Angulation of tooth
Most commonly used classification system with respect to treatment planning. Depending on the angulation the tooth might be classified as:

Mesioangular
Horizontal
Vertical
Distoangular
Palatal
Buccal
Lingual

Relationship of tooth to anterior border of ramus
This type of classification is based on the amount of impacted tooth that is covered with the mandibular ramus. It is known as the Pell and Gregory classification, classes 1, 2, and 3. Relationship of tooth to occlusal plane
The depth of the impacted tooth compared with the adjacent second molar gives the basis for this type of classification. This was also given by Pell and Gregory and is called as Pell and Gregory A, B and C classification. Relationship to occlusal plane Class A-C

Complications
Erupted teeth that are adjacent to impacted teeth are predisposed to periodontal disease. Since the most difficult tooth surface to be cleaned is the distal surface of the last tooth, in the presence of an impacted tooth there is always gingival inflammation around the second molar that is invariably present. Even this minor amount of inflammation can provide bacteria access to a larger portion of the root surface that results in early formation of periodontitis compromising the tooth. Even in situations in which no obvious communication exists between the mouth and the impacted third molar there may be enough communication to initiate dental caries (tooth decay). Pericoronitis
Pericoronitis is an infection of the soft tissue that covers the crown of an impacted tooth and is usually caused by the normal oral microbiota.
Pilocarpine has been known to cause excessive salivation, sweating, bronchial mucus secretion, bronchospasm, bradycardia, vasodilation, and diarrhea. Eye drops can result in brow ache and chronic use in miosis. It can also cause temporary blurred vision or darkness of vision, temporary shortsightedness, hyphema and retinal detachment. Pharmacology
Pilocarpine is a drug that acts as a muscarinic receptor agonist. It acts on a subtype of muscarinic receptor (M3) found on the iris sphincter muscle, causing the muscle to contract - resulting in pupil constriction (miosis). Pilocarpine also acts on the ciliary muscle and causes it to contract. When the ciliary muscle contracts, it opens the trabecular meshwork through increased tension on the scleral spur. This action facilitates the rate that aqueous humor leaves the eye to decrease intraocular pressure. Paradoxically, when pilocarpine induces this ciliary muscle contraction (known as an accommodative spasm) it causes the eyes lens to thicken and move forward within the eye. This movement causes the iris (which is located immediately in front of the lens) to also move forward, narrowing the Anterior chamber angle. Narrowing of the anterior chamber angle increases the risk of increased intraocular pressure. Society and culture
Preparation
Plants in the genus Pilocarpus are the only known sources of pilocarpine, and commercial production is derived entirely from the leaves of Pilocarpus microphyllus (Maranham Jaborandi). This genus grows only in South America, and Pilocarpus microphyllus is native to several states in northern Brazil.Pilocarpine is extracted from the powdered leaf material in a multi-step process.