Surgical correction of neonatal obstructive sleep apnea due to a temporomandibular joint ankylosis

In growing children, temporomandibular joint (TMJ) ankylosis and septic arthritis are uncommon. Retrognathia and micrognathia affect airway patency and can cause obstructive sleep apnea (OSA). No unified diagnostic criteria have been established for the management of this pathology. We describe the first case of treatment for pediatric TMJ ankylosis and severe OSA due to neonatal group B streptococcal septic TMJ arthritis. Untreated pathological changes in the TMJ will eventually lead to ankylosis. Among children, this will include facial growth disturbances leading to mandibular retrognathia, reduction in the oropharyngeal spaces, and OSA. Our patient had severe OSA with an apnea-hypopnea index of 24.9 events/h and oxygen saturation nadir of 73% as measured by polysomnography. She was treated successfully according to Andrade protocol. This is the first report of pediatric OSA due to TMJ ankylosis following neonatal group B streptococcal septic arthritis.

CITATION

Pesis M, Goldbart A, Givol N. Surgical correction of neonatal obstructive sleep apnea due to a temporomandibular joint ankylosis. J Clin Sleep Med. 2024;20(1):173-179.

Association between ARID2 and RAS-MAPK pathway in intellectual disability and short stature

BACKGROUND

ARID2 belongs to the Switch/sucrose non-fermenting complex, in which the genetic defects have been found in patients with dysmorphism, short stature and intellectual disability (ID). As the phenotypes of patients with ARID2 mutations partially overlap with those of RASopathy, this study evaluated the biochemical association between ARID2 and RAS-MAPK pathway.

METHODS

The phenotypes of 22 patients with either an ARID2 heterozygous mutation or haploinsufficiency were reviewed. Comprehensive molecular analyses were performed using somatic and induced pluripotent stem cells (iPSCs) of a patient with ARID2 haploinsufficiency as well as using the mouse model of Arid2 haploinsufficiency by CRISPR/Cas9 gene editing.

RESULTS

The phenotypic characteristics of ARID2 deficiency include RASopathy, Coffin-Lowy syndrome or Coffin-Siris syndrome or undefined syndromic ID. Transient ARID2 knockout HeLa cells using an shRNA increased ERK1 and ERK2 phosphorylation. Impaired neuronal differentiation with enhanced RAS-MAPK activity was observed in patient-iPSCs. In addition, Arid2 haploinsufficient mice exhibited reduced body size and learning/memory deficit. ARID2 haploinsufficiency was associated with reduced IFITM1 expression, which interacts with caveolin-1 (CAV-1) and inhibits ERK activation.

DISCUSSION

ARID2 haploinsufficiency is associated with enhanced RAS-MAPK activity, leading to reduced IFITM1 and CAV-1 expression, thereby increasing ERK activity. This altered interaction might lead to abnormal neuronal development and a short stature.

Tissue-specific analysis of Fgf18 gene function in palate development

BACKGROUND

Previous studies showed that mice lacking Fgf18 function had cleft palate defects and that the FGF18 locus was associated with cleft lip and palate in humans, but what specific roles Fgf18 plays during palatogenesis are unclear.

RESULTS

We show that Fgf18 exhibits regionally restricted expression in developing palatal shelves, mandible, and tongue, during palatal outgrowth and fusion in mouse embryos. Tissue-specific inactivation of Fgf18 throughout neural crest-derived craniofacial mesenchyme caused shortened mandible and reduction in ossification of the frontal, nasal, and anterior cranial base skeletal elements in Fgf18c/c ;Wnt1-Cre mutant mice. About 64% of Fgf18c/c ;Wnt1-Cre mice exhibited cleft palate. Whereas palatal shelf elevation was impaired in many Fgf18c/c ;Wnt1-Cre embryos, no significant difference in palatal cell proliferation was detected between Fgf18c/c ;Wnt1-Cre embryos and their control littermates. Embryonic maxillary explants from Fgf18c/c ;Wnt1-Cre embryos showed successful palatal shelf elevation and fusion in organ culture similar to the maxillary explants from control embryos. Furthermore, tissue-specific inactivation of Fgf18 in the early palatal mesenchyme did not cause cleft palate.

CONCLUSION

These results demonstrate a critical role for Fgf18 expression in the neural crest-derived mesenchyme for the development of the mandible and multiple craniofacial bones but Fgf18 expression in the palatal mesenchyme is dispensable for palatogenesis.

First Korean Case of Coffin-Siris Syndrome with a Novel Frameshift ARID1B Mutation

Coffin-Siris Syndrome (CSS) is a rare neurodevelopmental disorder characterized by intellectual disability, coarse facial features, hypoplastic digits/nails, and hypertrichosis. The genes causative of CSS mainly encode the SWI/SNF complex, which contributes to chromatin remodeling and regulates the access of transcriptional factors to specific gene sites. While ARID1B mutations account for a third of all CSS cases, the condition's phenotypic features vary widely. We document the case of a girl with CSS who presented with a variant facial appearance, global developmental delay with speech impairment, agenesis of the corpus callosum, funnel chest, and bilateral renal stones without hypertrichosis or hypoplasia of the fifth fingernail. Genetic analysis revealed that the patient had a novel heterozygous frameshift mutation c.2201dupG (p.Ser736Ilefs*27) on the ARID1B gene.

