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Localization of the mental foramen in relation to the mandibular bone using ultrasonography and orthopantomography: a
Ahmet Tohumcu1, Esin Akol Gorgun2, Serhat Efeoglu3
1Department of Oral Dental and Maxillofacial Radiology, Faculty of Dentistry, Adiyaman University, Adiyaman, 02100, Turkey. thmcahmet@gmail.com.
Background:
The mental foramen (MF) is a critical anatomical landmark in dental and maxillofacial procedures. Accurate localization is essential to avoid nerve injury. While orthopantomography (OPG) is commonly used, it has limitations due to its two-dimensional nature and susceptibility to artifacts. Ultrasonography (USG), which offers real-time imaging without ionizing radiation, has emerged as a promising alternative. This study aimed to compare the effectiveness of OPG and USG in identifying the MF and measuring its distance to the mandibular bone.
Methods:
A total of 120 patients (60 males, 60 females), aged 18 and older, were included in the study. A total of 240 mental foramina were evaluated. Vertical measurements were taken from the superior border of the MF to the alveolar crest and from the inferior border to the inferior cortical border of the mandible. Ultrasonographic imaging was performed using an extraoral probe in a longitudinal position. OPGs were acquired using standard protocols, and calibration was achieved by attaching orthodontic wires to the second premolars. All measurements were taken on calibrated digital images using dedicated measurement software. Statistical analysis included paired samples t-test, one-way ANOVA, independent samples t-test, and Pearson correlation.
Results:
Significant differences were found between the two methods in all regions (p < 0.05), with OPG yielding higher distance values than USG. MF-mandibular bone distances were significantly greater in males than in females (p < 0.01). OPG showed significantly greater inferior distances in participants aged 40 years and older, while USG revealed no significant age-related differences. A strong positive correlation (r = 0.801-0.911) and high intra-observer reliability (r = 0.982-0.996) were observed between the methods.
Conclusions:
This study demonstrates that USG is a reliable, non-invasive alternative to OPG for locating the mental foramen. Both methods showed a strong correlation (r = 0.801-0.911), with USG minimizing radiation exposure. OPG yielded higher distance values (14.42 mm right, 14.27 mm left) compared to USG (14.12 mm right, 14.03 mm left) (p < 0.05). MF-mandibular bone distances were significantly greater in males than females (p < 0.01). USG is a valuable complementary tool in clinical practice.
Trial Registration:
Not applicable. This study did not involve a health care intervention and was not a clinical trial.
