Craniofacial Measurements from Lateral Cephalograms Reveal Insights into Sleep Apnea

Hannah Finke, DMD

Credit: Research Gate

Findings from a recent study offer some evidence for altered craniofacial anatomy in patients with obstructive sleep apnea (OSA) when compared with individuals without the condition. Lateral cephalograms, commonly used in orthodontic evaluations, should be routinely screened for these identified measurements to aid in early diagnosis of OSA, the study stated.¹

OSA is a common sleep disorder that’s even more commonly underdiagnosed. The symptoms lead to reduced blood oxygen levels and pose significant cardiovascular risks when left untreated.²

Investigators led by Hannah Finke, DMD, Department of Orthodontics, University Hospital, Tübingen, Germany, sought to enhance early diagnosis with a systematic literature review and meta-analysis to identify craniofacial measurements associated with a higher risk of OSA. These measurements, obtained from lateral cephalograms, showed potential in improving the identification and management of OSA patients.¹

The Study: Identifying Craniofacial Measurements

The team of investigators performed a comprehensive analysis of 3016 publications, searching for terms related to orthodontics, craniofacial aspects, cephalometry, and sleep-disordered breathing. After evaluation, they selected 19 studies fulfilling the inclusion criteria for the systematic review and meta-analysis. Among these studies, 15 involved adult patients, and 4 focused on children.

In total, the team compared 16 different craniofacial measurements, including 6 angles and 10 distances. Out of these, 9 measurements showed notable variations that could influence the presence of OSA when compared with control groups.

• NSBa angle: Decreased by -0.28°
• ANB angle: Increased by +0.33°
• ML-NSL angle: Increased by +0.34°
• Me-Go-Ar angle: Increased by +0.33°
• SN distance: Decreased by -0.70 mm
• N–ANS distance: Decreased by -0.36 mm
• MP–H distance: Increased by +1.18 mm
• Uvula length: Increased by +1.07 mm
• Uvula thickness: Increased by +0.96 mm

Limitations of the Study

While the analysis provided valuable insights into craniofacial measurements associated with OSA, the study also had certain limitations. Investigators noted posterior airway measurements were not adequately described or consistently measured, which hindered their inclusion in the statistical analysis highlighting the need for further research to better understand the role of posterior airway measurements in OSA diagnosis.

“Cephalometric measurements are highly variable world-wide,” investigators wrote. “To facilitate research in this field, a standardization should be intended in the future, especially concerning the measurements of the PAS, that was almost not comparably described to be statistically evaluated.”

However, by identifying patients at higher risk for OSA, healthcare professionals can initiate timely interventions and treatments, potentially reducing the associated cardiovascular risks.

According to the study, the results are especially relevant for young patients with OSA. As symptoms in children can differ from those in adults, there is often a risk of misdiagnosis or delayed identification. By incorporating craniofacial orthopedics into the interdisciplinary treatment plan for pediatric OSA, healthcare providers can offer more personalized and effective interventions.

“Craniofacial anomalies can be a risk factor or an indicator for OSA. The identified most relevant measurements (UL and UT and hyoid bone position, as well as the rotation of the mandible) should be considered in every cephalometric evaluation in order to identify patients with a possibly higher risk of OSA,” they said. “There findings can improve the screening methods, while the diagnosis has to be determined via polygraphy or PSG.”

References:

1. Finke, H., Drews, A., Engel, C., & Koos, B. (2023). Craniofacial risk factors for obstructive sleep apnea—systematic review and meta-analysis. Journal of Sleep Research, e14004. https://doi.org/10.1111/jsr.14004
2. Grossi G. Reena Mehra, MD: Biomarkers and Endophenotypes for Personalized Patient Care. HCPLive. June 9, 2023. https://www.hcplive.com/view/reena-mehra-biomarkers-endophenotypes-personalized-patient-care