REVIEW ARTICLE


The Digital Diagnostic Approach to Stafne’s Bone Cavity (SBC): From a Review of the Literature to the Description of a Clinical Case.



Sabina Saccomanno1, *, Stefano Mummolo1, Daniele Laganà2, Francesca Greco3, Fabiana Fiasca4, Giuseppe Marzo1, Vincenzo Quinzi1
1 Post Graduate School of Orthodontics, Department of Life, Health and Environment Science, University of L’Aquila, L’Aquila, Italy
2 Student, Dental School, Catholic University of the Sacred Heart, Rome, Italy
3 Department of Radiology, Saint John the Baptist’s New Hospital, Foligno, Italy
4 Department of Life, Health and Environment Science, University of L’Aquila, L’Aquila, Italy


Article Metrics

CrossRef Citations:
0
Total Statistics:

Full-Text HTML Views: 272
Abstract HTML Views: 166
PDF Downloads: 132
Total Views/Downloads: 570
Unique Statistics:

Full-Text HTML Views: 132
Abstract HTML Views: 103
PDF Downloads: 120
Total Views/Downloads: 355



Creative Commons License
© 2021 Saccomanno et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Post Graduate School of Orthodontics, Department of Life, Health and Environment Science, University of L’Aquila, L’Aquila, Italy; E-mail: sabinasaccomanno@hotmail.it


Abstract

Introduction:

Stafne’s Bone Cavity [SBC] is a rare, well-defined, mandibular bone lesion, which was first discovered by Edward C. Stafne in 1942.

Objective:

The purpose of this article is to evaluate a digital diagnostic approach to Stafne’s Bone Cavity (SBC) through a review and description of some clinical cases.

Methods:

The review was conducted through an analysis of the literature of all articles published on Stafne’s Bone Cavity.

We report the case of a 55-year-old male patient who needed tooth implant rehabilitation, and therefore, a panoramic radiograph was taken as part of the routine evaluation and plan of care. After the diagnosis, the focus was on more precise imaging and the merits of choosing Computerized Tomography or Magnetic Resonance Imaging were compared.

Results:

According to our review of the literature, the prevalence of these cavities was found to be 0.14%, while 8% of them were found in male patients and 72% of them were found in male patients older than 44 years of age.

The patient’s panoramic radiograph revealed the presence of an SBC in his left posterior side of the mandible. In order to confirm and improve the diagnosis, the patient underwent a Computer Tomography exam, chosen for its benefits outweighing those of an MRI.

Conclusion:

Stafne’s bone cavity (SBC) is indeed an uncommon finding as it is asymptomatic and is identified only through panoramic imaging, CT scans or MRIs. However, it can pose some logistical problems in the application of dental implants. The typology of this case study confirmed the findings of the systematic review; the patient, being a middle aged male, presented a mandibular SBC, which was discovered only during a routine panoramic x-ray to plan the fitting of dental implants. The use of tomography confirmed the diagnosis of SBC and detailed the anatomical structure, thus guiding the restoration process.

Keywords: Stafne’s bone cavity, Digital imaging, Implant-prosthetic planning, CT scans, Anatomical structure, Magnetic Resonance Imaging.



1. INTRODUCTION

In 1942, Edward C. Stafne [1] found thirty-five bone cavities in 44 patients situated near the angle of the mandible; 80% of them were located in male patients and the average age of the patients was 47-53 years. The cavities had a diameter variable between 1 and 3 cm, a round or oval form, no preponderance of findings in one of the sides, no change or increase in size, and in only one case, they were present on both sides.

