Analysis of the mental foramen using cone beam computerized tomography

Abstract

ResumoIntrodução: O conhecimento das estruturas anatômicas localizadas na região entre os forames mentuais é de importância crucial nos planejamento pré-operatórios. Objetivo: Avaliar a posição do forame mentual relacionado aos ápices dos dentes, sua distância aos bordos da mandíbula com uso da tomografia computadorizada de feixe cônico. Material e método: Foram avaliadas 100 tomografias computadorizadas de feixe cônico da mandíbula realizada num único aparelho de tomografia. Cada imagem escolhida foi avaliada de forma repetida para ambos os lados da mandíbula, a posição do forame mentual, indicando a região em que o forame se encontrava e as medidas do forame mentual a cortical lingual e base da mandíbula. Os dados foram analisados inicialmente de forma descritiva. Um valor de p<0,05 foi escolhido como o nível de significância. Resultado: 42% dos forames mentuais estavam localizados no ápice do segundo pré-molar. A margem lingual do forame mentual localizou-se em média de 3,1 mm a partir da cortical lingual. A margem inferior do forame mentual foi localizada 7,25 mm acima da borda inferior da mandíbula. Conclusão: O forame mentual localizou-se com maior frequência em nível dos ápices dos segundos pré-molares, com distância à cortical lingual, em média, de 3,1 mm e base da mandíbula, em média, de 7,25 mm.Descritores: Nervo mandibular; mandíbula; tomografia computadorizada de feixe cônico. AbstractIntroduction: Knowledge of the anatomical structures located in the region between the mental foramina is of critical importance in pre-operative planning. Objective: To evaluate the position of the mental foramen relative to the apices of the teeth and the distance to the edges of the mandible, using cone beam computerized tomography. Material and method: One hundred cone beam computerized tomographs of the mandible were evaluated; the tomographs were taken using a single tomographic device. Each image chosen was evaluated repeatedly from both sides of the mandible, the position of the mental foramen, indicating the region in which the foramen was found and the measures of the mental foramen, the lingual cortex and the mandibular base. Initially, the data were analyzed descriptively. A value of p<0.05 was chosen as the level of significance. Result: Forty-two percent of the mental foramina were located in the apex of the second pre-molar. The lingual margin of the mental foramen was located, on average, 3.1mm from the lingual cortex. The lower margin of the mental foramen was located 7.25 mm above the lower edge of the mandible. Conclusion: The mental foramen was located more frequently at a level of the apices of the second pre-molars, with a distance to the lingual cortex, on average, of 3.1mm and to the base of the mandible, on average, of 7.25 mm.

Evaluation of mental foramen – A CBCT assessment

“…This findings correlated with the studies performed by Saito et al 4 and Pyun et al, 9 wherein Saito et al 4 found that the lingual edge was located, on average, 3.1 mm from the lingual cortex, with no statistically significant influence with age or sex had and Pyun et al, 9 who conducted a study to investigate the deviation of the buccolingual pathway from the mandibular canal and the relationship with the location of the mental foramen found a mean value of 5.60 mm of the buccolingual measurements, using computerized tomography and the most common location of MF was along the long axis of 2 nd premolar. Their results were larger than those of the present study as they measured from the center of the mandibular canal to the lingual cortex of the mandible.…”

“…It was in accordance with the studies performed by Saito et al 4 , Leila et al, 6 Haghanifar S et al 7 and Gupta S et al Saito et al 4 found about 45% of the mental foramina were located in the apex of the second premolar. Similar findings were recorded by Leila et al 6 who performed a study, using 158 CBCT images and Haghanifar S et al, 7 who evaluated 400 panoramic radiographs with regard to the location and symmetry of the mental foramina and found that in 49.2% of radiographs, MF was in line with the second premolar.…”

“…In case of the measurement of MF above the lower edge of mandible, it was found to be located on average of 8.4 mm (males) & 7.1 mm (females) which was similar to the study performed by Saito et al, 4 who found a mean value of 7.9 mm (males) & 7 mm (females), in 100 CBCT images. Age had no statistically significant influence (p=0.5109), but sex was found to have statistical significant (p=0.0001).…”

“…3 Although the region between the mental foramen and the mandible is considered a safe region for surgical procedures such as the removal of bone graft, placement of plates for the fixation of fractures, mentoplasty, orthognathic surgery and placement of osseointegratable implants, it presents a risk of injury to the neurovascular structures. 4 Hence the knowledge on the anatomic characteristics and variations of mental foramen is very important in surgical procedures involving that area.…”

Morphometric Evaluation of the Mental Foramen Using Cone Beam Computed Tomography in Different Facial Types.

“…The inferior alveolar nerve bundle enters the lower jawthrough the mandibular foramen, passes along the mandibular canal and exits from the mental foramen as the mental nerve on the body of the mandible above the tubercleof the chin [3] .Determining the precise location of the mental foramen is a key factor when considering placing dental implants or when surgical proceduresare planned in the foramenregion [4] . The precise location of such foramen is also important in some dental specialties including Operative Dentistry, Periodontics, Endodontics and OrthognathicSurgery, whenever a local anesthesia procedure is to be carried out [5][6][7][8] . In adults, the mental foramen islocated on average between 13mm and 15mm above the inferior mandibular border, but in adults presenting with bone resorption, the foramen is located closer to the alveolar crest and sometimes over it [9] .One problem in determining the precise location of the mental foramen is that such a structure cannot be neither visualized nor palpated and thus, more advanced visualization techniques DOI: 10.9790/0853-1606037885 www.iosrjournals.org 79 | Page have to be used.…”