A Multivariate Analysis of Unilateral Cleft Lip and Palate Facial Skeletal Morphology

Comparison of Superior Semicircular Canal Bone Thickness and Patterns in Unilateral and Bilateral Cleft Patients and Normal Controls: A CBCT Study

Superior Semicircular Canal Dehiscence (SSCD) is a recently-defined developmental defect may be associated with several craniofacial anomalies such as Cleft Lip/Palate (CLP). The present study aimed to compare subjects with unilateral and bilateral CLP and normal controls in terms of Superior Semicircular Canal (SSC) bone thickness and pattern.

A total of 238 Cone Beam Computed Tomography (CBCT) images were collected from 52 unilateral Cleft Lip and Palate (UCLP) subjects (104 temporal bones) and 38 Bilateral Cleft Lip and Palate (BCLP) (76 temporal bones) subjects and 148 healthy controls (296 temporal bones). The SSC bone thickness was measured twice and validated by a maxillofacial radiologist. The samples were then classified into five categories based on bone thickness: papyraceous or thin, normal, thick, pneumatized, and dehiscence. After all, the UCLP, BCLP, and normal control groups were compared concerning the SSC pattern and thickness.

The results revealed no significant difference among the three groups regarding the SSC pattern and thickness based on gender. The SSC patterns (P value = .001) and SSC thickness (0.01) were strongly correlated to the cleft type. The thinnest bone thickness and the highest incidence of SSCD were observed among the subjects with BCLP.

The results showed a significant association between the SSC patterns and SSC thickness and the study groups.

Three-dimensional finite element analysis of the effect of alveolar cleft bone graft on the maxillofacial biomechanical stabilities of unilateral complete cleft lip and palate

BACKGROUND

The objective is to clarify the effect of alveolar cleft bone graft on maxillofacial biomechanical stabilities, the key areas when bone grafting and in which should be supplemented with bone graft once bone resorption occurred in UCCLP (unilateral complete cleft lip and palate).

METHODS

Maxillofacial CAD (computer aided design) models of non-bone graft and full maxilla cleft, full alveolar cleft bone graft, bone graft in other sites of the alveolar cleft were acquired by processing the UCCLP maxillofacial CT data in three-dimensional modeling software. The maxillofacial bone EQV (equivalent) stresses and bone suture EQV strains under occlusal states were obtained in the finite element analysis software.

RESULTS

Under corresponding occlusal states, the EQV stresses of maxilla, pterygoid process of sphenoid bone on the corresponding side and anterior alveolar arch on the non-cleft side were higher than other maxillofacial bones, the EQV strains of nasomaxillary, zygomaticomaxillary and pterygomaxillary suture on the corresponding side were higher than other maxillofacial bone sutures. The mean EQV strains of nasal raphe, the maximum EQV stresses of posterior alveolar arch on the non-cleft side, the mean and maximum EQV strains of nasomaxillary suture on the non-cleft side in full alveolar cleft bone graft model were all significantly lower than those in non-bone graft model. The mean EQV stresses of bilateral anterior alveolar arches, the maximum EQV stresses of maxilla and its alveolar arch on the cleft side in the model with bone graft in lower 1/3 of the alveolar cleft were significantly higher than those in full alveolar cleft bone graft model.

CONCLUSIONS

For UCCLP, bilateral maxillae, pterygoid processes of sphenoid bones and bilateral nasomaxillary, zygomaticomaxillary, pterygomaxillary sutures, anterior alveolar arch on the non-cleft side are the main occlusal load-bearing structures before and after alveolar cleft bone graft. Alveolar cleft bone graft mainly affects biomechanical stabilities of nasal raphe and posterior alveolar arch, nasomaxillary suture on the non-cleft side. The areas near nasal floor and in the middle of the alveolar cleft are the key sites when bone grafting, and should be supplemented with bone graft when the bone resorbed in these areas.

Orofacial Cleft and Mandibular Prognathism-Human Genetics and Animal Models

Many complex molecular interactions are involved in the process of craniofacial development. Consequently, the network is sensitive to genetic mutations that may result in congenital malformations of varying severity. The most common birth anomalies within the head and neck are orofacial clefts (OFCs) and prognathism. Orofacial clefts are disorders with a range of phenotypes such as the cleft of the lip with or without cleft palate and isolated form of cleft palate with unilateral and bilateral variations. They may occur as an isolated abnormality (nonsyndromic-NSCLP) or coexist with syndromic disorders. Another cause of malformations, prognathism or skeletal class III malocclusion, is characterized by the disproportionate overgrowth of the mandible with or without the hypoplasia of maxilla. Both syndromes may be caused by the presence of environmental factors, but the majority of them are hereditary. Several mutations are linked to those phenotypes. In this review, we summarize the current knowledge regarding the genetics of those phenotypes and describe genotype-phenotype correlations. We then present the animal models used to study these defects.

