Early treatment for anterior open bite: Choosing adequate treatment approaches 前牙开合咬合的早期治疗：选择适当的治疗方法
Flavia Artese ^(a,**){ }^{\mathrm{a}, *}, Luciana Quintanilha Pires Fernandes ^("a "){ }^{\text {a }}, Sérgio Roberto de Oliveira Caetano ^(a){ }^{\mathrm{a}}, José Augusto M. Miguel ^("a "){ }^{\text {a }}^("a "){ }^{\text {a }} Department of Orthodontics, Rio de Janeiro State University, Boulevard 28 de Setembro, 157; Vila Isabel, Rio de Janeiro, RJ, Brazil ^("a "){ }^{\text {a }} 里约热内卢州立大学正畸学系，地址：Boulevard 28 de Setembro, 157; Vila Isabel, Rio de Janeiro, RJ, Brazil
Anterior open bite is considered one of the most challenging malocclusions to correct, especially regarding stability. There are numerous publications on the subject but with controversial information. Disagreements occur in most aspects of this malocclusion, such as the definition of an open bite, its etiological factors, treatment timing, and ideal treatment alternatives. The lack of consensus on the etiology of anterior open bite has led to different treatment approaches, which may explain the high rate of post-treatment instability. Furthermore, the etiological factors of this malocclusion typically result in myofunctional imbalance, which alters the harmony of muscular forces responsible for maintaining an adequate occlusion. Nevertheless, the literature indicates a scarcity of scientific evidence that myofunctional therapy helps to correct open bites. In addition, there is evidence that eliminating deleterious habits allows spontaneous overbite correction and brings physiological and psychological benefits to the child. Considering the possibility of a spontaneous reduction of this malocclusion with age, it is understood that not every child needs early treatment. To avoid overtreatment, the choice for intervention should assess possible causes and severity, the patient’s age, and parental concerns. Therefore, this paper discusses possible early treatment approaches for anterior open bite. 前牙开合咬合被认为是最难矫正的畸形之一，尤其是在稳定性方面。关于这一主题的出版物不胜枚举，但其中的信息却充满争议。在这种错颌畸形的大多数方面都存在分歧，如开放性咬合的定义、病因、治疗时机和理想的治疗方案等。由于对前开放性咬合的病因缺乏共识，导致了不同的治疗方法，这可能是治疗后不稳定率高的原因。此外，这种错颌畸形的病因通常会导致肌肉功能失衡，从而改变负责维持适当咬合的肌肉力量的协调性。然而，文献资料显示，很少有科学证据表明肌功能疗法有助于矫正开放性咬合。此外，有证据表明，消除不良习惯可使咬合过紧自发得到矫正，并给儿童带来生理和心理上的益处。考虑到这种错合畸形有可能随着年龄的增长而自发减少，因此并非每个儿童都需要早期治疗。为了避免过度治疗，在选择干预措施时应评估可能的原因和严重程度、患者的年龄以及家长的顾虑。因此，本文讨论了前牙开合咬合可能的早期治疗方法。
Introduction 导言
Anterior open bite (AOB) is defined as the lack of vertical overlap between the upper and lower anterior teeth. ^(1,2){ }^{1,2} According to the criteria used to define AOB, its prevalence ranges from 4.2%4.2 \% in children aged six years and 11%11 \% to 17%17 \% in girls and boys aged seven to nine years, respectively, while at 14 years, the prevalence decreases to 2.5%.^(3)2.5 \% .^{3} Generally, there is a significant self-correction of AOB, ^(4){ }^{4} as prevalence diminishes with age due to decreased sucking habits, incisor eruption, and oral function maturation. These characteristics were also observed by Alhammadi, who evaluated a general global prevalence of 4.93%4.93 \% of this malocclusion in mixed and permanent dentitions. ^(5){ }^{5} 前牙开合咬合（AOB）的定义是上下前牙之间缺乏垂直重叠。 ^(1,2){ }^{1,2} 根据 AOB 的定义标准，其发病率在 6 岁儿童中为 4.2%4.2 \% ，在 7 至 9 岁的女孩和男孩中分别为 11%11 \% 至 17%17 \% ，而在 14 岁时则降至 2.5%.^(3)2.5 \% .^{3} 、一般来说，由于吸吮习惯的减少、门牙的萌出和口腔功能的成熟，随着年龄的增长，AOB ^(4){ }^{4} 的患病率会逐渐降低，从而出现明显的自我矫正。Alhammadi 也观察到了这些特点，他评估了混合牙和恒牙中这种错颌畸形的全球普遍发生率 4.93%4.93 \% 。 ^(5){ }^{5}
