Achondroplasia: Craniofacial manifestations and considerations in dental management

Craniofacial disorders and dysplasias: Molecular, clinical, and management perspectives

There is a wide spectrum of craniofacial bone disorders and dysplasias because embryological development of the craniofacial region is complex. Classification of craniofacial bone disorders and dysplasias is also complex because they exhibit complex clinical, pathological, and molecular heterogeneity. Most craniofacial disorders and dysplasias are rare but they present an array of phenotypes that functionally impact the orofacial complex. Management of craniofacial disorders is a multidisciplinary approach that involves the collaborative efforts of multiple professionals. This review provides an overview of the complexity of craniofacial disorders and dysplasias from molecular, clinical, and management perspectives.

Dental characteristics of patients with four different types of skeletal dysplasias

OBJECTIVE

Skeletal dysplasia (SD) comprises more than 450 separate disorders. We hypothesized that their dental features would be distinctive and investigated the tooth characteristics of four patients with different SDs.

MATERIAL AND METHODS

Four SD patients with molecularly confirmed diagnoses, Pt-1 acromicric dysplasia, Pt-2 hypophosphatasia and hypochondroplasia, Pt-3 cleidocranial dysplasia, and Pt-4 achondroplasia, were recruited. A tooth from each patient was evaluated for mineral density (micro-computerized tomography), surface roughness (surface profilometer), microhardness, mineral contents (energy-dispersive X-ray), and ultrastructure (scanning electron microscopy and histology), and compared with three tooth-type matched controls.

RESULTS

Pt-1 and Pt-3 had several unerupted teeth. Pt-2 had an intact-root-exfoliated tooth at 2 years old. The lingual surfaces of the patients' teeth were significantly smoother, while their buccal surfaces were rougher, than controls, except for Pt-1's buccal surface. The patients' teeth exhibited deep grooves around the enamel prisms and rough intertubular dentin. Pt-3 demonstrated a flat dentinoenamel junction and Pt-2 had an enlarged pulp, barely detectable cementum layer, and ill-defined cemento-dentinal junction. Reduced microhardnesses in enamel, dentin, and both layers were observed in Pt-3, Pt-4, and Pt-1, respectively. Pt-1 showed reduced Ca/P ratio in dentin, while both enamel and dentin of Pt-2 and Pt-3 showed reduced Ca/P ratio.

CONCLUSION

Each SD has distinctive dental characteristics with changes in surface roughness, ultrastructure, and mineral composition of dental hard tissues.

CLINICAL RELEVANCE

In this era of precision dentistry, identifying the specific potential dental problems for each patient with SD would help personalize dental management guidelines.

Craniofacial Features of Dwarfism in the Paintings of Velázquez

This study describes the craniofacial features of achondroplastic dwarfism in the paintings of Velázquez. In a PubMed search, using [Velázquez] and [dwarf], 13 titles were found. In a Google Image search, [Velázquez] and [dwarf] retrieved 5 paintings. The craniofacial manifestations of the dwarfs depicted in the paintings were analyzed. Frontal bossing, antimongoloid slant, depressed nasal bridge (saddle nose), bulbous tip, malar hypoplasia, malocclusion, and chin asymmetry were observed. The presence of each manifestation was checked. In 5 paintings, portraits of 6 dwarfs having craniofacial deformities were found: Mariabárbola Asquin (left) in Las Meninas , Nicolasito Pertusato (right) in Las Meninas , Portrait of Sebastián de Morra, Portrait of Francisco Lezcano, The Jester Don Diego de Acedo, and Prince Balthasar Charles with a Dwarf. The most frequent craniofacial manifestation was malar hypoplasia (100%), followed by a bulbous tip (83.3%), saddle nose (66.7%), and frontal bossing (50%). Antimongoloid slant, malocclusion, and chin asymmetry were relatively rare (16.7% each). Through an analysis of 6 dwarfs in Velázquez's paintings, we can show that he realized and frequently expressed the craniofacial manifestations of achondroplasia: malar hypoplasia, bulbous tip, saddle nose, and frontal bossing. Despite the rarity of these presentations, he was also aware of antimongoloid slant, malocclusion, and chin asymmetry. Velázquez was a famous painter in the 17th century (i.e., during the Baroque period). Based on his excellent expression of the craniofacial manifestations of dwarfism, we can assume that he had a sound knowledge of anatomy, as well as malformations.

