Soft-tissue, non-osteogenic distraction of the mandible and lower face in bilateral hemifacial microsomia-technical report

The aim of this study is to present a sequential strategy of soft-tissue, non-osteogenic distraction with a novel device, followed by microvascular bony reconstruction for severe cases of mandibular hypoplasia. The case of a 21-year-old woman with Goldenhar syndrome is presented, whose mandible remained severely hypoplastic despite previous attempts at distraction and was not suitable for further osteogenic distraction. Soft tissue deficiency and pin track scarring prevented free fibular transfers. A personalized distractor, anchored to the cranium and the mandibular symphysis, was designed to expand the soft tissues while allowing for physiological temporomandibular joint (TMJ) movement without compression forces. Internal distractors were placed along the osteotomies to prevent condylar luxation. After completion of the soft tissue distraction, the native mandible was resected except for the condyles and reconstructed with two free fibula flaps. This report represents the proof of concept of a sequential approach to severe lower face soft-tissue and bone deficiency, which preserves TMJ function and avoids the transfer of poorly matched skin to the face.

Three-dimensional measurements of symmetry for the mandibular ramus

BACKGROUND

The study examines a sample of patients presenting for viscerocranial computer tomography that does not display any apparent signs of asymmetry, assesses the three-dimensional congruency of the mandibular ramus, and focuses on differences in age and gender.

METHODS

This cross-sectional cohort study screened viscerocranial CT data of patients without deformation or developmental anomalies. Segmentations were obtained from the left and right sides and superimposed according to the best-fit alignment. Comparisons were made to evaluate three-dimensional congruency and compared between subgroups according to age and gender.

RESULTS

Two hundred and sixty-eight patients were screened, and one hundred patients met the inclusion criteria. There were no statistical differences between the left and right sides of the mandibular ramus. Also, there were no differences between the subgroups. The overall root mean square was 0.75 ± 0.15 mm, and the mean absolute distance from the mean was 0.54 ± 0.10 mm.

CONCLUSION

The mean difference was less than one millimetre, far below the two-millimetre distance described in the literature that defines relative symmetry. Our study population displays a high degree of three-dimensional congruency. Our findings help to understand that there is sufficient three-dimensional congruency of the mandibular ramus, thus contributing to facilitating CAD-CAM-based procedures based on symmetry for this specific anatomic structure.

Three-Dimensional Modeling and Quantitative Assessment of Mandibular Volume in Ectodermal Dysplasia: A Case Series

Background and Objectives: Ectodermal dysplasia (ED)-a genetic disorder-is characterized by severe tooth deficiency. We compared the mandibular volume and the sagittal and horizontal mandibular widths between patients with ED (ED group) and individuals without tooth deficiency (control group) using three-dimensional modeling. We hypothesized that the mandibular volume differs in ED cases owing to congenital tooth deficiency. Materials and Methods: We used previously obtained cone-beam computed tomography (CBCT) images of 13 patients with ED. The control group data comprised retrospective CBCT images of patients of similar age and sex with a skeletal relationship of class 1. Further, using the three-dimensional image analysis software, the tooth crowns were separated from the mandible, the mandible was reconstructed and the gonion-to-gonion distance in the mandible was marked, the distance to the menton point was measured, and the distance between the two condyles was measured and compared with the control group. Results: Overall, 46.2% and 53.8% of the participants were men and women, respectively. In the ED group, the mean age of the participants was 15.46 (range, 6-24) years, and the mean number of mandibular teeth was 4.62. Notably, the edentulous mandible volume of the ED group (27.020 mm3) was statistically significantly smaller than that of the control group (49.213 mm3) (p < 0.001). There was no difference between the two groups in terms of the marked points. For data analysis, the Shapiro-Wilk test, independent samples t-test, and Mann-Whitney U test were used. Conclusions: It has been considered that mandible volume does not develop in ED cases because of missing teeth. Modern practices, such as the CBCT technique and three-dimensional software, may be effective in identifying the true morphologic features, especially in patients with genetic syndromes affecting the maxillofacial structure.

Machine Learning Effectively Diagnoses Mandibular Deformity Using Three-Dimensional Landmarks

BACKGROUND

Jaw deformity diagnosis requires objective tests. Current methods, like cephalometry, have limitations. However, recent studies have shown that machine learning can diagnose jaw deformities in two dimensions. Therefore, we hypothesized that a multilayer perceptron (MLP) could accurately diagnose jaw deformities in three dimensions (3D).

PURPOSE

Examine the hypothesis by focusing on anomalous mandibular position. We aimed to: (1) create a machine learning model to diagnose mandibular retrognathism and prognathism; and (2) compare its performance with traditional cephalometric methods.

STUDY DESIGN, SETTING, SAMPLE

An in-silico experiment on deidentified retrospective data. The study was conducted at the Houston Methodist Research Institute and Rensselaer Polytechnic Institute. Included were patient records with jaw deformities and preoperative 3D facial models. Patients with significant jaw asymmetry were excluded.

PREDICTOR VARIABLES

The tests used to diagnose mandibular anteroposterior position are: (1) SNB angle; (2) facial angle; (3) mandibular unit length (MdUL); and (4) MLP model.

MAIN OUTCOME VARIABLE

The resultant diagnoses: normal, prognathic, or retrognathic.

COVARIATES

None.

ANALYSES

A senior surgeon labeled the patients' mandibles as prognathic, normal, or retrognathic, creating a gold standard. Scientists at Rensselaer Polytechnic Institute developed an MLP model to diagnose mandibular prognathism and retrognathism using the 3D coordinates of 50 landmarks. The performance of the MLP model was compared with three traditional cephalometric measurements: (1) SNB, (2) facial angle, and (3) MdUL. The primary metric used to assess the performance was diagnostic accuracy. McNemar's exact test tested the difference between traditional cephalometric measurement and MLP. Cohen's Kappa measured inter-rater agreement between each method and the gold standard.

RESULTS

The sample included 101 patients. The diagnostic accuracy of SNB, facial angle, MdUL, and MLP were 74.3, 74.3, 75.3, and 85.2%, respectively. McNemar's test shows that our MLP performs significantly better than the SNB (P = .027), facial angle (P = .019), and MdUL (P = .031). The agreement between the traditional cephalometric measurements and the surgeon's diagnosis was fair. In contrast, the agreement between the MLP and the surgeon was moderate.

CONCLUSION AND RELEVANCE

The performance of the MLP is significantly better than that of the traditional cephalometric measurements.

