Evaluation of tongue/mandible volume ratio in children with obstructive sleep apnea

ABSTRACT Objective: The present study was an attempt to investigate tongue/mandible volume ratio in children, using volumetric magnetic resonance imaging (MRI) for early screening and to aid in treatment planning. Methods: Volumetric evaluation of tongue volume/mandible volume ratio (TV/MV ratio) in children with obstructive sleep apnea (OSA) using MRI was carried out retrospectively on available DICOM MR images of children in the age group of 10-14 years. MRI image records of patients diagnosed with OSA were obtained from interventional radiology department records, at Sharad Pawar Dental College and Hospital (Datta Meghe Institute of Medical Sciences, Nagpur/India). The age, gender, height and weight of the subjects were retrieved from patient database and registered. For the control group, available MRI images of healthy subjects without OSA were retrieved. Body mass index (BMI) was also calculated using the height and the weight present in the records. Measurements from MR images were made using DICOM image processing software. Soft tissue and bony structure segmentation was performed by manual tracing. The tongue volume and mandible volume were directly computed using the software. The tongue volume/mandible volume ratio (TV/MV) was generated using the above values and expressed as a percentage for both groups. Results: The difference between OSA group and control group with respect to TV/MV ratio was found to be highly significant at 0.05 level of significance. There was no significant correlation between BMI and TV/MV ratio in OSA group (p= 0.451) as well as in control group (p= 0.094). Conclusion: TV/MV ratio may be an appropriate variable to evaluate the risk of OSA, representing the balance between skeletal morphology and soft tissue morphology in craniofacial complex.

摘要 目的：本研究旨在借助容积磁共振成像（volumetric magnetic resonance imaging，MRI）探究儿童舌体与下颌骨容积比，以期用于阻塞性睡眠呼吸暂停（obstructive sleep apnea，OSA）的早期筛查，并辅助临床治疗方案的制定。方法：本研究回顾性分析了10~14岁儿童的可用DICOM格式磁共振影像，以评估阻塞性睡眠呼吸暂停（OSA）患儿的舌体容积/下颌骨容积比（tongue volume/mandible volume ratio，TV/MV比）。研究数据取自印度那格浦尔达塔梅赫医学科学研究所附属沙拉德帕瓦尔牙科学院与医院的介入放射科档案中确诊OSA患者的磁共振影像记录。从患者数据库中提取受试者的年龄、性别、身高与体重信息并完成登记。对照组选取无OSA的健康受试者的可用磁共振影像。根据记录中的身高与体重数据计算受试者的身体质量指数（body mass index，BMI）。利用DICOM影像处理软件对磁共振影像进行测量，通过手动描记完成软组织与骨结构的分割，随后由软件直接计算舌体容积与下颌骨容积，基于上述数值生成舌体容积/下颌骨容积比（TV/MV比），并以百分比形式呈现两组的该比值。结果：OSA组与对照组的TV/MV比差异在0.05的显著性水平下具有高度统计学意义。在OSA组（p=0.451）与对照组（p=0.094）中，身体质量指数与TV/MV比均无显著相关性。结论：舌体/下颌骨容积比可作为评估OSA风险的合适指标，其反映了颅颌面复合体中骨骼形态与软组织形态之间的平衡关系。