UNASSIGNED: Pycnodysostosis (PYCD), an autosomal recessive syndrome, is characterized by an imbalance in bone remodeling that produces various clinical and radiographic craniofacial manifestations. This review represents a systematic examination of these manifestations, as well as oral features associated with PYCD.
UNASSIGNED: A systematic review was conducted across 8 databases from February to March 2023. The search strategy focused on studies reporting cases of PYCD that examined the clinical and radiographic craniofacial and oral characteristics associated with this syndrome.
UNASSIGNED: The review included 84 studies, encompassing a total of 179 cases of PYCD. More than half of the patients were female (55.3%), and the mean age was 14.7 years. Parental consanguinity was reported in 51.4% of the cases. The most common craniofacial clinical manifestation was a prominent nose, observed in 57.5% of cases. Radiographically, the most frequently reported craniofacial characteristics included the presence of an obtuse mandibular angle (84.3%) and frontal cranial bosses (82.1%). Clinical and radiographic examinations revealed oral alterations, with micrognathia present in 62.6% of patients and malocclusion in 59.2%. Among dental anomalies, tooth agenesis was the most commonly reported, affecting 15.6% of patients.
UNASSIGNED: Understanding the clinical and radiographic craniofacial features of PYCD is crucial for dental professionals. This knowledge enables these clinicians to devise effective treatment plans and improve patient quality of life.

Pycnodysostosis is an ultra-rare osteosclerotic skeletal disorder characterized by short stature, susceptibly to fractures, acroosteolysis of the distal phalanges, and craniofacial features (frontal bossing, prominent nose, obtuse mandibular angle, micrognathia). Dental abnormalities (delayed eruption of teeth, hypodontia, malocclusion, dental crowding, persistence of deciduous teeth, enamel hypoplasia, and increased caries) are also frequent; due to bone metabolism alteration, the patients have an increased risk for jaw osteomyelitis, especially after tooth extraction or mandible fracture. Other complications are obstructive sleep apnea, endocrine alterations and cytopenia. Pycnodysostosis is caused by biallelic loss of function variants in CTSK gene, coding the lysosomal protease cathepsin K. CTSK is involved in the degradation of bone matrix proteins, such as type I and type II collagen. In pycnodysostosis, this degradation is decreased, leading to increased bone density and bone fragility with pathological fractures and poor healing. We present a clinical report of a female adult patient with typical pycnodysostosis phenotype. At the age of 52 years, she had a pathological spontaneous fracture of the right mandible complicated by osteonecrosis, treated with load bearing osteosynthesis. The direct sequencing of CTSK gene revealed the presence of the pathogenic homozygous variant c.746T>A, (p.Ile249Asn), that confirmed the diagnosis of pycnodysostosis. We also review the literature case series published to date, that suggest to always consider the diagnosis of pycnodysostosis in case of osteosclerosis, even in the absence of brachydactyly or short stature. This report details the natural history of the disease in this patient, from childhood to adulthood, and highlights the importance of a quality of life assessment. In addition, we describe a case of mandibular osteonecrosis and spontaneous fracture in pycnodysostosis, drawing attention on the maxillofacial complications in these patients and on the importance of a personalized follow-up.

BACKGROUND: Pycnodysostosis is a rare autosomal recessive lysosomal disorder of bone characterized by diffuse skeletal condensation with thickening of the cortex and narrowing of the medullary canal.
METHODS: We present the case of a 4-year-old girl diagnosed with pycnodysostosis and associated pathological tibial fracture. The tibia had an absence of medullary canal. Surgery included reduction and reaming of the canal with placement of a 5 mm diameter telescopic growing nail.
CONCLUSIONS: The presentation of pycnodysostosis as tibial fracture is rare and there is limited literature on its management. We showed its approach focusing mainly on the management of the absent medullary canal.
UNASSIGNED: HINTERGRUND: Die Pyknodysostose ist eine seltene, autosomal-rezessiv vererbte lysosomale Störung des Knochens, die durch eine diffuse Skelettkondensation mit Verdickung des Kortex und Verengung des Markraums charakterisiert ist. FALLPRäSENTATION: In diesem Beitrag wird der Fall eines 4‑jährigen Mädchens vorgestellt, bei dem eine Pyknodysostose und eine damit verbundene pathologische Tibiafraktur diagnostiziert wurde. Die Tibia wies einen fehlenden Markraum auf. Die Operation umfasste die Reposition und das Aufbohren des Markraums mit Einsetzen eines Teleskopnagels mit 5 mm Durchmesser.
UNASSIGNED: Eine Pyknodysostose, die sich als Tibiafraktur darstellt, ist selten, und es gibt nur wenig Literatur zu deren Behandlung. In diesem Artikel wird ein Ansatz vorgestellt, der sich hauptsächlich auf die Behandlung des fehlenden Markraums konzentriert.