Helical distraction is superior to linear and circular distraction in mandibular distraction osteogenesis: an in silico study

Helical mandibular distraction is theoretically better than linear or circular distraction. However, it is not known whether this more complex treatment will result in unquestionably better outcomes. Therefore, the best attainable outcomes of mandibular distraction osteogenesis were evaluated in silico, given the constraints of linear, circular, and helical motion. This cross-sectional kinematic study included 30 patients with mandibular hypoplasia who had been treated with distraction, or to whom this treatment had been recommended. Demographic information and the computed tomography (CT) scans showing the baseline deformity were collected. The CT scans of each patient were segmented and three-dimensional models of the face created. Then, the ideal distraction outcomes were simulated. Next, the most favorable helical, circular, and linear distraction movements were calculated. Finally, errors were measured: misalignment of key mandibular landmarks, misalignment of the occlusion, and changes in intercondylar distance. Helical distraction produced trivial errors. In contrast, circular and linear distractions resulted in errors that were statistically and clinically significant. Helical distraction also preserved the planned intercondylar distance, while circular and linear distractions led to unwanted changes in the intercondylar distance. It is now evident that helical distraction offers a new strategy to improve the outcomes of mandibular distraction osteogenesis.

Severity of Mandibular Dysmorphology in Treacher Collins Syndrome for Stratification of Perioperative Airway Risk

BACKGROUND

Patients with Treacher Collins syndrome (TCS) and attendant airway dysmorphology may be predisposed to airway complications in the perioperative period. However, limited data correlates severity of mandibular hypoplasia and airway status. This study aims to improve risk stratification for perioperative airway insufficiency in TCS by using a previously proposed mandibular severity index.

METHODS

Patient demographics, perioperative airway status, difficulty of intubation, and Cormack Lehane grade were collected and compared using a TCS mandibular hypoplasia severity grading scale in patients with TCS treated between 2000 and 2022.

RESULTS

Twenty-six patients underwent 222 procedures with institutional mandibular severity gradings as follows: 23% Grade I, 31% Grade II, 39% Grade III, 8% Grade IV. Our severity index was associated with intubation difficulty ( P <0.001) and difficult airway status ( P <0.001), with 72% of difficult airways found in grade III and grade IV patients. Mandibular retrusion and ramal hypoplasia subscores were positively correlated with measures of airway severity ( P <0.001), whereas the gonial angle was negatively correlated ( P <0.001). Age was negatively correlated with difficult visualization for endotracheal intubation ( P =0.02) but had no association with difficult airway status ( P =0.2).

CONCLUSIONS

This study found a positive correlation between severity of maxillomandibular dysmorphology and perioperative airway difficulty in TCS patients. Our findings suggest that severely affected patients require heightened vigilance throughout life, as difficult airways may not completely resolve with aging. Given the risk of morbidity and mortality associated with airway complications, proper identification and preparation for challenging airways is critical for TCS patients.

Morphological integration in inferior alveolar canal and mandibular shapes

OBJECTIVE

During embryogenesis of mandible, the initial ossification centre begins at the bifurcation of the inferior alveolar (IA) and the mental nerves. Additionally, in congenital anomalies like craniofacial microsomia (CFM), the IA canal is completely absent on the microsomic side. These observations led us to hypothesise that there may be a morphological integration between these structures - the IA nerve and the mandibular shapes. Therefore, the primary objective of this study was to test for morphological integration between these structures and the secondary objective was to determine if there were shape variations in these structures among skeletal Classes I, II and III subjects.

SETTING AND SAMPLE POPULATION

The sample size of the study is 80 full-head cone-beam computed tomography (CBCT) scans (age 16-56 years).

METHODS

We retrieved CBCT scans from our archived database using specific inclusion/exclusion criteria. In the de-identified CBCT scans, traditional coordinate landmarks and sliding semi-landmarks were placed on the mandible and the IA canal (proxy for IA nerve). Using geometric morphometric analyses, we tested integration between the IA canal and the mandibular shapes. We used Procrustes ANOVA to test for overall shape variations among the three skeletal classes (Classes I, II and III).

RESULTS

The IA canal and posterior/inferior border of mandible showed strong integration (r-PLS = .845, P = .001). Similar strong integration was also observed between the IA canal and the overall shape of the mandible (r-PLS = .866, P = .001). Additionally, there was a statistically significant variation in overall shape between skeletal Class I and Class II (P = .008) and Class II and Class III (P = .001).

CONCLUSIONS

The strong integration between two structures suggests that the IA nerve may play a role in establishing mandibular shape early in development. We posit this may be important in driving mandibular defects seen in CFM, which warrants further investigation.

The Outcome of Mandibular Distraction Osteogenesis in Infants with Severe Pierre Robin Sequence in Vietnam

The purpose of this study was to provide the experience of a single center with mandibular distraction osteogenesis (MDO) in Pierre Robin Sequence (PRS) patients. A longitudinal research analysis was conducted to identify PRS patients who underwent MDO at Vietnam National Children's Hospital between 2019 and 2021. The following criteria were used to determine inclusion: 1) those pediatric patients with PRS who were not well handled with conservative therapy, 2) those who received MDO with internal mandibular distractors, and 3) no previous treatment elsewhere. Demographic data, postoperative complications, and surgical results were all evaluated. The inclusion criteria were met by 73 patients. There were no difficulties associated with our distraction strategy. The majority of individuals with tracheostomies were successfully decannulated, and the remainder were able to avoid tracheostomies. Using MDO in PRS is an effective technique to avoid future airway issues. The success rate was lower and the complication rate higher for patients who had a tracheotomy before distraction and for those who underwent distraction at an age older than 2 months. The presence of laryngomalacia, gastric reflux disease, cardiac abnormalities, and GI anomalies did not increase the likelihood of MDO failure in PRS patients.

Hemifacial microsomia is linked to a rare homozygous variant V162I in FRK and validated in zebrafish

OBJECTIVES

Hemifacial microsomia (HFM) is a common birth defect involving the first and second branchial arch derivatives. Although several chromosomal abnormalities and causal gene variants have been identified, genetic etiologies in a majority of cases with HFM remain unknown. This study aimed to identify genetic mutations in affected individuals with HFM.

METHODS

Whole-exome sequencing and bioinformatics analysis were performed for 16 affected individuals and their family members. Sanger sequencing was applied for confirmation of selected mutations. Zebrafish embryos were used for in situ hybridization of candidate gene, microinjection with antisense morpholino, and cartilage staining.

RESULTS

A homozygous missense mutation (c.484G > A; p.V162I) in the FRK gene was identified in an 18-year-old girl with HFM and dental abnormalities. Heterozygous mutation of this mutation was identified in her parents, who are first cousins in a consanguineous family. FRK is highly expressed in the Meckel's cartilage during embryonic development in mouse and zebrafish. Knockdown of frk in zebrafish showed a lower length and width ratio of Meckel's cartilage, abnormal mandibular jaw joint, and disorganized ceratobranchial cartilage and bone.

