopantomograms were available from 48 subjects, aged between 2 and 32 years. Craniofacial growth was assessed by calculating age- and gender-specific standard deviation scores (SDS) for eight linear and five angular measurements. Tooth formation was evaluated by means of a dental delay score (i.e. dental age minus chronological age). The SDS for craniofacial growth measurements for the lateral aspect showed a short anterior cranial base (-1.8 SDS), a small retropositioned mandible (< or = -1.7 SDS) and a small maxilla (-1.5 SDS); a high mandibular plane angle (+1.9 SDS) and a wide cranial base angle (+1 SDS). These findings result in a small retrognathic face with a relatively increased lower anterior face height (+1.7 SDS). In contrast to skeletal maturation, dental age was not delayed. The general growth retardation is, apparently, reflected to a differential extent within the craniofacial complex, while dental maturation appears to be a distinct process tightly linked to chronological age, and independent of general growth and bone age.

Cephalometric characteristics of anterior open bite in a southern Chinese population

The cephalometric characteristics of skeletal anterior open bite (AOB) in a southern Chinese population were evaluated in a group of 104 subjects with AOB and were compared with a control group of 40 subjects without AOB. The anteroposterior jaw relationship in the AOB group was Class I in 43%, Class II in 14%, and Class III in 43%. Cephalometric analysis of all subjects was completed by using 24 skeletal and 12 dentoalveolar measurements. Sexually dimorphic variables were identified and compared separately between groups with independent t tests. Two levels of significance were used, P ≤ 0.05 and P ≤ 0.001. Sexual dimorphism of cephalometric variables was present in both the test and the control groups, but affected more variables in the test group. Significant findings in AOB were shorter anterior cranial base, upward and forward rotation of the maxilla, increased gonial and mandibular plane angles, increased upper posterior dental height, and increased lower anterior facial height. These findings generally coincided with those for white subjects, however, there was no conclusive evidence in this study regarding the contribution of the upper anterior facial height or the posterior facial height to the AOB deformity. (Am J Orthod Dentofacial Orthop 1998;113:165–72)

Craniofacial structure in diastrophic dysplasia--a cephalometric study.

Diastrophic dysplasia (DTD) is a well characterized, recessively inherited osteochondrodysplasia. Forty-eight patients with DTD were studied for craniofacial characteristics. Of these patients, 58% had cleft palate. A cephalometric analysis based on lateral cephalograms was performed. We observed a short anterior cranial base, vertical nasal bones, short and posteriorly positioned upper and lower jaws, increased anterior facial height, increase in the sagittal length of the body of the cervical vertebrae, and an abnormal dens of the second cervical vertebra. DTDST, in which mutations responsible for the disease occur, is a gene that codes for a sulphate transporter membrane protein. The craniofacial anomalies in DTD most likely result from deficient development and growth of cartilaginous structures and are probably due to defective sulfation of the proteoglycans of the cartilage.

The craniofacial pattern of the Lengua Indians of Paraguay

Lateral cephalometric headfilms of 30 male and 30 female Lengua Indians taken in the Chaco area of Paraguay were compared with a sample of 23 male and 25 female South African Caucasoids with excellent occlusion. The most obvious difference noted between the two population groups was the degree of prognathism evident in the Lengua. This was attributed to the generally shorter anterior cranial base in the latter group rather than to the size or forward positioning of their jaws. The significantly larger ANB (Subspinale, Nasion, Supramentale) angle observed in the Lengua was attributed to one or both of two factors, namely, the short anterior cranial base or the clockwise rotation (forward tipping) of the jaws relative to the anterior cranial base. Chinpoint position relative to the anterior cranial base in the Lengua is not much different from that of our Caucasoid sample. The lower incisor teeth in the Lengua, but not the upper ones, are more labially inclined than those of the Caucasoids.