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OBJECTIVES: Despite data linking smoking to increased risk of fetal morbidity and mortality, 11% of pregnant women continue to smoke or use alternative nicotine products. Studies confirm that nicotine exposure during pregnancy increases the incidence of birth defects; however, little research has focused on specific anatomic areas based on timing of exposure. We aim to determine critical in utero and postnatal periods of nicotine exposure that affect craniofacial development, specifically palate growth. Malformation of the palatal structures can result in numerous complications including facial growth disturbance, or impeding airway function. We hypothesized that both in utero and postnatal nicotine exposure will alter palate development. MATERIALS AND METHODS: We administered pregnant C57BL6 mice water supplemented with 100 µg/mL nicotine during early pregnancy, throughout pregnancy, during pregnancy and lactation, or lactation only. Postnatal day 15 pups underwent micro-computed tomography (µCT) analyses specific to the palate. RESULTS: Resultant pups revealed significant differences in body weight from lactation-only nicotine exposure, and µCT investigation revealed several dimensions affected by lactation-only nicotine exposure, including palate width, palate and cranial base lengths, and mid-palatal suture width. CONCLUSIONS: These results demonstrate the direct effects of nicotine on the developing palate beyond simple tobacco use. Nicotine exposure through tobacco alternatives, cessation methods, and electronic nicotine delivery systems (ENDS) may disrupt normal growth and development of the palate during development and the postnatal periods of breastfeeding. Due to the recent dramatic increase in the use of ENDS, future research will focus specifically on this nicotine delivery method.
ABSTRACT
OBJECTIVES: Antidepressants, specifically Selective Serotonin Re-uptake Inhibitors (SSRIs), that alter serotonin metabolism are currently the most commonly prescribed drugs for the treatment of depression. There is some evidence to suggest these drugs contribute to birth defects. As jaw development is often altered in craniofacial birth defects, the purpose of this study was to interrogate the effects of in utero SSRI exposure in a preclinical model of mandible development. MATERIALS AND METHODS: Wild-type C57BL6 mice were used to produce litters that were exposed in utero to an SSRI, Citalopram (500 µg/day). Murine mandibles from P15 pups were analysed for a change in shape and composition. RESULTS: Analysis indicated an overall shape change with total mandibular length and ramus height being shorter in exposed pups as compared to controls. Histomorphometric analysis revealed that first molar length was longer in exposed pups while third molar length was shorter in exposed as compared to control. Histological investigation of molars and surrounding periodontium revealed no change in collagen content of the molar in exposed pups, some alteration in collagen composition in the periodontium, increased alkaline phosphatase in molars and periodontium and decreased mesenchymal cell marker presence in exposed mandibles. CONCLUSION: The results of this study reveal SSRI exposure may interrupt mandible growth as well as overall dental maturation in a model of development giving insight into the expectation that children exposed to SSRIs may require orthodontic intervention.
Subject(s)
Selective Serotonin Reuptake Inhibitors , Serotonin , Animals , Mice , Selective Serotonin Reuptake Inhibitors/adverse effects , Serotonin/metabolism , Mice, Inbred C57BL , Citalopram/adverse effects , Mandible/metabolismABSTRACT
INTRODUCTION: Alveolar bone grafting aims to restore bony continuity of the alveolus and provide optimal periodontal support for teeth adjacent to the cleft. We created a survey of cleft surgeons to assess the current standard of care regarding this procedure. METHODS: A multiple choice survey was implemented using Qualtrics software and emailed to a list of 708 surgeons from the ACPA membership directory. Correlation between various provider factors and treatment practices was assessed with Fisher's exact test and likelihood ratio tests. RESULTS: The response rate was 17.5%. Eighty-seven percent of providers preferred to perform grafts prior to secondary canine eruption while 10% favored before central incisor eruption. Eighty-one percent favored palatal expansion prior to bone grafting. Wide variability existed regarding the time to initiate postoperative orthodontics; 43% waited 4 to 6 months. Sixty-four percent of surgeons now utilize cone beam CT to assess graft take. The majority of respondents utilized cancellous bone autograft (92%) from the anterior iliac crest (97%) as graft material. Seventy percent used three or more modalities for post-operative pain control management. Early career surgeons (0-5 years) appeared more likely to use non-autologous materials (p < .01) for grafting. CONCLUSION: Alveolar bone grafting prior to secondary canine eruption remains the most common strategy but other protocols are employed. Surgeons utilize multiple modalities for radiographic evaluation and most often use autologous cancellous bone as the primary grafting material. There is no true consensus on the perioperative timing and sequencing of orthodontic manipulation while principles of multimodal perioperative pain control appear widely accepted.