CONCLUSIONS

We identified a recessive variant in the FRK gene as a novel candidate gene for a patient with HFM and mandibular hypoplasia and revealed its effects on craniofacial and embryonic development in zebrafish.

Tracheostomy, the Not So Definitive Airway?: Tracheostomy Morbidity in Pediatric Craniofacial Patients

BACKGROUND

Tracheostomy is the definitive treatment for airway management in severe cases of craniofacial-associated upper airway obstruction, like the Pierre-Robin sequence, but is associated with significant morbidity. The purpose of this study was to examine tracheostomy-associated morbidities and mortalities in craniofacial patients to identify opportunities to improve clinical care and patient prognosis.

METHODS

The study was a retrospective review of pediatric craniofacial patients who were tracheostomized between 2016 and 2022. Data regarding their demographics, craniofacial diagnoses, endoscopic airway anomalies, intubation grade of view classification, tracheostomy-related complications, and causes of mortality were analyzed.

RESULTS

Sixteen of the 17 tracheostomized pediatric patients had the Pierre-Robin sequence, with 5 of those patients having an additional syndromic craniofacial diagnosis. Additional airway anomalies were found in 82.4% of the patients. The mean length of hospital stay after tracheostomy was 4.08 months. Infection was the most common complication, observed in 94.1% of patients, followed by stomal granulation in 76.5% of patients. Two mortalities were observed: one following the compassionate removal of ventilator support and the other following the accidental dislodgment of the tracheostomy tube.

CONCLUSIONS

Tracheostomy-related complications were observed in all craniofacial patients in this group. Compared with the general pediatric population, tracheostomized craniofacial patients may endure longer hospital stays and greater stomal granulation rates. Mandibular distraction osteogenesis may allow for tracheostomy avoidance in these patients, and future research should focus on comparing the long-term complication rates and outcomes between tracheostomy mandibular distraction osteogenesis in this challenging patient population.

Congenital mandibular coronoid process hyperplasia and associated diseases

Coronoid process hyperplasia (CPH) is an oral and maxillofacial surgical disease that can result in restricted jaw movement due to an enlarged and elongated mandibular coronoid process. It is characterized by the painless progressive restriction of unilaterally or bilaterally mouth opening. Clinically, unexplained bilateral CPH is less common and therefore often overlooked or misdiagnosed, and coronoidectomy can be very effective on improving mouth opening. Currently, the exact etiology and mechanism of congenital CPH have not yet been fully understood, but it is generally believed to be genetically related. In this paper, the relationship of the congenital mandibular CPH with the related diseases was examined based on cases collected in our clinic and literature review for the clinical diagnosis and treatment of patients with restricted mouth opening associated with CPH.

Feeding Outcomes After Mandibular Distraction for Airway Obstruction in Infants

Robin sequence is a congenital issue resulting in airway obstruction, difficulty feeding, and failure to thrive. Mandibular Distraction Osteogenesis is used to improve airway obstruction in these patients, but little data exists characterizing feeding outcomes following surgery. This study aims to evaluate feeding outcomes and weight gain following mandibular distraction for airway correction in infants. A single-center retrospective chart review was conducted, and patients under 12 months old who underwent mandibular distraction between December 2015 and July 2021 were included in the study. The presence of cleft palate, distance of distraction, and polysomnography results were recorded. The primary outcomes were the length of distraction, need for nasogastric tube or G-tube at discharge, time lapsed to achieve full oral feeds, and weight gain (kilogram). Ten patients met the criteria. Of those 10 patients, 4 were syndromic, 7 had a cleft palate, and 4 had a congenital cardiac diagnosis. The average length of stay postsurgery was 28 days. Eight patients achieved full oral feeds in an average of 65.6 days. Five patients required nasogastric tube or G-tube at discharge, with 3 of these patients later transitioning to full oral feeds. All patients gained weight 3 months postsurgery with an average of 0.521 kg/mo. Patients who achieved full oral feeds gained an average of 0.549 kg/mo. Patients with supplementation gained an average of 0.454 kg/mo. All patients demonstrated improvement in airway obstruction with an average postoperative apnea hypopnea index of 1.64. Further investigation is necessary to identify challenges seen in feeding after mandibular distraction osteogenesis and improve care.

[Sequential treatment of oral and maxillofacial deformities with hemifacial microsomia]

The incidence of the first and second branchial arch syndrome namely hemifacial microsomia (HFM) is the second only to cleft lip and palate, and it is a very common craniofacial developmental deformity. This congenital condition affects the development of the orbit, ear, and mandible, and the clinical manifestations of each patient are significantly heterogeneous. Clinical treatment needs to formulate corresponding treatment measures according to different degrees of tissue deformity at different ages. This article puts forward personal suggestions for the sequential treatment of oral and maxillofacial deformities of HFM from the perspective of patient age and classification.

Craniofacial Microsomia: New Updates in Spinal Anomalies

INTRODUCTION

Craniofacial microsomia (CFM) involves anomalies of the first and second pharyngeal arches, mainly of the mandible, maxilla, ears, and vertebral spine. This study aimed to identify the frequency and morphology of spinal anomalies of individuals with clinical diagnoses of CFM. In addition, the correlation between spinal anomalies and craniofacial involvement was performed.

MATERIALS AND METHODS

This study was a retrospective review of individuals with a clinical diagnosis of craniofacial microsomia. The inclusion criteria were a clinical diagnosis of CFM with no overlap with any other syndromes of first and second pharyngeal arches and radiograph availability in the hospital's database. Prevalence and morphology of spinal anomalies were calculated and clinical details were recorded: types of spinal anomalies and correlations according to OMENS score.

RESULTS

The sample consisted of 46 individuals with a clinical diagnosis of CFM, 24 (52,2%) female and 22 (47,8%) male (1M:1F). Twenty-one (45,7%) had unilateral craniofacial involvement and 25 (54,3%), bilateral. Twenty-eight (60,9%) individuals presented spinal anomalies. Those with unaltered spinal morphology showed a slight preference toward OMENS scores under 5: 7 patients did, only one of which had spinal alterations (14,3%); 68,8% (22) in the group with scores 5 to 9 (n=32) and 71,4% (5) in the 10 to 15 group (n=7) did as well.

DISCUSSION AND CONCLUSIONS

Spinal anomalies in individuals with CFM are more common than usually reported in medical literature, mainly when associated with radial anomalies and correlate with statistical significance to facial features, mainly the OMENS score.

[Lower jawbone structures symmetry evaluation using cone beam computed tomography]

OBJECTIVE

To assess the prevalence and quantitative characteristics of skeletal asymmetries of the body and lower jaw branches in three-dimensional space.

