Mandibular Angle Enlargement Plastic Surgery
The mandibular angle is located on the lower outer side of the face, consisting of the connection part between the ascending ramus and the body of the mandible. Its outer side is the masseter tuberosity, where the masseter muscle attaches. The inner side is the pterygoid tuberosity, where the pterygoid muscle attaches. The mandibular angles on both left and right sides, along with the zygomatic areas on both sides, form the basic contour of the face. Together with the mid-facial structures such as the nose and lips, they constitute the fundamental features of facial morphology, making it one of the important anatomical landmarks for facial appearance characteristics.
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Impact of Mandibular Angle Enlargement on Facial Shape
The shape, size, and position of the mandibular angle have a significant influence on facial appearance. Mandibular angle enlargement or overdevelopment, along with varying degrees of masseter muscle hypertrophy, can result in characteristic "square face" or "trapezoidal face." Since Easterners admire a "peach-shaped face" and consider it beautiful, the characteristic face shape caused by enlarged and robust mandibular angles is almost entirely contrary to traditional aesthetic views. Mandibular angle enlargement does not significantly harm bodily functions; most patients mainly experience its impact on facial appearance and psychological damage. With the improvement in economic living standards, the number of patients seeking surgical correction for mandibular angle enlargement to create a "peach-shaped face" or "oval face" is increasing. Surgical correction of mandibular angle enlargement has become an important aspect of facial cosmetic plastic surgery.
Causes of Mandibular Angle Enlargement
The main causes of mandibular angle enlargement are the "work-related hypertrophy" theory (Work Hypertrophy) and genetic factors.
1. Work-related hypertrophy
Mandibular angle enlargement is still diagnosed by Western scholars as "benign masseter hypertrophy." Research on the causes of benign masseter hypertrophy mainly focuses on pathological changes in the masseter muscle itself. In 1947, Gurney proposed the "work-related" cause of benign masseter hypertrophy, namely the "work-related hypertrophy" theory, suggesting that habits like clenching teeth, nocturnal bruxism, and excessive work of the masseter muscle lead to benign progressive hypertrophy and hyperplasia of the masseter muscle. Some scholars further propose that tooth loss, toothache, unilateral chewing, various occlusal relationship disorders, temporomandibular joint diseases, and emotional instability causing habitual teeth clenching may all contribute to benign masseter hypertrophy.
2. Genetic Factors
In 1986, Yugoslavian scholar Roncevic proposed the theory that genetic factors cause mandibular angle enlargement or benign masseter hypertrophy based on his practical experience. He disagreed with the "work-related hypertrophy" theory. He believed that while there are indeed cases of occlusal relationship disorders among patients with mandibular angle enlargement or benign masseter hypertrophy, it cannot be concluded that occlusal relationship disorders are the inducements for these conditions. Disorders could be primary or secondary because many patients with occlusal relationship disorders do not develop mandibular angle enlargement or benign masseter hypertrophy. Additionally, histopathological examinations of surgical specimens removed from patients with mandibular angle enlargement or benign masseter hypertrophy confirmed that they were all normal striated muscles, with no evidence of muscle fiber hypertrophy. Based on these reasons, Roncevic believed that benign masseter hypertrophy might be a congenital condition determined by genetic factors, resulting in muscle "deformities" due to mandibular angle enlargement. Therefore, diagnosing most "square faces" or enlargements and thickening in the mandibular angle region as mandibular angle enlargement would be more reasonable. This theory is widely accepted by Eastern scholars.