From the Guidelines
The incidence of absent frontal sinus in the general population is approximately 5-15%. This estimate is based on various studies, although a specific recent and high-quality study directly addressing this question is not provided in the given evidence. However, it's essential to consider that anatomical variations such as the absence of frontal sinuses are generally congenital and asymptomatic, often discovered incidentally during radiographic evaluations for unrelated reasons 1.
Key Points to Consider:
- The absence of frontal sinuses is a congenital condition resulting from the failure of pneumatization of the frontal bone during development.
- This condition is typically asymptomatic and is considered a normal anatomical variant rather than a pathological condition.
- The clinical significance of absent frontal sinuses is usually minimal but may be relevant in specific contexts such as forensic identification, surgical planning, or evaluating suspected frontal sinus pathology.
- Variations in incidence rates may exist across different ethnic groups and populations, with some studies suggesting higher rates in certain Asian populations compared to Caucasians. Given the information provided and the focus on morbidity, mortality, and quality of life, the absence of frontal sinuses does not require treatment and is generally of minimal clinical significance. When evaluating patients, it's crucial to consider this anatomical variation in the context of their overall health and the specific reasons for any radiographic evaluations, as noted in guidelines such as the European position paper on rhinosinusitis and nasal polyps 1.
From the Research
Incidence of Absent Frontal Sinus
The incidence of absent frontal sinus in the general population is a topic of interest in various medical studies.
- The presence of frontal sinus is approximately 90% in adults, as stated in the study 2.
- A study on Turkish individuals found that bilateral absence of frontal sinuses occurred in 3.8% of cases, while unilateral absence occurred in 4.8% of cases 2.
- In the Indian population, bilateral absence of frontal sinus was found in 8.0% of individuals, while absence of the left and right frontal sinus occurred in 3.3% and 1% of individuals, respectively 3.
- Another study found that unilateral or bilateral absence of the frontal sinus was seen in 5% of cases 4.
- A pilot study on unoperated older patients with craniosynostosis found that frontal sinus pneumatization was absent in 89% of the studied patients, compared to 12% in normal 7-year-old controls 5.
Variation in Incidence
The incidence of absent frontal sinus varies across different populations and studies.
- The study on Turkish individuals 2 reported a lower incidence of bilateral absence compared to the Indian population study 3.
- The study on craniosynostosis patients 5 reported a significantly higher incidence of absent frontal sinus pneumatization compared to normal controls.
- The variation in incidence may be due to factors such as genetic differences, environmental factors, and age-related changes 4.
Clinical Significance
The absence of frontal sinus can have clinical significance, particularly in surgical procedures and personal identification methods.
- The study on Turkish individuals 2 discussed the clinical significance of the frontal sinuses and their absence.
- The study on the Indian population 3 suggested that the frontal sinus can be effectively used in personal identification methods in forensic anthropology.
- The pilot study on craniosynostosis patients 5 highlighted the potential implications of absent frontal sinus in future frontal region trauma and frontal osteotomies.