**Question:** Caldwell-Luc's operation is done for:

A. Facial nerve injury
B. Nasal obstruction due to polyps or tumors
C. Mandibular angle fracture
D. Nasal septum deviation

**Core Concept:**
Caldwell-Luc's operation is a surgical procedure named after its inventor, Dr. Archibald Caldwell and Dr. Luc. It is a procedure designed to access the paranasal sinuses for diagnostic or therapeutic purposes, particularly in cases where the standard endoscopic approach is not feasible or effective. This can involve removing or decompressing the affected sinus, addressing any underlying pathology, and ensuring adequate drainage.

**Why the Correct Answer is Right:**
Caldwell-Luc's operation is typically performed for cases of nasal obstruction due to polyps or tumors (option B). This procedure allows for direct access to the sinuses, which are often difficult to reach endoscopically. By removing or decompressing the affected sinus, the surgery aims to alleviate symptoms and ensure proper drainage, especially when endoscopic techniques are inadequate or needed for specific indications.

**Why Each Wrong Option is Incorrect:**
A. Facial nerve injury is not a primary indication for Caldwell-Luc's operation. Instead, facial nerve injury would generally require a different surgical approach, such as a decompression or reconstruction procedure.

C. Mandibular angle fracture is not a common indication for Caldwell-Luc's operation. Instead, mandibular angle fractures are typically managed through closed reduction and fixation, with more complex interventions like Caldwell-Luc's operation reserved for specific cases.

D. Nasal septum deviation is another incorrect indication for Caldwell-Luc's operation. Septoplasty or turbinate surgery are more suitable treatments for nasal septum deviation, focusing on correcting the anatomic obstruction rather than accessing the paranasal sinuses.

**Clinical Pearl:**
In cases where standard endoscopic procedures are inadequate or contraindicated, Caldwell-Luc's operation provides a valuable option for accessing the paranasal sinuses for diagnosis or treatment. However, it is essential to consider alternative approaches for specific indications like facial nerve injury, mandibular angle fractures, and nasal septum deviations. This ensures that patients receive targeted and appropriate interventions for their unique conditions.