VARIATIONS IN MENTAL FORAMEN POSITION & NUMBER IN POPULATION OF MADHYA PRADESH STATE ( CENTRAL INDIA )

Address for Correspondence: Dr. Ritu Bala Soni , Assistant professor, Gandhi Medical College, Bhopal, M.P, India. E-Mail: ritubala602@gmail.com Introduction: Mental foramen is a important landmark for giving anesthesia and surgical operation of low jaw and teeth (dental surgery). Aim: So this study done with a purpose to knowing exact position of mandibular foramen . Materials and Methods: For this study Fifty mandible bones (toothed / Non-toothed mandibles) belonging to Madhya-Pradesh state were studied. All mandibles are of adult person (of either sex male/Female). In study we observe Position of mental foramen in relation with body of mandible (distance from symphysis menti, from posterior border of ramus of mandible, from base of mandible & from alveolar margin ) and in relation with tooth (below molar or below premolar). Result: We find out Mean Distance between mental foramen and base of mandible 10.5 mm , Mean Distance of mental foramen from alveolar margin -15.25 mm. Mean distance between mental foramen and symphysis menti was 30.00mm. Mean distance of mental foramen from posterior border of ramus -60.00mm . In study we also observe number of mental foramen on each side in a single mandible.


Article Information
Mental foramen located bilaterally on anterolateral surface of of mandible.From mental foramen, mental nerve (branch of Inferior alveolar nerve of mandibular nerve (Part of 5 th nerve) immerges [1].In dental operative surgery if there is damage of mental nerve, anesthesia occur in chin area.So identification of exact position of mental foramen is very necessary.In periodontal surgery, flap operation of lower teeth and other lower lip surgical operation, where block anesthesia for mental nerve is choice.Exact point of emergence of mental nerve is very important before implant dental surgery to avoid mental nerve injury.
Mandible is bone of lower jaw.It is a movable bone .Mandible is tooth bearing bone .Each mandible has a single body, two ramus, two condyle and two coronoid process It has 2 ramus (right & left) Rami at its upper end has 2 process , condyler (at anterior end) and coronoid (at posterior end).Each ramus has inner / medial and outer /lateral surface.Inner /medial surface of ramus has a mandibular foramen and outer /lateral surface has a mental foramen.Mandible has lower margin (base), upper margin (alveolar creast -in which tooth socket present),outer and inner surface.Outer surface of body of mandible is placed antero-laterally.
Present study was done on mandibles in Madhya-Pradesh state to find out exact position of mental foramen (For knowing exact emerging point of mental nerve).Aim and Objective: To find out exact position of Mental Foramen to prevent damage of mental nerve in dental surgery.But in our study mental foramen was found nearer to the base, This finding is also supported by Wang et al (1986).

MATERIALS AND METHODS
In our study ratio between oval & circular types of mental foramen was 1:2.33 .According to De Frietas et al (1979) 7 Mental foramen were absent in 0.4% mandible.But in our study mental foramen was found in each mandible.Absence of mental foramen not observed in our study.In our study double mental foramen (Accessory mental foramen) a mandible was found in 6% cases .Gershensn et al (1986) 8 found double mental foramen in 4.71% in adult Indian mandible and 2.8% in adult Israeli mandible.3 Mental foramen also reported in 1.14% in adult Israeli mandible.Accessory mental foramina of mandible are usually unnamed and infrequently described .Yet a study of 2450 mandible 300 accessory mental foramina was found (Sutton 1974).In this study we found Accessory mental foramina in 6% cases.Since mostly Accessory mental foramina transmit a small nerves to teeth (bransh from facial / mylohyoid / buccal / transverse cervical cutaneous ), their occurrence is significant in dental blocking procedure .(gray's anatomy) 9 After all above discussion measurement of body of mandible, position, size & No. of mental foramen vary with population.
In present study most common position of mental foramen was below between !st and 2 nd premolar (60%).According to Tebo & Telford

Fifty
dry human mandibles (toothed/Nontoothed mandibles) belonging to Madhya-Pradesh state (We collect Mandible from various medical college of Bhopal, Gajra Raja Medical College (Gwalior), Bundelkhand Medical College (sagar), M.P. are materials sued for this study.Various parameters measured from mental foramen on right and left side are (1) Vertical distance from alveolar crest (2) Vertical distance from base of mandible (3) Distance from symphysis menti (4) distance from posterior border of mandible along a line drawn parallel to horizontal plane (5) Relationship of mental foramen to teeth (Molar/Premolar) (6) Number of mental foramen on each side.(7)Shape (oval/circular) All these above parameter measured by a digital vernier caliper and statistically analyzed by mean.
ramus (P)-60.00mmRatio between (S )& (P) -1:2 (3) It was observed that mental foramen is nearer to base of mandible -Distance between base to mental foramen (B) -10.5 mm (4) Distance between alveolar margin to mental foramen (A) -15.25 cm.Total height of body of mandible (From alvelor crest to base of mandible) -25.75 mm (A+B distance) Various parameter studied are follows (1) Mean distance between mental foramen and symphysis menti was (S)-30.00mm.(2) Mean distance from posterior border of

2 (
1950) position of mental foramen in 49% case was below to apex of 2 nd premolar.It was position below 2 nd premolar byMiller (1953) 3 .By Wang et al (1986)4 it was 58.98% cases.How ever in British mandible (santini & land, 1990)5 , the mental foramen lie below between 1 st & 2 nd Premolar teeth in 65% cases.In present study ratio of distance from symphy-Conflicts of Interests: None

Table 1 :
Measurements of various parameters.

Table 2 :
Position of mental foramenMandible showing most common position of mental foramen -between 1 st & 2 nd premolar Fig. 8: Showing mental foramen Below 2 nd Premolar

Table 3 :
Shape of mental foramen: Ritu Bala Soni, Sushil Jiwane, et al., VARIATIONS IN MENTAL FORAMEN POSITION & NUMBER IN POPULATION OF MADHYA PRADESH STATE (CENTRAL INDIA).