CLINICAL ANATOMY OF THE MANDIBULAR AND MAXILLOFACIAL REGIONS OF THE INDIGENOUS BLACK BENGAL GOAT. 

                               
A Clinical Report Submitted By:
       Roll No: 2003/30
       Reg. No: 126
       Internship ID: F-28
       Session: 2002-2003

Submitted in partial of the requirement for the fulfillment of the degree of
Doctor of Veterinary Medicine (DVM)

Chittagong Veterinary and Animal Sciences University
Khulshi, Chittagong-4202

June, 2009

CLINICAL ANATOMY OF THE MANDIBULAR AND MAXILLOFACIAL REGIONS OF THE INDIGENOUS BLACK BENGAL GOAT.

A Clinical Report Submitted By:
                                    		      Name: Md. Mominul Islam
       Roll No: 2003/30
       Reg. No: 126
       Internship ID: F-28
       Session: 2002-2003

Submitted in partial of the requirement for the fulfillment of the degree of Doctor of Veterinary Medicine (DVM)

Approved as to style and content by

(DR. MOHAMMAD MEJBAH UDDIN)
Assistant Professor
Department of Anatomy and Histology

Chittagong Veterinary and Animal Sciences University
Khulshi, Chittagong-4202

June, 2009

INDEX
Sl. No.	Name of the contents	Page	
01	Acknowledgement	V	
02	Abstract	VI	
03	Introduction	01	
04	Review of Literature	02-04	
05	Materials and Methods	05-08	
06	Results and Discussion	09-10	
07	Conclusion 	11	
08	Reference	12-13	

LIST OF THE TABLES
Table No.	Name of the tables	Page	
01	The measurements of the upper jaw and mandible of black Bengal goats (cm)	09	

LIST OF THE FIGURES
Fig. No.	Name of the figures	Page	
01	Skull of black Bengal goat, Lateral view	06	
02	Mandible of black Bengal goat, Lateral view	07	
03	Mandible of black Bengal goat, Median view	07	
04	Mandible of black Bengal goat, Median view	08	

ACKNOWLEDGEMENT

                                  The author would like to express his deep sense of gratitude to beloved teacher and Supervisor DR. Mohammad Mejbah Uddin, Assistant Professor, Department of Anatomy and Histology, Chittagong Veterinary and Animal Sciences University for his scholastic guidance, suggestion and appreciation during study period. 

The author wise to thanks beloved teacher Asraf Ali. Biswas, Director, External affairs and Associate Professor, Department of Animal Science and Animal Nutrition, Chittagong Veterinary and Animal Sciences University. 

The author would like to express his deep sense of gratitude and thanks to Professor Dr. Md. Abdul Matin Prodhan, Dean, Veterinary Medicine, Chittagong Veterinary and Animal Sciences University.

The author would like to express his deep sense of gratitude and thanks to Professor Dr. Nitish Chandra Debnath, Vice- Chancellor, Chittagong Veterinary and Animal Sciences University.

The author wise to thanks to Biplob Ahmed, Laboratory attended, Department of Anatomy and Histology for helping me during my laboratory activities. 

 Author

Clinical Anatomy of the Mandibular and Maxillofacial Regions of the Indigenous Black Bengal Goat in Bangladesh

ABSTRACT

The study involved the measurements of some clinically important landmarks for regional anesthesia in the mandibles and upper jaws of thirty black Bengal goats. The length and maximum height of the mandibles were 14.21 cm and 8.83 cm respectively. The distance from Caudal border of mandible to below mandibular foramen was 1.47 cm, while the distance from the mandibular foramen to the base of the mandible, Caudal border of mandibular to the level of mandibular foramen and mandibular foramen to border of mandibular angle were 3.64 cm, 0.90 cm and 2.65 cm respectively. The distance between the lateral end of the alveolus of the incisor tooth to the mental foramen was 2.11 cm from the mental foramen to the caudal Mandibular border was 11.69 cm. Facial tuberosity to the infraorbital canal and from the latter to the root of the alveolar tooth directly ventral to it were in the range of 1.85- 2.07 cm and 1.59 – 2.09 cm respectively. These data was discussed with regard to their application in proper tracking of mandibular, mental and infraorbital nerves in aid of regional anesthetic procedures for the clinical affection around the head of the black Bengal goat such as during dental extraction and was compared with the both West African Dwarf and Red Sokoto goat breeds.

