Journal of International Oral Health

: 2019  |  Volume : 11  |  Issue : 5  |  Page : 256--259

Radiographic detecting for the presence of extra chin foramen for the chosen Ramadi City Community Iraq

Mohanad Aftan Hammad 
 Department of Oral Diagnosis-Dental Radiology, College of Dentistry AL-Anbar university, Iraq

Correspondence Address:
Mohanad Aftan Hammad
Department of Oral Diagnosis-Dental Radiology, College of Dentistry, AL-Anbar University.


Aims and Objectives: The extra chin foramen (ECF) is a scarce structure in the anatomy of human lower jaw. When it is present, the dental surgeon should take care during anesthesia and surgical procedures for anterior teeth. To investigate the existence of the ECF and the direction in relation to chin foramen in chosen Ramadi City community persons, Al-Anbar Governorate, Iraq, digital panoramic and conventional intraoral (bisecting line angle technique) X-ray was used. Materials and Methods: A total of 100 patients (200 sides of mandible), 54 males and 46 females were selected. Each one was subjected to digital panoramic and conventional intraoral technique. The obtained images were evaluated for the existence of ECF in both male and female patients on each direction of lower jaw (left and right). Age relation to ECF existence was reported. Position of ECF to chin foramen (anterior or posterior) was calculated. The collected data were treated by the Statistical Package for the Social Sciences (SPSS) software, version 22. Results: ECFs were seen within 3.5% of the chosen population. Nonsignificant variations were observed between the existence of ECFs regarding gender, side of mandible, age coterie, and position of ECF to chin foramen (P > 0.05). Conclusion: A total of 7 (3.5%) ECFs were detected from 200 sides of mandible. ECFs were observed more in males (5 ECFs, 2.5%), at left side of mandible (4 ECFs, 2%), young patients (4 ECFs, 2%), and anterior to chin foramen (5 ECFs, 2.5%), so they were subjected to complications of damage to nerves and vessels during interventional dental surgery and anesthesia.

How to cite this article:
Hammad MA. Radiographic detecting for the presence of extra chin foramen for the chosen Ramadi City Community Iraq.J Int Oral Health 2019;11:256-259

How to cite this URL:
Hammad MA. Radiographic detecting for the presence of extra chin foramen for the chosen Ramadi City Community Iraq. J Int Oral Health [serial online] 2019 [cited 2021 Dec 6 ];11:256-259
Available from:

Full Text


The chin (mentum) foramen means a pore found on lateral direction for human mandible via it neurovascular bundles of inferior alveolar stream are projected.[1],[2],[3],[4] This chin opening positioned on the forward and outside of the lateral cortex of the body of the lower jaw bone[5] is 13–15mm above lower edge of the mandibular base. The direction for emerging of chin foramen is outside, upside, and behind direction.[6] The situation of the chin foramen is important to carry out anesthetic cut before dental management for mandibular incisors and canines teeth area.[7]

The chin pore when it is more than one, naturally alone in mankind, the added hole is called accessory or extra chin (mentum)foramen (ECF). An ECF is considered as a scarce anatomy in the lower jaw, with a frequent rate of approximately 1.4%–10%.[8] Reversely, the streams were not originated in the lower jaw canal and their sides diminished are called as a supplement canals.[9]

The entity of ECFs may be assessed with variable manner, including macroscopic execution on dry skulls,[10] dental radiography (intraoral X-ray and dental panoramic tomography), and advanced depiction techniques, which give the details of objects in slices and multiplanar reconstruction views.[11] The diagnostic aid used in Ramadi population, Iraq for investigation on ECF is dental radiography by both intraoral and panoramic view (conventional and digital). This study was based on conventional intraoral and digital panoramic view.

The detecting of ECF is necessary in root canal treatments and surgical operation such as dental implant, bone augmentation, and mandibular osteotomy, so that it can decrease the trouble of bleeding, after surgery distress, also numbness feeling after any dental dealing.

The aims of this study were to assess the existence (side, age, and gender relations) and position of the ECF to chin (mentum) foramen in chosen Ramadi City Folk guys by digital panoramic and conventional intraoral (bisecting line angle) radiographic techniques.

 Materials and Methods

A retrospective study for 100 patients (54 males and 46 females) aged from 17–49 years was carried out with the help of the digital panoramic and conventional intraoral view (bisecting line angle) for left and right side of mandible in the premolar’s area (200 sides) in the Ramadi City for dental radiology. This study was achieved under agreement of ethical approval committee of University of Anbar, Iraq (NO.21 IN 5/11/2017).

Images were obtained for wisdom tooth extraction and examination of apical disorders. The inclusion features were images with less technical mistakes, proper density and contrast, clearance of mental foramen, and the presence of mandibular first and second premolars. The exclusion features were pathological lesions in the periapical area of mandibular first and second premolars, no bone resorption or fracture, and no teeth crowding in the mandibular premolars area.