Several changes in the dental arch mark the mixed dentition period, and the appearance of some transient occlusal characteristics that can be confused with malocclusions are part of normal development. A typical period of this stage is the so-called “ugly duckling” ^(6){ }^{6} phase, when the upper incisors are projected buccally, with an apical to incisal divergence of their long axis, deep overbite, and diastemas (Fig. 1). It is important to note that during the transition phase of the deciduous to the mixed dentition, the absence of vertical overlap of the incisors or even the presence of a very slight overlap may tend to self-correct. However, if this condition persists in the second transitional phase of the 牙弓的一些变化标志着混合牙列时期的到来，一些短暂的咬合特征的出现可能会与畸形相混淆，这些都是正常发育的一部分。这个阶段的一个典型时期就是所谓的 "丑小鸭" ^(6){ }^{6} 期，此时上切牙向颊侧突出，其长轴从根尖到切缘发散，深覆合和反合（图 1）。值得注意的是，在乳牙向混合牙列的过渡阶段，门牙没有垂直重叠，甚至存在非常轻微的重叠，都有可能自我纠正。但是，如果这种情况持续到混合牙列的第二个过渡阶段
mixed dentition this may indicate a functional imbalance and, an intervention may be needed. 混合牙列可能表明功能失衡，需要进行干预。
Another aspect that should be taken into account is that depending on its severity, AOB may result in esthetic and functional impairment, which could negatively affect the children’s quality of life, as demonstrated in a study by Pithon et al. ^(7){ }^{7} Early treatment of any malocclusion is characterized by being carried out during the deciduous or mixed dentition, in the period that precedes pubertal growth spurt and which aims to improve the occlusion. Bearing that the primary purpose of early treatment is to make the subsequent treatment as simple and short as possible, ^(8,9){ }^{8,9} this paper aims to review the etiological factors of anterior open bite and discuss their importance in choosing interceptive treatment methods pursuing stable results. ^(7){ }^{7} 任何错合畸形的早期治疗的特点都是在乳牙期或混合牙列期，即青春期生长突增之前的时期进行，目的是改善咬合。鉴于早期治疗的主要目的是使后续治疗尽可能简单和简短， ^(8,9){ }^{8,9} 本文旨在回顾前牙开合咬合的致病因素，并讨论这些因素在选择追求稳定效果的阻断性治疗方法时的重要性。
Etiological factors 致病因素
Treating AOB should start with a correct diagnosis of its etiology. Many factors are described in the literature as associated with AOB, ranging from oral habits, atypical speech and swallowing, mouth breathing, and inadequate tongue posture at rest to a hyperdivergent growth pattern. ^(1,10-14){ }^{1,10-14} An anterior open bite may also be associated with ankylosis of anterior teeth, idiopathic condylar resorption, and amelogenesis 治疗 AOB 应从正确诊断病因开始。文献中描述了许多与 AOB 相关的因素，从口腔习惯、不典型的言语和吞咽、口呼吸、静息时舌头姿势不正确到过度发散的生长模式，不一而足。 ^(1,10-14){ }^{1,10-14} 前牙开合咬合也可能与前牙强直、特发性髁状突吸收和成髓作用有关。
quate overbite and divergence of the long axes of the upper incisors and diastemas. 牙齿咬合过大，上门牙的长轴发散，牙间隙过大。
imperfecta. As this paper addresses the treatment of AOB in children, we will focus on the etiological factors associated with functional problems, which may require an interceptive treatment approach. 畸形。由于本文讨论的是儿童畸形牙的治疗，我们将重点关注与功能性问题相关的病因，这些问题可能需要采用截骨治疗方法。
Non-Nutritive sucking habits 非营养性吸吮习惯
Deleterious habits, also known as non-nutritive habits, include paci-fier-sucking and finger-sucking. They are usually related to emotional and physiological needs for sucking in cases where natural breastfeeding is not enough and the child makes prolonged use of bottles. ^(15){ }^{15} The pacifier can be used for calming or distracting children. However, when used for a long time during the day, and not just in certain situations, a habit can be established, and removing the pacifier becomes challenging. 有害习惯也称为非营养性习惯，包括吮吸奶嘴和吮吸手指。它们通常与情感和生理上对吸吮的需求有关，因为自然母乳喂养是不够的，孩子需要长期使用奶瓶。 ^(15){ }^{15} 安抚奶嘴可用于安抚或分散儿童的注意力。但是，如果在一天中长期使用，而不仅仅是在某些情况下使用，就会形成一种习惯，取下奶嘴就会变得很困难。
Finger-sucking, however, is a habit that can start in intrauterine life and should be replaced after birth by natural breastfeeding. However, it can persist due to several factors, including the sudden withdrawal of the pacifier, and result in AOB (Fig. 2 and 3). Generally, its adverse effects are more significant than those of pacifiers, as it is a more difficult habit to disrupt. ^(16){ }^{16} 然而，吸吮手指的习惯可能在宫内就开始了，出生后应由自然母乳喂养取代。然而，吸吮手指的习惯可能会因一些因素而持续存在，包括突然撤掉安抚奶嘴，从而导致婴儿窒息死亡（图 2 和图 3）。一般来说，其不良影响比安抚奶嘴更严重，因为安抚奶嘴是一种更难戒除的习惯。 ^(16){ }^{16}