MATERIALS AND METHODS

Using depersonalized data archive, of 400 CBCT scans, forty studies were picked randomly. Patients aged 25 to 35 years participated in research, no history of maxillofacial reconstructive surgery; gender, race, and facial anomaly were ignored. Three experienced doctors, independently, identified 15 reference points on radiographic images of AUTOPLAN software. Expert consensus found in the orientation determination. Six planes and eight points were constructed, using Math algorithms and the Python OOP; body and branches of the lower jaw length measurements performed and processed automatically.

RESULTS

The study identified symmetry, using a method for determining parameters of the lower jaw in 3D space (Priority Reference No.2023100466 at 10.01.2023), modern dentistry research method. Both sides of data obtained shown asymmetry of the body and branches of the lower jaw occurred in 45% (18 people) and 67.5% (27 people) of cases. Forty percent of cases were noted with Mild asymmetry of the lower jaw body (16 people), moderate asymmetry noted in 5% (2 people). These parameters were 57.5% for branches, (23 people) and 10% (4 people). Combined form of anomaly observed in 37.5% (15 people) of cases, among which 12 people (75%) showed adaptive compensation of anomalies, which requires further investigation on a larger number of patients.

CONCLUSION

Lower body jaw asymmetry is prevalent (80%). Patients with moderate and serious anomaly form appeared in 15% of cases.

[Surgical treatment of a patient with mandibular micrognathia accompanied by obstructive sleep apnea syndrome using extended genioplasty]

A method for diagnosing, planning and surgical treatment of patients with micrognathia of the mandible with physiological occlusion is proposed, which makes it possible to objectively assess the severity of the anomaly and concomitant functional disorders of external respiration in the nasopharynx and oropharynx, as well as to identify the pathophysiological mechanisms of obstructive sleep apnea syndrome (OSAS) and develop an optimal surgical treatment plan with high functional and aesthetic results.

Two Decades after Mandibuloacral Dysplasia Discovery: Additional Cases and Comprehensive View of Disease Characteristics

Pathogenic variants in the LMNA gene cause a group of heterogeneous genetic disorders, called laminopathies. In particular, homozygous or compound heterozygous variants in LMNA have been associated with “mandibuloacral dysplasia type A” (MADA), an autosomal recessive disorder, characterized by mandibular hypoplasia, growth retardation mainly postnatal, pigmentary skin changes, progressive osteolysis of the distal phalanges and/or clavicles, and partial lipodystrophy. The detailed characteristics of this multisystemic disease have yet to be specified due to its rarity and the limited number of cases described. Here, we report three unrelated Egyptian patients with variable severity of MAD features. Next-generation sequencing using a gene panel revealed a homozygous c.1580G>A-p.Arg527His missense variant in LMNA exon 9 in an affected individual with a typical MADA phenotype. Another homozygous c.1580G>T-p.Arg527Leu variant affecting the same amino acid was identified in two additional patients, who both presented with severe manifestations very early in life. We combined our observations together with data from all MADA cases reported in the literature to get a clearer picture of the phenotypic variability in this disease. This work raises the number of reported MADA families, argues for the presence of the founder effect in Egypt, and strengthens genotype–phenotype correlations.

Deep learning neural networks to differentiate Stafne's bone cavity from pathological radiolucent lesions of the mandible in heterogeneous panoramic radiography

This study aimed to develop a high-performance deep learning algorithm to differentiate Stafne’s bone cavity (SBC) from cysts and tumors of the jaw based on images acquired from various panoramic radiographic systems. Data sets included 176 Stafne’s bone cavities and 282 odontogenic cysts and tumors of the mandible (98 dentigerous cysts, 91 odontogenic keratocysts, and 93 ameloblastomas) that required surgical removal. Panoramic radiographs were obtained using three different imaging systems. The trained model showed 99.25% accuracy, 98.08% sensitivity, and 100% specificity for SBC classification and resulted in one misclassified SBC case. The algorithm was approved to recognize the typical imaging features of SBC in panoramic radiography regardless of the imaging system when traced back with Grad-Cam and Guided Grad-Cam methods. The deep learning model for SBC differentiating from odontogenic cysts and tumors showed high performance with images obtained from multiple panoramic systems. The present algorithm is expected to be a useful tool for clinicians, as it diagnoses SBCs in panoramic radiography to prevent unnecessary examinations for patients. Additionally, it would provide support for clinicians to determine further examinations or referrals to surgeons for cases where even experts are unsure of diagnosis using panoramic radiography alone.

Cutaneous and metabolic defects associated with nuclear abnormalities in a transgenic mouse model expressing R527H lamin A mutation causing mandibuloacral dysplasia type A (MADA) syndrome

LMNA gene encodes for lamin A/C, attractive proteins linked to nuclear structure and functions. When mutated, it causes different rare diseases called laminopathies. In particular, an Arginine change in Histidine in position 527 (p.Arg527His) falling in the C-terminal domain of lamin A precursor form (prelamin A) causes mandibuloacral dysplasia Type A (MADA), a segmental progeroid syndrome characterized by skin, bone and metabolic anomalies. The well-characterized cellular models made difficult to assess the tissue-specific functions of 527His prelamin A. Here, we describe the generation and characterization of a MADA transgenic mouse overexpressing 527His LMNA gene, encoding mutated prelamin A. Bodyweight is slightly affected, while no difference in lifespan was observed in transgenic animals. Mild metabolic anomalies and thinning and loss of hairs from the back were the other observed phenotypic MADA manifestations. Histological analysis of tissues relevant for MADA syndrome revealed slight increase in adipose tissue inflammatory cells and a reduction of hypodermis due to a loss of subcutaneous adipose tissue. At cellular levels, transgenic cutaneous fibroblasts displayed nuclear envelope aberrations, presence of prelamin A, proliferation, and senescence rate defects. Gene transcriptional pattern was found differentially modulated between transgenic and wildtype animals, too. In conclusion, the presence of 527His Prelamin A accumulation is further linked to the appearance of mild progeroid features and metabolic disorder without lifespan reduction.

Stafne's bone defects from Spain: report of four cases and brief archaeological literature review

OBJECTIVE

To present for the first time in the north-western Spanish osteological record prevalence data on Stafne's bone defect, to compare the results with those reported by other studies, and to increase the dataset for future inter-population comparisons.

MATERIAL

In all, 143 complete adult mandibles recovered from two necropolises were analyzed (n = 118, San Juan Bautista of Guardo, Palencia province, 16th-19th centuries; n = 25, Plaza del Grano, city of León, 12th-15th centuries).

METHODS

Differential diagnosis of the lesions was made through macroscopic and Computed Tomography (CT) analyses.