Pycnodysostosis (PYCD) is an autosomal recessive lysosomal storage disorder of the bone which leads to stereotypical abnormalities consisting of, but not limited to, sclerotic and fragile bone, shortened distal phalanges, and obtuse mandibular angle. Current literature describes the otolaryngological manifestations and treatment of this disorder; however, the treatment of orthopedic fractures in PYCD patients is seldom described and remains a controversial topic. We aim to systematically review the current evidence regarding the optimal treatment of PYCD patients with fractures. We performed a literature search using PubMed, MEDLINE, Web of Science, and Google Scholar databases. Elig-ibility criteria consisted of English-language literature of PYCD patients undergoing treatment for orthopedic surgery fractures. Non-English papers or literature focused on maxillofacial manifestations/treatment were excluded. The database search resulted in the identification of 500 articles. After removing duplicates and enforcing our inclusion criteria, 29 case reports/series (40 patients) were included. The average age was 31.25 (-±18.2) years, with 57.5% of patients being female. Overall, 62.5% of patients had consanguineous parents. Additionally, 86.2% reported a history of previous fractures while 47.5% reported a spontaneous or minor trauma fracture, with most fractures occurring in the femur (60.0%) and tibia (40.0%). Radiographic features consisted of densification in the femur 45.0% (18/40), tibia 37.5% (15/40), and spine 25.0% (10/40). Overall, 84.2% of patients were treated with surgical management consisting of internal plate fixation (IPF) (48.3%), intramedullary fixation (20.7%), and Ilizarov external fixation (IEF) (13.8%). Overall, the refracture rate was 25.0% and was lowest in intramedullary fixation (0/6), compared to IPF (3/14) and IEF (3/4). Average time until refracture was 40.6 months (3-132 months). Long-term follow-up is recommended in patients with PYCD due to the propensity for fractures/refractures. While this study provides the groundwork for the treatment of PYCD patients, further research with higher-evidence studies should be conducted to establish the optimal orthopedic treatment of this disorder.

There is a lack of knowledge regarding pycnodysostosis (PYCD), which is commonly misdiagnosed as other, similar malformations. This study aims to report a patient with PYCD and conjointly present a comprehensive literature review regarding oral complications after oral surgery procedures.
This study aims to report a noteworthy case of a 40-year-old woman with PYCD who suffered from a midface defect after iatrogenic fracture during extraction of the upper right molars. A comprehensive electronic search was carried out in January 2020 for detection and analysis of the most commonly encountered dentoalveolar PYCD-related complications. The study was granted an exemption from the local institutional review board.
The electronic search yielded 35 articles reporting 41 PYCD cases with 62 various reported dentoalveolar complications. The survey reported a prevalence of osteomyelitis (n = 39) followed by pathologic fracture (n = 17), iatrogenic fracture (n = 5), and oronasal communication (n = 1).
This study advocates handling patients with PYCD with care through the use of extensive clinical and radiographic examinations, giving priority to any conservative treatment modalities, atraumatic surgical procedures, prophylactic antibiotic prescriptions, and a regular follow-up schedule to tackle any anticipated complications.