Tongue Abnormalities Are Associated to a Maternal Folic Acid Deficient Diet in Mice

It is widely accepted that maternal folic acid (FA) deficiency during pregnancy is a risk factor for abnormal development. The tongue, with multiple genes working together in a coordinated cascade in time and place, has emerged as a target organ for testing the effect of FA during development. A FA-deficient (FAD) diet was administered to eight-week-old C57/BL/6J mouse females for 2–16 weeks. Pregnant dams were sacrificed at gestational day 17 (E17). The tongues and heads of 15 control and 210 experimental fetuses were studied. In the tongues, the maximum width, base width, height and area were compared with width, height and area of the head. All measurements decreased from 10% to 38% with increasing number of weeks on maternal FAD diet. Decreased head and tongue areas showed a harmonic reduction (Spearman nonparametric correlation, Rho = 0.802) with respect to weeks on a maternal FAD diet. Tongue congenital abnormalities showed a 10.9% prevalence, divided in aglossia (3.3%) and microglossia (7.6%), always accompanied by agnathia (5.6%) or micrognathia (5.2%). This is the first time that tongue alterations have been related experimentally to maternal FAD diet in mice. We propose that the tongue should be included in the list of FA-sensitive birth defect organs due to its relevance in several key food and nutrition processes.

Morphological Evaluation of Changes in Velopharyngeal Function following Maxillary Distraction in Patients with Repaired Cleft Palate during Mixed Dentition

Objective

To describe the morphological changes of nasopharyngeal components after maxillary distraction and clarify whether the morphological characteristics are related to velopharyngeal function (VPF).

Design

Perceptual judgments of hypernasality and nasendoscopy were performed before and after treatment. Lateral cephalograms were obtained to describe the morphological changes.

Setting

Department of Oral and Maxillofacial Surgery, Miyazaki Medical College, Miyazaki, Japan.

Participants

Nine patients with repaired cleft palate in the mixed dentition stage underwent maxillary distraction using a face mask and an intraoral fixed appliance system.

Outcome Measures

The severity of hypernasality, velopharyngeal insufficiency, and measurements such as pharyngeal depth, velar length, and the rotation of the palatal plane were evaluated.

Results

Increase in pharyngeal depth was not always proportional to the amount of advancement. It depended on the posture of the posterior pharyngeal wall and the rotation of palatal plane.

Conclusion

Cephalometric measurements of the nasopharynx before and after surgery confirmed subsequent changes in VPF. These were suggested to be useful in predicting future VPF. When performing maxillary distraction in patients with cleft palate in the mixed dentition stage, and when velopharyngeal closure is found to occur by velar contact against the hypertrophied adenoid, patients should be counseled about risks of subsequent deterioration in their speech before surgery.

Management of the Impaired Adult Cleft Patient: The Last Chance

Objective

Unfortunately, not all patients receive the benefits of a well-trained, experienced, multidisciplinary cleft team, and a significant number of patients reach adulthood with severe neglected cleft related problems. The vast majority of this group have made their way through several surgical procedures, usually performed by different surgeons in different centers, and still carry the original cleft stigmata aggravated by variable degrees of maxillary hypoplasia, fistulae, scarring, muscle pull, soft tissue tension, lost teeth, dental adaptation, and instability of bony fragments. Adult patients who reach this stage with their original deformities have, in most instances, lost their best opportunity to be properly treated. With this assumption in mind, an aggressive surgical plan focused mainly on the deformities that can objectively achieve functional and aesthetical improvement should be individualized for each patient. In this article, experience with 38 consecutive adult patients with cleft managed following a two-stage protocol used at our cleft clinic for the last 4 years is presented.

Conclusion

An algorithm to help definitively solve these deformities is suggested.

Dual Segmental Distraction Osteogenesis of the Midface in a Patient with Apert Syndrome

Objective

To present orthodontic treatment combined with dual segmental distraction osteogenesis in a patient with Apert syndrome.

Patient

A 15-year-old boy exhibited severe midfacial hypoplasia with retruded and hypoplastic maxilla and anterior open bite. The patient was treated with a rigid external distraction II system for distraction osteogenesis, a preadjusted edgewise appliance, and a modified maxillary protraction headgear. The concave profile with midfacial hypoplasia was improved. A tight occlusal relationship between maxillary and mandibular teeth was achieved. Postoperative treatment results have been stable for 1 year.

Genotype-phenotype correlation of Coffin-Siris syndrome caused by mutations in SMARCB1, SMARCA4, SMARCE1, and ARID1A

Coffin-Siris syndrome (CSS) is a rare congenital malformation syndrome, recently found to be caused by mutations in several genes encoding components of the BAF complex. To date, 109 patients have been reported with their mutations: SMARCB1 (12%), SMARCA4 (11%), SMARCE1 (2%), ARID1A (7%), ARID1B (65%), and PHF6 (2%). We review genotype-phenotype correlation of all previously reported patients with mutations in SMARCB1, SMARCA4, SMARCE1, and ARID1A through reassessment of their clinical and molecular findings. Cardinal features of CSS included variable degrees of intellectual disability (ID) predominantly affecting speech, sucking/feeding difficulty, and craniofacial (thick eyebrows, long eyelashes), digital (hypoplastic 5th fingers or toes, hypoplastic 5th fingernails or toenails), and other characteristics (hypertrichosis). In addition, patients with SMARCB1 mutations had severe neurodevelopmental deficits including severe ID, seizures, CNS structural abnormalities, and no expressive words as well as scoliosis. Especially, those with a recurrent mutation "p.Lys364del" represented strikingly similar phenotypes including characteristic facial coarseness. Patients with SMARCA4 mutations had less coarse craniofacial appearances and behavioral abnormalities. Patients with SMARCE1 mutations had a wide spectrum of manifestations from severe to moderate ID. Patients with ARID1A also had a wide spectrum of manifestations from severe ID and serous internal complications that could result in early death to mild ID. Mutations in SMARCB1, SMARCA4, and SMARCE1 are expected to exert dominant-negative or gain-of-function effects, whereas those in ARID1A are expected to exert loss-of-function effects.