Subject(s)
Alveolar Bone Grafting , Cleft Lip , Cleft Palate , Surgeons , Humans , Bone Transplantation/methods , Cleft Palate/surgery , Cleft Lip/surgery , Palatal Expansion Technique , Alveolar Bone Grafting/methods , North America , Retrospective StudiesABSTRACT
OBJECTIVE: We aimed to assess significant ethnic variabilities in infants' nasolabial anthropometry to motivate variations in surgical correction of a synchronous bilateral cleft lip/nasal anomaly, specifically whether a long columella is a European feature, therefore accepting a short columella and/or delayed columellar lengthening suitable for reconstruction in ethnic patients. METHODS: Thirty-three infants without craniofacial pathology (10 African American [AA], 7 Hispanic [H], and 16 of European descent [C]), ages 3 to 8 months, presenting to the Johns Hopkins All Children's general pediatric clinic were recruited. Four separate 3D photographs (2 submental and frontal views each) were taken using the Vectra H1 handheld camera (Canfield Imaging). Eighteen linear facial distances were measured using Mirror 3D analysis (Canfield Imaging Systems). Difference between ethnicities was measured using analysis of variance with the Bonferroni/Dunn post hoc comparisons. Pearson correlation was employed for interrater reliability. All statistical analyses were carried out using SPSS version 21.0 (IBM Corp), with statistical significance set at P < .05. RESULTS: Nasal projection (sn-prn) and columella length (sn-c) did not differ significantly between groups (P = .9). Significant differences were seen between ethnic groups in nasal width (sbal-sbal [C-AA; P = .02]; ac-ac [C-AA; P = .00; H-AA; P = .04]; al-al [C-AA; P = .00; H-AA; P = .001]) and labial length (sn-ls [C-AA; P = .041]; sn-sto [C-AA; P = .005]; Cphs-Cphi L [C-AA; P = .013]; Cphs-Cphi R [C-AA; P = .015]). Interrater reliability was good to excellent and significantly correlated for all measures. CONCLUSIONS: African American infants exhibited wider noses and longer lips. No difference was noted in nasal projection or columella length, indicating that these structures should be corrected during the primary cleft lip and nasal repair for all patients and should not be deferred to secondary correction.
Subject(s)
Cleft Lip , Nose Diseases , Anthropometry , Child , Cleft Lip/diagnostic imaging , Cleft Lip/surgery , Ethnicity , Humans , Infant , Nasal Septum , Nose/abnormalities , Reproducibility of ResultsABSTRACT
INTRODUCTION: Surgical outcomes for patients with complete cleft lips are not as ideal as those achieved for milder phenotypes. We hypothesized that in addition to the greater width of the cleft, patients with complete cleft lip and palate exhibit a greater degree of hypoplasia and asymmetry. METHODS: Stereophotographs of 14 infants with unrepaired unilateral complete and 14 with incomplete cleft lips were measured using Vectra imaging software (Canfield Imaging). Unpaired t tests were used to compare measured asymmetry between groups. Measurements included nasion to endocathion, sn-sbal, subnasale to alare (sn-al), subnasale to crista philtra, subalare to crista philtra (sbal-cphi), chelion to crista philtra, lateral lip element fullness, medial lip element fullness (mef), and non-cleft lip fullness. Duplicate measurements allowed Pearson correlation to be used to determine intra-rater reliability. Statistical significance was set at P < .05. RESULTS: Degree of asymmetry of the nasal base, sn-al, and sn-sbal was significantly greater for patients with complete clefts (P = .0001, P = .0001). Hypoplasia of the lateral lip element was seen when comparing lateral and mef (P = .04, P = .004) and lateral lip height (sbal-cphi''; P = .002). The degree of cupid's bow asymmetry did not differ between groups (P = .23). Intrarater reliability was high for all facial measures, ranging from 0.70 to 0.99. CONCLUSIONS: More severe, complete cleft lips demonstrate statistically significant greater asymmetry in surgically relevant dimensions. There was greater width of the nasal base. Vertical asymmetry of cupid's bow was unaffected by cleft severity, but that asymmetry was greater in patients with complete clefts due to hypoplasia of the lateral lip element. This may contribute to the less favorable results in these patients.