Table 1. Review of literature regarding the prevalence of Stafne's bone cavity (SBC).
Author[s] [Ref] Year Cases Nationality Cross-section Number of SBCs Rate of SBCs [%]
Lilly et al. [2] 1965 1,283 USA Dentists 2 0.16
Karmiol and Walsh [3] 1968 4,693 USA Veterans 18 0.38
Johonson [4] 1970 2,486 USA Veterans 10 0.40
Oikarinen and Julku [5] 1974 10,000 Finland Patients 10 0.10
Uemura et al. [6] 1976 3,000 Japan Patients 10 0.33
Ehara et al. [7] 1977 10,000 Japan Patients 21 0.21
Chen and Ohba [8] 1978 23,000 Japan Patients 24 0.10
Correll et al. [9] 1980 2,693 USA Veterans 13 0.48
Sisman et al. [10] 2012 34,221 Turkey Patients 29 0.08
Assef et al. [11] 2014 14,005 Germany Patients 11 0.08
All US studies 11,155 USA All 43 0.39
All Japanese studies 36,000 Japan Patients 55 0.15
All patients 98,919 All Patients 123 0.12
Total 105,381 All All 148 0.14

These rare, asymptomatic, radiolucent, well-demarcated, mainly unilateral and anterior lesions are commonly called Stafne’s Bone Cavities (SBC) from the surname of the first discoverer, but they are also known as latent, idiopathic or developmental mandibular bone cavities, cysts, defects or depressions.

In the literature, ten published studies have been found on the prevalence of the SBC in the population conducted between 1965 and 2014, and the average rate of SBCs was found to be 0,14%; all the studies carried out by American researchers suffered from the bias of an only-male (in the cases of military veterans) or a mostly-male (in the case of the dentists in 1965) population, so excluding those studies, the average rate decreased to 0.12%. Unfortunately, there are no American studies without gender bias, so investigating the eventual presence of the highest SBCs rate in both sexes in the USA is not possible; however, the rate reported by Lilly et al. [2] is very close to the average world rate, so it may be reasonable to think that the real American average rate of the prevalence of these cavities is no different from the other countries (Table 1).

Some of these studies allowed us to consider the gender variability, and we found that 88% of the cases of SBCs were diagnosed in male patients. In the study of Sisman et al. [10], it was possible to obtain additional confirmation of this aspect, as the prevalence of SBC in male patients was ten times higher than the prevalence in female patients (Table 2).

The same studies reported in Table 2 and the study by Correll et al. [9] allowed us to evaluate age variability as well, and we found that 72% of the cases of SBCs were diagnosed in patients with an age range between forty-five and ninety-five years. The study of Sisman et al. [10] confirmed this data as the prevalence of SBC in patients between the ages forty-one and ninety-five resulted in being twenty-seven times higher than the prevalence in patients between the age of four and forty (Table 3).

Table 2. Review of literature regarding the association between male sex and Stafne's bone cavity.
Author[s] [Ref] Year Male
Cases
Nationality Number of
SBCs
Rate of SBCs [%]
Oikarinen and Julku [5] 1974 10 Finland 10 100
Uemura et al. [6] 1976 8 Japan 10 80
Chen and Ohba [8] 1978 20 Japan 24 83
Sisman et al. [10] 2012 25 Turkey 29 86
Assef et al. [11] 2014 11 Germany 11 100
Total 74 All 84 88
Table 3. Review of literature regarding the association between old age and Stafne's bone cavity.
Author[s] [Ref] Year 45+ old Nationality Number
of SBCs
Rate of SBCs%
Oikarinen and Julku [5] 1974 8 Finland 10 80
Uemura et al. [6] 1976 8 Japan 10 80
Chen and Ohba [8] 1978 14 Japan 24 58
Correll et al. [9] 1980 11 USA 13 85
Sisman et al. [10] 2012 21 Turkey 29 72
Assaf et al. [11] 2014 8 Germany 11 73
Total 70 97 72

2. CASE REPORT

A 55 year-old male patient had routine panoramic radiography done in preparation for prosthetic rehabilitation (Fig. 1). The panoramic imaging revealed an oval cyst-like well-defined lesion (Fig. 2) in the left posterior mandible, anterior to the mandibular angle and the third molar, below a wide edentulous area. The patient was asymptomatic, and there was no report of paresthesia or anesthesia.