Clinical features, diagnostic criteria, and management of Coffin-Siris syndrome

Coffin-Siris syndrome (OMIM#135900) is a multiple congenital anomaly syndrome classically characterized by hypo- or aplasia of the fifth digit nails or phalanges, as well as coarse facial features, sparse scalp hair, and moderate to severe cognitive and/or developmental delay. The recent identification of molecular etiologies has served to effectively characterize a large set of patients who have been described with Coffin-Siris between the time of its initial description and the present. However, despite recent advances, a number of patients who traditionally fit the diagnosis have yet to have identified causes. This could be due to patients who lie outside the defined phenotype, or alternatively, to additional as yet unidentified genes which may play roles. Here we outline the range of clinical features described in the broader diagnostic category, review the continuing phenotypic challenges and note those subsets of patients for whom molecular causes have yet to be clarified. Finally, we discuss recommendations for clinical management of these individuals.

The ARID1B phenotype: what we have learned so far

Evidence is now accumulating from a number of sequencing studies that ARID1B not only appears to be one of the most frequently mutated intellectual disability (ID) genes, but that the range of phenotypes caused by ARID1B mutations seems to be extremely wide. Thus, it is one of the most interesting ID genes identified so far in the exome sequencing era. In this article, we review the literature surrounding ARID1B and attempt to delineate the ARID1B phenotype. The vast majority of published ARID1B patients have been ascertained through studies of Coffin-Siris syndrome (CSS), which leads to bias when documenting the frequencies of phenotypic features. Additional observations of those individuals ascertained through exome sequencing studies helps in delineation of the broader clinical phenotype. We are currently establishing an ARID1B consortium, aimed at collecting ARID1B patients identified through genome-wide sequencing strategies. We hope that this endeavor will eventually lead to a more comprehensive view of the ARID1B phenotype.

Coffin-Siris syndrome and related disorders involving components of the BAF (mSWI/SNF) complex: historical review and recent advances using next generation sequencing

This issue of Seminars in Medical Genetics, American Journal of Medical Genetics Part C investigates the human diseases caused by mutations in the BAF complex (also known as the mammalian SWI/SNF complex) genes, particularly focusing on Coffin-Siris syndrome (CSS). CSS is a rare congenital malformation syndrome characterized by developmental delay or intellectual disability (ID), coarse facial appearance, feeding difficulties, frequent infections, and hypoplasia/aplasia of the fifth fingernails and fifth distal phalanges. In 2012, 42 years after the first description of CSS in 1970, five causative genes (SMARCB1, SMARCE1, SMARCA4, ARID1A, ARID1B), all encoding components of the BAF complex, were identified as being responsible for CSS through whole exome sequencing and pathway-based genetic screening. The identification of two additional causative genes (PHF6, SOX11) followed. Mutations in another BAF complex gene (SMARCA2) and (TBC1D24) were found to cause clinically similar conditions with ID, Nicolaides-Baraitser syndrome and DOORS syndrome, respectively. Also, ADNP was found to be mutated in an autism/ID syndrome. Furthermore, there is growing evidences for germline or somatic mutations in the BAF complex genes to be causal for cancer/cancer predisposition syndromes. These discoveries have highlighted the role of the BAF complex in the human development and cancer formation. The biology of BAF is very complicated and much remains unknown. Ongoing research is required to reveal the whole picture of the BAF complex in human development, and will lead to the development of new targeted therapies for related disorders in the future.

Females with de novo aberrations in PHF6: clinical overlap of Borjeson-Forssman-Lehmann with Coffin-Siris syndrome

Recently, de novo aberrations in PHF6 were identified in females with intellectual disability and with a distinct phenotype including a characteristic facial gestalt with bitemporal narrowing, prominent supraorbital ridges, synophrys, a short nose and dental anomalies, tapering fingers with brachytelephalangy, clinodactyly and hypoplastic nails, short toes with hypoplastic nails, and linear skin hyperpigmentation. In adolescent or older patients, this phenotype overlaps but is not identical with Borjeson-Forssman-Lehmann syndrome in males, caused by X-linked recessive mutations in PHF6. In younger girls there seems to be a striking phenotypic overlap with Coffin-Siris syndrome, which is characterized by intellectual disability, sparse hair and hypoplastic nails. This review will summarize and characterize the female phenotype caused by de novo aberrations in PHF6 and will discuss the overlapping and distinguishing features with Coffin-Siris syndrome.

Deficiency in origin licensing proteins impairs cilia formation: implications for the aetiology of Meier-Gorlin syndrome

Mutations in ORC1, ORC4, ORC6, CDT1, and CDC6, which encode proteins required for DNA replication origin licensing, cause Meier-Gorlin syndrome (MGS), a disorder conferring microcephaly, primordial dwarfism, underdeveloped ears, and skeletal abnormalities. Mutations in ATR, which also functions during replication, can cause Seckel syndrome, a clinically related disorder. These findings suggest that impaired DNA replication could underlie the developmental defects characteristic of these disorders. Here, we show that although origin licensing capacity is impaired in all patient cells with mutations in origin licensing component proteins, this does not correlate with the rate of progression through S phase. Thus, the replicative capacity in MGS patient cells does not correlate with clinical manifestation. However, ORC1-deficient cells from MGS patients and siRNA-mediated depletion of origin licensing proteins also have impaired centrosome and centriole copy number. As a novel and unexpected finding, we show that they also display a striking defect in the rate of formation of primary cilia. We demonstrate that this impacts sonic hedgehog signalling in ORC1-deficient primary fibroblasts. Additionally, reduced growth factor-dependent signaling via primary cilia affects the kinetics of cell cycle progression following cell cycle exit and re-entry, highlighting an unexpected mechanism whereby origin licensing components can influence cell cycle progression. Finally, using a cell-based model, we show that defects in cilia function impair chondroinduction. Our findings raise the possibility that a reduced efficiency in forming cilia could contribute to the clinical features of MGS, particularly the bone development abnormalities, and could provide a new dimension for considering developmental impacts of licensing deficiency.