Subject(s)
Cleft Lip , Cleft Palate , Cleft Lip/diagnostic imaging , Cleft Lip/surgery , Cleft Palate/diagnostic imaging , Cleft Palate/surgery , Humans , Infant , Lip/diagnostic imaging , Nose , Reproducibility of ResultsABSTRACT
INTRODUCTION: Oronasal fistulae following palatoplasty may affect patients' quality of life by impacting their ability to eat, speak, and maintain oral hygiene. We aimed to quantify the impact of previous oronasal fistula repair on patients' quality of life using patient-reported outcome psychometric tools. METHODS: A cross-sectional study of 8- to 9-year-old patients with cleft palate and/or lip was completed. Patients who had a cleft team clinic between September 2018 and August 2019 were recruited. Participants were divided into 2 groups (no fistula, prior fistula repair). Differences in the individual CLEFT-Q and Child Oral Health Impact Profile-Short Form 19 (COHIP-SF 19) Oral Health scores between the 2 groups were evaluated using a multivariate analysis controlling for Veau classification and syndromic diagnosis. RESULTS: Sixty patients with a history of cleft palate were included. Forty-two (70%) patients had an associated cleft lip. Thirty-two (53.3%) patients had no history of fistula and 28 (46.7%) patients had undergone a fistula repair. CLEFT-Q Dental, Jaw, and Speech Function were all higher in patients without a history of a fistula repair; however, none of these differences were statistically significant. The COHIP-SF 19 Oral Health score demonstrated a significantly lower score in the fistula group, indicating poorer oral health (P = .05). CONCLUSIONS: One would expect that successful repair of a fistula would result in improved function and patient satisfaction, but the consistent trend toward lower CLEFT-Q scores and significantly increased COHIP-SF 19 Oral Health scores in our study group suggests that residual effects linger and that the morbidity of a fistula may not be completely treated with a secondary correction.
Subject(s)
Cleft Lip , Cleft Palate , Fistula , Child , Cleft Lip/surgery , Cleft Palate/surgery , Cross-Sectional Studies , Humans , Oral Fistula , Oral Health , Patient-Centered Care , Postoperative Complications , Quality of Life , Retrospective Studies , Treatment OutcomeABSTRACT
Timing of craniofacial suture fusion is important for the determination of demographics and primate ontogeny. There has been much work concerning the timing of fusion of calvarial sutures over the last century, but little comprehensive work focusing on facial sutures. Here we assess the relationships of facial suture fusion across ontogeny among select catarrhines. Fusion timing patterns for 5 facial sutures were examined in 1,599 crania of Homo, Pan, Gorilla, Pongo, Hylobatidae, Papio, and Macaca. Calvarial volume (early ontogeny) and dental eruption (late ontogeny) were used as indicators of stage of development. General linear models, test for homogeneity of slopes, and ANOVA were used to determine differences in timing of fusion by taxon. For calvarial volume, taxonomic groups segregated by regression slopes, with models for Homo indicating sutural fusion throughout ontogeny, Pongo, Macaca, and Papio representing earlier and more complete suture fusion, and Pan, Gorilla, and Hylobatidae indicating very early facial suture fusion. Similar patterns are observed when dental eruption is used for developmental staging. Only Gorilla and Hylobatidae are observed to, generally, fuse all facial suture sites in adulthood. Finally, Homo appears to be unique in its delay and patency of sutures into late ontogeny. The taxonomic patterns of facial suture closure identified in this study likely reflect important evolutionary shifts in facial growth and development in catarrhines.
Subject(s)
Cranial Sutures , Hominidae , Skull , Animals , Hominidae/anatomy & histology , Skull/anatomy & histologyABSTRACT
Large bone injuries, defects, and chronic wounds present a major problem for medicine. Several therapeutic strategies are used clinically to precipitate bone including a combination therapy delivering osteoinductive bone morphogenetic protein 2 (rhBMP-2) via an osteoconductive scaffold (absorbable collagen sponge [ACS], i.e., INFUSE). Adverse side effects reportedly associated with rhBMP2 administration include rampant inflammation and clinical failures. Although acute inflammation is necessary for proper healing in bone, inflammatory cascade dysregulation can result in sustained tissue damage and poor healing. We hypothesized that a subclinical dose of rhBMP2 modeled in the murine calvarial defect would not precipitate alterations to inflammatory markers during acute phases of bone wound healing. We utilized the 5 mm critical size calvarial defect in C57BL6 wild-type mice which were subsequently treated with ACS and a subclinical dose of rhBMP2 shown to be optimal for healing. Three and 7-day postoperative time points were used to assess the role that rhBMP-2 plays in modulating inflammation vs. ACS alone by cytokine array and histological interrogation. Data revealed that rhBMP-2 delivery resulted in substantial modulation of several markers associated with inflammation, most of which decreased to levels similar to control by the 7-day time point. Additionally, while rhBMP-2 administration increased macrophage response, this peptide had a little noticeable effect on traditional markers of macrophage polarization (M1-iNOS, M2-Arg1). These results suggest that rhBMP-2 delivered at a lower dose does not precipitate rampant inflammation. Thus, an assessment of dosing for rhBMP-2 therapies may lead to better healing outcomes and less surgical failure.