RESULTS

Four mandibles (n = 3, Guardo, Palencia; n = 1, León) presented bone cavities on the lingual aspect of the mandible below the mylohyoid channel, between the first molar and the angle of the mandible. CT scan showed unilateral well-defined unilocular oval/round concavities in the lingual mandibular cortex below the inferior alveolar canal. Neither the macroscopic nor the radiological characteristics are compatible with inflammatory or malignant pathology, favoring instead a diagnosis of Stafne's bone defect.

CONCLUSIONS

Four cases of Stafne's defects are added to the bioarchaeological inventory. The calculated prevalence is 2.54% for San Juan Bautista and 4% for Plaza del Grano, values in close agreement to those presented in other osteoarchaeological studies.

SIGNIFICANCE

The identification of all examples of Stafne's bone defects in past populations will contribute to elucidate which factors may be responsible for this trait's cultural, ecological, temporal, and geographical patterning.

LIMITATIONS

The skeletal samples are relatively small.

SUGGESTIONS FOR FURTHER RESEARCH

In future investigations of Stafne's bone defects, CT analysis of dry bone specimens is recommended, whenever possible.

Knockout of the gene encoding the extracellular matrix protein SNED1 results in early neonatal lethality and craniofacial malformations

BACKGROUND

The extracellular matrix (ECM) is a fundamental component of multicellular organisms that orchestrates developmental processes and controls cell and tissue organization. We previously identified the novel ECM protein SNED1 as a promoter of breast cancer metastasis and showed that its level of expression negatively correlated with breast cancer patient survival. Here, we sought to identify the roles of SNED1 during murine development.

RESULTS

We generated two novel Sned1 knockout mouse strains and showed that Sned1 is essential since homozygous ablation of the gene led to early neonatal lethality. Phenotypic analysis of the surviving knockout mice revealed a role for SNED1 in the development of craniofacial and skeletal structures since Sned1 knockout resulted in growth defects, nasal cavity occlusion, and craniofacial malformations. Sned1 is widely expressed in embryos, notably by cell populations undergoing epithelial-to-mesenchymal transition, such as the neural crest cells. We further show that mice with a neural-crest-cell-specific deletion of Sned1 survive, but display facial anomalies partly phenocopying the global knockout mice.

CONCLUSIONS

Our results demonstrate requisite roles for SNED1 during development and neonatal survival. Importantly, the deletion of 2q37.3 in humans, a region that includes the SNED1 locus, has been associated with facial dysmorphism and short stature.

Asymmetrical mandibular malformation and failure to suck in neonatal calves

A congenital condition of cattle in the UK that hinders effective sucking in neonatal calves has been recognised for some years. With anecdotal reports from practitioners suggesting it is being seen more often, this focus article aims to raise awareness of the condition.

Management of recurrent central giant cell granuloma of mandible using intralesional corticosteroid with long-term follow-up

Central giant cell granuloma (CGCG) is an expansile osteolytic lesion of the jawbone. Conventional treatment of CGCG is surgical and vary from simple curettage to more aggressive resection of the jaw. However, surgical management is associated with drawbacks including requirement of hospitalisation and general anaesthesia, damage to vital anatomic structures and continuity defect of the mandible requiring reconstruction surgery. Use of intralesional injections of corticosteroid for the management of CGCG have been inconsistently used as an alternative non-surgical method of management of CGCG with varying success. While the use of such conservative modality over ablative surgery can significantly reduce postoperative morbidity, follow-up of such cases for a long period is important to study the possible recurrence. This paper reports successful treatment of a recurrent CGCG of posterior mandible by intralesional administration of triamcinolone acetonide in a 27-year old female patient, with long-term follow-up of 10 years.

The unusually lower position of the mandibular foramen and the canal of the neck of mandible

BACKGROUND

The inferior alveolar nerve (IAN) courses through the mandibular foramen (MF) to enter the first segment of the mandibular canal (MC) in the mandibular ramus, to further supply with trigeminal fibers the lower teeth of that hemimandible. As the IAN also supplies the mylohyoid nerve, it is a mixed nerve.

METHODS

Unusual morphologies of the mandibular ramus were encountered during a retrospective study of archived CBCT files.

RESULTS

A previously unreported anatomic variation was found bilaterally in an edentulous mandible, consisting of a lowered position of the MF, with seemingly compensatory lengthening and enlargement of the sulcus colli, thus shortened MCs. Also, a rare neurovascular canal of the neck of the mandible was incidentally found unilaterally in another case and is reported here.

CONCLUSIONS

Such possibilities of variation could justify the individual effect of the IAN block.

Hemifacial microsomia: skeletal abnormalities evaluation using CBCT (case report)

The article presents a case report and literature review of hemifacial microsomia with cervical vertebral anomalies. Unilateral hypoplasia of the mandible, congenital anomalies of the external ear and cervical spine pathology identified in this case are common major signs/symptoms of Goldenhar (Goldenhar-Gorlin) syndrome. Complete fusion of bodies and spinous processes of the second and third cervical vertebrae as well as atlantooccipital assimilation and anterior cleft of the atlas were also found. All abnormalities were accidentally identified and not accompanied by clinical symptoms.

Thalidomide leads to mandible hypoplasia through inhibiting angiogenesis and secondary hemorrhage in the fetal craniofacial region in rabbits

The effect of thalidomide on mandibular development is unclear. In this study, thalidomide was delivered to pregnant rabbits from the 8th to 14th day of gestation. Then, embryos were harvested for examination on the 16th day (GD16), 20th day (GD20) and 24th day (GD24) of gestation. The results showed obvious hemorrhage and hematoma on one side of the craniofacial region in 50 % of the thalidomide-treated embryos and obvious hemorrhage and hematoma on both sides of the craniofacial region in 50 % of the thalidomide-treated embryos at GD16. Histological examination showed soft tissues and mandible defects on the affected side of the maxillofacial region. The expression of Vegf-α, Ki67 and Sox9 on the affected side was significantly down-regulated in comparison to their expression on the unaffected side at GD20. There was also an obvious defect in the affected mandible, and the density of the skull and mandible was decreased compared to the unaffected side or the control group at GD24. These findings demonstrated that thalidomide may lead to hemorrhage and hematoma in the craniofacial region by inhibiting angiogenesis, resulting in the abnormal development of cranial neural crest cells that are involved in the normal development of the mandible in rabbits.

A mandibular bone defect of uncertain significance: report of a paleopathological case

Anatomical variations of the mandibular canal as well as the presence of accessory canals and foramina are common findings in the human mandible. Here, we present a previously unreported type of anatomical variation, consisting of a large full-thickness bone defect of the right mandibular ramus, observed in a young male unearthed from a mediaeval cemetery located in North-Eastern Italy. The defect was located very close to, yet not directly connected with, the mandibular canal. Awareness of the existence of deviations from the anatomical norm such as that we describe here is strategic to avoid diagnostic misinterpretations, minimise technical hitches, and prevent clinical complications during invasive procedures in the region of the mandible.