[The treatment of mandibular micrognathia secondary to temporomandibular joint ankylosis with distraction osteogenesis]

OBJECTIVE

To evaluate the clinical effect of distraction osteogenesis for patients with mandibular micrognathia secondary to temporomandibular joint (TMJ) ankylosis.

METHODS

43 patients (aged from 2 to 61 years old) with mandibular micrognathia were treated with mandibular distraction osteogenesis. Two types of mechanical distraction were utilized in this study. Ten patients (age ranged from 2 to 16-years-old, mean age 7.6 years old) with severe micrognathia underwent bilateral mandibular distraction with rigid external distraction (RED) device. Other 33 patients were treated with unilateral(6 cases) or bilateral (27 cases) mandibular distraction using internal distraction device. Distraction was started on the 4th to 8th day after operation and distraction rate was 0.25 mm every time, four times a day. Distractor was removed after 3 to 6 months of consolidation period.

RESULTS

Eighty sides of mandible in 43 patients were lengthened. The mean distraction distance was 23.2 mm (ranged from 14 to 35 mm). After distraction, the average posterior airway space (PAS) was enlarged from 4.9 mm to 10.4 mm and average angle of sella-nasion-point B (SNB) was increased from 64.2 degrees to 74.5 degrees. The apnea hypopnea index (AHI) was decrease significantly. The profile was improved and OSA was improved effectively in each patient. No complication occurred during treatment. No persistent numbness of lower lip was observed. All patients were satisfied with the results. After a mean follow-up period of 20.3 months(5 to 103 months) , the result was stable and no obvious relapse of micrognathia was observed.

CONCLUSIONS

Distraction osteogenesis is an effective way in correction of mandibular micrognathia secondary to TMJ ankylosis. RED is a new method for treatment of children and adolescence with severe mandibular micrognathia. The procedure is simple and safe with stable result.

Severe rhizomelic chondrodysplasia punctata in a fetus due to maternal mixed connective tissue disorder

Maternal systemic lupus erythematosus and autoimmune diseases have been extremely rarely reported to cause rhizomelic chondrodysplasia punctata. We report on a fetus aborted spontaneously at 21 weeks of gestation due to complications of maternal mixed connective tissue disorder. The fetus had micrognathia, a depressed nasal bridge, flat nose, long philtrum, short columella and rhizomelia. Radiographic study showed stippling of carpal and tarsal bones, short humeri and coronal clefts in the vertebrae. Ossification centers were present at the lower end of the femora and upper end of the tibiae.

Transantral distraction devices in correction of severe maxillary deformity in cleft patients

Maxillary advancement by Le Fort I osteotomy in cleft patients has an average relapse of about 40-60 percent. With extraoral distraction devices it is possible to obtain an almost unlimited advancement of the upper jaw. Due to the social problems the retention period is normally reduced to some monthes. A relapse of 10-25 % can be seen in these cases. Le Fort I internal distraction osteogenesis offers an alternative to one-step orthognathic advancement, with advantages of gradual lengthening through scar and earlier treatment in growing patients. The objective of this study was to present our experience in the treatment of maxillary deficiency in cleft patients using transantral internal distraction devices. The distraction procedure was successfully accomplished in seventeen patients. For all the seventeen patients maxillary distraction device designed by Konrad Wangerin was used. The distraction distances were 8 to 24 mm. Preoperative, postoperative, and follow-up (12 and 24 months) lateral cephalogram measurements were compared including angular and linear changes. A good new bone was found that was formed in distraction pitch between lines of osteotomy. After distraction of median facial zone, occlusion and profile of soft tissues were considerably improved. All patients after postoperative time required final orthodontic treatment and their final occlusal relationships were satisfactory. The transantral distraction device is a new option for the treatment of severe maxillary hypoplasia in cleft patients.

Dental manifestations associated with Seckel syndrome type II: a case report

Seckel syndrome is a rare form of primordial dwarfism that is characterized by short stature, skeletal defects, mental retardation, and characteristic facial features such as microcephaly, micrognathia, and a bird-head appearance. Dental findings include hypodontia, enamel hypoplasia, crowding, and Class II malocclusion. The purpose of this paper was to report the case of a female patient with Seckel syndrome type II and describe her orodental manifestations. She presented with interesting dental findings, including gingival hyperplasia, recession and ulceration, significant crowding, and early exfoliation of the primary dentition with accelerated eruption of the permanent dentition. The patient received comprehensive dental care under general anesthesia, and hard and soft tissue samples were collected for histologic analysis. The patient was followed for over 3 years.

Distraction osteogenesis: role and clinical applications in the maxillofacial region

Distraction osteogenesis or callostasis is a technique of new bone formation by gradual separation of bony fragments. The method was first developed for limb lengthening but recently this process was widely applied to the cranio-maxillofacial bones. The application included unlimited bone lengthening and reconstruction of segmental defects. Several designs of extra-oral and intra-oral distraction devices were invented to suit different areas of craniofacial bone. Nevertheless intraoral distractors have several advantages including minimal scarring and being less cumbersome. Clinical cases using distraction osteogenesis as an alternative treatment to conventional surgical procedures for maxillo-mandibular lengthening and reconstruction of alveolar segmental defects after tumour resection before implant installation are presented and discussed.

