Snehlata Oberoi

Volumetric Assessment of Secondary Alveolar Bone Grafting Using Cone Beam Computed Tomography

Objective: To assess the radiographic outcome of secondary alveolar bone grafting in individuals with nonsyndromic unilateral or bilateral cleft lip and palate using cone beam computed tomography. Methods: This prospective study was conducted at the University of California at San Francisco Center for Craniofacial Anomalies on 21 consecutive nonsyndromic complete cleft lip and palate individuals between 8 and 12 years of age who required alveolar bone grafting. Seventeen unilateral and four bilateral cleft lip and palate individuals had preoperative and postoperative cone beam computed tomography scans that were analyzed using Amira 3.1.1 software. Results: The average volume of the preoperative alveolar cleft defect in unilateral cleft lip and palate was 0.61 cm3, and the combined average volume of the right and left alveolar cleft defects in bilateral cleft lip and palate was 0.82 cm3. The average percentage bone fill in both unilateral cleft lip and palate and bilateral cleft lip and palate was 84%. The outcome of alveolar bone grafting was assessed in relation to (1) type of cleft, (2) size of preoperative cleft defect, (3) presence or absence of lateral incisor, (4) root development stage of the maxillary canine on the cleft side, (5) timing, and (6) surgeon. None of these parameters significantly influenced the radiographic outcome of alveolar bone grafting. Conclusions: Secondary alveolar bone grafting of the cleft defect in our center was successful, based on radiographic outcome using cone beam computed tomography scans. Volume rendering using cone beam computed tomography and Amira software is a reproducible and practical method to assess the preoperative alveolar cleft volume and the adequacy of bone fill postoperatively.

Andersen‐Tawil syndrome: Prospective cohort analysis and expansion of the phenotype

Andersen‐Tawil syndrome (ATS) is an autosomal dominant multisystem disorder characterized by developmental, cardiac, and neuromuscular abnormalities. Approximately 70% of patients have mutations in KCNJ2, resulting in dysfunction of the inward‐rectifying potassium channel Kir2.1. Variable expression complicates the diagnosis of ATS, which in many cases, is not made until years after the first recognized symptom. To better define the distinctive clinical features of ATS and facilitate earlier diagnosis, we conducted a prospective, standardized evaluation of 10 subjects with confirmed KCNJ2 mutations. Detailed anthropometric, neurological, and cardiac evaluations were performed. Using this approach, we identified novel skeletal and dental findings and proposed additional diagnostic criteria for ATS dysmorphology.

Developmental disorders of the dentition: An update

Dental anomalies are common congenital malformations that can occur either as isolated findings or as part of a syndrome. This review focuses on genetic causes of abnormal tooth development and the implications of these abnormalities for clinical care. As an introduction, we describe general insights into the genetics of tooth development obtained from mouse and zebrafish models. This is followed by a discussion of isolated as well as syndromic tooth agenesis, including Van der Woude syndrome (VWS), ectodermal dysplasias (EDs), oral‐facial‐digital (OFD) syndrome type I, Rieger syndrome, holoprosencephaly, and tooth anomalies associated with cleft lip and palate. Next, we review delayed formation and eruption of teeth, as well as abnormalities in tooth size, shape, and form. Finally, isolated and syndromic causes of supernumerary teeth are considered, including cleidocranial dysplasia and Gardner syndrome.

Three-Dimensional Assessment of the Eruption Path of the Canine in Individuals With Bone-Grafted Alveolar Clefts Using Cone Beam Computed Tomography

Objective To evaluate the eruption path of the permanent maxillary canine during a 1-year period after secondary alveolar bone grafting and to (1) compare the canine eruption path on the cleft and noncleft side, (2) examine the number of congenially missing lateral incisors and the rate of canine impaction, and (3) examine the relationship between the eruption status of the canine and timing of alveolar bone grafting relative to age and canine root development using cone beam computed tomography (CBCT). Methods Cone beam computed tomography scans for 17 nonsyndromic unilateral cleft lip and palate (UCLP), and four bilateral cleft lip and palate (BCLP) consecutive cases of alveolar bone grafting surgery were obtained after orthodontic expansion and before alveolar bone grafting and at least 1 year postsurgery on the Hitachi MercuRay CBCT machine. The DICOM files were imported into Dolphin 3D Imaging 10.5 and reoriented for consistency. The X, Y, and Z coordinates were determined for the canine cusp tip and root tip on both the cleft and noncleft sides. The direction of movement of the canine in 1 year was determined. Results Most canines on both the cleft and noncleft sides moved incisally, facially, and mesially. Twelve percent of the canines on the cleft side appeared to require surgical exposure. Eighty percent of the canines had less than half root development at the time of bone grafting. The amount of root development did not affect the outcome in terms of eruption amount or direction. Conclusions Most canines on both the cleft and noncleft side moved incisally, facially, and mesially.