It was suggested that these habits should be removed at four or five years of age so that the development of the dentoalveolar region and permanent dentition is not affected. ^(17){ }^{17} The child should be encouraged to stop the habit, explaining the adverse consequences that the pacifier or finger can cause. When removed in the appropriate period and in cases where other dysfunctions are absent, such as improper tongue 建议在孩子四五岁时戒除这些习惯，以免影响牙槽骨区和恒牙列的发育。 ^(17){ }^{17} 应鼓励儿童戒除这种习惯，并解释安抚奶嘴或手指可能造成的不良后果。如果在适当的时期和没有其他功能障碍（如舌头不正常）的情况下取下安抚奶嘴或手指，就会对孩子的牙齿发育产生积极的影响。
posture at rest, self-correction of the malocclusion is observed (Fig. 4 and 5). A recent systematic review suggests that there is self-correction of AOB after discontinuing the non-nutritive sucking, even in cases older than four years of age. The authors conclude that due to the low quality of evidence, it is not clear after what age habit removal is unlikely to facilitate AOB self-correction. ^(18){ }^{18} 在静止状态下，可以观察到错颌畸形的自我矫正（图 4 和图 5）。最近的一项系统性综述表明，即使在四岁以上的病例中，在停止非营养性吸吮后，也会出现错牙合畸形的自我矫正。作者总结说，由于证据质量不高，目前还不清楚在多大年龄之后，去除习惯不太可能促进 AOB 的自我纠正。 ^(18){ }^{18}
An AOB may be installed in habit-persistent cases, with projected upper incisors and maxillary constriction. These characteristics hinder passive lip sealing and may result in inadequate tongue positioning, especially at rest. ^(19){ }^{19} Psychologic and speech therapy treatments and palatal cribs or spurs are routinely used. However, despite the importance of this subject, more scientific evidence is needed on methods to prevent and interrupt these habits. Not much is known concerning the most effective therapy, the appropriate treatment time and age to intervene, or the psychological consequences of abrupt disruption of non-nutritive sucking habits. ^(20){ }^{20} Studies evaluating interventions for the cessation of non-nutritive sucking habits in children suggested for high-quality trials to be conducted and the need for a consolidated, standardized approach to report outcomes in these trials. ^(21){ }^{21} 习惯顽固、上门牙突出和上颌缩窄的病例可以安装自动牙托。这些特征会阻碍被动唇部密封，并可能导致舌头定位不足，尤其是在休息时。 ^(19){ }^{19} 心理和言语治疗以及腭骨架或腭骨刺是常规使用的方法。然而，尽管这一问题非常重要，但仍需要更多的科学证据来证明预防和中断这些习惯的方法。关于最有效的治疗方法、适当的治疗时间和干预年龄，以及突然中断非营养性吸吮习惯的心理后果，我们所知甚少。 ^(20){ }^{20} 对停止儿童非营养性吸吮习惯的干预措施进行评估的研究表明，需要进行高质量的试验，并需要采用统一、标准化的方法来报告这些试验的结果。 ^(21){ }^{21}
Atypical speech and swallowing 言语和吞咽异常
In normal swallowing, the tip of the tongue rests on the palatal papilla, the dorsum of the tongue presses the palate, the teeth are in light contact, and the lips are closed to create negative pressure and perform a peristaltic movement to push the food bolus towards the esophagus. 正常吞咽时，舌尖靠在腭乳头上，舌背压在腭上，牙齿轻度接触，嘴唇闭合以产生负压，并进行蠕动，将食团推向食道。
Fig. 2. Patient in mixed dentition presenting AOB due to thumb sucking. 图 2.因吮吸拇指而出现 AOB 的混合牙患者。
Fig. 3. The same patient in Fig. 2 with a fixed palatal crib to prevent the habit of finger-sucking. 图 3.图 2 中的同一患者，为防止吮吸手指的习惯，固定了腭窝。
Fig. 4. Patient in the deciduous dentition phase with AOB due to prolonged pacifier habit. 图 4.乳牙期患者，因长期使用安抚奶嘴而出现 AOB。
Fig. 5. The same patient in Fig. 4., now in the mixed dentition, shows a self-correction of the anterior open bite after removing the habit. 图 5.图 4 中的同一患者，现在是混合牙列，在去除习惯性咬合后，前牙开合咬合得到了自我矫正。
Atypical swallowing is accompanied by tongue or lip thrusting between anterior teeth, which seems not an etiological factor for AOB. ^(19){ }^{19} According to the concept of Graber’s triad, ^(22){ }^{22} which states that the severity of the habit depends on its duration, frequency, and intensity, it is more likely that AOB is installed by inadequate tongue posture at rest and not by swallowing or inadequate speech. ^(23){ }^{23} 非典型吞咽伴有舌头或嘴唇插入前牙之间，这似乎不是非典型吞咽的病因。 ^(19){ }^{19} 根据格拉伯三联征（Graber's triad） ^(22){ }^{22} 的概念，即习惯的严重程度取决于其持续时间、频率和强度。 ^(23){ }^{23}