Minimizing pin complications when using the rigid external distraction (RED) system for midface distraction

In this review we describe the advantages, complications, and preventive considerations encountered as a result of the use of a halo for distraction of a retrusive nasomaxillary complex. Distraction osteogenesis is a well accepted combined orthodontic-surgical technique used in the treatment of patients with hypoplastic craniofacial components. The rigid external distraction (RED) system is a useful external distraction device for the advancement of severe retrusive maxilla especially in cleft palate patients. However, the addition of this new technique to the surgeon's armamentarium is accompanied by new complications and risks. Review of the literature on complications of the use of halo revealed that most complications are pin related. Complications with the use of RED have mainly included the penetration of intracranial pins. Risk management and preventive considerations propose several procedures to minimize the side effects when using RED: preoperative skull computerized tomography, pediatric neurosurgical consultation, proper pin care during distraction, frequent monitoring of the patient's general condition, proper pin and torque design, and special attention to the removal process of the RED.

Early dental management of patients with Mobius syndrome

OBJECTIVE(S)

The aim of this study was to evaluate the orofacial manifestations in patients with Mobius syndrome (MS), establish an early adequate dental treatment and discuss the possible etiology of all cases examined based on information about the gestational intercurrences.

DESIGN

Prospective study.

SETTING

Special Care Dentistry Center, School of Dentistry, University of Sao Paulo, Brazil. Subject(s) and methods: Twenty-nine patients with MS aged 0 to 4 underwent prospective dental examination as well as early orthodontic treatment.

RESULTS

All patients presented micrognathia, lack of lip seal, high arched palate and weak soft palate. The use of orthopedic appliances was recommended to all 29 patients, but only 13 adhered to treatment and were monitored for at least 24 months. We observed that, after 24 months of treatment, the palate was expanded and micrognathia became less severe in the majority of the cases. Pregnancy-related complications were reported by 27 (97%) of the 29 mothers.

CONCLUSION(S)

The early use of orthopedic appliances was important to prevent malocclusion and glossoptosis. Attempted abortion with misoprostol is associated with an increased risk of MS in infants.

Advancement of maxillary anterior segment by distraction osteogenesis (DO): a case report

Distraction osteogenesis (DO) is a technique that leads to osseus generation and osteosynthesis by means of slow traction applied to the bone and the soft tissues. Distraction can be both unilateral and bilateral and can correct deficiencies on one, two or three different levels. Using a horizontal osteotomy and the application of a Mia Quad Helix we achieved the aims of the correction of the anterior segment of the maxillary arch, the bite closure and to obtain a class I molar and canine relationship. The final result can be considered acceptable both from the aesthetic and functional viewpoint. Although it is not the most common approach to solve the lack of maxillary projection, this procedure can be very useful in cases where the hypoplasia is due to the premature extractions of the upper cuspids.

[Distractios osteogenesis in maxillofacial surgery]

For more than one decade the extremity surgery already used distraction osteogenesis. This new therapy in the region of the maxillofacial surgery (in the case of malformation of the maxilla and mandible) was adapted from the extremity surgeons. The authors summarized and classified the methods and history of the osteodistraction surgery based on literature. The indication fields, the used protocols and the most common distractor types are listed. The authors emphasized the multidisciplinary feature of the therapies, underlined the leading role of the orthodontist. With presenting their own two mandible distraction case reports they introduced the practical use of the distractors while using intra- and extraoral devices. They also emphasized the difficulties and failure opportunities. Their aim was to make suggestions for the further development of this method in our country.

New fixation method for maxillary distraction osteogenesis using locking attachments

PURPOSE

The external traction hooks of the intraoral splint used in the rigid external distraction (RED) system for maxillary distraction osteogenesis interfere with the surgical procedures. The purpose of this study is to introduce an innovative splint fixation method for maxillary distraction osteogenesis with Locking Attachments and evaluate their advantages, such as reduction of operating time compared with the traditional intraoral splint method.

PATIENTS AND METHODS

Retrospective comparison of operative times of maxillary Le Fort I osteotomy procedures was carried out with the traditional protocol using the intraoral splint cemented to the maxillary dentition (n = 14), and a removable intraoral splint that is inserted postsurgically (n = 14). Operative procedure times were compared and analyzed statistically using the data extracted from the surgical records.

RESULTS

There were no complications inserting the removable splint postsurgically, including pain, discomfort, or time-consuming procedure. Stable and secure splint fixation was obtained before the distraction procedure and the desired treatment goals were obtained in all patients. The total operative procedure times were significantly reduced in the Locking Attachments group by 24% to 41% (approximately 65 minutes) compared with earlier operations involving the conventional splints (P < .05).

CONCLUSIONS

Maxillary distraction osteogenesis with the Locking Attachments is a highly effective fixation approach to manage severe hypoplastic maxilla, eliminating lip constraints resulting from scarring and allowing for easier, more deliberate and careful dissection. The use of the Locking Attachments is reliable in craniofacial surgery and has proved to be advantageous in the reduction of the operating time and surgical risks.

Mandibular morphology and growth with and without hypodontia in subjects with Pierre Robin sequence

INTRODUCTION

Mandibular micrognathia is the hallmark of Pierre Robin sequence (PRS). A high prevalence of mandibular hypodontia has been reported in subjects with PRS. The hypothesis of this study is that the morphology of the mandible in subjects with PRS and mandibular hypodontia is different from that in subjects with PRS but without mandibular hypodontia.

METHODS

The study was conducted at the craniofacial center of The Hospital for Sick Children in Toronto. The study sample comprised 16 caucasian children with nonsyndromic PRS (7 boys, 9 girls) with mandibular hypodontia and 18 white children with nonsyndromic PRS (6 boys, 12 girls) without hypodontia. Longitudinal lateral cephalograms were available before orthodontic treatment (T1; mean age, 11.7 years) and after orthodontic treatment but before orthognathic surgery (T2; mean age, 16.6 years). A new, customized cephalometric analysis with additional landmarks and measurements to study mandibular morphology was performed. Differences in measurements were studied by using analysis of variance adjusted for age and sex.

