Section of Orthodontics, Department of Oral Growth and Development, Fukuoka Dental College, 2-15-1 Tamura, Sawara-ku, Fukuoka, 8140193, Japan.
Executive Trustee, Educational Institution, Fukuoka Gakuen, 2-15-1 Tamura, Sawara-ku, Fukuoka, 8140193, Japan.
BMC Oral Health. 2021 Mar 10;21(1):111. doi: 10.1186/s12903-021-01454-x.
Larsen syndrome (LS) is a rare disorder of osteochondrodysplasia. In addition to large-joint dislocations, craniofacial anomalies are typical characteristics. In this report, we performed orthodontic analyses, including skeletal and occlusal evaluations, to examine whether the craniofacial skeletal morphology leads to the craniofacial anomalies in LS.
A 5 year old Japanese girl who was clinically diagnosed with LS was referred to the orthodontic clinic in the Fukuoka Dental College Medical and Dental Hospital because of a malocclusion. Clinical findings at birth were knee-joint dislocations, equinovarus foot deformities, and cleft soft palate. The patient showed craniofacial anomalies with hypertelorism, prominent forehead, depressed nasal bridge, and flattened midface. To evaluate the craniofacial skeletal morphology, cephalometric analysis was performed. In the frontal cephalometric analysis, the larger widths between bilateral points of the orbitale were related to hypertelorism. The lateral cephalometric analysis revealed the midface hypoplasia and the retrognathic mandible. These findings were responsible for the flattened appearance of the patient's face, even if the anteroposterior position of the nasion was normal. Her forehead looked prominent in relation to the face probably because of the retrognathic maxilla and mandible. Both the study model and the frontal cephalometric analysis indicated constriction of the upper and lower dental arches. The posterior crossbite facilitated by the premature contacts had developed in association with the constriction of the upper dental arch.
This patient had some craniofacial anomalies with characteristic appearances in LS. It was evident that the underlying skeletal morphology led to the craniofacial dysmorphism.
Larsen 综合征（LS）是一种罕见的骨软骨发育不良疾病。除了大关节脱位外，颅面异常也是其典型特征。在本报告中，我们进行了正畸分析，包括骨骼和咬合评估，以检查颅面骨骼形态是否导致 LS 中的颅面异常。
一名 5 岁日本女孩因咬合不正被转诊至福冈齿科大学医疗牙科医院的正畸科。出生时的临床发现为膝关节脱位、马蹄内翻足畸形和腭裂。患者表现出颅面异常，包括眼距过宽、额骨突出、鼻梁凹陷和中面部扁平。为了评估颅面骨骼形态，进行了头颅侧位片分析。在额状面头颅侧位片分析中，双侧眶点之间的宽度较大与眼距过宽有关。侧位头颅片分析显示中面部发育不良和下颌后缩。这些发现导致了患者面部扁平的外观，即使前颅底的位置正常。她的额头相对于面部看起来突出，可能是由于上颌和下颌后缩。研究模型和额状面头颅侧位片分析均表明上下牙弓狭窄。由于上颌牙弓狭窄，导致了早期接触形成的后牙反合。
该患者具有 LS 特有的一些颅面异常。很明显，潜在的骨骼形态导致了颅面畸形。