......................................................................................................................................................
KEY WORDS: Clinical Anatomy; Skull; Goat. 

Chapter-I

INTRODUCTION

       Black Bengal goat is the only recognized breed among the domestic species in Bangladesh. The goats are known to be famous for their adaptability, prolificacy, delicacy of meat and superior skin quality. They have tremendous demand all over the world due to production of extra ordinary quality meat and skin (Islam et al., 1991; Singh et al., 1991a; Singh et al., 1991b).
The form and relationships of all organs present in a particular area are directly concerned with regional anatomy which helps the clinician / surgeon to visualize details of structures relevant to the case at hand and form one of the important foundations for clinical and surgical practice (Dyce et al., 1996). 
        Vital organs and structures such as the brain, tongue, eyes as well as ears, teeth, nose, lips, horn and skull are situated in head region. The regional anatomy of head region is needed for coordinatining the body as well as for deglutition, olfaction and defiance (Dyce et al.; Olopade, 2003) especially the foramina in the skull are very important for clinical /surgical aspect/ regional anesthesia around the head (Hall et al., 2000). Some previous work had been done on the heads of domestic animals including the horse, ox, dog and West African Dwarf Goat (Getty, 1975; Dyce et al.; Onar et al., 2001; Olopade & Onwuka, 2005; Olopade & Onwuka, 2007). However, apart forms a preliminary report on the brain morphometry (Onwuka et al., 2003), dental eruption and oral pathologies (Otesile & Obasaju, 1982; Kene & Agbo, 1998), clinical applications of the mandibular and maxillofacial osteometry of the West African Dwarf goat (Olopade & Onwuka, 2005, 2006, 2007). There is very little information on the regional anatomy of the head of black Bengal goats. 

Objective
•	To provide anatomical information on clinically important parameters that may aid regional anesthesia of the head in the lower and upper jawbones of the black Bengal goat.

Chapter-II

REVIEW OF LITERATURE

The maxillary nerve runs across the wall of the pterygopalatine fossa ventral to the orbit. It bears or lies close to the pterygopalatine ganglion but the relationship is purely topographical. It then enters the infraorbital canal at the maxillary foramen where it becomes known as the infraorbital nerve in anticipation of its reappearance on the face at the infraorbital foramen.     Within the infraorbital canal the infraorbital nerve detaches short twigs to the alveoli of the cheek teeth and nasal mucosa and longer rostral alveolar branches that continue within the bone beyond the infraorbital foramen to the alveoli of the canine and incisors teeth(Dyce et al., 1996).

The infraorbital nerve is the direct continuation of the maxillary nerve. It enters the infraorbital canal at the maxillary foramen and reappears rostrally on the face through the infraorbital foramen. It gives off alveolar branches (rami alveolares) to the maxillary cheek teeth and innervates the muzzle and the upper lip(Konig and Liebich, 2005).

The infraorbital nerve is the continuation of the maxillary nerve in the infraorbital canal. In the canal it gives off the middle maxillary alveolar branches which supply dental branches to the first molar teeth. The infraorbital nerve then emerges in the lateral nasal region through the infraorbital foramen. Here it is deeply situated to the depressor labii maxillaries, the caninus muscle and the levator labii maxillaries and usually divides into a dorsal and ventral group of branches. The dorsal group is larger and after coursing rostrad, gives off the external and internal nasal branches and then continues as the rostal maxillary labial branches. The external nasal branches ramify in the skin of the lateral and nasal regions. The internal nasal branches distribute in the mucosa and skin of the nasal vestibule. The rostral maxillary labial branches terminate in the rostral portion of the upper lip. The ventral group is usually constituted by a small branch, the caudal maxillary labial branch which in some cases leaves the infraorbital canal through an accessory foramen located ventral to the infraorbital foramen. It courses rostrad and ventrad to the caudal portion of the upper lip(Getty, 1975).

The infra-orbital nerve is the continuation of the maxillary division of the fifth cranial nerve after it crosses the pterygopalatine fossa and enters the infra-orbital canal. The nerve emerges on the face as a flat band about 1 cm broad, through the infra-orbital foramen where it is partly covered by the levator nasolabialis muscle. During its course along the infra-orbital canal it supplies to the upper molar, canine and incisor teeth on that side with their alveoli and contiguous gum(Hall et al., 2000).