From the objective exam and the panoramic radiography, we observed the presence of multiple edentulous areas which needed to be rehabilitated. As part of an implant-prosthetic plan of care, Spiral Computerized Tomography was prescribed to him (Fig. 3), obtaining bi-dimensional reconstructions as panorex, parasagittal slices by multiplanar reformation and tridimensional reconstructions by volume rendering [12, 13].

In this radiographic exam, we found an oval notch with radiolucent, clear and regular borders, located in the inferior portion of the horizontal branch of the mandible, on the lingual side, near the angle of the mandible, and below the mandibular canal. The X-ray allowed precise measurement showing a height ranging between 13.5 mm and 17 mm and breadth between 6 and 8 mm (Figs. 4-5).

The bi-dimensional reconstructions in parasagittal slices also permitted better identification of the closeness of the bone cavity to the canal of the alveolar inferior omolateral nerve, whereas the computerized volume rendering offered a more accurate view of the surrounding anatomical features (Figs. 6-12).

Fig. (1). The panoramic radiography.

Fig. (2). A detail of the panorama.

Fig. (3). Tridimensional reconstruction with volume rendering.

Fig. (4). Parasagittal slice.

Fig. (5). Parasagittal slice.

Fig. (6). Parasagittal slice.

Fig. (7). Parasagittal slice.

Fig. (8). Bidimensional reconstruction with multiplanar reformation of the left hemimandible.

Fig. (9). Bidimensional reconstruction with multiplanar reformation of the left hemimandible.

Fig. (10). Bidimensional reconstruction with multiplanar reformation of the left hemimandible.

Fig. (11). Bidimensional reconstruction with multiplanar reformation of the left hemimandible.

Fig. (12). Bidimensional reconstruction with multiplanar reformation of the left hemimandible.

3. DISCUSSION

The case that we have described here corresponds to the most common manifestation of SBC and confirms the finding of the studies reviewed; the bone cavity is present in a male sex patient, a mature adult (age 55), in a position located posteriorly in the mandible.

Table 4. Advantages and disadvantages of CT and MRI in diagnosing SBC.
Advantages Disadvantages
CT High level of resolution Exposure to radiation
Ease of use Soft tissues not well visualized
Low cost
Comfortable for the patient
May be used in dental offices
MRI Good visualization of soft tissues Distortion artifact caused by metal
No exposure to radiation Higher cost
Less comfortable for the patient
Less ease of use

The very low prevalence of this lesion, 0.14%, according to our review, is the main reason why the majority of the studies in the literature are case reports, with very few retrospective analyses and no systematic reviews.

Given the paucity of cases reported, it would be interesting in the future to explore other aspects of the SBC that could make its finding more common, such as investigating whether or not there is a specific original event that could have caused or contributed to the formation of the bone cavity, such as metabolic disorders, traumas, dental extractions, or a past dental abscess. Finding a common factor could guide the use of proper diagnostic tools and prosthetic procedures. Although rare, it would be useful to understand the long-term impact of SBCs, especially vis-a-vis the normal life of implanted prosthetics.

It is impossible to diagnose an SBC with just an objective examination because it is usually asymptomatic, so thanks to radiographic exams that dentists can identify this lesion and often this finding is serendipitous, happening when the imaging is performed for other purposes, as it happened in this case.

After visualizing the bone cavity by panoramic x-rays, we requested a Computerized Tomography (CT) scan, because it is a very versatile and powerful instrument for dental diagnosis and it has additional advantages for the volumetric reproduction of cranium and soft tissues, the absence of the overlap of anatomic parts that limits the visibility of the structures and the presence of a constant and easily reproducible reference system [14, 15].