A rare anatomic variation: Triple mental foramina

Multiple mental foramina (MF) are rarely found in the human mandible. We report on the case, as documented using cone beam computed tomography (CBCT), of the triple MF that were identified on the right hemimandible of a 28-year-old female patient. The distal foramen was located on the mandible between the apices of the second premolar root and the first molar mesiovestibular root, being reached by a thin canal that left the mandibular canal. A pair of mesial foramina were identified between the apices of the premolar teeth. Thus, the three foramina corresponded to a surface area of 23.49mm² of the mandible. On the opposite side, a single mental foramen had a surface area of just 13.25mm². On each side, retromolar canals that opened into the retromolar fossae were also found. The anatomic possibility of multiple MF increases the surface area at risk during surgical procedures, increases the risk of neurovascular damage and obscures the common tooth-related location of the mental foramen. Practitioners should, therefore, consider a personalised and imaging-documented approach so as to avoid treatment failure.

Evaluation of changes in the upper airway after Twin Block treatment in patients with Class II malocclusion

The purpose of this prospective case control study is to describe in growing patients with mandibular hypoplasia, treatment outcomes following functional therapy in terms of volumetric changes in nasopharynx and oropharynx, that is, upper and lower pharynx. We recruited 60 study participants aged between 8 and 12 years having mandibular Class II malocclusion and a reduced upper airway (UA) size, as determined by McNamara cephalometric analyses. Forty patients received Twin Block treatment, whereas the remaining 20 patients did not receive treatment, thus constituting the control group. The control group included patients who did not start treatment after their first visit but returned for a consultation one or 2 years later. All patients underwent an initial teleradiography examination of the skull and a final teleradiography examination to measure changes using McNamara cephalometric analysis of the UA. Pretreatment and posttreatment changes were assessed using Student's t test for independent samples with a significance level of 0.05. Both anatomical structures analyzed-the upper pharynx (nasopharynx) and lower pharynx (oropharynx)-showed significant increases after treatment regardless of whether the patients were boys or girls. The controls showed a decrease in UA size on average after approximately 2 years of growth. A clear relationship exists between the mandibular advancement achieved with TB treatment and an increased UA size. Therefore, the appliance is considered suitable for improving the respiratory quality of growing patients with a decreased UA size.

Analysis of Cause of Endodontic Failure of C-Shaped Root Canals

The purpose of this study was to analyze various characteristics and classification of C-shaped root canals and evaluate the causes of endodontic failure of C-shaped root canals by examining the resected root surface with an endodontic microscope and a scanning electron microscope (SEM). Forty-two teeth with C-shaped root canals were included in this study and had undergone intentional replantation surgery. Before surgery, periapical radiography and cone-beam computed tomography were taken. The root canal configuration was analyzed and classified according to Melton's classification at coronal and apical level. After injection of 1 : 100,000 epinephrine with 2% lidocaine, the tooth was carefully extracted. After the root-end resection, the resected root surface was examined using an operating microscope and SEM. Mandibular second molars were most frequently involved teeth (90.4%). The most frequently observed root canal configurations were C1 at the coronal level (45.2%) and C3 at the apical 3 mm level (45.2%). The most common cause of failure for a C-shaped root canal treatment was a leaky canal (45.2%), followed by an isthmus (23.8%), missing canal, overfilling, and iatrogenic problems. In conclusion, C-shaped root canals were most frequently found in mandibular second molars. The most common cause of failure was a leaky canal and isthmus.

Chronic exposure to diclofenac induces delayed mandibular defects in medaka (Oryzias latipes) in a sex-dependent manner

Diclofenac is widely distributed in freshwater environments. To support a robust aquatic risk assessment, medaka (Oryzias latipes) were exposed to diclofenac at sublethal concentrations of 0.608, 2.15, 7.29, 26.5, and 94.8 μg/L (as mean measured concentrations) from fertilized eggs to 90-day posthatch. Except for the induction of mandibular defects, no deleterious effects were observed on hatching success and time to hatching at the embryonic stage, or on posthatch mortality, growth in hatched larvae and juveniles, and no abnormal behavior was observed. After 40-day posthatch, mandibular defects in the fish were observed at a concentration of 7.29 μg/L and above. Cumulatively, a morphological examination showed that 4% of the fish in the 7.29 μg/L treatment, 20% in the 26.5 μg/L treatment, and 38% in the 94.8 μg/L treatment exhibited mandibular defects, and the sex ratio of fish with mandibular defects was skewed toward males. These results suggest that diclofenac affects bone remodeling in the lower jaw of medaka after puberty in a sex-dependent manner. The lowest observed-effect concentration and no observed-effect concentration of diclofenac for mandibular dysmorphism through the partial life cycle exposure of the medaka were 26.5 and 7.29 μg/L, respectively.

A New Approach to Maxillary Protrusion with an Unstable Mandibular Position Accompanied with Unidentified Complaints: Case Report

This case report describes the importance of combining morphological and functional examination with psychological examination in the establishment ofstable mandibular position in the treatment of maxillary protrusion with unstable mandibular position accompanied by unidentified complaints, which ensures safe orthodontic treatment.

Mandibular asymmetries and associated factors in orthodontic and orthognathic surgery patients

OBJECTIVES

To estimate the prevalence of mandibular asymmetries in orthodontic and orthognathic surgery patients and to investigate demographic and skeletal factors associated with this disharmony.

MATERIALS AND METHODS

Cone-beam computed tomography images of 1178 individuals aged 19 through 60 years with complete dentitions were analyzed. Outcomes were classified as relative mandibular symmetry, moderate asymmetry, and severe asymmetry. Factors recorded included sex, age, side of mandibular deviation, sagittal jaw relationship, vertical skeletal pattern, angle of the cranial base, and maxillary asymmetry. Ordinal logistic regression was used to estimate simple and adjusted odds ratios (OR) for the individuals with moderate and severe mandibular asymmetry, as well as 95% confidence intervals.

RESULTS

Prevalence values of 55.2%, 27.2%, and 17.6% were observed for relative mandibular symmetry, moderate asymmetry, and severe asymmetry, respectively. An independent association with the side of mandibular deviation and the presence of maxillary asymmetry was observed, both for subjects with moderate mandibular asymmetry (left side: OR = 1.50; 95% CI: 1.01-2.24 / maxillary asymmetry: OR = 2.07; 95% CI: 1.11-3.76) and for those with severe asymmetry (left side: OR = 2.09; 95% CI: 1.27-3.44 / maxillary asymmetry: OR = 4.93; 95% CI: 2.64-9.20).