CBCT in orthodontics: a systematic review on justification of CBCT in a paediatric population prior to orthodontic treatment

BACKGROUND

Taking into account radiation doses, safety, and protection, we highlighted the features in which cone-beam computed tomography (CBCT) can offer an advantage compared to the conventional two-dimensional imaging in paediatric dentistry before orthodontic treatment.

OBJECTIVE

The aim of this article was to conduct a systematic review to assess the diagnostic efficacy of CBCT in the paediatric population at a pre-orthodontic phase.

SEARCH METHODS

MEDLINE via PubMed was searched to identify all peer-reviewed articles potentially relevant to the review until 1 July 2018. Relevant publications were selected by two reviewers independently.

SELECTION CRITERIA

The literature selection for this systematic review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and was based on predetermined inclusion criteria.

DATA COLLECTION AND ANALYSIS

Data were collected on overall study characteristics and examination characteristics of the selected studies. Methodological quality of the selected studies was evaluated. Original studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. Thereafter, levels of evidence were obtained according to Grading of Recommendations Assessment, Development and Evaluation criteria.

RESULTS

As a result of the QUADAS assessment, a total of 37 articles were included in the protocol. Following a proper protocol, CBCT was regarded as a reliable tool for assessment and management of impacted canine and root fracture. It provided a better evaluation of normal and pathological condylar shape and volume. CBCT was a superior choice for pre-surgical diagnostic applications in cleft lip and/or palate over a medical computed tomography based on its lower radiation exposure, shorter investigation time, and low purchase costs.

CONCLUSIONS

CBCT is justified only in those cases where conventional radiography fails to provide a correct diagnosis of pathology. Therefore, it cannot be regarded as a standard method of diagnosis. CBCT imaging may also be justified when it positively affects treatment options or provides treatment optimization.

REGISTRATION

None.

CONFLICT OF INTEREST

None to declare.

Three-Dimensional Analysis of Craniofacial Structures of Individuals With Nonsyndromic Unilateral Complete Cleft Lip and Palate

ABSTRACT

Cleft lip and palate (CLP) is one of the most common congenital deformities. Primary surgeries at an early age result in scar formation, which may impede the growth of craniofacial structures of the maxilla. Orthodontist's role in the management of individuals with CLP is important and starts from the time of birth. The knowledge of craniofacial structures in individuals with a cleft is essential for treatment planning. The purpose of this study was to analyze and compare craniofacial structures of cleft and noncleft side of individuals with non-syndromic unilateral complete cleft lip and palate (NSUCCLP) using cone-beam computed tomography (CBCT). CBCT scans of individuals with NSUCCLP (n = 42) were retrieved from the databases of two cleft centers, which followed the same protocols for timing and type of primary surgeries and secondary alveolar bone grafting (SABG). DICOM files of CBCT scans were integrated into Dolphin 3D software, and analysis was carried out in multiplanar views. The craniofacial structures of individuals with NSUCCLP were analyzed using fourteen parameters. Measurements were also recorded between the cleft and noncleft sides for comparison. The volume of the maxilla was generated by isolating it from adjacent structures on a 3D reconstructed model. MAWC, MAWPM1, MAWPM2, MAWM1, and MV of the cleft side was less than noncleft side (P < 0.05). MHP @ N Aper is less on the noncleft side (P < 0.05). There is an asymmetry of structures around the dentoalveolar and nasal region; however, asymmetries were not affected at deeper structures of the craniofacial region of individuals with NSUCCLP.