The pressures exerted by the tongue during swallowing are smaller in patients with anterior open bites when compared to normal occlusion. ^(24){ }^{24} When compared with AOB patients, individuals with normal occlusion have more significant lingual pressure in the vertical and intermediate directions than in the horizontal direction. In contrast, individuals with an open bite have approximately equal pressure in all planes, supporting the adaptive functional hypothesis of the tongue in an existing open bite. ^(25){ }^{25} 与咬合正常的患者相比，前开放性咬合患者在吞咽过程中舌头施加的压力较小。 ^(24){ }^{24} 与开放性咬合患者相比，咬合正常的患者在垂直和中间方向的舌压力比水平方向的舌压力大。相比之下，开放性咬合患者在所有平面上的压力大致相同，这支持了舌头在现有开放性咬合中的适应性功能假说。 ^(25){ }^{25}
But, in the face of the lack of high-quality studies evaluating the causal effects of articulating disorders and abnormal swallowing in the occlusion, one may state that AOB is associated with these disorders. ^(26){ }^{26} It may only be speculated that these impaired functions may rather be a consequence of an already installed AOB malocclusion instead of the cause. 但是，由于缺乏高质量的研究来评估发音障碍和吞咽异常对咬合的因果影响，人们可能会说 AOB 与这些障碍有关。 ^(26){ }^{26} 我们只能推测，这些功能受损可能是已经形成的 AOB 错合畸形的结果，而不是原因。
Mouth breathing 口呼吸
When an obstruction prevents or hinders nasal breathing, such as the deviated septum, allergies, or hypertrophic adenoids, mouth breathing sets in. Mouth breathing may affect the muscular development of the face, as seen in the study by Harvold et al. ^(27){ }^{27} By blocking the nasal passages of monkeys, the authors evaluated the effects of mouth breathing in these animals compared to controls. They observed that this habit resulted in lower mandibular positioning, which may be associated with tongue projection. Therefore, mouth breathers usually present AOB with a change in tongue posture to a lower-than-normal position, which may result in maxillary constriction and posterior crossbites. ^(28){ }^{28} Other clinical characteristics that define the “long face syndrome” usually present in these patients are the appearance of fatigue with the presence of dark circles around the eyes, increased facial height, poorly developed nostrils, hypotonic and half-open lips to facilitate oral airflow, short upper lip, and voluminous and everted lower lip, as well as divergent occlusal planes. ^(29-31){ }^{29-31} Although long-faced subjects usually have a higher mean value of nasal resistance, the range of variation is so great that it compromises the diagnosis of nasal obstruction only by assessing the facial morphology. ^(32){ }^{32} 当鼻腔呼吸受阻或受阻时，如鼻中隔偏曲、过敏或腺样体肥大，就会出现口呼吸。 ^(27){ }^{27} 通过阻塞猴子的鼻腔，作者评估了与对照组相比，口呼吸对这些动物的影响。他们观察到，这种习惯导致下颌定位降低，这可能与舌头突出有关。因此，口呼吸者在出现 AOB 时通常会将舌头的姿势改变到比正常位置更低的位置，这可能会导致上颌收缩和后交叉咬合。 ^(28){ }^{28} 这些患者通常表现出的 "长脸综合征 "的其他临床特征包括：疲倦的外观和黑眼圈、面部高度增加、鼻孔发育不良、嘴唇张力不足和半开以促进口腔气流、上唇短小、下唇丰满和外翻，以及咬合平面分叉。 ^(29-31){ }^{29-31} 虽然长脸受试者的鼻阻力平均值通常较高，但其变化范围非常大，以至于只能通过评估面部形态来诊断鼻阻塞。 ^(32){ }^{32}
The treatment for this condition may include an otorhinolaryngologist to remove the cause of the nasal obstruction and a speech therapist to exercise facial muscles during function. Linder-Aronson et al. followed a group of children submitted to adenoidectomy. They observed that one year after surgery, those patients who changed mouth breathing to nasal breathing showed changes in lip and tongue posture, resulting in protrusion of the upper and lower incisors, increased width of the upper arch, and decreased width of the lower arch, thus reducing the chances of posterior crossbite. ^(33){ }^{33} The authors state that these alterations indicate that the previous tongue posture, low and projected, was corrected to a higher and posterior position, favoring AOB correction. 这种情况的治疗可能包括由耳鼻喉科医生消除鼻腔阻塞的原因，以及由语言治疗师锻炼面部肌肉的功能。Linder-Aronson 等人对一组接受腺样体切除术的儿童进行了跟踪调查。他们观察到，术后一年，那些将口呼吸改为鼻呼吸的患者唇舌姿势发生了变化，导致上下门牙突出，上牙弓宽度增加，下牙弓宽度减少，从而降低了后交叉咬合的几率。 ^(33){ }^{33} 作者指出，这些改变表明，以前低而突出的舌姿被矫正到了较高的后方位置，有利于 AOB 矫正。