What to Expect of Feeding Abilities and Nutritional Aspects in Achondroplasia Patients: A Narrative Review

Achondroplasia is an autosomal dominant genetic disease representing the most common form of human skeletal dysplasia: almost all individuals with achondroplasia have identifiable mutations in the fibroblast growth factor receptor type 3 (FGFR3) gene. The cardinal features of this condition and its inheritance have been well-established, but the occurrence of feeding and nutritional complications has received little prominence. In infancy, the presence of floppiness and neurological injury due to foramen magnum stenosis may impair the feeding function of a newborn with achondroplasia. Along with growth, the optimal development of feeding skills may be affected by variable interactions between midface hypoplasia, sleep apnea disturbance, and structural anomalies. Anterior open bite, prognathic mandible, retrognathic maxilla, and relative macroglossia may adversely impact masticatory and respiratory functions. Independence during mealtimes in achondroplasia is usually achieved later than peers. Early supervision of nutritional intake should proceed into adolescence and adulthood because of the increased risk of obesity and respiratory problems and their resulting sequelae. Due to the multisystem involvement, oral motor dysfunction, nutrition, and gastrointestinal issues require special attention and personalized management to facilitate optimal outcomes, especially because of the novel therapeutic options in achondroplasia, which could alter the progression of this rare disease.

Airways and craniofacial assessment in children affected by achondroplasia with and without sleep-disordered breathing: quantitative magnetic resonance study

PURPOSE

To identify MRI-based quantitative craniofacial variables linked to airways narrowing and obstructive sleep apnea (OSA) development in children with achondroplasia.

METHODS

We evaluated skull base and midface MRI in two cohorts of children affected by achondroplasia, with (group 1) or without OSA (group 2). 3DFSPGR-T1weighted images were used to assess airways volume (nasopharynx, oropharynx, and laryngopharynx), jugular foramina (JF) and hypoglossal foramina (HF) areas, foramen magnum area, cervical cord area, and maxillary retrusion (SNA angle).

RESULTS

Nineteen out of 27 children with achondroplasia exhibited different degrees of obstructive respiratory impairment (n.4 mild, n.8 moderate, n.7 severe), while 8 children did not show OSA. Each group was compared with age-matched controls without neuroimaging abnormalities. Both groups showed reduced nasopharynx volume, JF areas, and SNA angle, while group 1 showed also reduced oropharynx volume, ratio of FM/cervical cord areas, and HF areas (p < 0.05). A positive correlation between nasopharynx volume and SNA angle was found in both groups, while a positive correlation among upper airways volume, JF and HF areas was found only in group 1. No correlation between upper airways volume and OSA severity was found.

CONCLUSION

In children with achondroplasia, multifaced craniofacial abnormalities contribute to airways volume reduction predisposing to sleep disordered breathing. MRI-based quantitative assessment allows the appraisal of craniofacial variables linked to the development of sleep-disordered breathing such as FM stenosis, jugular and hypoglossal foramina stenosis, and retruded maxillary position and may be a valuable tool for clinical surveillance.

International Consensus Statement on the diagnosis, multidisciplinary management and lifelong care of individuals with achondroplasia

Achondroplasia, the most common skeletal dysplasia, is characterized by a variety of medical, functional and psychosocial challenges across the lifespan. The condition is caused by a common, recurring, gain-of-function mutation in FGFR3, the gene that encodes fibroblast growth factor receptor 3. This mutation leads to impaired endochondral ossification of the human skeleton. The clinical and radiographic hallmarks of achondroplasia make accurate diagnosis possible in most patients. However, marked variability exists in the clinical care pathways and protocols practised by clinicians who manage children and adults with this condition. A group of 55 international experts from 16 countries and 5 continents have developed consensus statements and recommendations that aim to capture the key challenges and optimal management of achondroplasia across each major life stage and sub-specialty area, using a modified Delphi process. The primary purpose of this first International Consensus Statement is to facilitate the improvement and standardization of care for children and adults with achondroplasia worldwide in order to optimize their clinical outcomes and quality of life.

Neuroimaging and calvarial findings in achondroplasia

Achondroplasia is the most common hereditary form of dwarfism and is characterized by short stature, macrocephaly and various skeletal abnormalities. The phenotypic changes are mainly related to the inhibition of endochondral bone growth. Besides the several commonly known physical features that are characteristic of this syndrome, achondroplasia can affect the central nervous system. The impact on the central nervous system can cause some important clinical conditions. Thus, awareness of detailed neuroimaging features is helpful for the follow-up and management of complications. Although the neuroimaging findings in children with achondroplasia have been noted recently, no literature has specifically reviewed these findings extensively. Radiologists should be familiar of these findings because they have an important role in the diagnosis of achondroplasia and the recognition of complications. The aim of this pictorial essay is to review and systematize the distinctive characteristics and abnormalities of the central nervous system and the calvarium in children with achondroplasia.

[Rare diseases and their clinical oral manifestations in two Hospitals in Yaoundé]

Introduction

Les maladies rares ont pour certaines des manifestations orales. Celles-ci sont souvent sous-étudiées; ce qui contribue à limiter l'offre de soins bucco-dentaires pour cette catégorie de patients. Le but est de déterminer les aspects épidémiologiques et cliniques des manifestations bucco-dentaires dans les maladies rares dans notre milieu.

