Histological changes at the commissure of the lip on approaching from its cutaneous to the mucosa region in males.

Introduction: The morphology of the epithelium of the oral lips comprised keratinized external epithelium (anteriorly) and nonkeratinized or sometimes parakeratinized mucous membrane epithelium (posteriorly). Knowledge of morphometry of the lip lining helps in deciding the best site for choosing graft for its better uptake during several dermal grafting procedures following trauma or tumor excision following craniofacial cancers or cosmetic procedures.

Materials And Methods: Ten human male cadavers were procured at the Department of Anatomy King George's Medical University, Lucknow, Uttar Pradesh. The rectangle-shaped skin specimen through the right commissure of the lip which included the skin, mucocutaneous junction, and mucosa was stained with hematoxylin and eosin stain. A total of 30 slides were prepared. Thus, the readings were obtained for three regions, respectively, with the help of CAT-CAM E-series HD cameras which were installed in a light microscope.

Results: Thickness of skin (epidermis + dermis) of the lip ranged from 756 μm to 1068 μm among males. Epidermal thickness increases on moving from the cutaneous region to the mucosa region of the lip. The lowest contribution of the stratum corneum in thickness of the epidermis was observed in the vermillion region, while the highest contribution was observed in the skin region. It was found to be absent in the mucosa region of the lip. Rete pegs at the dermoepidermal junction was found to be maximum in the vermillion region and minimum in the skin region. Its depth increased as we move from the skin to the mucosa region of the lip. Depth of the dermis was found to be maximum in the skin region, while minimum in the vermillion region. It ranged between 291 μm and 693 μm.

Conclusion: Care should be taken while using dermal fillers in lip augmentation surgeries, especially in the vermillion region due to its close proximity to musculature in the core of the lip.