Craniofacial Analysis May Indicate Co-Occurrence of Skeletal Malocclusions and Associated Risks in Development of Cleft Lip and Palate

Non-syndromic orofacial clefts encompass a range of morphological changes affecting the oral cavity and the craniofacial skeleton, of which the genetic and epigenetic etiologic factors remain largely unknown. The objective of this study is to explore the contribution of underlying dentofacial deformities (also known as skeletal malocclusions) in the craniofacial morphology of non-syndromic cleft lip and palate patients (nsCLP). For that purpose, geometric morphometric analysis was performed using full skull cone beam computed tomography (CBCT) images of patients with nsCLP (n = 30), normocephalic controls (n = 60), as well as to sex- and ethnicity- matched patients with an equivalent dentofacial deformity (n = 30). Our outcome measures were shape differences among the groups quantified via principal component analysis and associated principal component loadings, as well as mean shape differences quantified via a Procrustes distance among groups. According to our results, despite the shape differences among all three groups, the nsCLP group shares many morphological similarities in the maxilla and mandible with the dentofacial deformity group. Therefore, the dentoskeletal phenotype in nsCLP could be the result of the cleft and the coexisting dentofacial deformity and not simply the impact of the cleft.

Morphological variability in unrepaired bilateral clefts with and without cleft palate evaluated with geometric morphometrics

In subjects with orofacial clefts, there is an unresolved controversy on the effect of congenital maxillary growth deficiency vs. the effect of surgical intervention on the outcome of treatment. Intrinsic growth impairment in subjects with orofacial clefts can be studied by comparing facial morphology of subjects with untreated cleft and unaffected individuals of the same ethnic background. Bilateral cleft lip and palate is the most severe and least prevalent form of the orofacial cleft. The aim of this study was to compare facial morphology in subjects with unrepaired complete bilateral clefts and unaffected controls using geometric morphometrics. Lateral cephalograms of 39 Indonesian subjects with unrepaired bilateral complete cleft lip and alveolus (mean age: 24 years), or unrepaired bilateral complete cleft lip, alveolus, and palate (mean age: 20.6 years) and 50 age and ethnically matched controls without a cleft (25 males, 25 females, mean age: 21.2 years) were digitized and traced and shape variability was explored using principal component analysis, while differences between groups and genders were evaluated with canonical variate analysis. Individuals with clefts had a more pronounced premaxilla than controls. Principal component analysis showed that facial variation in subjects with clefts occurred in the anteroposterior direction, whereas in controls it was mostly in the vertical direction. Regression analysis with group, sex, and age as covariates and principal components from 1 to 6 as dependent variables demonstrated a very limited effect of the covariates on the facial shape variability (only 11.6% of the variability was explained by the model). Differences between cleft and non-cleft subjects in the direction of facial variability suggest that individuals with bilateral clefts can have an intrinsic growth impairment affecting facial morphology later in life.

Evaluation of the Facial Soft-Tissue Thickness in Patients With Cleft Lip and Palate

AIM

In this study the authors aimed to evaluate craniofacial morphology and facial soft tissue thickness of the patients with cleft lip and palate.(CLP), and to compare the results with a sex and age-matched noncleft healthy control group.

METHODS

Craniofacial and soft tissue thickness measurements of 20 patients with unilateral cleft lip palate (UCLP) and 20 patients with bilateral cleft lip palate (BCLP) were compared with 20 noncleft control subjects. Angles between Sella-Nasion-A point, Sella-Nasion-B point, Nasion-A and Nasion-B line, Sella-Nasion line and Gonion-Gnation line, and linear (glabella, rhinion, subnasale, labrale superius, stomion, labrale inferius, labiomentale, pogonion, and gnathion) measurements were assessed on lateral cephalometric radiographs. Group differences were evaluated with 1-way analysis of variance and post hoc Tukey test.

RESULTS

Unilateral cleft lip palate and BCLP groups demonstrated lower values of skeletal measurements than control group except for Sella-Nasion line and Gonion-Gnation line value (P < 0.01). Maxillary incisors were retruded in BCLP group compared with the other groups (P < 0.001). Thickness of the rhinion, subnasale, and stomion demonstrated no significant difference between UCLP and BCLP groups (P > 0.05). Thickness of rhinion and stomion was found significantly higher in both groups, and thickness of the subnasale was found significantly lower than the healthy group (P < 0.05).

CONCLUSION

Findings of the study suggested that patients with CLP showed differences on craniofacial morphology and facial soft tissue thickness. Before planning orthodontic treatment and esthetic surgeries, soft tissue thickness should be taken into consideration in addition to skeletal measurements in CLP patients.

