Unilateral and Complete Agenesis of Right Pectoralis Major Muscle.

Introduction: Pectoralis major Myocutaneous flaps (PMMC) are extensively used for Head, Neck, Face and post mastectomy mammary gland reconstructive surgeries. Pectoralis major is responsible for flexion, adduction and medial rotation of shoulder joint. Its absence may obvious because of compromised movement of shoulder joint or as a part Poland’s syndrome or may be sporadic as seen in our case. Case study: Pectoralis major muscle was completely absent on right side of an adult female cadaver. Result: Complete unilateral agenesis of right Pectoralis major muscle was found in an adult female cadaver during routine undergraduate dissection in the department of Anatomy. Right Mammary gland was lying directly on hypertrophied Pectoralis minor muscle. Discussion: Awareness about absence of Pectoralis major muscle is a must for planning and success of various reconstructive surgeries, flawless interpretation of Radiographs, CT and MRI scans. Unilateral and complete agenesis of Pectoralis major muscle not associated with any other anomaly visible to naked eye as seen in our case is a rare finding and hence needs to be documented.

Morphometric study of infraorbital foramen in dry human skulls.

Background & Objectives:To study the most precise location, shape and direction of infraorbital foramen in dry human skulls, in relation to Infraorbital Margin, Piriform Aperture(PA) and Upper Alveolar Margin(AM). Method: A total of one hundred dry human skulls of unknown gender were measured using digital calliper with Infraorbital Margin, Piriform Margin and Alveolar Margin as reference points. The location, shape, size, direction and number of accessory foramina were observed. Results: The mean distance between the Infraorbital Margin(IOM) and Infraorbital foramen(IOF) was 7.82mm. There was a statically significant difference on right and left sides. The mean distance between the IOF and the piriform aperture(PA) was 16.01mm. The overall vertical diameter of the IOF was 3.23±0.98mm (right) and 3.25±1.03mm (left ). The overall horizontal diameter of IOF was 3±0.76mm(right) and 3.28±0.99mm ( left).The majority of IOF were directed inferiomedially on both the right (51%) and left (50%) side. There was a superiomedially directed IOF in 1% of skulls, which was not mentioned in the previous literatures. Accessory foramina were found in 20% skulls. Interpretation & Conclusion: Infraorbital foramen is located close to important anatomical structures like orbit, nose, oromaxillary sinuses and upper teeth. The knowledge of anatomical characteristics of the location ,dimension, shapes, directions and number of accessory foramina have clinical implications in the infraorbital nerve block. This information should be kept in mind during local anaesthetic planning for surgeries in the field of Dentistry, ENT, Anaesthesia, Ophthalmology and Surgery.