In literature, some authors were observed to prefer the use of Magnetic Resonance Imaging (MRI). Probst et al. [16], preferred the use of an MRI instead of a CT because it does not emit radiation and it reproduces the soft tissues better than the CT, whereas Boffano et al. [17] recommended the use of a CT scan because MRI is very expensive and distortion artifacts may result from the presence of metal. Moreover, Sisman et al. [10] observed that a CT scan can be easily done in dental offices and it is reported to have a higher level of image resolution than the MRI, whereas Segev et al. [18] defined MRI as a primary diagnostic technique where SBC is suspected, underlining that the use of intravenous contrast material is not necessary for these lesions (Table 4).

In addition, in cases of an atypical SBC and a very difficult differential diagnosis, Li et al. [17] suggested the combination of CT and sialography, if needed, although this technique may be difficult to perform and uncomfortable for the patient.

Because the SBC is an asymptomatic and non-developmental lesion, the most suggested approach in the literature is conservative and the majority of the studies advised a follow-up radiographic examination; especially, Probst et al. [16] judged the radiographic follow-up as a reasonable recommendation, considering the possible progression reported by Prechtl et al. [20].

According to Venkatesh [21], CT should be used in the follow-up, whereas Boffano et al. [16] concluded that both CT and MRI are suitable for the follow-up, while Schneider et al. [22] explicitly affirmed that panoramic radiograph seems to be insufficient for this purpose.

Because the CT entails a higher exposure of radiation compared to a panoramic X-ray, a legitimate question could be the frequency of the follow-ups with radiographs. Dereci and Duran [23] proposed an X-ray to be conducted in 6 months follow-up and they monitored the symptomatology of the patient for 2 years, whereas Queiroz et al. [24] followed the patient for 4 years but used panoramics. Other studies have also advised a 6-month follow-up period, but many authors suggest that the follow-up should be regular and adequate.

CONCLUSION

Stafne’s bone cavity (SBC) is indeed an uncommon finding, as it is asymptomatic and is identified only through panoramic imaging, CT scans or MRIs. However, it could pose some logistical problems in the application of dental implants. The typology of this case study confirmed the findings of the literature review, the patient being a middle age man presenting a mandibular SBC, discovered only during a routine panoramic x-ray to plan for the fitting of dental implants. The use of tomography confirmed the diagnosis of SBC and its anatomical structure, thus guiding the restoration process. Considering all the advantages of a CT scan compared to an MRI, such as the lower cost, a higher level of resolution, a higher level of comfort for the patient, the absence of distortion artifacts caused by intraoral metal and the facility of use, we recommend a CT scan in oral reconstruction, so as not to miss possible cases of SBC.

The article has been translated into American English by Licia Coceani Paskay, MS, CCC-SLP.

CONSENT FOR PUBLICATION

Not applicable.

FUNDING

None.

CONFLICT OF INTEREST

The authors declare no conflict of interest, financial, or otherwise.

ACKNOWLEDGEMENTS

Declared none.