Subject(s)
Bone Morphogenetic Protein 2/pharmacology , Collagen/pharmacology , Fractures, Bone/pathology , Inflammation/pathology , Osteogenesis/drug effects , Wound Healing/drug effects , Absorbable Implants , Animals , Disease Models, Animal , Fractures, Bone/drug therapy , Mice , Mice, Inbred C57BL , Osteogenesis/physiology , Tissue Scaffolds , Wound Healing/physiologyABSTRACT
BACKGROUND: The use of subgaleal drains following primary cranioplasty for craniosynostosis has undergone limited investigation. Proposed benefits include prevention of seroma, detection of postoperative bleeding, and cerebrospinal fluid leak. We conducted a systematic review of the literature and surveyed craniofacial surgeons to ascertain the current evidence pertaining to drain use following primary cranioplasty for craniosynostosis and to determine surgical practice patterns. METHODS: PubMed and Embase databases were searched to identify relevant articles. Abstracts were reviewed by 2 investigators, and a Cohen κ statistic was calculated. Patient demographic and outcome data were extracted and compared. A 9-question survey was e-mailed to active and associate members of the American Society of Craniofacial Surgeons. RESULTS: A total of 7395 unique citations were identified. Only 2 retrospective chart reviews met inclusion criteria. All objective parameters demonstrated no difference between patients with and without drains. A subjective benefit of limiting facial swelling was proposed without objective analysis. Fifty (32.5%) of the 154 craniofacial surgeons responded to the survey. Forty-two percent used postoperative drains. A significant association (P = .01) was found between the belief that drains limited facial swelling and their use. CONCLUSIONS: The literature examining postoperative drain use in primary cranioplasty for craniosynostosis is restricted. The current studies show no definite benefit to drain use but are limited in their assessment of key outcomes. There is wide variability among surgeons regarding drain use, and this seems to be motivated by belief and tradition.
Subject(s)
Craniosynostoses , Postoperative Complications , Craniosynostoses/surgery , Craniotomy , Drainage , Humans , Retrospective Studies , Surgeons , Surveys and QuestionnairesABSTRACT
An estimated 3% of US pregnancies are affected by maternal thyroid dysfunction, with between one and three of every 1000 pregnancies being complicated by overactive maternal thyroid levels. Excess thyroid hormones are linked to neurological impairment and excessive craniofacial variation, affecting both endochondral and intramembranous bone. Using a geometric morphometric approach, this study evaluates the role of in utero thyroxine overexposure on the growth of offspring mandibles in a sample of 241 mice. Canonical variate analysis utilized 16 unilateral mandibular landmarks obtained from 3D micro-computed tomography to assess shape changes between unexposed controls (nâ =â 63) and exposed mice (nâ =â 178). By evaluating shape changes in the mandible among three age groups (15, 20 and 25â days postnatal) and different dosage levels (low, medium and high), this study found that excess maternal thyroxine alters offspring mandibular shape in both age- and dosage-dependent manners. Group differences in overall shape were significant (Pâ <â 0.001), and showed major changes in regions of the mandible associated with muscle attachment (coronoid process, gonial angle) and regions of growth largely governed by articulation with the cranial base (condyle) and occlusion (alveolus). These results compliment recent studies demonstrating that maternal thyroxine levels can alter the cranial base and cranial vault of offspring, contributing to a better understanding of both normal and abnormal mandibular development, as well as the medical implications of craniofacial growth and development.
Subject(s)
Mandible/diagnostic imaging , Mandible/growth & development , Prenatal Exposure Delayed Effects/chemically induced , Prenatal Exposure Delayed Effects/diagnostic imaging , Thyroxine/toxicity , Animals , Facial Bones/diagnostic imaging , Facial Bones/drug effects , Facial Bones/growth & development , Female , Male , Mandible/drug effects , Mice , Mice, Inbred C57BL , Pregnancy , Skull/diagnostic imaging , Skull/drug effects , Skull/growth & development , X-Ray Microtomography/methodsABSTRACT
BACKGROUND AIMS: Previous studies identified a circulating human osteoblastic population that expressed osteocalcin (OCN), increased following fracture and pubertal growth, and formed mineralized colonies in vitro and bone in vivo. A subpopulation expressed CD34, a hematopoietic/endothelial marker. These findings led to our hypothesis that hematopoietic-derived CD34+OCN+ cells exist in the circulation of mice and are modulated after fracture. METHODS: Flow cytometry was used to identify CD34+OCN+ cells in male B6.SJL-PtprcaPepcb/BoyJ and Vav-Cre/mTmG (VavR) mice. Non-stabilized tibial fractures were created by three-point bend. Fractures were longitudinally imaged by micro-computed tomography, and immunofluorescent staining was used to evaluate CD34+OCN+ cells within fracture callus. AMD3100 (10 mg/kg) was injected subcutaneously for 3 days and the CD34+OCN+ population was evaluated by flow cytometry. RESULTS: Circulating CD34+OCN+ cells were identified in mice and confirmed to be of hematopoietic origin (CD45+; Vav1+) using two mouse models. Both circulating and bone marrow-derived CD34+OCN+ cells peaked three weeks post-non-stabilized tibial fracture, suggesting association with cartilage callus transition to bone and early mineralization. Co-expression of CD34 and OCN in the fracture callus at two weeks post-fracture was observed. By three weeks, there was 2.1-fold increase in number of CD34+OCN+ cells, and these were observed throughout the fracture callus. AMD3100 altered CD34+OCN+ cell levels in peripheral blood and bone marrow. DISCUSSION: Together, these data demonstrate a murine CD34+OCN+ circulating population that may be directly involved in fracture repair. Future studies will molecularly characterize CD34+OCN+ cells, determine mechanisms regulating their contribution, and examine if their number correlates with improved fracture healing outcomes.