Digital panoramic radiography was performed with CS8100 digital panoramic system (Carestream Dental, Marne la Vallee Cedex 2,France). The exposure settings were 83 KVP and 8 MA and exposure time 11.48s, the gray scale and bits for panoramic machine was 4096–12 bites. Panoramic images were analyzed by CS Imaging software, SDK Modules,Trophy, France, version 7. The conventional intraoral radiograph was achieved with the CS 2100 intraoral X-ray system (Carestream Dental). The exposure settings were 60 KVP, 7 mA, and depiction duration 0.50s. Image receptor by high E-speed film was used for conventional intraoral technique with chairside developing box.

The panoramic image and intraoral images of premolars in each side of mandible for each patient were assessed for the existence of ECF in males and females, whereas ECF found on face (right or left division of lower jaw) were documented[12] and also of age coterie young and old.[13] According for position, ECFs were divided in two classes in agreement with Naitoh et al.[14] in front or behind the chin foramen [Figure 1].{Figure 1}

All obtained variables were statistically analyzed using the Statistical Package for the Social Sciences (SPSS) software, version 22.0 (IBM 200W, Madison St, Chicago, USA); χ2 test to compare between the existence of ECFs and gender of person, side of mandible, age coterie, and location of ECFs to chin foramen.


A concerned panoramic in addition to conventional intraoral images were calculated for each direction of mandible, which appeared (108 men, 54% and 92 women, 46%). The range of age of conditions was 33 years, the least was 17 years and the eldest was 49 years.

The existence for ECF by gender and mandible side was assessed. In both panoramic and conventional intraoral radiograph seven ECFs (3.5%) were found in all of the selected Ramadi City population from 200 sides of 100 persons, five ECFs for males (2.5%) were observed. Three ECFs (1.5%) were in the left side and two ECFs (1%) were in the right side. For females, two ECFs (1%) were observed, one ECF (0.5%) was in the left side and one ECF (0.5%) was in the right side). Nonsignificant variation was observed in the existence of ECF with respect to gender in both directions (left and right) of mandible bone (P > 0.05) [Table 1].{Table 1}

The presence of ECF by age coterie (n = 200) was analyzed by studying each panoramic and conventional intraoral radiograph. Four ECFs (2% from 3.5%) were seen in age group 17–35 years (111 from 200 individuals), whereas three ECFs (1.5% from 3.5%) were found in the age above 35 years (89 of 200 individuals), nonsignificant variation was observed in the presence of ECF and age coterie (P > 0.05) [Table 2].{Table 2}

The position of ECF to chin foramen was examined. The data from images of panoramic and conventional intraoral radiographs showed five ECFs (2.5%) positioned anterior from chin foramen. Meanwhile, two ECFs (1%) were located posterior to chin foramen, nonsignificant difference was observed between the positions of ECFs to chin foramen (P > 0.05) [Table 3].{Table 3}


In this study, Panoramic radiograph is plain study for demonstration the occurrence of extra chin foramens, other studies were used the panoramic to study many parameters on chin foramen and extra chin foramen. Because of a broad field of clear anatomy appearance in panoramic image. But two-dimensional images such as intra mouth and panoramic techniques had limited uses because of overlapping of anatomical parts in the lower jaw.[15]

The existences of extra chin foramens in Polish, Greek, and Japanese populations were 7%, respectively.[12],[14],[16] In Turkey, ECFs were found in 6.5% of the population.[17] In this study, the presence of ECFs was observed in 3.5% of Ramadi City population.

The extra chin foramens were observed more in males (5 ECFs, 2.5%) than that in females (2 ECFs, 1%) but the variation was statistically nonsignificant between them at (P = 0.06); studies conducted by Göregen et al.[18] (18 in men and 10 in women), Khojastepour et al.[10] (6 in men and 2 in women), and Meshram et al.[19] (9 in males and 4 in females) showed the same results, that is, males more than females.

Zmysłowska-Polakowska et al.[12] found ECFs in the right side of the mandible to be more (15 ECFs) than that in the left side (13 ECFs), but in our study, the left side had more (4 ECFs) compared to the right (3 ECFs).

In this study, the ECFs in the age group below 35 years (4 ECFs) were found to be more than that in the older age group (3 ECFs), which agrees with an earlier study by Naitoh et al.[14] The position of extra chin foramens is very important to avoid interfere during dental anesthesia and interventiona teethl surgery with neurovascular bundles emit from this foramen leads to damage them.

Katakami et al.[20] was observed of 150 patients, the 17(59%) ECFs were positioned posteriorly to chin foramen, while in this study 2 ECFs (1%) were located back to chin foramen. In our study the ECFs were located anteriorly (5, 2.5%) more than that were posteriorly. On the contrary, a study on Turkish population[18] revealed the occurrence of 22 ECFs, 12 of the ECFs were positioned anteriorly. Two-dimensional X-rays, such as intraoral or panoramic, are used in detecting ECF because they need geometry of anatomical point.[21] A conical shaped radiation techniques with computer-aided programmer and three-sided views are the most aids which are used to examine the presence of ECFs.