CONCLUSIONS

Moderate and severe mandibular asymmetries were present in 44.8% of the sample, being associated with the side of mandibular deviation and with maxillary asymmetry.

[Evaluation of dental and craniofacial characteristics in patients with mild skeletal facial asymmetry]

PURPOSE

The purpose of this study was to investigate the dental and craniofacial morphological characteristics in patients with mild skeletal facial asymmetry, and to investigate the relationship between mild skeletal facial asymmetry and dental anomalies.

METHODS

Thirty patients with mild skeletal facial asymmetry (experimental group) and 30 patients with normal faces (control group) were selected. All patients were scanned by cone-beam computed tomography (CBCT) and X-ray machine, Winceph software was used to measure the posteroanterior cephalometric radiographs, NNT software was used to measure the CBCT data. The results were analyzed by Chi-square test, paired t test and independent sample t test using SPSS 19.0 software package.

RESULTS

There were significant differences between the left and right sides of faces, teeth and alveolar bone of the first molar in the experimental group. The angle of mandibular dental midline and facial midline, the inclination of the frontal mandibular plane, the inclination of the first molar, the inclination of alveolar bone of the mandibular first molar, the width of alveolar bone of the mandibular first molar showed significant differences between the experimental group and the control group (P<0.05). There are some correlations among menton deviation, inclination of the first molar and alveolar bone of the first molar.

CONCLUSIONS

Patients with mild skeletal facial asymmetry showed some specific skeletal and dental characteristics. There could be some correlations between these features．.

Engineering of Neuron Growth and Enhancing Cell-Chip Communication via Mixed SAMs

The interface between cells and inorganic surfaces represents one of the key elements for bioelectronics experiments and applications ranging from cell cultures and bioelectronics devices to medical implants. In the present paper, we describe a way to tailor the biocompatibility of substrates in terms of cell growth and to significantly improve cell-chip communication, and we also demonstrate the reusability of the substrates for cell experiments. All these improvements are achieved by coating the substrates or chips with a self-assembled monolayer (SAM) consisting of a mixture of organic molecules, (3-aminopropyl)-triethoxysilane and (3-glycidyloxypropyl)-trimethoxysilane. By varying the ratio of these molecules, we are able to tune the cell density and live/dead ratios of rat cortical neurons cultured directly on the mixed SAM as well as neurons cultured on protein-coated SAMs. Furthermore, the use of the SAM leads to a significant improvement in cell-chip communications. Action potential signals of up to 9.4 ± 0.6 mV (signal-to-noise ratio up to 47) are obtained for HL-1 cells on microelectrode arrays. Finally, we demonstrate that the SAMs facilitate a reusability of the samples for all cell experiments with little re-processing.

Definitive diagnosis of mandibular hypoplasia, deafness, progeroid features and lipodystrophy (MDPL) syndrome caused by a recurrent de novo mutation in the POLD1 gene

Segmental progeroid syndromes with lipodystrophy are extremely rare, heterogeneous, and complex multi-system disorders that are characterized by phenotypic features of premature aging affecting various tissues and organs. In this study, we present a "sporadic/isolated" Japanese woman who was ultimately diagnosed with mandibular hypoplasia, deafness, progeroid features, and progressive lipodystrophy (MDPL) syndrome (MIM #615381) using whole exome sequencing analysis. She had been suspected as having atypical Werner syndrome and/or progeroid syndrome based on observations spanning a 30-year period; however, repeated genetic testing by Sanger sequencing did not identify any causative mutation related to various subtypes of congenital partial lipodystrophy (CPLD) and/or mandibular dysplasia with lipodystrophy (MAD). Recently, MDPL syndrome has been described as a new entity showing progressive lipodystrophy. Furthermore, polymerase delta 1 (POLD1) gene mutations on chromosome 19 have been identified in patients with MDPL syndrome. To date, 21 cases with POLD1-related MDPL syndrome have been reported worldwide, albeit almost entirely of European origin. Here, we identified a de novo mutation in exon 15 (p.Ser605del) of the POLD1 gene in a Japanese case by whole exome sequencing. To the best of our knowledge, this is the first identified case of MDPL syndrome in Japan. Our results provide further evidence that mutations in POLD1 are responsible for MDPL syndrome and serve as a common genetic determinant across different ethnicities.

Syngnathia-Congenital Maxillomandibular fusion: Case Report and Literature Review

Congenital maxillomandibular fusion is a rare disorder of the craniofacial region. Maintenance of the airway and difficulty in feeding are the main concerns for such patients. We performed a PubMed search to identify reported cases of syngnathia. With reference to the site of fusion and corresponding anomalies, the available studies were reviewed. The maxillomandibular fusion can be anterior fusion, unilateral or bilateral fusion, and complete fusion. The condition can be an isolated problem or associated with a syndrome. The condition requires immediate attention because it can be fatal. A case of isolated unilateral syngnathia, with the detailed review of the published data, is reported.

Reconstruction of Mandibular Contour Using Individualized High-Density Porous Polyethylene (Medpor®) Implants Under the Guidance of Virtual Surgical Planning and 3D-Printed Surgical Templates

BACKGROUND

The mandibular contour plays a significant role in the beautiful and youthful look but the reconstruction remains a challenging problem. The objective of this study was to evaluate the use of individualized high-density porous polyethylene (Medpor^®) implants for comprehensive reconstruction of mandibular contour with the aid of computer-aided design/computer-aided manufacturing (CAD/CAM).

METHODS

From 2010 to 2014, 12 patients with mandibular contour deformities were enrolled in our retrospective study. Mandible models and individualized surgical templates were fabricated by three-dimensional (3D) printing and Medpor^® implants were made according to the surgical templates. The Medpor^® implants were used for both unilateral and bilateral mandibular contour deformities. In four cases, simultaneous mandibular orthognathic surgery was performed with unilateral mandibular contour reconstruction.

RESULTS

Eleven patients had a reposeful postoperative recovery with no complication. Delayed infection was shown in one patient and the Medpor^® implant was removed. All the 11 patients had the mandibular contour reconstructed satisfactorily.

CONCLUSION

The technique and cases presented demonstrate the utility of Medpor^® implants with CAD/CAM in comprehensive mandibular contour reconstruction.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

[Bifid mandibular canal]

The article describes three types of bifurcations of the mandibular canal that were identified as accidental findings in cone-beam computed tomograms of the maxillofacial area of patients subjected to dental treatment. Bifid mandibular canal types are illustraded with clinical cases.