Breaking Symmetry: A Quantitative Analysis of Facial Skeleton Disharmony in Children Born with Bilateral Cleft Lip and Palate

Bilateral cleft lip and palate (BCLP) occurs when craniofacial precursors fail to form or fuse properly during development. The aim of this retrospective, cross-sectional investigation was to quantify directional asymmetry (DA) of the facial skeleton of children born with Veau Class IV nonsyndromic BCLP. To accomplish this goal, coordinate values of anatomical landmarks were acquired from three-dimensional cone beam computed tomographic images of the craniofacial skeleton of middle- to late-aged children born with BCLP and age- and sex-matched controls and used to compare patterns of asymmetry variation. Multivariate analyses revealed different patterns of DA variation across samples and identified approximately 30% of DA measures as significantly different. Magnitudes of statistically significant linear distances differ in the craniofacial region, with most smaller DA differences located near the orbits and frontal bone, while larger differences were localized mostly to the midface, alveolar ridge, and nasal borders. Generally, areas of the craniofacial skeleton derived from the maxillary and nasal prominences demonstrated the highest magnitudes of DA. The methods and results presented will be useful to biomedical researchers when identifying the extent to which patients with BCLP diverge from typical developmental expectations. Quantifying DA and assessing local differences across the craniofacial complex can aid medical practitioners when developing treatments to improve BCLP surgical algorithms and outcomes. Anat Rec, 302:1726-1732, 2019. © 2019 American Association for Anatomy.

A morphometric analysis of developmental instability in children born with unilateral cleft lip and palate

Unilateral cleft lip and palate (UCLP) is a congenital deformity that occurs due to inadequate merging of the nasal and maxillary prominences during fetal development. Randomly distributed bilateral asymmetries known as fluctuating asymmetry (FA) occur in normally symmetric organisms when evolved mechanisms of developmental stability or equilibrium are disturbed by genetic, environmental, or unknown factors. Here, we hypothesize that facial skeleton FA will be increased in a sample of individuals born with UCLP (n = 24) relative to sex- and age-matched controls (n = 24). To test this hypothesis, 23 anatomical landmarks were measured on individual anonymized cone-beam computerized tomography (CBCT) images in children and adolescents (7-17 years). For each individual, 81 pairs of linear distances were used to estimate FAs across the face. To explore sample variation and statistical differences, a principal components analysis and Euclidean Distance Matrix Analysis multivariate bootstrap approach were carried out. Samples show some separation in multivariate space with 44.44% of FA differences being significantly different. The magnitude of FA was larger in the UCLP sample for every significant measurement. The magnitude of significant FA is highest near regions derived from the maxillary and nasal prominences, such as the nasal aperture. These results are useful for medical and dental practitioners when developing treatment options for children and adolescents with UCLP. Clin. Anat. 32:206-211, 2019. © 2018 Wiley Periodicals, Inc.

Cone beam computed tomography imaging of superior semicircular canal morphology: a retrospective comparison of cleft lip/palate patients and normal controls

OBJECTIVE

This study evaluated the prevalence and morphological characteristics of the superior semicircular canal (SSCC) in cleft lip and palate (CL/P) patients using cone beam computed tomography (CBCT).

MATERIALS AND METHODS

CBCT images of 53 CL/P patients (28 males and 25 females) and a control group of 76 patients (42 males and 34 females) were evaluated. Retrospectively, 258 temporal bone images from 129 patients were evaluated in terms of SSCC morphology and divided into a normal pattern (0.6-1.7 mm in thickness), a papyraceous pattern (<0.5 mm), a thick pattern (>1.8 mm), a pneumatized pattern and dehiscent. The chi-squared test was used to compare differences among semicircular canal dehiscence (SSCD) patterns in the CL/P and control groups; p ≤ .05 was taken to reflect statistical significance.

RESULTS

The characteristics of the SSCC were evaluated on CBCT images in patients with CL/P and controls. In total, 158 (61%) cases were normal (0.6-1.7 mm in thickness), 31 (12%) papyraceous (<0.5 mm), 8 (3%) thick, and 34 (13%) pneumatized. SSCD was observed in 27 (11%) cases. Statistically significant differences between the CL/P and control groups were evident in terms of SSCC morphology (p < .001).

CONCLUSIONS

SSCD should be considered if a CL/P patient exhibits a vestibular system deficiency. Oral and maxillofacial radiologists should pay attention to SSCD when interpreting CBCT images. Future studies should use high-level spatial resolution CBCT to focus on cleft site and SSCC morphology in larger patient populations.