BACKGROUND: Pycnodysostosis is a rare autosomal recessive syndrome that provides the abnormal bone metabolism that increases the susceptibility of patients to develop osteomyelitis.
OBJECTIVE: This systematic review was conducted to analyze the risk factors associated with the development of complications in the jaws (fractures and osteomyelitis), as well as their clinical-pathological characteristics and therapeutic approaches in patients with pycnodysostosis.
METHODS: Searches were performed in the PubMed, Web of Science, Scopus, Lilacs, and Cochrane databases. Case reports or case series that met the eligibility criteria according to the PRISMA statement were included. The full texts of 31 articles were retrieved. Twenty of these articles published between 1969 and 2018 were selected, which described 26 cases of osteomyelitis in patients with pycnodysostosis.
RESULTS: The mean age of the patients was 37.84 years; the male-to-female was 1.36:1. The mandible was the most affected site (76.9%). Tooth extraction was the main risk factor for osteomyelitis (61.5%), followed by infection (26.8%) and mandibular fracture (23.0%). Antibiotic therapy alone or combined with some surgical procedure was the treatment used in most cases (80.7%).
CONCLUSIONS: The findings of this review showed that patients with pycnodysostosis are more likely to develop osteomyelitis of the jaws after surgical procedures, especially tooth extraction which remains the main risk factor for its establishment. In addition, prophylactic antibiotic-therapy in the pre- and postoperative periods may prevent the development of osteomyelitis in pycnodysostosis.

暂无摘要。

Pycnodysostosis is a lysosomal autosomal recessive skeletal dysplasia characterized by osteosclerosis, short stature, acro-osteolysis, facial features and an increased risk of fractures. The clinical heterogeneity of the disease and its rarity make it difficult to provide patients an accurate prognosis, as well as appropriate care and follow-up. French physicians from the OSCAR network have been asked to fill out questionnaires collecting molecular and clinical data for 27 patients issued from 17 unrelated families. All patients showed short stature (mean = -3.5 SD) which was more severe in females (P = .006). The mean fracture rate was moderate (0.21 per year), with four fractures in total average. About 75% underwent at least one surgery, with an average number of 2.1 interventions per patient. About 50% required non-invasive assisted ventilation due to sleep apnea (67%). About 29% showed psychomotor difficulties and 33% needed a school assistant or adapted schooling. No patient had any psychological evaluation or follow-up. Molecular data were available for 14 families. Growth hormone administration was efficient on linear growth in 40% of cases. We propose several axis of management, such as systematic cerebral MRI for Chiari malformation screening at diagnosis and regular psychological follow-up.

OBJECTIVE: Aim of the present study was to present a case report of a patient suffering from pycnodysostosis and assess how it may manifest and affect the dental/ orthodontic treatment.
METHODS: An 11-year-old patient who was diagnosed with pycnodysostosis at the age of 18 months, attended the orthodontics department requiring treatment for extensive carious lesions, periodontal disease and severe crowding.
RESULTS: After an accurate radiographic, clinical and orthodontic assessment of the patient taking into consideration the severity of the condition and the patient\'s necessities, we have formulated a treatment plan, which was accepted by both the patient and parents. We took into consideration the risks and benefits of the options available and the requests of the patient.
CONCLUSIONS: We have decided to opt for the extraction of teeth to relieve the crowding as this was impeding good oral hygiene and hence increasing the risk of caries and periodontal disease. Such patients must be placed under an oral hygiene prevention scheme, a treatment plan must be accurately designed and the patient must be constantly motivated.

Pycnodysostosis is an autosomal recessive disorder due to a mutation in the cathepsin K gene, which causes a decrease of the bone turnover; a review of the literature suggests that pycnodysostosis is frequently associated with severe respiratory obstruction, which needs surgical treatment. The aim of this paper is to describe the surgical treatment of a 3½-year-old girl affected by Pycnodysostosis complicated by a severe sleep-related respiratory disorder. The surgical treatment, consisting of adenotonsillectomy and palatoplasty, resulted in a striking amelioration of respiratory parameters and increased posterior airway space, and allowed the patient to avoid tracheotomy while awaiting for maxillo-mandibular surgery.