In general, lymphoid tissues undergo involution during puberty, allowing the tongue to spontaneously adopt a more posterior position than usual. ^(32){ }^{32} However, Linder-Aronson et al. ^(33){ }^{33} found that dentoalveolar response to adenoidectomy is highly variable and should not be considered a prophylactic procedure for developing AOB. Indeed, not all patients with mouth breathing due to partial nasal blockage develop AOB. ^(34){ }^{34} Despite the clear association of mouth breathing improvement after removing hypertrophic lymphoid tissues, the ideal moment for such intervention is still unknown. 一般来说，淋巴组织在青春期会发生萎缩，使舌头自发地采取比平时更靠后的位置。 ^(32){ }^{32} 然而，Linder-Aronson 等人 ^(33){ }^{33} 发现，牙槽骨对腺样体切除术的反应变化很大，不应将其视为发生 AOB 的预防性手术。事实上，并非所有因鼻腔部分阻塞而导致口呼吸的患者都会出现 AOB。 ^(34){ }^{34} 尽管切除肥大淋巴组织后口呼吸明显改善，但这种干预的理想时机仍然未知。
Tongue posture at rest 舌头静止时的姿势
As previously seen, a non-nutritive sucking habit, such as pacifier sucking or mouth breathing, may favor an inadequate tongue posture at rest and, consequently, the maintenance of AOB , even in cases where the habit has been removed. ^(35){ }^{35} This association can be explained by the findings of Proffit, who stated that the muscular pressure of the tongue and lips and the contact points between the teeth are responsible for the balance in maintaining tooth position. ^(36){ }^{36} Thus, any change in this balance can allow the development of a malocclusion. 如前所述，非营养性的吸吮习惯，如吸吮安抚奶嘴或口呼吸，可能会使舌头在休息时保持不适当的姿势，从而导致 AOB 的维持，即使在这种习惯已经去除的情况下也是如此。 ^(35){ }^{35} 这种关联可以用 Proffit 的研究结果来解释，他指出舌头和嘴唇的肌肉压力以及牙齿之间的接触点是保持牙齿位置平衡的原因。 ^(36){ }^{36} 因此，这种平衡的任何改变都可能导致错颌畸形的发生。
The tongue is a complex structure composed of external muscles connected to bone structures and internal muscles that intertwine, giving the tongue extreme mobility. The muscle responsible for tongue protrusion is the genioglossus, which makes up most of the body of the tongue. ^(37){ }^{37} It has been shown that the genioglossus in patients with AOB has a lower activity threshold and that slight jaw rotation ranging from 0.5 to 3^(@)3^{\circ} is sufficient for the tongue to protrude. ^(38){ }^{38} However, the amount of pressure the tongue exerts in patients with AOB is not different from those with normal occlusion. It is believed that the resting position of the tongue exerts low and constant forces, which are sufficient to cause AOB. ^(39){ }^{39} Considering that the proper position at rest is when the dorsum of the tongue remains in contact with the palate and the tip of the tongue 舌头是一种复杂的结构，由与骨骼结构相连的外部肌肉和内部肌肉交织组成，使舌头具有极强的活动能力。造成舌头突出的肌肉是舌根肌，它构成了舌体的大部分。 ^(37){ }^{37} 研究表明，AOB 患者的舌根肌活动阈值较低，下颌轻微转动 0.5 到 3^(@)3^{\circ} 就足以使舌头突出。 ^(38){ }^{38} 然而，AOB 患者舌头施加的压力与咬合正常的患者并无不同。一般认为，舌头的静止位置会产生较低且持续的力，这足以导致 AOB。 ^(39){ }^{39} 考虑到静止时的正确位置是舌背与上颚保持接触，舌尖
Fig. 6. Graphic representation of the high tongue position, showing the point of support of the tip of the tongue on the upper incisors, which results in AOB with projecting upper incisors, no posterior crossbite, and no impairment of the lower occlusal plane. 图 6.高舌位的图示，显示舌尖在上切牙上的支撑点，这导致上切牙突出的 AOB，没有后交叉咬合，也没有损害下咬合面。
in contact with the palatal papilla, any changes in this scenario can lead to AOB. 腭乳头接触，这种情况下的任何变化都可能导致 AOB。