Three-dimensional assessment of impacted canines and root resorption using cone beam computed tomography.

OBJECTIVE The objective of this study was to localize impacted canines in 3 dimensions and determine the most common location of impaction using cone beam computed tomography (CBCT). We also assessed root resorption of adjacent teeth. The cusp tip of each impacted canine was located and digitized using Dolphin 3D imaging, after viewing sagittal, coronal, and axial views. The position on the occlusal plane where the normally erupted canine cusp tip should be located was used as a control reference point. The degree of impaction was defined by the difference between the impacted canine cusp tip and reference cusp tip positions. MATERIALS AND METHODS CBCT scans of 29 consecutive individuals with impacted canines undergoing orthodontic treatment at the UCSF Orthodontic Clinic were included in this study. RESULTS The average degree of mesial impactions was 10.1 mm, of distal impactions was 4.2 mm, of facial impactions was 4.16 mm, of palatal impactions was 1.8 mm, and of gingival impactions was 10 mm; 40.4% had no root resorption, 35.7% showed slight root resorption, 14.2% showed moderate resorption, and 4% showed severe root resorption of the adjacent lateral incisor. CONCLUSION We reliably assessed the position of impacted canines in 3 dimensions using CBCT, thereby improving accuracy of location and facilitating precise surgical and orthodontic management. In our study 40.4% had no root resorption, 35.7% showed slight root resorption, 14.2% showed moderate resorption, and 4% showed severe root resorption of the adjacent lateral incisor. The most frequent location of impacted canines was palatal, mesial, and gingival.

Morphologic and Management Characteristics of Individuals With Unilateral Cleft Lip and Palate Who Required Maxillary Advancement

Objective: To delineate factors that may contribute to maxillary hypoplasia requiring maxillary advancement surgery in individuals with nonsyndromic unilateral cleft lip and palate (UCLP). Methods: This retrospective, longitudinal study used lateral cephalometric radiographs and chart reviews of 16 nonsyndromic UCLP individuals who underwent Le Fort I maxillary advancement and 16 controls matched for cleft type, age, and gender. Cephalometric measurements were made at three time points (T1, T2, and T3): mean ages of 10.7, 13.3, and 15.8 years for the Le Fort group and 10.11, 12.9, and 15.7 years, respectively, for the control group. Information regarding team care, timing and number of surgical procedures, and number of congenitally missing teeth were determined from clinical records. Results: The Le Fort group had significant maxillary hypoplasia at all time points compared to the UCLP controls, indicated by midface length measurements, ANB and Wits analysis (p < .001). The Le Fort group had twice the number of palatal surgical procedures and number of missing teeth in the maxillary arch as compared with the cleft controls. Most of the control group had consistent team care, while most of the surgical group did not. Conclusions: Maxillary hypoplasia that will require a Le Fort I advancement can be determined as early as age 10. Multiple missing maxillary teeth, secondary palate procedures including pharyngeal flaps, and inconsistent team care with delayed orthodontic intervention are contributing factors to maxillary underdevelopment.

Case reports of oculofaciocardiodental syndrome with unusual dental findings.

We report on two new cases of oculofaciocardiodental (OFCD) syndrome characterized by cataracts, microphthalmia, facial anomalies, cleft palate, cardiac septal defects, and canine radiculomegaly. We also review previous patients. The syndrome is caused by mutations in the BCOR gene, which maps to Xp11.4. Mutational analysis in one of our patients showed a deletion of a single nucleotide, c.2613delC, predicting a novel frameshift mutation with a premature stop codon, p.F871Lfs8X.