RESULTS

Cephalometric measurements were smaller in the group with mandibular hypodontia at T1: mandibular length (3.36 mm, P = .04), ramal length (2.78 mm, P = .04), posterior facial height (3.97 mm, P = .03), and mandibular molar eruption (1.96 mm, P = .02). At T2, the differences increased: mandibular length (4.56 mm, P = .02), ramal length (4.04 mm, P = .002), posterior facial height (5.98 mm, P = .001), and mandibular molar eruption (2.08 mm, P = .04). Comparison of growth increments between the 2 groups from T1 to T2 showed a greater cranial base deflection increment in the group with mandibular hypodontia (0.88 degrees, P = .02) and a larger posterior facial height increment in the group without mandibular hypodontia (2.02 mm, P = .04).

CONCLUSIONS

Children with nonsyndromic PRS with mandibular hypodontia had smaller mandibles than children with nonsyndromic PRS and normal complements of mandibular teeth. Their patterns of growth did not improve during adolescence, and the magnitude of differences increased.

Intraoral distraction osteogenesis for the correction of facial deformities following temporomandibular joint ankylosis: a modified technique

The aim of this study was to evaluate the feasibility of transoral bimaxillary distraction osteogenesis before releasing temporomandibular joint (TMJ) ankylosis using intraoral mandibular distractors. Nine patients (5 males, 4 females) aged 14-35 (mean 19) years were included. A bilateral Le Fort I osteotomy was performed together with a mandibular osteotomy on the affected side(s). An intraoral distractor(s) was inserted in the lower jaw, followed by an intermaxillary fixation (IMF) to maintain preoperative dental occlusion. The distractor was activated, after a latency period of 5-7 days, 2 times daily by 0.5 mm. There followed a consolidation period of 6-8 weeks. TMJ ankylosis was then released via a peri-auricular incision, a gap arthroplasty was performed, and mandibular movement was established after removal of the IMF and distractor. Optimal results were achieved clinically and radiologically with minimal relapse and complications. Apart from minor complaints, the distraction process was smooth and tolerable in all cases. Total mandibular elongation ranged from 17 to 25 mm (20.7 mm). Occlusal canting decreased to 0 degrees in 7 patients and to 1 degree in 2 patients (mean 0.2 degrees). After a mean follow-up period of 17 months, a mean postoperative mouth opening of 34.7 mm was achieved (0.6 mm preoperatively) and no re-ankylosis was detected. Intraoral distraction of a deformed mandible and maxilla before releasing TMJ ankylosis is a feasible and perhaps advantageous technique.

Report of ankylosis of the temporomandibular joint: treatment with a temporalis muscle flap and augmentation genioplasty

A case of true bilateral ankylosis of the temporomandibular joint (TMJ) is presented. A 19-year-old male patient had a life-threatening ear infection at the age of ten resulting in a progressive restriction of his mouth opening. He presented with almost complete lack of mobility of the mandible. Surgical treatment was a resection of the ankylotic mass, interpositional temporalis composite muscle flaps, and early mobilization and aggressive physiotherapy. The functional results of the interpositional arthroplasty were excellent. After a two-year follow up, an augmentation genioplasty was performed in order to improve facial aesthetics.

[Growth defects of fibular flaps in children]

BACKGROUND

Mandibular reconstruction with fibula free flap is a challenge in pediatric patients because of the size of the bone and absence of growth without epiphyseal transplantation.

CASE REPORT

We report 2 cases of free fibula flap in children for mandibular reconstruction. The 2 patients presented with growth insufficiency of the bone graft after few years of evolution.

DISCUSSION

Growth insufficiency was treated with different surgical procedures which were discussed We review the consequences on growth after fibula free flap and the specific indications to achieve epiphyseal fibular growth in children.

Pharyngeal narrowing as a common feature in pycnodysostosis—a cephalometric study

We report on pycnodysostosis presenting as severe snoring caused by pharyngeal narrowing in two siblings. Cephalograms showed pharyngeal narrowing at the level of the soft palate and the base of the tongue caused by the long soft palate and mandibular hypoplasia. From the literature review and our results, we suggest that respiratory insufficiency such as snoring or obstructed sleep apnea are common and under-appreciated symptoms of pycnodysostosis.

Swallowing disorders in Pierre Robin sequence: its correction by distraction

Pierre Robin sequence is characterized by micro-gnathia, glossoptosis, feeding difficulties, and upper respiratory obstruction, which are frequently complicated by bronchial aspiration and pulmonary infection. Gastroesophageal reflux is also common in these patients. To assess the results of mandibular distraction, a study was performed in 18 patients to detect swallowing disorders associated with apnea episodes and gastroesophageal reflux. Polysomnography, barium pharyngoscopy, determination of blood gases, and esophageal pH measurements were undertaken before and 4 months after distraction osteogenesis. Bilateral corticotomies, followed by distraction with external devices, were performed, achieving 7 to 19 mm of elongation (mean = 12 mm). Gastroesophageal reflux was found in 83% of cases associated with apnea episodes, but it disappeared after distraction osteogenesis. Mean preoperative oxygen saturation was 72%, and it was 93% afterward. The preoperative apnea index was 18.3, and the preoperative 8.5 hypopnea index was 8.5; both disappeared. Pharyngeal transit time became less than 1 second after treatment. Abnormal tongue movements and barium stasis in the pharyngeal recess and in the trachea were eliminated in all the patients.

A new Le Fort I internal distraction device in the treatment of severe maxillary hypoplasia

PURPOSE

The purpose of this pilot study was to test a new Le Fort I internal distraction device.