Méthodes

Nous avons effectué une étude transversale et descriptive sur une durée de 7 mois, dans deux hôpitaux de référence de Yaoundé: les informations ont été recueillies des dossiers médicaux, de l'interrogatoire des parents ou tuteurs et de l'examen bucco-dentaire des patients. Le seuil de significativité considéré pour p < 0,05.

Résultats

Les manifestations orales sur maladies rares sont variables et fonction du groupe d'affections, de la denture, et ont souvent un retentissement fonctionnel. Elles étaient présentes dans 97,2% de nos patients. En denture temporaire (59,4%), c'était plus des anomalies de forme et de position dentaire (conicité dentaire 7 cas/22, soit 32%), et en denture permanente des lésions carieuses (7 cas/10 soit 70%) et des anomalies de structure dentaire (4 cas/10 d'usure dentaire). Un lien significatif existait entre le type de denture, l'anomalie de structure (p=0,001) et de nombre (p=0,018). Les difficultés à la mastication (p=0,023) et à la succion (p=0,033) étaient liées aux groupes de maladies rares.

Conclusion

Les lésions orales dans les maladies rares bien que présentes dans notre milieu, sont souvent négligées. Les soins bucco-dentaires devraient être intégrés dans le paquet minimum des activités des formations sanitaires et rendus gratuits ou financièrement accessibles à ces patients handicapés ou présentant des besoins spécifiques.

Achondroplasia: Orocraniofacial Features and Orthodontic-Surgical Management Guidelines Proposal

In this study, the authors aimed to describe orocraniofacial features and to suggest orthodontic-surgical managements in achondroplasia, based on a literature review. The authors focused on skeletal and dentoalveolar malocclusion in order to highlight the place of orthognathic surgery, based on our experience of 3 patients. Maxillary hypoplasia in achondroplasia typically results in an Angle class III malocclusion with an anterior open bite. The other orocraniofacial features include enlarged calvarium, prominent forehead and frontal bossing, midface hypoplasia, elongated lower face and saddle-shaped nose due to lack of development of the nasomaxillary complex.All our patients had a typical facial appearance but each of them had their own particularities regarding medical history and severity of the dentoskeletal dysmorphosis. Two of them were successfully treated by orthognathic surgery; the other declined surgical treatment and underwent orthopedic treatment only (anchorage plates). The treatment failure of this 3rd patient raises the question of the efficiency of anchorage plates in achondroplasia. In the light of the literature and our results, the authors conclude the need for personalized management based on age, medical history, severity of the dentoskeletal dysmorphosis, functional and/or esthetic disorders, and the patient's needs and requests. In any patient, orthodontic management should be initiated at an early age, and orthognathic surgery modalities should be personalized and adapted to each situation.

Achondroplasia with multiple supplemental supernumerary teeth and multiple talon cusps: A rare case report

Achondroplasia is the most common cause of dwarfism, which is inherited as an autosomal dominant disorder, caused by genetic mutation in fibroblast growth factor 3, leading to defective maturation of chondrocytes. It is known to be associated with various oral and dental manifestations such as delayed dental development, midfacial hypoplasia and constricted maxilla with a relatively large mandible, resulting in skeletal/dental Class III malocclusion, posterior crossbite, anterior reverse jet and anterior overbite. However, the association of achondroplasia with talon cusp and supernumerary teeth has never been reported in the literature. Wehereby reported a case of achondroplasia associated with such unusual findings. Moreover, all the three variants of talon cusp, i.e., "true talon,""semitalon" and "trace talon" are observed in the present case, which makes it a unique one. Further double talon cusps were noticed in the palatal aspect of maxillary central incisors.

Achondroplasia with Polydactyly: A Case Report

An eight-year-old girl child reported to the Department of Oral Medicine and Radiology with the chief complaint of unerupted permanent teeth for past two years. The child presented features like disproportionately short stature, rhizomelic shortening of arms and legs, long face, frontal bossing and saddle nose. Based on the findings of chest and spine radiographs and ultrasound the case was diagnosed as a rare bone disorder "Achondroplasia". This case also presents a unique feature of polydactyly. Polydactyly is a manifestation in clinical medicine because it can serve as an indicator for a plethora of congenital anamolies. This case gained dental interest because of its characteristic craniofacial features. This article highlights the peculiar manifestations of this anamoly.

Achondroplasia with oligodontia: Report of a rare case

Achondroplasia is considered as a form of skeletal dysplasia/dwarfism that manifests with stunted stature and disproportionate limb shortening. Achondroplasia is of special interest in the field of dentistry because of its characteristic craniofacial features. It has been considered as the most common short-limbed dwarfism syndrome. Very few authors have reported the presence of oligodontia in achondroplastic patients. The present paper reports a rare case of oligodontia in a young, female, achondroplastic patient.