The data were collected in this study showed that the two-dimensional X-ray methods such as intramouth and panoramic projections could be provided anatomical informations in the area of chin to investigate about any variations in chin foramen but with diminishing benefits when they were compared to multi slices and 3-sided rendering depiction. In this study, the warning during mental anesthetic cutoff, dental implant in premolars area, and/or any teeth procedure maneuver in the chin field for males in left face of lower jaw, also young aged group less than 35 years, and area in front of chin foramen should be taken due to the existence of anatomical disturbances of chin foramen, which is referred as added hole (accessory) chin foramen, they were more exposed to injury of blood and nerves supplied from this extra chin pore during invasive teeth operation in this field such as hemorrhage and paresthesia. So the radiographic view by bidirectional dental X-ray is very necessary in presurgical treatment protocol to avoid any aforementioned complications in chin and premolar region that mean take care with risky categories.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


1Boopathi S, Chakravarthy Marx S, Dhalapathy SL, Anupa S Anthropometric analysis of the infraorbital foramen in a South Indian population. Singapore Med J 2010;51:730-5.
2Concepcion M, Rankow HJ Accessory branch of the mental nerve. J Endod 2000;26:619-20.
3Iwanaga J, Saga T, Tabira Y, Nakamura M, Watanabe K, Yamaki K The clinical anatomy of accessory mental nerves and foramina. Clin Anat 2015;28:848-56.
4Iwanaga J, Watanabe K, Saga T, Tabira Y, Kitashima S, Kusukawa J, et al. Accessory mental foramina and nerves: application to periodontal, periapical, and implant surgery. Clin Anat 2016;29:493-501.
5Bavitz JB, Harn SD, Hansen CA, Lang M An anatomical study of mental neurovascular bundle-implant relationships. Int J Oral Maxillofac Implants 1993;8:563-7.
6Haghanifar S, Rokouei M Radiographic evaluation of the mental foramen in a selected Iranian population. Indian J Dent Res 2009;20:150-2.
7Julian, RD, Chapel Hill NC Position of the mental foramen in a North American, white population. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1998;85:457-60.
8Igarashi C, Kobayashi K, Yamamoto A, Morita Y, Tanaka M Double mental foramina of the mandible on computed tomography images: a case report. Oral Radiol 2004;20:68-71.
9Torres MGG, de Faro Valverde L, Andion Vidal MT, Crusoé-Rebell IM Accessory mental foramen: A rare anatomical variation detected by cone-beam computed tomography. Imaging Sci Dent 2015;45:61-5.
10Khojastepour L, Mirbeigi S, Mirhadi S, Safaee A Location of mental foramen in a selected Iranian population: A CBCT assessment. Iran Endod J 2015;10:117-21.
11Imada TS, Fernandes LM, Centurion BS, de Oliveira-Santos C, Honório HM, Rubira-Bullen IR Accessory mental foramina: prevalence, position and diameter assessed by cone-beam computed tomography and digital panoramic radiographs. Clin Oral Implants Res 2014;25:e94-9.
12Zmysłowska-Polakowska E, Michał Łęski MR, Ledzion S, Łukomska-Szymańska M, Polguj M The assessment of accessory mental foramen in a selected polish population: A CBCT study. BMC Medical Imaging 2017;17:17.
13AL-Shayyab MH, Alsoleihat F, Dar-odeh NS, Ryalat S, Baqain ZH The mental foramen II: Radiographic study of the superior-inferior position, appearance and accessory foramina in Iraqi population. Int J Morphol 2016;34:310-9.
14Naitoh M, Hiraiwa Y, Aimiya H, Gotoh K, Ariji E Accessory mental foramen assessment using cone-beam computed tomography. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;107:289-94.
15Shoko G, Yui M, Michiko N, Hironori A, Yumiko O, Yasutomo I Accessory mental foramen misdiagnosed as radiolucent tumor by dental radiography conventional. Open J Radiol 2014;4:173-6.
16Zografos J, Mutzuri A [Incidence of double mental foramen in a sample of Greek population]. Odontostomatol Proodos 1989;43:521-3.
17Kalender A, Orhan K, Aksoy U Evaluation of the mental foramen and accessory mental foramen in Turkish patients using cone-beam computed tomography images reconstructed from a volumetric rendering program. Clin Anat 2012;25:584-92.
18Göregen M, Özkan M, İbrahim E, İbrahim ŞB, Hayati MA The assessment of accessory mental foramina using cone beam computed tomography. Turk J Med Sci 2013; 43:479-83.
19Meshram S, Gattan D, Shewale A, Gudadhe B, Dhuldhwa R Assessment of inferior alveolar nerve canal position and accessory mental foramen using CBCT to overcome surgical complication. Open Access Libr J 2017;4:1-8.
20Katakami K, Mishima A, Shiozak K, Shimoda S, Hamada Y, Kobayashi K Characteristics of accessory mental foramina observed on limited cone-beam computed tomography images. J Endod 2009;34:1441-5.
21Angelopoulos C, Thomas SL, Hechler S, Parissis N, Hlavacek M Comparison between digital panoramic radiography and cone beam computed tomography for the identification of the mandibular canal as part of presurgical dental implant assessment. Int J Oral Maxillofac Surg 2008;66:2130-5.