PATIENTS AND METHODS

A new internal Le Fort I distraction device designed by 1 of the authors was used in 3 patients with cleft lip and palate and severe maxillary hypoplasia who needed maxillary advancements in excess of 12 mm. Presurgical planning used CASSOS (SoftEnable Technology, Ltd, Hong Kong SAR, China) prediction tracing software and a stereolithographic model to calculate the distraction vector. The distractors were pre-bent and installed on the stereolithographic model and activated to advance the maxilla. Surgery was performed in a conventional manner, and distraction was started after a 7-day latency phase at the rate of 1 mm/day and continued until the presurgical plan was achieved. The distractor was removed after a 3-month consolidation phase. Cephalometric radiographs were taken at the completion of each phase.

RESULTS

This new Le Fort I internal distraction device successfully distracted the maxillae as planned in all 3 patients. At the end of the distraction phase, the maxillary advancement was measured at 15.8 mm, 15.8 mm, and 13.5 mm, respectively. In each patient, a clockwise rotation of the maxilla was observed with a tendency to a posterior open bite. Postoperative radiographs also showed that the actual distraction vectors differed from the planned vectors. After the consolidation phase, radiographs showed a relapse of 2.6 mm, 0 mm, and 5.0 mm, respectively. There was no further relapse on 3-month follow-up radiographs. Each case showed radiographic evidence of excellent new bone formation at the osteotomy sites.

CONCLUSION

The new Le Fort I internal distraction device produced the necessary advancement in all 3 patients. The study also showed that the actual distraction vector differed from the planned vector. This discrepancy was caused by a clockwise rotation of the maxilla during the distraction. Finally, the study showed a variable relapse rate not previously reported in maxillary distraction.

Maxillofacial intraoral distraction osteogenesis followed by elastic traction in cleft maxillary deformity

We present a case of severe maxillary hypoplasia in a 16 years old cleft patient treated by distraction osteogenesis maxillary advancement. Initial evaluation showed vertical and antero-posterior maxillary deficiencies, and a Class III malocclusion. Two intraoral distractors (Zurich Pediatric Maxillary Distractor, KLS Martin, Tuttlingen, Germany) were placed in a high Le Fort I osteotomy. An initial advancement of 11 mm was obtained, but the resulting occlusion was unsatisfactory (end-to-end occlusion). The consolidation period was reduced to 3 weeks to allow the mechanical manipulation of the newly formed bone with Class III elastics. An additional advancement of 3 mm, caused by elastic orthodontic traction produced both normal skeletal relationship and satisfactory occlusion. This observation shows that it is possible to carry on a skeletal maxillary displacement by interdental elastics before the complete fusion of the callus. After 12 months of postoperative follow-up no osseous relapse could be detected and the occlusal result was stable.

Congenital Trismus Secondary to Masseteric Fibrous Bands: A 7-Year Follow-Up Report as an Approach to Management

A 7-year prospective follow-up report, which was previously presented in this journal as an initial pediatric case report, is presented as an approach to management of congenital trismus secondary to masseteric fibrous bands. Adams and Rees discussed management, including endoscopic exploration at 18 months of age with early recurrence of trismus. Under the care of the same plastic surgeon and his team, the progress of this patient over 7 years has given us an insight into management. The cause of trismus is not fully elucidated, but the condition can result in compromised caloric intake, speech development, facial appearance, dental care, and oral hygiene. The decreased oral opening may be secondary to shortening of the muscles of mastication, which may cause tension moulding and distortion of the coronoid process; yet, there is no consensus on the optimal management of temporomandibular joint trismus and all its causes. The patient presented in this report, now aged 7 years, has proceeded through to open surgery on two occasions yet, regrettably, has persistently tight masseter muscles and only 8 mm of jaw opening.

Functional and esthetic rehabilitation after mandibular resection in a child using a tooth/implant-supported distraction device: a case report

After resection and autogenous bone grafting in infancy and childhood, hypotrophy of the concerned jaw can often be observed. A 6-year-old male patient with osteogenic sarcoma was treated with partial resection of the mandible from the left first molar to the right first premolar. The aim was to rehabilitate the patient functionally and esthetically as he grew. At the age of 16, after the placement of 4 Brånemark System implants in the consolidated autogeneous bone graft, the patient was treated with horizontal distraction osteogenesis. A new and unconventional type of individual tooth/implant-supported distraction device was used to lengthen the mandible by 16 mm. The implants placed to support the device were later used for prosthodontic rehabilitation. Progress in bone reconstruction, plastic coverage, and implant dentistry, as well as distraction osteogenesis, have enabled the compensation of functional and esthetic impairments caused by resection, especially in infants and young children.

Bilateral bifid mandibular condyle

The bifid condyle is a rather uncommon condition that is diagnosed radiographically. Its etiology is unknown, although the most tenable theory is that it is of traumatic origin. The purpose of this article is to report a new case of a bilateral bifid condyle (the left one manifested a trifid appearance) and to review the relevant literature.

New internal Le Fort I distractor for the treatment of midface hypoplasia

A new Le Fort I internal distraction device was developed by one of the authors (J. G.) and successfully used on a patient with cleft lip and palate and severe maxillary hypoplasia. The device consisted of an upper plate and a lower plate, which were installed above and below the Le Fort I osteotomy. The upper plate was shaped like a "U," and the lower plate was shaped like an inverted "U." The design of the device was unique in that the distraction screws were placed in the maxillary sinus and orientated parallel to the sagittal plane. Presurgical planning used a stereolithographic (STL) model and the CASSOS software to calculate the distraction vector. The distractors were prebent and installed on the STL model and activated to advance the maxilla 15.5 mm. Surgery was performed in a conventional manner, and distraction was started on the seventh day after surgery. At the completion of distraction, a total of 15.5 mm of distraction was achieved. The distractors were removed 3 months after surgery. Results showed that the patient's severe maxillary hypoplasia was corrected as predicted and there was excellent new bone formation between the edges of the osteotomy.

The role of simultaneous gap arthroplasty and distraction osteogenesis in the management of temporo-mandibular joint ankylosis with mandibular deformity in children

INTRODUCTION

Temporo-mandibular joint ankylosis is a common cause of acquired deformity in children.