Subject(s)
Antigens, CD34/metabolism , Fracture Healing/physiology , Fractures, Bone/pathology , Osteoblasts/cytology , Osteocalcin/metabolism , Animals , Benzylamines , Biomarkers/blood , Bone Marrow/drug effects , Cyclams , Disease Models, Animal , Fractures, Bone/diagnostic imaging , Heterocyclic Compounds/pharmacology , Mice, Transgenic , Osteoblasts/drug effects , Osteoblasts/pathologyABSTRACT
INTRODUCTION: Direct anthropometric and three-dimensional (3D) photogrammetry measurements have been used extensively in cleft/craniofacial surgery to assess morphological changes and surgical outcomes. Craniofacial procedures alter the sagittal projection of periorbital bony prominences. Mulliken described a method of measuring their projection relative to the corneal plane but is impractical in clinical practice. Three-dimensional photogrammetry may offer a solution; however, the cornea is not visualized on this. The authors propose to develop new normative measurements of facial projection relative to the pupil. METHODS: Five 3D photographs were taken of 5 individuals using Vectra M5 camera. Facial projection measurements were taken of the sagittal projection of the bilateral periorbital landmarks and nasal radix relative to the pupil using Mirror 3D analysis. Standard deviations (SD) were determined for each subject and laterality. Chi-square tests confirmed all SD <1 mm. Intra and inter-rater reliability were confirmed with an intraclass correlation coefficient assessment. RESULTS: Three male and 2 female subjects were photographed with 5 unique images. Standard deviations of repeat measures of all landmarks were <0.5 mm. Chi-square tests confirmed with statistical significance that SD for all values except for the radix was <1 mm (P<0.05). Intrarater reliability was high for all landmarks (intraclass correlation coefficient coefficients 0.93-0.99). Inter-rater reliability was good for the lateral canthi and excellent for all others. CONCLUSION: This technique demonstrates repeatability with high reliability on serial photographs and is applicable to measuring surgery effects and growth on facial projection. Establishment of age-specific normative values for landmark projection will refine usage applicability in operative planning.
Subject(s)
Anthropometry/methods , Eye/anatomy & histology , Imaging, Three-Dimensional , Photogrammetry/methods , Adult , Anatomic Landmarks , Face/anatomy & histology , Female , Humans , Male , Reproducibility of Results , Young AdultABSTRACT
OBJECTIVES: An overexpression of Tgf-ß2 leads to calvarial hyperostosis and suture fusion in individuals with craniosynostosis. Inhibition of Tgf-ß2 may help rescue fusing sutures and restore normal growth. The present study was designed to test this hypothesis. DESIGN: Twenty-eight New Zealand White rabbits with delayed-onset coronal synostosis had radiopaque markers placed on either side of the coronal sutures at 10 days of age. The rabbits were randomly assigned to: (1) sham control rabbits (n = 10), (2) rabbits with control IgG (100 µg/suture) delivered in a collagen vehicle (n = 9), and (3) rabbits with Tgf-ß2 neutralizing antibody (100 µg/suture) delivered in a collagen vehicle (n = 9). Longitudinal growth data were collected at 10, 25, 42, and 84 days of age. Sutures were harvested at 84 days of age for histomorphometry. RESULTS: Radiographic analysis showed significantly greater ( P < .05) coronal suture marker separation, craniofacial length, cranial vault length, height, shape indices, cranial base length, and more lordotic cranial base angles in rabbits treated with anti-Tgf-ß2 antibody than in controls at 42 and 84 days of age. Histologically, rabbits treated with anti-Tgf-ß2 antibody at 84 days of age had patent and significantly ( P < .05) wider coronal sutures and greater sutural area compared to controls. CONCLUSIONS: These data support our hypothesis that antagonism of Tgf-ß2 may rescue fusing coronal sutures and facilitate craniofacial growth in this rabbit model. These findings also suggest that cytokine therapy may have clinical significance in infants with progressive postgestational craniosynostosis.