Three Dimensional Assessment of the Pharyngeal Airway in Individuals with Non-Syndromic Cleft Lip and Palate

Introduction Children with cleft lip and palate (CLP) are known to have airway problems. Previous studies have shown that individuals with CLP have a 30% reduction in nasal airway size compared to non-cleft controls. No reports have been found on cross-sectional area and volume of the pharyngeal airway in clefts. Introduction of Cone-Beam CT (CBCT) and imaging software has facilitated generation of 3D images for assessment of the cross-sectional area and volume of the airway. Objective To assess the pharyngeal airway in individuals with CLP using CBCT by measuring volume and smallest cross-sectional areas and compare with 19 age- and sex-matched non-cleft controls. Methods Retrospective study of CBCT data of pre-adolescent individuals (N = 19, Mean age = 10.6, 7 females, 12 males, UCLP = 6, BCLP = 3) from the Center for Craniofacial Anomalies. Volumetric analysis was performed using image segmentation features in CB Works 3.0. Volume and smallest cross-sectional were studied in both groups. Seven measurements were repeated to verify reliability using Pearson correlation coefficient. Volume and cross-sectional area differences were analyzed using paired t-tests. Results The method was found to be reliable. Individuals with CLP did not exhibit smaller total airway volume and cross sectional area than non-CLP controls. Conclusion 3D imaging using CBCT and CB Works is reliable for assessing airway volume. Previous studies have shown that the nasal airway is restricted in individuals with CLP. In our study, we found that the pharyngeal airway is not compromised in these individuals.

Hypoplasia and Hypodontia in Van der Woude Syndrome

Objective The purpose of this study was (1) to assess maxillary development in cleft individuals with Van der Woude syndrome (VWS) and (2) to compare hypodontia in VWS and nonsyndromic cleft matched controls. Design and Setting Retrospective case-control study from the Center for Craniofacial Anomalies, University of California, San Francisco, California. Patients and Participants The sample consisted of 15 individuals with Van der Woude syndrome and 15 nonsyndromic cleft lip and/or palate controls paired for age, gender, and cleft type in the age range of 5 to 13 years. Main Outcome Measures Cephalograms were digitized, and 31 linear and angular measurements were made. Serial panoramic radiographs were used to assess the presence or absence of permanent teeth. Results The maxillary sagittal position represented by midface length (Co-A) was significantly shorter in the Van der Woude syndrome subjects than in the matched controls (p = .031), suggesting a trend towards greater maxillary hypoplasia, particularly in Van der Woude syndrome with bilateral cleft lip and/ or palate. Measurements indicating sagittal jaw relationship (ANB angle and the Wits) were significantly smaller in the children with Van der Woude syndrome than in matched controls (p = .008 and p = .006). A significantly larger number of individuals with Van der Woude syndrome than matched controls had missing teeth (p = .014). The mandibular second premolar was missing more frequently in children with Van der Woude syndrome than in the matched controls (p = .031). The differences concerning both maxillary hypoplasia and hypodontia were most marked in the more severe cleft type, represented by bilateral cleft lip and/or palate. Conclusions Based on these findings, the expectation is that there will be maxillary hypoplasia and hypodontia of greater severity in Van der Woude syndrome than in nonsyndromic clefts.

Taurodontism and Van der Woude syndrome. Is there an association

OBJECTIVE To report the occurrence of taurodontism in a clinical sample of Van der Woude syndrome (VWS) and describe its association with hypodontia and cleft type. MATERIALS AND METHODS This retrospective, cross-sectional study was carried out on chart reviews and radiographs of 13 persons with VWS. Mean age was 10 years 11 months +/- 1 year 5 months. Panoramic radiographs were used to confirm the presence or absence of teeth and to measure crown body and root lengths of mandibular first molars. Three-dimensional cone beam computed tomography (CT) scans were available on two persons with VWS. Both volumetric and linear measurements were obtained. RESULTS The occurrence of taurodontism of the mandibular first molar was 35%: 27% hypodont and 8% mesodont. Of the 13 subjects with VWS, 6 (4 males and 2 females) had at least one tooth identified with taurodontism. Half of the cases were unilateral and half were bilateral, and all of the unilateral cases were on the left side. Five of the six subjects with taurodontism had missing incisors and premolars. Taurodontism was two times more frequent in those who were missing their second premolars than in those who had their second premolars. There was no correlation between cleft type and presence of taurodontism. The cone beam CT pilot study on two persons showed very abnormal morphology of both crown and roots, which was not apparent on the standard panoramic radiograph. Both the volumetric and linear measurements of the ratio of crown body to root were highly indicative of taurodontism. Further genetic studies are needed. CONCLUSION There is a likely association between VWS and taurodontism.