[Influence of distal misalignment of the mandible on the development of postural pathology]

The aim of this study was to study the relationship between the distal displacement of the mandible in the temporomandibular joint (TMJ) with postural pathology. We examined 20 people from the control group (age 18-25 years) and 70 patients of the same age with temporomandibular joint dysfunction (TMJD) complicated by dentoalveolar anomalies (distal bite - 27 persons, orthognathic with anomalies of the position of individual teeth - 18, deep - 16, mesial - 4, straight - 2, open - 2, cross - 1), before and after treatment with occlusive tires. Cone beam computer tomography (CBCT) of the TMJ and photometric analysis were made to all those examined. The CBCT analysis was carried out according to the method developed by us, photometric analysis - with the help of the computer program developed by us. Thus, as a result of the study in patients with TMJD complicated by dentoalveolar anomalies were detected significant displacement of the mandible backwards and upwards, as well as according to the photometric analysis of the presence of postural disorders both in the frontal plane (the change of the head position relative to the shoulders and horizontally, impaired facial configuration in the form of an asymmetry of the arrangement of the lines of the eyes, the corners of the mouth and shoulders) and in the sagittal (the forward displacement of the head and the inclination of the vertical axis of the body forward). Treatment of patients with occlusive tires allowed to normalize the position of the lower jaw and posture.

Early Craniofacial Morphology and Growth in Children with Bilateral Complete Cleft Lip and Palate

Purpose

Analysis of craniofacial morphology and growth in children with bilateral complete cleft lip and palate (BCCLP), compared with a control group with unilateral incomplete cleft lip (UICL), before any treatment as well as 20 months after lip closure.

Material

The children were drawn from a group representing all Danish children with cleft born 1976 to 1981. Sixty-four children were included in the study (19 BCCLP and 45 UICL). The ages were 2 and 22 months at examinations 1 and 2, respectively.

Method

The method of investigation was infant cephalometry in three projections. The craniofacial morphology was analyzed using linear, angular, and area variables. Growth was defined as the displacement vector from the coordinate of the corresponding landmark in the x-ray at examination 1 to its coordinate at examination 2, corrected for x-ray magnification. The growth of an anatomical region in a patient was assessed by investigating the growth pattern formed by a collection of individual growth vectors in that region.

Results

The BCCLP group differed significantly from the UICL group. The most striking findings in BCCLP were an extremely protruding premaxilla; markedly increased posterior maxillary width; increased width of the nasal cavity; short maxilla with reduced posterior height; short mandible; bimaxillary retrognathia; severe reduction in the size of the pharyngeal airway; and a more vertical facial growth pattern.

Conclusion

Our findings indicate that a facial type including a wide and posterior short maxilla, short mandible, and bimaxillary retrognathia might be a liability factor that increases the probability of developing cleft lip and palate.

A Case of Unilateral Coronal Synostosis in a Child with Craniofacial Microsomia

Craniofacial microsomia is a congenital malformation complex associated with a wide array of craniofacial and extracraniofacial anomalies. Frontal plagiocephaly has been shown to occur in approximately 5% to 12% of patients with craniofacial microsomia. The etiology of craniofacial microsomia–associated frontal plagiocephaly is unclear; of the cases described in the literature, all but one had physical findings suggestive of deformational plagiocephaly. In the case with equivocal physical findings, radiographic studies showed no evidence of craniosynostosis. Unlike the above cases, we report a documented case of radiologically-confirmed unilateral coronal synostosis in a child with craniofacial microsomia.

Mandibular Widening by Distraction Osteogenesis in the Treatment of a Constricted Mandible and Telescopic Bite

Objective

Documentation of the application of mandibular widening by distraction osteogenesis and orthodontics.

Patients

Three patients with telescopic bite resulting from an extremely constricted mandible related to hypoglossia-hypodactyly syndrome.

Intervention

Mandibular widening by distraction osteogenesis using an extraoral device and subsequent orthodontic treatment.

Results

The extremely constricted mandible and telescopic bite were dramatically improved by mandibular widening using distraction osteogenesis and subsequent orthodontics. Two of the three patients had transient complications; one reported temporomandibular joint pain and the other showed evidence of periodontal damage.

Conclusion

Mandibular widening by distraction osteogenesis is an effective technique for the treatment of telescopic bite resulting from an extremely constricted mandible.

A Suspected Case of Abruzzo-Erickson Syndrome

The features of Abruzzo-Erickson syndrome are described. A case report of an adult female suspected to have this condition is described and illustrated. The possible link to Abruzzo-Erickson syndrome and differential diagnosis of CHARGE is discussed.

The effects of surgically assisted rapid maxillary expansion (SARME) on the dental show and chin projection

OBJECTIVE

To quantify the postoperative changes of the dental show and chin projection following SARME using 3D CBCT imaging.

MATERIAL AND METHODS

78 patients with transversal maxillary hypoplasia and mandibular hypoplasia who underwent SARME were enrolled into the study. A cone beam computed tomography (CBCT) scan was acquired preoperatively and at least 1 year postoperatively. 3D postoperative changes in the dental show and pogonion position were measured based on soft tissue and hard tissue landmarks.

RESULTS

68 patients (87%) exhibited a postoperative increase in the dental show. The dental show was increased by a mean of 2.2 ± 2.0 mm (p < 0.01). The mean horizontal and vertical displacement of the chin (pogonion) following SARME was 1.6 ± 2.5 mm posteriorly and 1.6 ± 2.0 mm inferiorly (p < 0.01). An inferior displacement of the maxilla and maxillary tooth as well as a consequent clockwise pitch of the mandible seemed to play a role in inducing these postoperative changes.

CONCLUSION

An increase in dental show and a posterior and inferior displacement of the chin should be considered prior to SARME to prevent undesirable postoperative changes of the facial esthetics.

Comparison of Cephalometric Hard and Soft Tissues of Adolescents with Angle Class II Division 1 Malocclusion between Northern Chinese Population and Northern Indian Population

OBJECTIVE

To determine if there was a difference in hard and soft tissue between northern Chinese and northern Indian adolescents with Angle Class II division 1 malocclusion.

METHOD

A total of 40 Angle Class II division 1 patients, including 20 boys and 20 girls aged 10 to 13 years with no prior treatment, were selected from northern China and northern India, respectively. Overall, 80 cephalometric data were analysed based on two-sample t-test with SPSS software.

RESULTS

The Chinese subjects had larger anterior facial height and mandibular plane angle. Analysis of dentoalveolar complex showed that the Chinese subjects had more proclined incisors, protruding upper lips and more upper posterior tooth height than that of the Indian subjects. The length of the maxilla and mandible was larger in the Indian subjects than that of the Chinese subjects, but the length of mandible was not significantly different between the two groups.

CONCLUSION

Compared with the Indian subjects, the Chinese subjects with Class II division 1 malocclusion had less prognathic maxillas, more protruding lips, steeper mandibular plane angles and more proclined maxillary incisors. Within the same gender, the Indian boys had more protruded faces and Indian girls had more protruded maxillas, steeper mandibular plane angles and fuller lips.