Subject(s)
Cranial Sutures , Craniosynostoses , Transforming Growth Factor beta2 , Animals , Rabbits , Animals, Newborn , Cranial Sutures/diagnostic imaging , Cranial Sutures/drug effects , Cranial Sutures/growth & development , Craniosynostoses/diagnostic imaging , Craniosynostoses/prevention & control , Disease Models, Animal , Random Allocation , Transforming Growth Factor beta2/antagonists & inhibitorsABSTRACT
Thyroid hormone is important for skull bone growth, which primarily occurs at the cranial sutures and synchondroses. Thyroid hormones regulate metabolism and act in all stages of cartilage and bone development and maintenance by interacting with growth hormone and regulating insulin-like growth factor. Aberrant thyroid hormone levels and exposure during development are exogenous factors that may exacerbate susceptibility to craniofacial abnormalities potentially through changes in growth at the synchondroses of the cranial base. To elucidate the direct effect of in utero therapeutic thyroxine exposure on the synchondroses in developing mice, we provided scaled doses of the thyroid replacement drug, levothyroxine, in drinking water to pregnant C57BL6 wild-type dams. The skulls of resulting pups were subjected to micro-computed tomography analysis revealing less bone volume relative to tissue volume in the synchondroses of mouse pups exposed in utero to levothyroxine. Histological assessment of the cranial base area indicated more active synchondroses as measured by metabolic factors including Igf1. The cranial base of the pups exposed to high levels of levothyroxine also contained more collagen fiber matrix and an increase in markers of bone formation. Such changes due to exposure to exogenous thyroid hormone may drive overall morphological changes. Thus, excess thyroid hormone exposure to the fetus during pregnancy may lead to altered craniofacial growth and increased risk of anomalies in offspring.
Subject(s)
Prenatal Exposure Delayed Effects/pathology , Skull Base/drug effects , Skull Base/growth & development , Thyroxine/toxicity , Animals , Female , Male , Mice , Mice, Inbred C57BL , Pregnancy , Thyroid Hormones/toxicity , X-Ray MicrotomographyABSTRACT
BACKGROUND: Craniosynostosis ranges in severity from single suture involvement with prenatal onset to multiple suture involvement with postnatal onset. The present study was designed to test the hypothesis that increasing homozygosity may be responsible for more severe phenotypic expression by examining the relationship between inbreeding and phenotypic expression in synostotic rabbits. METHODS: Data were obtained from 173 litters and 209 rabbits with familial craniosynostosis. Five distinct phenotypes were identified (normal n = 62; unicoronal delayed onset synostosis (DOS) n = 47; bicoronal DOS n = 21; unicoronal early onset synostosis (EOS) n = 26, and bicoronal EOS n= 53). Wright's coefficients of inbreeding (CI) were calculated using CompuPed software. Radiographs were taken at 10, 25, 42, 84, and 126 days of age to assess coronal suture, craniofacial, and skeletal growth. The relationship between CI and growth data was assessed using correlation coefficients. RESULTS: Mean CIs ranged from 15.68 (±2.22) in normal rabbits to 25.89 (±5.03) in bicoronal DOS, to 36.29 (±2.10) in unicoronal EOS to 42.85 (±2.10) in bicoronal EOS rabbits. Significant differences were noted among groups (F = 11.48; P < .001). Significant negative correlations were noted between CI and sutural and craniofacial growth at 25 (r = -.45, P < .001; and r = -.66, P < .001) through 126 (r = -.40, P < .001 and r = -.46, P < .001) days of age. CONCLUSIONS: While the synostotic phenotype is inherited in an autosomal dominant fashion in these rabbits, increasing homozygosity is associated with more severely affected phenotypes. These findings suggest that an accumulation of additional, modifier genes may determine the severity of the synostotic phenotype in rabbits.
Subject(s)
Craniosynostoses/genetics , Animals , Animals, Newborn , Biological Variation, Population , Craniosynostoses/pathology , Homozygote , Inbreeding , Phenotype , RabbitsABSTRACT
BACKGROUND: Craniosynostosis, the premature fusion of one or more of the cranial sutures, is estimated to occur in 1:1800 to 2500 births. Genetic murine models of craniosynostosis exist, but often imperfectly model human patients. Case, cohort, and surveillance studies have identified excess thyroid hormone as an agent that can either cause or exacerbate human cases of craniosynostosis. METHODS: Here we investigate the influence of in utero and in vitro exogenous thyroid hormone exposure on a murine model of craniosynostosis, Twist 1 +/-. RESULTS: By 15 days post-natal, there was evidence of coronal suture fusion in the Twist 1 +/- model, regardless of exposure. With the exception of craniofacial width, there were no significant effects of exposure; however, the Twist 1 +/- phenotype was significantly different from the wild-type control. Twist 1 +/- cranial suture cells did not respond to thyroxine treatment as measured by proliferation, osteogenic differentiation, and gene expression of osteogenic markers. However, treatment of these cells did result in modulation of thyroid associated gene expression. CONCLUSION: Our findings suggest the phenotypic effects of the genetic mutation largely outweighed the effects of thyroxine exposure in the Twist 1 +/- model. These results highlight difficultly in experimentally modeling gene-environment interactions for craniosynostotic phenotypes. Birth Defects Research (Part A) 106:803-813, 2016. © 2016 Wiley Periodicals, Inc.