On leaving the cranium, the mandibular nerve detaches in close succession several nerves that pass to the masseter, temporalis, medial and lateral pterygoid, tensor veli ralatini, and tensor tympani muscles. The mandibular nerve continues between the medial and lateral pterygoid muscles before dividing into its end-branches, the lingual and inferior alveolar nerves. The inferior alveolar nerve detaches the mylohyoid nerve for the mylohyioideus and rostral belly of the digastricus before entering the mandibular canal at the mandibular foramen. The inferior alveolar nerves supplies the lower cheek teeth before a large part reappears at the mental foramen as the mental nerve which supplies tissues of the lower lip and chin(Dyce et al., 1996).

The mandibular is as strong as the maxillary nerve but in contrast to the other branches of the trigeminal nerve it is both sensory and motor. It provides motor innervation to the buccal cavity, tongue, mandibular teeth, lower lip and parts of the facial skin. The mandibular nerve terminates by bifurcating into the lingual and the inferior alveolar nerves. The inferior alveolar nerves passes between the lateral and medial pteryigoid muscles. Before entering the mandibular canal at the mandibular foramen, it detaches its last motor branch, the mylohyoid nerve which innervates the mylohyioideus muscle and the rostral belly of the digastric muscle. It passes through the mandibular canal supplying alveolar sensory nerves to the teeth and reappears at the mental foramen as the mental nerve which innervates the skin and mucosa of the lower lip and chin(Konig and Liebich, 2005).

The mandibular nerve detaches from the ventral aspect of the trigeminal ganglion. It leaves the cranial cavity through the oval foramen, courses ventrad, rostrad and a little lateral, covered by pterygoideus lateralis muscle. After a short distance the mandibular nerves gives off from its dorsal aspect a large branch from which arise the buccal, massereric and lateral pterygoid nerves and supplies pterygoideus lateralis muscle, temporalis muscle and masseter muscle. The mandibular nerve continues coursing ventrad and rostrad and before dividing into its terminal branches, the lingual and mandibular alveolar nerves. The mandibular alveolar nerve courses ventrad over the lateral surface of the pterygoideus medialis muscle and in company with the artery of like name, penetrates the mandibular foramen close to its origin it furnishes the mylohyoid nerve. The mylohyoid nerve courses parallel with and caudal to the parent trunk and passes obliquely between the insertion portion of the pterygoideus medialis muscle and the body of the mandible. At the border of the mylohyioideus muscle it gives off several twigs to this muscle and to the rostral belly of the digastricus muscle. It then course rostrad along the medial surface of the mylohyioideus muscle, perforates this muscle and reaches the rostral portion of the mandibular space distributing to the skin of the region. Inside the mandible the mandibular alveolar nerve runs in the mandibular canal where it gives off caudal and middle mandibular alveolar branches to the molar teeth. At the mental foramina it continues as the mental nerves which are distributed to the skin of mental region and adjacent areas(Getty,1975).
 
The alveolar branch of the mandibular division of the fifth cranial nerve enters the mandibular foramen on the medial aspect of the vertical ramus of the mandible under cover of the medial pterygoid muscle. It transverses the mandibular canal, giving off dental and alveolar branches on that side and emerges from the bone through the mental foramen. From this point it is styled the mental nerve. The nerve supplies the canine and incisor teeth arise from the parent trunk within the e canal 3 to 5 cm behind the mental foramen and pass to the teeth within the bone(Hall et al., 2000). 

Some measurements in the mandibles and upper jaws of West African Dwarf goats were estimated. The length and height of the mandibles were 12.00 cm and 6.90 cm respectively. The distance from the lateral alveolar root to the mental foramen, from the mental foramen to the caudal mandibular border, from mandibular foramen to base of mandible were 1.56 cm, 9.96 cm and 2.58 cm respectively. The distance from facial tuberosity to infraorbital canal and from infraorbital canal to root of alveolar tooth were 1.6-1.8 cm and 1.3-1.6 cm respectively(Olopade & Onwuka, 2005).The measurements of some clinically important landmarks for regional anesthesia in the head of Red Sokoto goats were analyzed. The length and maximum height of the mandibles were 12.7 cm and 7.7 cm respectively. The distance from the mandibular foramen to base of mandible was 3.0 cm while the distance between the lateral alveolar root & mental foramen and from facial tuberosity to the infraorbital canal were 2.00 cm and 1.8 cm respectively (Olopade & Onwuka, 2007).    