According to Artese et al., ^(40){ }^{40} we can observe four tongue positions in different AOB morphologies according to the tongue’s resting place. A classification based on these positions was suggested, yet to be validated: a) high, b) horizontal, c) low, and d) very low. In the high tongue posture, the tip of the tongue rests a little lower than the normal position, pressing the upper incisors and affecting these teeth vertically and anteroposteriorly. In this case, the lower occlusal plane will be normal (Fig. 6). The horizontal position is when the tongue tip rests between the upper and lower incisors. In this case, the clinical characteristics of the upper incisors and the lower occlusal plane are the same as the previous ones (Fig. 7); In the low position, the tip of the tongue rests on the lower incisors, it affects these teeth vertically and anteroposteriorly. In this case, the lower occlusal plane will have two levels, and a posterior crossbite may be present due to the absence of transverse support for the maxilla (Fig. 8). The very low posture is when the tip of the tongue rests 根据 Artese 等人的研究， ^(40){ }^{40} 在不同的 AOB 形态中，我们可以根据舌头的停留位置观察到四种舌头位置。根据这些位置提出了一种分类方法，但尚待验证：a) 高位；b) 水平位；c) 低位；d) 极低位。高舌位时，舌尖的位置比正常位置略低，压迫上切牙，影响这些牙齿的垂直和前向。在这种情况下，下咬合面是正常的（图 6）。水平位置是指舌尖位于上下门牙之间。在这种情况下，上切牙和下咬合面的临床特征与前一种情况相同（图 7）；在低位时，舌尖停留在下切牙上，对这些牙齿产生垂直和前向的影响。在这种情况下，下咬合面会有两个水平，由于上颌骨缺乏横向支撑，可能会出现后交叉咬合（图 8）。非常低的姿势是指舌尖停留在
on the alveolar bone below the crowns of the lower incisors, resulting in retroclination of these teeth. In this case, the lower occlusal plane will also have two levels, and there is a greater chance that a posterior crossbite will be present (Fig. 9). 下切牙牙冠下方的牙槽骨上，导致这些牙齿后倾。在这种情况下，下咬合面也会有两个水平，出现后交叉咬合的几率也会增大（图 9）。
Despite these specific characteristics for each morphology of AOB, the clinical diagnosis of tongue posture at rest is sometimes difficult, especially in patients with passive lip seal. As an alternative, it has been demonstrated that three-dimensional ultrasound could help diagnose tongue posture at rest by showing the distance from the dorsum of the tongue to the palate. ^(35){ }^{35} When tongue posture at rest was diagnosed by the radiologist and compared to orthodontists, otorhinolaryngologists, and speech therapists, it was found that this 3D ultrasound could detect a more significant number of patients with inadequate tongue posture. We may soon be able to use this non-invasive, radiation-free technology as a diagnostic tool to assess tongue position more precisely. Diagnosing tongue posture at rest is a determinant factor to define which treatment approach will be used, as will be further described. 尽管 AOB 的每种形态都有这些特定的特征，但临床诊断静息状态下的舌姿有时仍很困难，尤其是在被动唇密封的患者中。作为一种替代方法，三维超声可以显示舌背到上颚的距离，从而帮助诊断静息时的舌姿。 ^(35){ }^{35} 当放射科医生诊断静止状态下的舌姿，并与正畸医生、耳鼻喉科医生和语言治疗师进行比较时，发现这种三维超声波能检测出更多舌姿不足的患者。我们也许很快就能利用这种无创、无辐射的技术作为诊断工具，更精确地评估舌头的位置。诊断静息状态下的舌位是确定采用哪种治疗方法的决定性因素，这一点将进一步说明。
Fig. 7. Graphic representation of the horizontal tongue position, showing the fulcrum of the tip of the tongue between the upper and lower incisors, which results in AOB with projecting upper incisors, a tendency to posterior crossbite and no compromise of the lower occlusal plane. 图 7.舌头水平位置的图示，显示舌尖的支点位于上下门牙之间，这导致上门牙突出的 AOB、后交叉咬合的趋势以及下咬合面不受损害。
Fig. 8. Graphic representation of the low tongue position, showing the fulcrum of the tip of the tongue on the lower incisors, which results in AOB with projecting lower incisors, posterior crossbite, and uneven lower occlusal plane. 图 8.舌位低的图示，显示舌尖的支点在下切牙上，导致下切牙突出、后交叉咬合和下咬合面不平的 AOB。
Fig. 9. Graphical representation of the very low tongue position shows the point of support of the tongue tip on the alveolar bone below the crowns of the lower incisors, which results in AOB with retroclined lower incisors, crossbite posterior, and uneven lower occlusal plane. 图 9.极低舌位的图形显示，舌尖的支撑点位于下切牙牙冠下方的牙槽骨上，导致下切牙后倾、后交叉咬合和下咬合面不平的 AOB。
AOBA O B functional treatments AOBA O B 功能治疗
Speech and myofunctional therapy 语言和肌功能治疗