Subject(s)
Abnormalities, Drug-Induced , Craniosynostoses , Gene-Environment Interaction , Nuclear Proteins/genetics , Phenotype , Thyroxine/adverse effects , Twist-Related Protein 1/genetics , Abnormalities, Drug-Induced/genetics , Abnormalities, Drug-Induced/metabolism , Abnormalities, Drug-Induced/pathology , Animals , Craniosynostoses/chemically induced , Craniosynostoses/genetics , Craniosynostoses/metabolism , Craniosynostoses/pathology , Disease Models, Animal , Gene Expression Regulation , Mice , Mice, Mutant Strains , Osteogenesis/drug effects , Osteogenesis/genetics , Thyroxine/pharmacologyABSTRACT
BACKGROUND: Management of the previously infected craniofacial defect remains a significant clinical challenge, posing obstacles such as wound healing complications, lack of donor site availability, and predisposition to failure of the repair. Optimal therapy would reconstruct like with like, without donor site morbidity. The purpose of this study was to compare the efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2)-mediated bone regeneration with the current standard of autologous bone graft for repair of previously infected calvarial defects. METHODS: Nineteen adult New Zealand white rabbits underwent subtotal calvariectomy. Bone flaps were inoculated with Staphylococcus aureus and replanted. After 1 week of infection, bone flaps were removed, and wounds were debrided, followed by 10 days of antibiotic treatment. After 6 weeks, animals underwent scar debridement followed by definitive reconstruction in 1 of 4 groups: empty control (n = 3), vehicle control (buffer solution on absorbable collagen sponge [ACS], n = 3), autologous bone graft (n = 3), or rhBMP-2 repair (rhBMP-2/ACS, n = 10). Animals underwent computed tomography imaging at 0, 2, 4, and 6 weeks postoperatively, followed by euthanization and histological analysis. Percent healing was determined by 3-dimensional analysis. A (time × group) 2-way analysis of variance was performed on healing versus treatment group and postoperative time. RESULTS: At 6 weeks postoperatively, rhBMP-2/ACS and autologous bone graft resulted in 93% and 68% healing, respectively, whereas the empty and vehicle control treatment resulted in 27% and 26% healing (P < 0.001). Histologically, compared to autologous bone graft, bone in the rhBMP-2/ACS group was more cellular and more consistently continuous with wound margins. CONCLUSIONS: The rhBMP-2 therapy is effective in achieving radiographic coverage of previously infected calvarial defects.
Subject(s)
Bone Morphogenetic Protein 2/pharmacology , Recombinant Proteins/pharmacology , Skull/surgery , Transforming Growth Factor beta/pharmacology , Wound Healing/drug effects , Analysis of Variance , Animals , Disease Models, Animal , Rabbits , Plastic Surgery Procedures/methods , Skull/transplantation , Transplantation, AutologousABSTRACT
BACKGROUND: Selective serotonin reuptake inhibitor (SSRI) use in pregnancy has been linked to craniofacial birth defects. Little is known about the effects of serotonin or SSRIs on craniofacial development. Here, we provide evidence that citalopram (SSRI) alters the osteogenic profile of murine calvarial cells and leads to craniofacial dysmorphology. METHODS: We used mouse calvarial pre-osteoblast cells (MC3T3-E1) to study the biochemical profile (microarray and quantitative reverse transcription polymerase chain reactions) after treatment with a titrated dose of citalopram. We used C57BL-6 wild-type breeders to produce litters treated with a clinical dose of citalopram during the third trimester of pregnancy. We used micro-computed tomography and morphometric measures to determine effects on craniofacial development. RESULTS: Controls included untreated cells and age matched untreated litters. We observed decreases in proliferation and increases in alkaline phosphatase activity after citalopram exposure. We confirmed altered expression of genes linked to osteogenesis including Ocn and significant increase in expression of Alp after 7 days of treatment. Our data suggest altered expression of several genes related to craniofacial development (Fgf2, Fgfr2, Tgfßr2 Irs1, Igf1) and statistically significant changes in expression for (Col2a1, Gdf6, Hmox1, and Notch1). We also observed changes in regulation of the serotonin pathway (Sert, Tph1, Tph2, Htr2a, Lrp5) after treatment with citalopram. After in utero exposure to citalopram, mice displayed shorter narrow snouts, more globular skulls and several craniofacial anomalies. CONCLUSION: Our results provide confirmatory evidence that citalopram exposure is associated with cellular and morphological alterations of the craniofacial complex, which may have important implications for use during pregnancy.