Chapter-III

MATERIALS AND METHODS

 A total of 30 back Bengal goats were used for this study. The live animals were first selected during antemortem examination at an abattoir based on parameters of apparent good health and no skeletal deformation. After slaughter, the heads were severed at the occipitoatlantal joint, purchased and processed in the anatomy laboratory of Chittagong Veterinary and Animal Sciences University using the hot water maceration techniques as described by Simoens et al., (1996) which briefly were:
1. On the working day, frozen goat head were allowed to thaw. 
2. Skin and most of the muscles were separated and eyes were enucleated
3. Heads were heated to over 80ºC for at least 1 hour in solution of polycaboxylate and anionic surfactant (detergent) and soap chips.
4. Muscle of boiled heads were separated with the aid of forceps and scalpel in running water
5. Further separation of muscles and ligaments from the skulls was done after left in detergent water at least 20-30 minutes
6. Separation of remaining muscles and ligaments from the skull was done after left I n 1% sodium hypochlorite solution for at least 24 hours
8. After that, the skulls were left in the above solution, for 48-72 hours with solution, being changed at least twice and clean in running tap water 
9. The skulls were then left to dry. 
 A total of 12 measurements were done in the upper jaw and mandibles using metric rules and the results were presented and as means ± sd in table 1.   The parameters measured of the upper and lower jawbones of the Black Bengal skulls are described below and shown in Figs.1- 4.
A.	Facial tuberosity to infra-orbital canal: From the level of the most lateral bulging of the facial tuberosity to the mid level of the infra-orbital canal 
B.	Infra-orbital canal to root of alveolar tooth: Measurement is taken vertically from the mid-level of   the in infra-orbital canal to the root of the alveolar tooth
C.	Mandibular length: From the level of the cranial extremity of the alveolar root of the incisor to the level of the caudal border of the mandible.
D.	Lateral alveolar root to mental foramen: Shortest distance from the mental foramen to the lateral extent of the alveolar root of lower incisor.
E.	Mental foramen to the caudal mandibular border: From the level of the mental foramen to the extreme caudal border of the mandible.
F.	Mandibular foramen to base of mandible: Vertical line from the ventral limit of the mandibular foramen to the base of the mandible.
G.	Caudal border of mandible to below mandibular foramen: Length from the caudal most border of the mandible to the vertical line produced by description of measurement of mandibular foramen to base of the mandible.
H.	Condyloid fossa to height of mandible: From the maximum height of mandible to the condyloid fossa.
I.	Condyloid fossa to the base of the mandible.
J.	Maximum mandibular height: From the basal level of the mandible to the highest level of the coronoid process.   
K.	Caudal border of mandibular to the level of mandibular foramen
L.	Mandibular foramen to mandibular angle:  Shortest distance from the mandibular foramen to the extreme caudal border of the angle of the mandible.

Fig. 1. Skull of black Bengal goat, Lateral view.
A: Facial tuberosity to infraorbital canal
B: Infraorbital canal to root of alveolar tooth

Fig. 2. Mandible of black Bengal goat, Lateral view.
C: Mandibular length , D: Lateral alveolar root to mental foramen
E: Mental foramen to caudal base of mandible

Fig. 3. Mandible of black Bengal goat, Median view. 
F: Mandibular foramen to base of mandible, G: Caudal border of mandible to below mandibular foramen, H: Condyloid fossa to height of mandible, I:  Condyloid fossa to the base of the mandible, J: Maximum mandibular height.

Fig. 4. Mandible of black Bengal goat, Median view.
K: Caudal border of mandibular to the level of mandibular foramen
L:  Mandibular foramen to border of mandibular angle

Chapter-IV
RESULTS AND DISCUSSIN

Table 1. The measurements of the upper jaw and mandible of black Bengal goats (cm)
	Mean value	sd	
A 	1.85	0.14	
B 	1.75	0.19	
C	14.21	0.98	
D	2.11	0.17	
E	11.69	0.40	
F	3.64	0.23	
G	1.47	0.25	
H	2.36	0.23	
I	6.38	0.51	
J	8.83	0.57	
K	0.90	0.15	
L	2.65	0.31	
   