PURPOSE

Surgical correction of the ankylosis only leaves the patient with an uncorrected mandibular deformity. This study was to evaluate the use of distraction osteogenesis for simultaneous correction of the mandibular deformity.

MATERIAL

This study was done on six children with temporo-mandibular joint ankylosis and mandibular deformity. Uniaxial double pin distractors with Schanz pins were used in this study.

METHODS

The patients underwent simultaneous gap arthroplasty and mandibular osteotomy (retromolar) with distractor insertion. Distraction was started on the fifth post-operative day. The patients were put on dynamic temporo-mandibular joint exercises on the first post-operative day.

RESULTS

All patients had a satisfactory mouth opening on follow-up. Satisfactory cosmetic correction of the mandibular deformity was also achieved in all these patients. Some degree of malocclusion resulted from treatment due to which the patients were placed on orthodontic treatment.

CONCLUSIONS

Distraction osteogenesis can be used simultaneously with gap arthroplasty in patients with temporo-mandibular ankylosis, for the correction of the mandibular deformity.

Watershed infarcts in the fetal and neonatal brainstem. An aetiology of central hypoventilation, dysphagia, Möibius syndrome and micrognathia

Watershed zone infarcts of the human cerebral cortex at the overlapping junctions of the anterior and middle cerebral arterial territories are well known. Another watershed zone exists in the brainstem tegmentum, between the terminal perfusion zones of the paramedian penetrating and long circumferential arteries, which are paired segmental vessels arising from the basilar artery. The vertebrobasilar circulation achieves its mature configuration and caudorostral flow by 9 weeks gestation. Systemic hypotension and other conditions of reduced basilar perfusion in the fetus, either early or late in gestation, may result in symmetrical longitudinal columns of infarction in the midbrain and tegmentum of the pons and medulla oblongata and laminar necrosis of the midbrain tectum. Within this zone are cranial nerve nuclei III-XII, the nucleus and tractus solitarius or central pneumotaxic center, as well as the nucleus ambiguus and other somatic motor nuclei that subserve muscles of swallowing, mastication and tongue movement. Watershed infarcts in the human fetal and neonatal brainstem are clinically expressed as multiple cranial neuropathies, failure of central respiratory drive and apnea, dysphagia and aspiration, Möbius syndrome and Pierre Robin sequence. MRI is sometimes helpful, but most of the involved neuroanatomical structures are beneath the resolution of present imaging techniques, and the diagnosis during life depends upon clinical neurological examination of the neonate, sometimes supported by evoked potential studies. Postmortem examination confirms the diagnosis and dates the lesions, but also contributes to better understand transient or persistent vascular insufficiencies in the fetal and neonatal brainstem.

An atypical Hallermann-Streiff syndrome. Focus on dental care and differential diagnosis

The Hallermann-Streiff syndrome (HSS) is a rare congenital disorder characterized by dyscephaly, birdlike facies, hypoplastic mandible, congenital cataracts, microphthalmia, hypotrichosis, skin atrophy, proportionate short stature, and dental anomalies. A case of a 29-year-old man with atypical HSS with neither cataracts, hair and skin alterations, nor short stature is reported, with special consideration to oral findings and dental management. Dental extractions, scaling, restorations, and endodontics were performed under local anesthesia. Later, orthodontic rehabilitation with fixed brackets was carried out. Finally, a removable partial denture for the maxillary arch was designed using transparent acrylic, and this also served as a retention splint. Young patients with HSS and other similar syndromes must be involved in personalized oral health prevention programs as early as possible. Despite numerous systemic anomalies, some of these patients may undergo conventional dental procedures under local anesthesia in the dental office.

Smith-Lemli-Opitz syndrome: a review, case report and dental implications

Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive developmental disorder characterized by multiple congenital malformations, dysmorphic craniofacial features, and mental impairment. SLOS is caused by a deficiency of the enzyme 7-dehydrocholesterol delta7 reductase which converts 7-dehyrocholesterol to cholesterol. This error results in elevated serum levels of 7-dehydrocholesterol and decreased levels of serum cholesterol. This article describes the clinical features and medical treatment of SLOS. A case report is included, with recommended guidelines for providing safe and comprehensive dental care for individuals with SLOS.

Shprintzen-Goldberg syndrome: case report

OBJECTIVE

The Shprintzen-Goldberg syndrome is an extremely rare syndrome with a characteristic face. This is one of a group of disorders characterized by craniosynostosis and marfanoid features. The aim of this study was to present a new sporadic case of the syndrome and describe in detail the findings at the maxillofacial region.

Osteogenic distraction and orthognathic surgery to correct sequelae of ankylosis of the temporomandibular joint: a case report

A 17-year-old female patient presented with sequelae to ankylosis of the temporomandibular joint, which included vertical maxillary protrusion, anterior open bite, labial incompetence, micrognathia, undefined neck angle, facial asymmetry, Class II molar relationship, and Class III canine relationship. She presented with the following cephalometric and soft tissue data: SNA angle = 78 degrees, SNB angle = 70 degrees, incisor-nasion-point A = 11 degrees, incisor-nasion-point B = 33 degrees, Frankfort-mandibular plane angle = 43 degrees, occlusal plane = 25 degrees, subnasale-stomion = 20 mm, stomion superius-stomion inferius = 9 mm, stomion inferius-soft tissue menton = 30 mm, neck angle = 144 degrees, and chin projection = 10 mm. Orthognathic surgery and mandibular osteogenic distraction were employed, specifically Le Fort I osteotomy to decrease a vertical excess of 12 mm, augmentation genioplasty of 17 mm, and bilateral extraoral distractors of bidirectional vector for a 14-mm augmentation of the mandible. The result was satisfactory with minimal adverse complications.