REFERENCES

[1] Stafne E. Bone cavities situated near the angle of the mandible. J Am Dent Assoc 1942; 29: 1969-72.
[2] Lilly GE, Steiner M, Irby WB, Tiecke RW. Oral health evaluation: Analysis of radiographic findings. J Am Dent Assoc 1965; 71: 635-9.
[3] Johnson CC. Analysis of panoramic survey. J Am Dent Assoc 1970; 81(1): 151-4.
[4] Karmiol M, Walsh RF. Incidence of static bone defects of the mandible. Oral Surg 26: 225-229, 1968. Johnson CC: Analysis of panoramic survey. J Am Dent Assoc 1970; 81: 151-4.
[5] Oikarinen VJ, Julku M. An orthopantomographic study of developmental mandibular bone defects (Stafne’s idiopathic bone cavities). Int J Oral Surg 1974; 3(2): 71-6. [Stafne’s idiopathic bone cavities].
[6] Uemura S, Fujishita M, Fuchihata H. Radiographic interpretation of so-called developmental defect of mandible. Oral Surg Oral Med Oral Pathol 1976; 41(1): 120-8.
[7] Ehara M, Uchinoumi K, Koseki Y, et al. Radiographic study of so-called developmental bone defect of mandible. Dent Radiol 1977; 17: 44.
[8] Chen CY, Ohba T. An analysis of radiological findings of Stafne’s idiopathic bone cavity. Dentomaxillofac Radiol 1981; 10(1): 18-23.
[9] Correll RW, Jensen JL, Rhyne RR. Lingual cortical mandibular defects: A radiographic incidence study. Oral Surg Oral Med Oral Pathol 1980; 50(3): 287-91.
[10] Sisman Y, Miloglu O, Sekerci AE, Yilmaz AB. Demirtas O andTokmak TT: Radiographic evaluation on prevalence of Stafnebone defect: A study from two centres in Turkey. Dentomaxillofac Radiol 2012; 41: 152-8.
[11] Assaf AT, Solaty M, Zrnc TA, et al. Prevalence of Stafne’s bone cavity--retrospective analysis of 14,005 panoramic views. In Vivo 2014; 28(6): 1159-64.
[12] Frascaria M, Casinelli M, Marzo G, Gatto R, Baldi M, D’Amario M. Digital implant planning for a minimally invasive surgery approach: A case letter of a full-arch rehabilitation. J Oral Implantol 2015; 41(2): 205-8.
[13] Lo Giudice A, Quinzi V, Ronsivalle V, Martina S, Bennici O, Isola G. Description of a Digital Work-Flow for CBCT-Guided Construction of Micro-Implant Supported Maxillary Skeletal Expander. Materials (Basel) 2020; 13(8): 1815.
[14] Saccomanno S, Greco F, D’Alatri L, et al. Role of 3D-CT for orthodontic and ENT evaluation in Goldenhar syndrome. Acta Otorhinolaryngol Ital 2014; 34(4): 283-7.
[15] Saccomanno S, Greco F, DE Corso E, et al. Eagle’s Syndrome, from clinical presentation to diagnosis and surgical treatment: A case report. Acta Otorhinolaryngol Ital 2018; 38(2): 166-9.
[16] Probst FA, Probst M, Maistreli IZ, Otto S, Troeltzsch M. Imaging characteristics of a Stafne bone cavity--panoramic radiography, computed tomography and magnetic resonance imaging. Oral Maxillofac Surg 2014; 18(3): 351-3.
[17] Boffano P, Gallesio C, Daniele D, Roccia F. An unusual trilobate Stafne bone cavity. Surg Radiol Anat 2013; 35(4): 351-3.
[18] Segev Y, Puterman M, Bodner L. Stafne bone cavity--magnetic resonance imaging. Med Oral Patol Oral Cir Bucal 2006; 11(4): E345-7.
[19] Li B, Long X, Cheng Y, Wang S. Cone beam CT sialography of Stafne bone cavity. Dentomaxillofac Radiol 2011; 40(8): 519-23.
[20] Prechtl C, Stockmann P, Neukam FW, Schlegel KA. Enlargement of a Stafne cyst as an indication for surgical treatment - a case report. J Craniomaxillofac Surg 2013; 41(3): 270-3.
[21] Venkatesh E. Stafne bone cavity and cone-beam computed tomography: A report of two cases. J Korean Assoc Oral Maxillofac Surg 2015; 41(3): 145-8.
[22] Schneider T, Filo K, Locher MC, et al. Stafne bone cavities: systematic algorithm for diagnosis derived from retrospective data over a 5-year period. Br J Oral Maxillofac Surg 2014; 52(4): 369-74.
[23] Dereci O, Duran S. Intraorally exposed anterior Stafne bone defect: A case report. Oral Surg Oral Med Oral Pathol Oral Radiol 2012; 113(5): e1-3.
[24] Queiroz LMG, Rocha RS, de Medeiros KB, da Silveira EJ, Lins RD. Anterior bilateral presentation of Stafne defect: An unusual case report. J Oral Maxillofac Surg 2004; 62(5): 613-5.