There is an association between malocclusions and speech disorders, and lip praxis is performed with greater difficulty in subjects with open bite. ^(41){ }^{41} Patients with AOB usually have some imbalance in oral function and, therefore, may need orthodontic treatment and myofunctional treatment to exercise the tongue and the entire perioral muscle structure correctly. One study evaluated 76 patients with AOB, in which 27 of them received orthodontic treatment and myofunctional therapy (MT), while 49 in the control group only received orthodontic treatment. The MT consisted of exercises to adapt the orofacial muscles at rest and during swallowing, mastication, and speech. The amount of AOB, lip and tongue posture at rest, swallowing pattern, presence of oral habits, and errors during phonation before and after the experiment were evaluated. As a result, the authors reported that, on average, 0.5 mm of AOB relapse in the group that received orthodontic treatment associated with MT. In the control group, relapse was, on average, 3.4 mm . Thus, they concluded that orthodontic treatment in conjunction with MT efficiently corrected the AOB and that the risk of relapse was significantly lower in cases where the tongue was low, protruding posture and the swallowing pattern were restored. ^(42){ }^{42} 畸形咬合与语言障碍之间存在关联，开牙合畸形患者在进行唇部练习时会遇到更大的困难。 ^(41){ }^{41} 开牙合畸形患者通常口腔功能失衡，因此可能需要正畸治疗和肌功能治疗来正确锻炼舌头和整个口周肌肉结构。一项研究评估了 76 名 AOB 患者，其中 27 人接受了正畸治疗和肌功能治疗（MT），而对照组中的 49 人仅接受了正畸治疗。肌功能疗法包括在休息时以及在吞咽、咀嚼和说话时调整口面部肌肉的练习。对实验前后的 AOB 量、休息时的唇舌姿势、吞咽模式、是否有口腔习惯以及发音时的错误进行了评估。结果，作者报告说，在接受与 MT 相关的正畸治疗的组中，AOB 平均复发了 0.5 毫米。而对照组的复发率平均为 3.4 毫米。因此，他们得出结论：结合 MT 的正畸治疗可有效矫正 AOB，在舌低位、前突姿势和吞咽模式得到恢复的病例中，复发风险显著降低。 ^(42){ }^{42}
Orofacial myofunctional treatment can significantly change tongue elevation strength, tongue posture at rest, and tongue position while swallowing solid food. ^(43){ }^{43} Studies suggest that combining myofunctional therapy with orthodontic intervention is valuable for treating open bite cases associated with tongue projection. ^(23){ }^{23} However, clinically, we can observe significant improvements in overbite in patients undergoing myofunctional therapy alone, as illustrated in Figs. 10 and 11. 口腔颌面肌功能治疗可以显著改变舌头的抬高力度、静止时舌头的姿势以及吞咽固体食物时舌头的位置。 ^(43){ }^{43} 研究表明，将口颌肌功能治疗与正畸干预相结合，对于治疗与舌前突有关的开放性咬合病例很有价值。 ^(23){ }^{23} 然而，在临床上，我们可以观察到单纯接受肌功能治疗的患者的咬合过大情况有明显改善，如图 10 和图 11 所示。
Palatal crib 腭窝
Palatal cribs can be fixed or removable (Fig 12) and perform mainly dental effects in AOB treatments by decreasing the inclination of upper incisors. ^(44){ }^{44} More favorable treatment results are seen with fixed cribs, probably because there is no need for patient cooperation. Tongue pressure has been evaluated before, during, and after treatment with a fixed palatal crib in patients with AOB who were followed up for ten months of appliance use and after 12 months of its removal. Results showed a significant decrease in tongue pressure over time on both the upper and lower incisors, demonstrating an adaptive tongue behavior using a fixed palatal crib. ^(45){ }^{45} 腭嵴可以是固定的，也可以是活动的（图 12），在 AOB 治疗中主要通过减小上门牙的倾斜度来实现牙科效果。 ^(44){ }^{44} 固定式腭侧架的治疗效果更佳，这可能是因为不需要患者的配合。在使用腭侧固定矫治器治疗前、治疗中和治疗后，我们都对 AOB 患者的舌压进行了评估，并在使用矫治器 10 个月和拆除矫治器 12 个月后对患者进行了随访。结果显示，随着时间的推移，上下门牙的舌压都有明显的下降，这表明使用固定腭楔后，舌头的行为会发生适应性变化。 ^(45){ }^{45}
Regarding treatment stability, Huang et al. ^(11){ }^{11} conducted a study evaluating AOB treatment with a fixed palatal crib in patients with and without growth, followed for a minimum period of seven years after treatment. The results showed that 17.4%17.4 \% of the patients without growth presented relapse, while there was no relapse in growing patients. Therefore, from these results, one can observe the importance of establishing a dentoalveolar and muscular balance to achieve stability in cases of AOB, preferably when the patient is still growing. 关于治疗的稳定性，Huang 等人 ^(11){ }^{11} 进行了一项研究，评估了使用固定腭摇床对有生长发育和无生长发育患者进行 AOB 治疗的情况，并在治疗后进行了至少 7 年的随访。结果显示， 17.4%17.4 \% 未长牙的患者出现了复发，而长牙的患者没有复发。因此，从这些结果中，我们可以看到建立牙槽骨和肌肉平衡的重要性，以实现 AOB 病例的稳定性，最好是在患者仍在生长发育的时候。
Tongue spurs 舌刺