Subject(s)
Biomarkers/metabolism , Citalopram/pharmacology , Craniofacial Abnormalities/genetics , Gene Expression Regulation, Developmental/drug effects , Osteoblasts/drug effects , Prenatal Exposure Delayed Effects/genetics , Selective Serotonin Reuptake Inhibitors/pharmacology , Stem Cells/metabolism , Animals , Cells, Cultured , Craniofacial Abnormalities/metabolism , Female , Gene Expression Profiling , Mice , Mice, Inbred C57BL , Oligonucleotide Array Sequence Analysis , Pregnancy , Pregnancy Trimester, Third , Prenatal Exposure Delayed Effects/metabolism , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Stem Cells/cytology , Stem Cells/drug effectsABSTRACT
BACKGROUND: Bone morphogenetic protein 2 (BMP-2) has been used to reconstruct mandibular defects. An elegant addition to this reconstruction method would be incorporation of a nerve graft wrapped in a BMP-2 carrier to reconstitute the inferior alveolar nerve (IAN) and restore sensation to the lower face. We developed a rabbit model to determine the effect BMP-2 has on nerve regeneration following neurorrhaphy. METHODS: An inferior border mandibulectomy was created in 16 adult New Zealand white rabbits. The IAN was protected, divided, and repaired with either primary neurorrhaphy or reverse autografts. Bone defects were treated with no treatment controls (n = 2), absorbable collagen sponge (ACS) (vehicle controls) (n = 7), and ACS soaked in BMP-2 (treatment group) (n = 7). Animals underwent computed tomography (CT) 2 days and 6 weeks postoperatively. The percent bone defect healing was calculated using Amira 3D imaging software. At 6 weeks, IANs were harvested mesial to the reconstruction and were evaluated with toluidine blue histology to identify myelinated axons. Reconstructed mandible segments were evaluated with micro-CT and hematoxylin-eosin histology. RESULTS: Bone morphogenetic protein 2-treated animals demonstrated significantly more bone healing than did the ACS and empty defect groups (82%, 38%, 44%, respectively; P < 0.01). One hundred percent of ACS-treated nerves (n = 4) demonstrated axon regrowth, whereas only 25% of BMP-2-treated nerves (n = 4) did. Micro-CT and histology showed BMP-2 caused bone growth around the IAN, but regenerated bone infiltrated the repair site and created a physical barrier to axon growth. CONCLUSIONS: Bone morphogenetic protein 2 can successfully heal bone defects in the rabbit mandible, but ectopic bone growth can inhibit IAN recovery after repair. Level of Evidence: Not gradable.
Subject(s)
Bone Morphogenetic Protein 2/therapeutic use , Bone Regeneration/drug effects , Mandibular Diseases/surgery , Mandibular Nerve/drug effects , Nerve Regeneration/drug effects , Plastic Surgery Procedures/methods , Animals , Axons/drug effects , Collagen , Coloring Agents , Disease Models, Animal , Image Processing, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Mandible/drug effects , Mandible/surgery , Mandibular Nerve/surgery , Nerve Fibers, Myelinated/drug effects , Osteogenesis/drug effects , Rabbits , Tissue Scaffolds , Tolonium Chloride , Tomography, X-Ray Computed/methods , Trigeminal Nerve Injuries/surgery , Wound Healing/drug effects , X-Ray Microtomography/methodsABSTRACT
BACKGROUND: Velopharyngeal insufficiency occurs in a nontrivial number of cases following cleft palate repair. We hypothesize that a conversion Furlow palatoplasty allows for long-term correction of VPI resulting from a failed primary palate repair, obviating the need for pharyngoplasty and its attendant comorbidities. METHODS: A retrospective review of patients undergoing a conversion Furlow palatoplasty between 2003 and 2010 was performed. Patients were grouped according to the type of preceding palatal repair. Velopharyngeal insufficiency was assessed using Pittsburgh Weighted Speech Scale (PWSS). Scores were recorded and compared preoperatively and postoperatively at 3 sequential visits. RESULTS: Sixty-two patients met inclusion criteria and were grouped by preceding repair (straight-line repair (n = 37), straight-line repair with subsequent oronasal fistula (n = 14), or pharyngeal flap (n = 11). Median PWSS scores at individual visits were as follows: preoperative = 11, first postoperative = 3 (mean, 114.0 ± 6.7 days), second postoperative = 1 (mean, 529.0 ± 29.1 days), and most recent postoperative = 3 (mean, 1368.6 ± 76.9 days). There was a significant difference between preoperative and postoperative PWSS scores in the entire cohort (P < 0.001) with overall improvement, and post hoc analysis showed improvement between each postoperative visit (P < 0.05) with the exception of the second to the most recent visit. There were no differences between postoperative PWSS scores in the operative subgroupings (P > 0.05). Eight patients failed to improve and showed no differences in PWSS scores over time (P > 0.05). Patients with a PWSS score of 7 or greater (n = 8) at the first postoperative visit (0-6 months) displayed improvement at the most recent visit (P< 0.05). CONCLUSIONS: Conversion Furlow palatoplasty is an effective means for salvaging speech. Future studies should elucidate which factors predict the success of this technique following failed palate repair.