    The mandibular length of 14.21± 0.98 cm maximum mandibular height of 8.83 ± 0.57 cm in black Bengal goat were higher than the value obtained for West African Dwarfs goats of Nigeria which were 12.00±1.89 cm and 6.90±1.09 cm respectively (Olopade &Onwuka, 2005), similar observations were seen in the values of the distances between the condyloid fossa to height of mandible, Condyloid fossa to the base of the mandible, Mandibular foramen to base of mandible (Fig 2, 3)(Olopade &Onwuka, 2005, 2006)
The caudal border of the mandible to the vertical line downwards form the middle of the mandibular foramen (Fig. 3) was 1.47± 0.25 cm, while the distance from the mandibular foramen to the base of the mandible, Caudal border of mandibular to the level of mandibular foramen and mandibular foramen to border of mandibular angle were 3.64 ± 0.23cm, 0.90 ± 0.15 cm and 2.65 ± 0.31 cm. (Fig 3 & 4). These parameters are of clinical important landmarks that will aid the regional anesthesia of mandibular nerve block necessary for desensitization of all the teeth in lower jaw of the side of the block (Hall et al., 2000). Equivalent figures for West African Dwarfs goats of Nigeria were 1.57±0.44 cm, 2.58±0.34cm respectively for Caudal border of mandible to below mandibular foramen and mandibular foramen to the base of the mandible (Olopade &Onwuka, 2005) though in the horse and dogs were 3cm and 1.5 to 2 cm respectively for the distance between the mandible foramen and base of the mandible (Hall et al., 2000). 
The distance between the lateral end of the alveolus of the incisor tooth to the mental foramen was 2.10 ± 0.17 cm as seen in fig 2 is an important landmark in achieving this block in black Bengal goat while that was 1.6 ± 0.22 cm and 2.0± 0.3 cm in West African Dwarf goat and Red Sokoto (Maradi) goat of Nigeria respectively (Olopade &Onwuka, 2005, 2007). In the anterior aspect of the mandibular canal, injection can be made through the mental foramen to desensitize mental aspect of the mandibular nerve. This will ensure the loss of sensation of the lower incisors, premolar and lower lip on that side (Hall et al., 2000)
The distance from the facial tuberosity to the infraorbital canal and from the latter to the root of the alveolar tooth directly ventral to it were 1.85 ± 0.14 cm and 1.75± 0.19 cm respectively in black Bengal goat while in West African Dwarfs goats   were 1.6 -1.8 cm and 1.3-1.6 cm .The data is of clinical importance because the facial tuberosity is very prominent even in live animals as a guide to tracking the infraorbital nerve, and the data obtained in this study will greatly facilitate precise tracking of the nerve, the desensitization of which affects the skin of the lip, nostril and face on that side of the level of the foramen. The injection of local anesthetic agents within the canal via the infra-orbital foramen will also lead to analgesia of the incisor, canine and first two premolars. 
The infra-orbital foramen was located directly dorsal to the second or junction of the first and second upper premolar in black Bengal Goat where as in premolar two in Red Sokoto goats (Olopade &Onwuka, 2006).This information coupled with the observed distance of 1.59 cm – 2.08 cm between the root of the teeth and the foramen would prove a vital guide to regional anesthesia involving the infra-orbital nerve in the black Bengal goat. 
As earlier stated, there is no previous information on these parameters in black Bengal goat, nor in any other goat breeds and domestic animals in Bangladesh with which comparisons could be made. We therefore believe that the data presented above will form a vital baseline for further work especially comparability and compatibility are now desirable traits as efforts are geared up towards massive improvement in the livestock sector of the international economy. 

Chapter-V

CONCLUSION

Anesthetic agents should inject in appropriate site for good surgery. Therefore the study was undertaken to provide information on clinical important parameters that may help regional anesthesia of the head in the lower and upper jawbones of the Black Bengal Goat. The length of the mandibles was 14.21 cm and maximum height was 8.83 cm. The distance from Caudal border of mandible to below mandibular foramen was 1.47 cm, while the distance from the mandibular foramen to the base of the mandible, Caudal border of mandibular to the level of mandibular foramen and mandibular foramen to border of mandibular angle were 3.64cm, 0.90 cm and 2.65 cm respectively. The distance between the lateral end of the alveolus of the incisor tooth to the mental foramen was 2.11 cm from the mental foramen to the caudal Mandibular border was 11.69 cm. Facial tuberosity to the infraorbital canal and from the latter to the root of the alveolar tooth directly ventral to it were in the range of 1.85- 2.07 cm and 1.59 – 2.09 cm respectively. These measurements may help in proper tracking of mandibular, mental and infraorbital nerves in aid of regional anesthesia during any surgical affections of the head region of the black Bengal goat.

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