Tongue spurs can be welded to a lingual arch or bonded to the lingual surfaces of lower and upper incisors (Fig.13). When the tongue movement was evaluated in a child before, and after the use of spurs using electromyography, it was observed that there was a decrease in the sagittal movement of the tongue, that is, the tongue was retracted, and most importantly, there was an increase in the vertical movement of the tongue, demonstrating that the tongue was raised. ^(46){ }^{46} Although it is known that soldered or bonded spurs are efficient in correcting AOB^(47)\mathrm{AOB}^{47} and that soldered spurs to the lingual arch cause discomfort for only ten 舌骨钉可以焊接在舌弓上，也可以粘接在上下门牙的舌面上（图 13）。在使用舌骨钉之前和之后，使用肌电图对儿童的舌头运动进行评估时发现，舌头的矢状运动减少了，即舌头后缩了，最重要的是，舌头的垂直运动增加了，这表明舌头抬高了。 ^(46){ }^{46} 虽然众所周知，焊接或粘接的舌骨钉可以有效地矫正 AOB^(47)\mathrm{AOB}^{47} ，而且焊接在舌弓上的舌骨钉只在十天内引起不适。
Fig. 10. Patient at 8.6 years of age presented lip hypotonicity and lip projection when speaking and swallowing. 图 10.患者 8.6 岁时出现嘴唇张力不足，说话和吞咽时嘴唇突出。
Fig. 11. The same patient in Fig. 10, at age 10.6 years, underwent myofunctional therapy and slightly improved the overbite. 图 11.图 10 中的同一患者在 10.6 岁时接受了肌功能治疗，咬合过度的情况略有改善。
Fig. 14. Initial intraoral photographs of a patient with AOBA O B with protruding maxillary incisors and leveled mandibular occlusal plane due to high tongue posture. 图 14. AOBA O B 患者的初始口内照片，该患者因舌头姿势过高导致上颌切牙突出，下颌咬合面变平。
days, ^(48){ }^{48} this treatment modality is usually associated with pain. Still, not much is known about pain with bonded spurs. 然而， ^(48){ }^{48} 这种治疗方式通常会带来疼痛。然而，人们对粘结骨刺疼痛的了解并不多。
When to use palatal cribs and when to use tongue spurs? 何时使用腭嵴，何时使用舌刺？
The existence of an AOB is due to muscular imbalance, and if there are no external factors, such as non-nutritive sucking habits, tongue posture at rest might be the cause for AOB. Therefore, the professional must aim at correcting the patient’s tongue posture rather than the tooth position. In high or horizontal tongue posture cases, the tongue needs to be retracted, and blocking mechanisms such as palatal cribs will suffice (Figs. 14-17). Tools that redirect the tongue to a higher position, such AOB 的存在是由于肌肉失衡造成的，如果没有外部因素（如非营养性吸吮习惯），静止时的舌头姿势可能是造成 AOB 的原因。因此，专业人员必须以纠正患者的舌姿而不是牙齿位置为目标。在舌位偏高或水平的情况下，需要将舌头缩回，并使用腭嵴等阻挡装置即可（图 14-17）。将舌头转到较高位置的工具，如
as spurs, will be preferred in low or very low posture (Figs. 18-20). Rapid maxillary expansion has been shown to raise low tongue posture ^(49,50){ }^{49,50} and can also be associated with tongue spurs, as shown in Figs. 21-23. 在低姿态或极低姿态下，舌尖和舌刺（如图 18-20 所示）将是首选。如图 21-23 所示，上颌快速扩张会使低舌位 ^(49,50){ }^{49,50} 升高，也可能与舌骨刺有关。
Although a systematic review did not demonstrate differences in the results of anterior open bite correction using cribs or spurs, ^(51){ }^{51} non-nutritive sucking habits were not excluded from the inclusion criteria in that study. According to different tongue postures, the suggested clinical approach is to be applied in patients with AOB with no secondary habits, such as thumb or pacifier sucking or even mouth breathers. This approach needs to be further evaluated for the early orthodontic 虽然一项系统性综述并未显示使用楔状肌或距骨矫正前开放性咬合的结果存在差异，但 ^(51){ }^{51} 该研究的纳入标准并未排除非营养性吸吮习惯。根据不同的舌位，建议的临床方法适用于无继发习惯的前开放性咬合患者，如吮吸拇指或奶嘴，甚至口呼吸者。这种方法需要在早期正畸中进一步评估。
Fig. 15. Follow-up photographs after fixed palatal crib treatment. Note the improvement in the overbite between the incisors. 图 15.固定腭楔治疗后的随访照片。注意门牙之间咬合过度的情况有所改善。
Corresponding author at: Boulevard 28 de Setembro, 157 - Vila Isabel, Rio de Janeiro, RJ Zip code 20551-030, Brazil. 通讯作者 Boulevard 28 de Setembro, 157 - Vila Isabel, Rio de Janeiro, RJ Zip code 20551-030, Brazil.
E-mail address: flaviaartese@gmail.com (F. Artese). 电子邮件地址：flaviaartese@gmail.com (F. Artese)。
quate overbite and divergence of the long axes of the upper incisors and diastemas.
